events.yml

# https://en.wikipedia.org/wiki/Timeline_of_human_evolution
eras:
  - name: Big Bang
    label: 13.82 billion years ago
    events:
      - name: Big Bang, universe appears
        necessary: true
        actual: 13820000000
        label: 13.82 billion years ago
        source: https://en.wikipedia.org/wiki/Big_Bang
        image:
          name: big-bang.jpg
          link: https://commons.wikimedia.org/wiki/File:CMB_Timeline300_no_WMAP.jpg
          height: 65

      - name: First hadron particles begin to form, including protons and neutrons
        necessary: true
        actual: 13820000000
        label: 10<sup>-6</sup> seconds after big bang
        source: https://en.wikipedia.org/wiki/Timeline_of_the_formation_of_the_Universe
        image:
          name: proton.jpg
          link: https://commons.wikimedia.org/wiki/File:Quark_structure_proton.svg
          height: 100

      - name: First lepton particles begin to form, including electrons
        necessary: true
        actual: 13820000000
        label: 1 second after big bang
        source: https://en.wikipedia.org/wiki/Timeline_of_the_formation_of_the_Universe
        image:
          name: standard-model.jpg
          link: https://commons.wikimedia.org/wiki/File:Standard_Model_of_Elementary_Particles.svg
          height: 95.75

      - name: Protons and neutrons start combining to form first atomic nuclei
        necessary: true
        actual: 13820000000
        label: Few minutes after big bang
        source: https://en.wikipedia.org/wiki/Timeline_of_the_formation_of_the_Universe
        image:
          name: helium-nucleus.jpg
          link: https://commons.wikimedia.org/wiki/File:Helium_Nucleus.svg
          height: 99

      - name: First hydrogen atoms begin to form, universe visibility horizon (cosmic microwave background)
        necessary: true
        actual: 13819621000
        label: 379,000 years after big bang
        source: https://en.wikipedia.org/wiki/Cosmic_microwave_background
        image:
          name: cosmic-microwave-background.jpg
          link: https://commons.wikimedia.org/wiki/File:Ilc_9yr_moll4096.png
          height: 50

      - name: First stars begin to form
        necessary: true
        actual: 13670000000
        label: 150 million years after big bang
        source: https://en.wikipedia.org/wiki/Chronology_of_the_universe
        image:
          name: star-formation.jpg
          link: https://commons.wikimedia.org/wiki/File:LH_95.jpg
          height: 75

      - name: First galaxies begin to form, including the Milky Way
        necessary: true
        actual: 13420000000
        label: 400 million years after big bang
        source: https://en.wikipedia.org/wiki/GN-z11
        image:
          name: galaxy-formation.jpg
          link: https://commons.wikimedia.org/wiki/File:Hubble_-_infant_galaxy.jpg
          height: 75

      - name: Peak rate of star formation in the universe, cosmic high noon
        actual: 10000000000
        label: 3.5 billion years after big bang (10 billion years ago)
        source: https://news.ucsc.edu/2017/07/superluminous-supernova.html
        image:
          name: hubble-deep-field.jpg
          link: https://en.wikipedia.org/wiki/File:Hubble_ultra_deep_field.jpg
          height: 75

  - name: Milky Way and Earth
    label: 9 billion years ago
    events:
      - name: Formation of Milky Way galaxy thin disk - where the Sun later formed
        actual: 9000000000
        label: 9 billion years ago
        source: https://en.wikipedia.org/wiki/Milky_Way
        image:
          name: milky-way.jpg
          link: https://commons.wikimedia.org/wiki/File:236084main_MilkyWay-full-annotated.jpg
          height: 100

      - name: Expansion of the universe begins accelerating, dark energy dominated era begins
        actual: 5000000000
        label: 5 billion years ago
        source: https://en.wikipedia.org/wiki/Accelerating_expansion_of_the_universe
        image:
          name: expanding-universe.jpg
          link: https://commons.wikimedia.org/wiki/File:Dark_Energy.jpg
          height: 62.5

      - name: Formation of our solar system, Sun begins burning
        necessary: true
        actual: 4600000000
        label: 4.6 billion years ago
        source: https://en.wikipedia.org/wiki/Formation_and_evolution_of_the_Solar_System
        image:
          name: early-solar-system.jpg
          link: https://commons.wikimedia.org/wiki/File:Protoplanetary-disk.jpg
          height: 54.16

      - name: Formation of Earth
        necessary: true
        actual: 4540000000
        label: 4.54 billion years ago
        source: https://en.wikipedia.org/wiki/History_of_Earth
        image:
          name: early-earth.jpg
          link: https://commons.wikimedia.org/wiki/File:Earth_formation.jpg
          height: 100

      - name: Formation of Moon - possibly the aftermath of impact with Earth
        actual: 4510000000
        label: 4.51 billion years ago
        source: https://en.wikipedia.org/wiki/Origin_of_the_Moon
        image:
          name: moon.jpg
          link: https://commons.wikimedia.org/wiki/File:Cara-oculta-luna.jpg
          height: 102.33

      - name: Liquid water starts accumulating on Earth, beginning of oceans
        necessary: true
        actual: 4400000000
        label: 4.4 billion years ago
        source: https://en.wikipedia.org/wiki/Origin_of_water_on_Earth
        image:
          name: water-earth.jpg
          link: https://commons.wikimedia.org/wiki/File:BlueMarble-2001-2002.jpg
          height: 50

  - name: Early Life
    label: 4 billion years ago
    events:
      - name: RNA molecules (made of amino acids) grow so large that they split in half, cloning themselves - beginning of life and genetics
        necessary: true
        actual: 4100000000
        label: 4.1 - 3.8 billion years ago
        source: https://en.wikipedia.org/wiki/Abiogenesis
        image:
          name: rna.jpg
          link: https://commons.wikimedia.org/wiki/File:Hammerhead_ribozyme_ribbons.png
          height: 101.25

#      - name: Last universal common ancestor
#        actual: 3800000000
#        label: 3.8 - 3.5 billion years ago
#        source: https://en.wikipedia.org/wiki/Last_universal_common_ancestor

      - name: First cells and membranes, prokaryotes
        necessary: true
        actual: 3500000000
        label: 3.5 billion years ago
        source: https://en.wikipedia.org/wiki/Prokaryote
        image:
          name: prokaryote.jpg
          link: https://commons.wikimedia.org/wiki/File:Prokaryote_cell.svg
          height: 112.13

      - name: First bacteria
        necessary: true
        actual: 3500000000
        label: 3.5 billion years ago
        source: https://en.wikipedia.org/wiki/Timeline_of_the_evolutionary_history_of_life
        image:
          name: bacteria.jpg
          link: https://commons.wikimedia.org/wiki/File:EscherichiaColi_NIAID.jpg
          height: 84.13

      - name: First organisms to perform photosynthesis
        actual: 3400000000
        label: 3.4 billion years ago
        source: https://en.wikipedia.org/wiki/Evolution_of_photosynthesis
        image:
          name: calvin-cycle.jpg
          link: https://commons.wikimedia.org/wiki/File:Simple_photosynthesis_overview.svg
          height: 82.5

      - name: First cells to use ATP for energy transfer
        necessary: true
        actual: 3000000000
        label: 3 billion years ago
        source: https://www.ncbi.nlm.nih.gov/books/NBK26849/
        image:
          name: krebs-cycle.jpg
          link: https://commons.wikimedia.org/wiki/File:Citric_acid_cycle_with_aconitate_2.svg
          height: 79.5

      - name: Eukaryotes evolve from prokaryotes - nucleus, mitochondria
        necessary: true
        actual: 2500000000
        label: 2.5 billion years ago
        source: https://en.wikipedia.org/wiki/Eukaryote
        image:
          name: animal-cell.jpg
          link: https://commons.wikimedia.org/wiki/File:Animal_Cell.svg
          height: 57.75

      - name: Oxygen suddenly becomes abundant in atmosphere - possibly due to photosynthesis
        necessary: true
        actual: 2300000000
        label: 2.3 billion years ago
        source: https://en.wikipedia.org/wiki/Great_Oxygenation_Event
        image:
          name: cyanobacteria.jpg
          link: https://commons.wikimedia.org/wiki/File:Cyanobacteria_(248_07)_Mixture;_native_preparation;_green_filter.jpg
          height: 64

      - name: First multicellular organisms, beginning of cell specialization
        necessary: true
        actual: 1700000000
        label: 1.7 billion years ago
        source: https://en.wikipedia.org/wiki/Evolutionary_history_of_life
        image:
          name: c-elegans.jpg
          link: https://commons.wikimedia.org/wiki/File:Adult_Caenorhabditis_elegans.jpg
          height: 32.88

      - name: Fungi diverge from other life (an aquatic lifeform with flagellum)
        actual: 1500000000
        label: 1.5 billion years ago
        source: https://en.wikipedia.org/wiki/Evolution_of_fungi
        image:
          name: fungi.jpg
          link: https://commons.wikimedia.org/wiki/File:Aspergillus.jpg
          height: 66.8

      - name: First evidence of sexual reproduction, significant increase in rate of evolution
        necessary: true
        actual: 1200000000
        label: 1.2 billion years ago
        source: https://en.wikipedia.org/wiki/Evolution_of_sexual_reproduction
        image:
          name: gametic-meiosis.jpg
          link: https://commons.wikimedia.org/wiki/File:Gametic_meiosis.png
          height: 73.11

  - name: Animals
    label: 655 million years ago
    events:
      - name: Animals evolve from flagellated eukaryotes - single-celled organisms with whip-like tail, similar to sperm
        necessary: true
        actual: 665000000
        label: 665 - 610 million years ago
        source: https://en.wikipedia.org/wiki/Animal
        image:
          name: choanoflagellate.jpg
          link: https://commons.wikimedia.org/wiki/File:1singlelate.jpg
          height: 76.98

      - name: Early decentralized nervous system, bilateral symmetry - worm-like creature
        necessary: true
        actual: 600000000
        label: 600 million years ago
        source: https://en.wikipedia.org/wiki/Evolution_of_nervous_systems
        image:
          name: neuron.jpg
          link: https://commons.wikimedia.org/wiki/File:Neuron1.jpg
          height: 87.38

      - name: Mouth evolves, early digestive system
        necessary: true
        actual: 600000000
        label: 600 million years ago
        image:
          name: earthworm.jpg
          link: https://commons.wikimedia.org/wiki/File:Earthworm_head.svg
          height: 59.75

      - name: Skeletal system evolves
        necessary: true
        actual: 560000000
        label: 560 million years ago
        source: https://www.livescience.com/18933-oldest-skeleton-animal.html
        image:
          name: coronacollina-acula.jpg
          link: https://www.livescience.com/18933-oldest-skeleton-animal.html
          height: 51.5

      - name: Last common ancestor of all bilateral animals
        actual: 555000000
        label: 555 million years ago
        source: https://en.wikipedia.org/wiki/Urbilaterian
        image:
          name: symsagittifera-roscoffensis.jpg
          link: https://commons.wikimedia.org/wiki/File:Symsagittifera_roscoffensis(Jersey).jpg
          height: 75

      - name: Brain evolves
        necessary: true
        actual: 550000000
        label: 550 million years ago
        source: https://en.wikipedia.org/wiki/Evolution_of_the_brain
        image:
          name: earthworm-brain.jpg
          link: https://commons.wikimedia.org/wiki/File:Earthworm_nervous_system.png
          height: 65.58

      - name: First arthropods evolve - which would later include insects, crustaceans, and arachnids
        actual: 545000000
        label: 545 million years ago
        source: https://en.wikipedia.org/wiki/Arthropod
        image:
          name: spriggina-floundensi.jpg
          link: https://commons.wikimedia.org/wiki/File:Spriggina_floundersi_-_MUSE.jpg
          height: 50.38

      - name: First fungi on land
        actual: 542000000
        label: 542 million years ago
        source: https://en.wikipedia.org/wiki/Evolution_of_fungi
        image:
          name: chytrid-fungus.jpg
          link: https://commons.wikimedia.org/wiki/File:CSIRO_ScienceImage_1392_Scanning_Electron_Micrograph_of_Chytrid_Fungus.jpg
          height: 80.25

      - name: Cambrian explosion
        actual: 542000000
        label: 542 - 517 million years ago
        source: https://en.wikipedia.org/wiki/Cambrian_explosion
        image:
          name: opabinia.jpg
          link: https://commons.wikimedia.org/wiki/File:Opabinia_BW2.jpg
          height: 75

      - name: Eyes evolve
        necessary: true
        actual: 540000000
        label: 540 million years ago
        source: https://en.wikipedia.org/wiki/Evolution_of_the_eye
        image:
          name: planarian.jpg
          link: https://commons.wikimedia.org/wiki/File:Smed.jpg
          height: 51.98

      - name: Heart evolves
        necessary: true
        actual: 540000000
        label: 540 million years ago
        source: https://en.wikipedia.org/wiki/Circulatory_system
        image:
          name: fish-heart.jpg
          link: https://commons.wikimedia.org/wiki/File:Two_chamber_heart.svg
          height: 62.5


  - name: Vertebrates
    label: 530 million years ago
    events:
      - name: Vertebrates evolve in water, including fish
        necessary: true
        actual: 530000000
        label: 530 million years ago
        source: https://en.wikipedia.org/wiki/Evolution_of_fish
        image:
          name: lamprey.jpg
          link: https://commons.wikimedia.org/wiki/File:J%C3%B5esilmud2.jpg
          height: 66.63

      - name: Trilobites evolve from early arthropods, dominate oceans
        actual: 521000000
        label: 521 million years ago
        source: https://en.wikipedia.org/wiki/Trilobite
        image:
          name: trilobite.jpg
          link: https://commons.wikimedia.org/wiki/File:Kainops_invius_lateral_and_ventral.JPG
          height: 87.13

      - name: Plants evolve from algae
        actual: 510000000
        label: 510 million years ago
        source: https://en.wikipedia.org/wiki/Evolutionary_history_of_plants
        image:
          name: liverwort.jpg
          link: https://commons.wikimedia.org/wiki/File:Lunularia_cruciata.jpg
          height: 75.5

      - name: Teeth evolve
        necessary: true
        actual: 495000000
        label: 495 million years ago
        source: https://en.wikipedia.org/wiki/Evolution_of_fish
        image:
          name: conodont.jpg
          link: https://commons.wikimedia.org/wiki/File:Manticolepis_subrecta.jpg
          height: 75

      - name: Insects evolve from crustaceans (part of arthropods)
        actual: 480000000
        label: 480 million years ago
        source: https://en.wikipedia.org/wiki/Evolution_of_insects
        image:
          name: cockroach.jpg
          link: https://commons.wikimedia.org/wiki/File:Baltic_amber_inclusions_-_Cockroach_(Pterygota,_Neoptera,_Dictyoptera,_Blattodea).JPG
          height: 75

      - name: Jaw evolves
        necessary: true
        actual: 430000000
        label: 430 million years ago
        source: https://en.wikipedia.org/wiki/Fish_jaw#Evolution
        image:
          name: spiny-shark.jpg
          link: https://commons.wikimedia.org/wiki/File:Acanthodes_BW.jpg
          height: 56.25

      - name: First animals on land (invertebrates)
        actual: 428000000
        label: 428 million years ago
        source: https://en.wikipedia.org/wiki/Pneumodesmus
        image:
          name: pneumodesmus.jpg
          link: https://commons.wikimedia.org/wiki/File:Pneumodesmus_newmani.jpg
          height: 80

      - name: Bones evolve to replace cartilage
        necessary: true
        actual: 420000000
        label: 420 million years ago
        image:
          name: sphenacanthus.jpg
          link: https://commons.wikimedia.org/wiki/File:Sphenacanthus1DB.jpg
          height: 56.25

      - name: Flying insects evolve, first flying organism
        actual: 400000000
        label: 400 million years ago
        source: https://en.wikipedia.org/wiki/Evolution_of_insects
        image:
          name: winged-insect.jpg
          link: https://commons.wikimedia.org/wiki/File:Evolution_of_wing_of_insect-V2.png
          height: 91.16

      - name: Trees evolve from early plants
        actual: 385000000
        label: 385 million years ago
        source: https://en.wikipedia.org/wiki/Wattieza
        image:
          name: gilboa.jpg
          link: https://en.wikipedia.org/wiki/File:Gilboa2.jpg
          height: 69.16

      - name: Arachnids evolve from early arthropods
        actual: 380000000
        label: 380 million years ago
        source: https://en.wikipedia.org/wiki/Evolution_of_spiders
        image:
          name: kreischeria-spider.jpg
          link: https://commons.wikimedia.org/wiki/File:Kreischeria_Vienna.jpg
          height: 73.25

  - name: Land
    label: 370 million years ago
    events:
      - name: Amphibians evolve from fish - lungs, limbs, digits, tongue
        necessary: true
        actual: 370000000
        label: 370 million years ago
        source: https://en.wikipedia.org/wiki/Amphibian
        image:
          name: ichthyostega.jpg
          link: https://commons.wikimedia.org/wiki/File:Ichthyostega_BW.jpg
          height: 56.25

      - name: Evolution of hearing
        necessary: true
        actual: 350000000
        label: 350 - 250 million years ago
        source: https://www.sciencedaily.com/releases/2015/02/150206125257.htm
        image:
          name: salamander.jpg
          link: https://www.sciencemag.org/news/2015/02/early-land-animals-heard-sounds-their-lungs
          height: 56.25

      - name: Reptiles evolve from early amphibians - dry skin
        necessary: true
        actual: 320000000
        label: 320 million years ago
        source: https://en.wikipedia.org/wiki/Evolution_of_reptiles
        image:
          name: casineria.jpg
          link: https://commons.wikimedia.org/wiki/File:Casineria_kiddi_reconstruction.jpg
          height: 82

      - name: Largest extinction event, 90-96% of all species, including trilobites
        actual: 252000000
        label: 252 million years ago
        source: https://en.wikipedia.org/wiki/Permian%E2%80%93Triassic_extinction_event
        image:
          name: great-dying.jpg
          link: https://news.mit.edu/2014/an-extinction-in-the-blink-of-an-eye-0210
          height: 66.63

      - name: Fungi briefly become most abundant organisms on Earth
        actual: 252000000
        label: 252 million years ago
        source: https://en.wikipedia.org/wiki/Evolution_of_fungi
        image:
          name: prototaxites.jpg
          link: https://commons.wikimedia.org/wiki/File:Prototaxites_Dawson1888.PNG
          height: 92

      - name: Dinosaurs diverge from other archosaurs - which would later include crocodiles
        actual: 234000000
        label: 234 million years ago
        source: https://en.wikipedia.org/wiki/Evolution_of_dinosaurs
        image:
          name: scleromochlus.jpg
          link: https://commons.wikimedia.org/wiki/File:Scleromochlus_BW.jpg
          height: 56.25

      - name: First flying vertebrate, reptile group called pterosaurs (includes pterodactyls)
        actual: 232000000
        label: 232 million years ago
        source: https://en.wikipedia.org/wiki/Pterosaur
        image:
          name: pterosaur.jpg
          link: https://commons.wikimedia.org/wiki/File:Pterodactylus_kochi_in_Wien.JPG
          width: 600
          height: 400

      - name: Pangaea supercontinent formed of almost all land mass, mostly in southern hemisphere
        actual: 225000000
        label: 225 million years ago
        source: https://en.wikipedia.org/wiki/Pangaea
        image:
          name: pangaea.jpg
          link: https://commons.wikimedia.org/wiki/File:Pangaea_continents.svg
          height: 85.67

      - name:
            Mammals evolve from early reptiles - loss of color vision (possibly due to nocturnality),
            warm-blooded, hair, neocortex, mammary glands, ear drum, Y-chromosome for determining sex
        necessary: true
        actual: 210000000
        label: 210 million years ago
        source: https://en.wikipedia.org/wiki/Evolution_of_mammals
        image:
          name: hadrocodium.jpg
          link: https://www.nature.com/news/2011/110519/full/news.2011.302.html
          height: 89.83

  - name: Dinosaurs
    label: 201 million years ago
    events:
      - name: Mass extinction event, 70-75% of all species
        actual: 201000000
        label: 201 million years ago
        source: https://en.wikipedia.org/wiki/Triassic%E2%80%93Jurassic_extinction_event
        image:
          name: keichousaurus.jpg
          link: https://commons.wikimedia.org/wiki/File:Keichousaurus_hui_fossil.JPG
          height: 51.38

      - name: Dinosaurs become dominant organisms on Earth
        actual: 201000000
        label: 201 million years ago
        source: https://en.wikipedia.org/wiki/Dinosaur
        image:
          name: allosaurus.jpg
          link: https://commons.wikimedia.org/wiki/File:Allosaurus_Revised.jpg
          height: 56.25

      - name: Birds evolve from dinosaurs, only dinosaurs still living today
        actual: 150000000
        label: 150 million years ago
        source: http://www.sciencemag.org/news/2014/07/flight-may-have-evolved-multiple-times-birds
        image:
          name: archaeopteryx.jpg
          link: https://www.independent.co.uk/news/science/worlds-oldest-bird-archaeopteryx-wore-feather-trousers-9581647.html
          height: 78.75

      - name: Flowers evolve
        actual: 125000000
        label: 125 million years ago
        source: https://en.wikipedia.org/wiki/Flower
        image:
          name: archaefructus.jpg
          link: https://commons.wikimedia.org/wiki/File:Archaefructus_liaoningensis.jpg
          height: 75

      - name: Placentals evolve to carry offspring rather than lay eggs
        necessary: true
        actual: 120000000
        label: 120 million years ago
        source: https://en.wikipedia.org/wiki/Placentalia
        image:
          name: purgatorius.jpg
          link: https://commons.wikimedia.org/wiki/File:Purgatorius_BW.jpg
          height: 64.88

      - name: Snakes evolve
        actual: 112000000
        label: 112 million years ago
        source: https://en.wikipedia.org/wiki/Snake
        image:
          name: tetrapodophis.jpg
          link: https://commons.wikimedia.org/wiki/File:Tetrapodophis_amplectus_3483.jpg
          height: 89.19

      - name: Largest land animal of all time, Patagotitan - 120 ft long, 75 tons
        actual: 100000000
        label: 100 million years ago
        source: https://en.wikipedia.org/wiki/Patagotitan
        image:
          name: largest-land-animal.jpg
          link: https://commons.wikimedia.org/wiki/File:Patagotitan-Scale-Diagram-Steveoc86.svg
          width: 600
          height: 300

      - name: Opposable thumbs evolve in pre-primates
        necessary: true
        actual: 70000000
        label: 70 million years ago
        source: https://www.quora.com/How-long-did-it-take-for-opposable-thumbs-to-emerge-from-a-common-ancestor-to-humans-with-a-dewclaw
        image:
          name: tarsier.jpg
          link: https://commons.wikimedia.org/wiki/File:Bohol_Tarsier.jpg
          height: 75

      - name: Largest flying animal of all time, pterosaur called Quetzalcoatlus - 40 ft wingspan
        actual: 68000000
        label: 68 million years ago
        source: https://en.wikipedia.org/wiki/Quetzalcoatlus
        image:
          name: largest-flying-animal.jpg
          link: https://commons.wikimedia.org/wiki/File:Mesa-Museum_of_Natural_History-Pterosaurs.JPG
          width: 600
          height: 349

  - name: Mammals and Primates
    label: 66 million years ago
    events:
      - name:
          Mass extinction event, 75% of all species,
          extinction of all dinosaurs except birds,
          extinction of all pterosaurs
        actual: 66000000
        label: 66 million years ago
        source: https://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_extinction_event
        image:
          name: mass-extinction.jpg
          link: https://commons.wikimedia.org/wiki/File:Impact_event.jpg
          height: 69.63

      - name: Mammals become dominant organisms on Earth
        necessary: true
        actual: 66000000
        label: 66 million years ago
        source: https://en.wikipedia.org/wiki/Mammal
        image:
          name: mouse.jpg
          link: https://commons.wikimedia.org/wiki/File:%D0%9C%D1%8B%D1%88%D1%8C_2.jpg
          height: 52.75

      - name: Primates evolve
        necessary: true
        actual: 65000000
        label: 65 million years ago
        source: https://en.wikipedia.org/wiki/Evolution_of_primates
        image:
          name: plesiadapis.jpg
          link: https://commons.wikimedia.org/wiki/File:Plesiadapis_NT.jpg
          height: 63.16

      - name: Bats evolve, only flying mammals
        actual: 52000000
        label: 52 million years ago
        source: https://en.wikipedia.org/wiki/Bat
        image:
          name: bat.jpg
          link: https://commons.wikimedia.org/wiki/File:Big-eared-townsend-fledermaus.jpg
          height: 60.77

      - name: Branch of mammals begin evolving in water, leading to whales, dolphins, seals, etc (closest living land relative - hippo)
        actual: 50000000
        label: 50 million years ago
        source: https://en.wikipedia.org/wiki/Evolution_of_cetaceans
        image:
          name: rodhocetus.jpg
          link: https://commons.wikimedia.org/wiki/File:Rhodocetus_BW.jpg
          height: 50.5

      - name: Simians diverge from other primates (monkeys and apes)
        necessary: true
        actual: 42000000
        label: 42 million years ago
        source: https://en.wikipedia.org/wiki/Simian
        image:
          name: simian.jpg
          link: https://commons.wikimedia.org/wiki/File:BrownSpiderMonkey_(edit2).jpg
          height: 87.3

      - name: Early simians regain color vision (possibly to see ripe fruit)
        necessary: true
        actual: 40000000
        label: 40 - 30 million years ago
        source: http://anthro.palomar.edu/primate/color.htm
        image:
          name: monkey-fruit.jpg
          link: https://www.zsl.org/zsl-london-zoo/news/game-set-and-match-for-zsl-london-zoos-squirrel-monkeys
          height: 67.56

      - name:
          Catarrhines diverge from other simians - no tail, more
          ground-dwelling, greater sexual dimorphism, less pair bonding
        necessary: true
        actual: 35000000
        label: 35 million years ago
        source: https://en.wikipedia.org/wiki/Catarrhini
        image:
          name: stumptail-monkeys.jpg
          link: https://commons.wikimedia.org/wiki/File:Macaca_arctoides.png
          height: 73.38

      - name:
          Hominids diverge from other catarrhines - more freedom of
          motion in shoulders (possibly for tree swinging)
        necessary: true
        actual: 20000000
        label: 20 million years ago
        source: https://en.wikipedia.org/wiki/Hominidae
        image:
          name: proconsul.jpg
          link: https://commons.wikimedia.org/wiki/File:Proconsul_NT.jpg
          height: 68.33

      - name: Last common ancestor of humans and apes
        necessary: true
        actual: 13000000
        label: 13 - 4 million years ago
        source: https://en.wikipedia.org/wiki/Chimpanzee%E2%80%93human_last_common_ancestor
        image:
          name: chimpanzee.jpg
          link: https://commons.wikimedia.org/wiki/File:Pan_troglodytes_(male).jpg
          height: 75

  - name: Early Humans
    label: 5 million years ago
    events:
      - name: Modern human thumb evolves
        necessary: true
        actual: 5000000
        label: 5 million years ago
        source: https://en.wikipedia.org/wiki/Thumb
        image:
          name: baboon-hand.jpg
          link: https://peterkarlladage.wordpress.com/2012/11/20/review-of-ecology-a-new-story-by-dr-brian-swimme/
          height: 66.5

      - name: First bipedal humans (possibly to carry food)
        necessary: true
        actual: 4000000
        label: 4 million years ago
        source: https://en.wikipedia.org/wiki/Bipedalism
        image:
          name: australopithecus.jpg
          link: https://commons.wikimedia.org/wiki/File:A.afarensis.jpg
          height: 93.36


      - name: First stone tools, beginning of stone age
        necessary: true
        actual: 3400000
        label: 3.4 million years ago
        source: https://en.wikipedia.org/wiki/Stone_Age
        image:
          name: stone-tools.jpg
          link: https://commons.wikimedia.org/wiki/File:National_park_stone_tools.jpg
          height: 66.48

      - name:
          Homo erectus evolves (originated in Africa, eventually
          spread into Europe and as far east as China)
        necessary: true
        actual: 1900000
        label: 1.9 million years ago
        source: https://en.wikipedia.org/wiki/Homo
        image:
          name: homo-erectus.jpg
          link: https://commons.wikimedia.org/wiki/File:Homo_erectus_new.JPG
          height: 85

      - name:
          First use of fire, cooking
        necessary: true
        actual: 1900000
        label: 1.9 million years ago
        source: https://en.wikipedia.org/wiki/Cooking
        image:
          name: early-cooking.jpg
          link: https://commons.wikimedia.org/wiki/File:Diorama,_cavemen_-_National_Museum_of_Mongolian_History.jpg
          height: 66.63

      - name: First use of paint
        necessary: true
        actual: 500000
        label: 500,000 years ago
        source: http://www.telegraph.co.uk/news/1528419/Art-of-body-painting-may-date-back-500000-years.html
        image:
          name: homo-heidelbergensis.jpg
          link: https://commons.wikimedia.org/wiki/File:Homo_heidelbergensis_(10233446).jpg
          height: 80.38

      - name: Invention of spears using stone spear heads
        necessary: true
        actual: 400000
        label: 400,000 years ago
        source: https://en.wikipedia.org/wiki/Spear
        image:
          name: cavemen-spears.jpg
          link: http://www.navarroilustracion.com/pleistoceno-en-murcia/
          height: 70.88

  - name: Homo Sapiens
    label: 200,000 years ago
    events:
      - name:
          Homo sapiens evolve from homo erectus (Africa) - larger brain,
          proper language, less hair, shorter, less sexual dimorphism
        necessary: true
        actual: 200000
        label: 200,000 years ago
        source: https://en.wikipedia.org/wiki/Homo_sapiens
        image:
          name: homo-sapiens.jpg
          link: https://www.sapiens.org/evolution/homo-sapiens-and-tool-making/
          height: 54.63

      - name: First use of adhesives (tar), stronger tools
        actual: 200000
        label: 200,000 years ago
        source: https://en.wikipedia.org/wiki/Adhesive
        image:
          name: spear-adhesive.jpg
          link: https://commons.wikimedia.org/wiki/File:Mesa_Verde_spear_and_knife.jpg
          height: 64.75

      - name: First use of clothing
        necessary: true
        actual: 500000
        label: 170,000 years ago
        source: http://news.ufl.edu/archive/2011/01/uf-study-of-lice-dna-shows-humans-first-wore-clothes-170000-years-ago.html
        image:
          name: clothes.jpg
          link: http://handbill.us/2013/12/08/uf-study-of-lice-dna-shows-first-clothes-170000-years-ago/
          height: 74.83

      - name: First wave of homo sapiens leave Africa
        actual: 125000
        label: 125,000 years ago
        source: https://en.wikipedia.org/wiki/Recent_African_origin_of_modern_humans
        image:
          name: human-migration.jpg
          link: https://commons.wikimedia.org/wiki/File:Map-of-human-migrations.jpg
          height: 71.38

      - name:
          Beginning of most recent glacial period, 18°F drop
          in average global temperature (ice age)
        actual: 110000
        label: 110,000 years ago
        source: https://en.wikipedia.org/wiki/Last_glacial_period
        image:
          name: ice-age.jpg
          link: https://commons.wikimedia.org/wiki/File:Fryxellsee_Opt.jpg
          height: 69.38

      - name: First evidence of collecting and eating wild grains
        necessary: true
        actual: 105000
        label: 105,000 years ago
        source: http://www.nature.com/news/2009/091217/full/news.2009.1147.html
        image:
          name: grains.jpg
          link: https://commons.wikimedia.org/wiki/File:Wheat_close-up.JPG
          height: 75

      - name: First homo sapiens in China
        actual: 100000
        label: 100,000 years ago
        source: https://en.wikipedia.org/wiki/Early_human_migrations
        image:
          name: human-migration-2.jpg
          link: https://www.nature.com/news/teeth-from-china-reveal-early-human-trek-out-of-africa-1.18566
          height: 88.88

      - name: First human burials
        actual: 100000
        label: 100,000 years ago
        source: https://en.wikipedia.org/wiki/Burial
        image:
          name: burial.jpg
          link: https://www.heritagedaily.com/2013/02/early-human-burials-varied-widely-but-most-were-simple/77394
          height: 64.13

      - name: First jewelery
        actual: 100000
        label: 100,000 years ago
        source: https://en.wikipedia.org/wiki/Jewellery
        image:
          name: first-jewelery.jpg
          link: https://www.sciencedaily.com/releases/2015/03/150311160442.htm
          height: 75

      - name: First harpoon fishing
        necessary: true
        actual: 90000
        label: 90,000 years ago
        source: https://en.wikipedia.org/wiki/Semliki_harpoon
        image:
          name: harpoons.jpg
          link: https://www.cam.ac.uk/research/features/sharpening-our-knowledge-of-prehistory-on-east-africas-bone-harpoons
          height: 67.78

      - name:
          Toba supereruption, global volcanic winter (Indonesia,
          possibly reduced total human population to less than 10,000)
        actual: 75000
        label: 75,000 years ago
        source: https://en.wikipedia.org/wiki/Toba_catastrophe_theory
        image:
          name: toba-supereruption.jpg
          link: https://commons.wikimedia.org/wiki/File:Tobaeruption.png
          height: 74.13

      - name: Homo erectus becomes extinct
        actual: 70000
        label: 70,000 years ago
        source: https://en.wikipedia.org/wiki/Homo_erectus
        image:
          name: homo-erectus-2.jpg
          link: https://commons.wikimedia.org/wiki/File:Homo_erectus_adult_female_-_head_model_-_Smithsonian_Museum_of_Natural_History_-_2012-05-17.jpg
          height: 85.75

      - name: First use of compound adhesives, stronger tools (South Africa)
        actual: 70000
        label: 70,000 years ago
        source: https://en.wikipedia.org/wiki/Adhesive
        image:
          name: adhesive.jpg
          link: http://www.pbs.org/wgbh/nova/evolution/neanderthal-superglue.html
          height: 56.25

  - name: Global Inhabitation
    label: 60,000 years ago
    events:
#      - name: Second wave of homo sapiens leave Africa
#        actual: 60000
#        label: 60,000 years ago

      - name: First homo sapiens in Australia, extinction of Australian megafauna
        actual: 60000
        label: 60,000 years ago
        source: https://en.wikipedia.org/wiki/Prehistory_of_Australia
        image:
          name: diprotodon.jpg
          link: https://commons.wikimedia.org/wiki/File:Diprotodon11122.jpg
          height: 59

      - name: First instrument (wooden flute, Europe)
        necessary: true
        actual: 41000
        label: 41,000 years ago
        source: https://en.wikipedia.org/wiki/Prehistoric_music
        image:
          name: flute.jpg
          link: https://commons.wikimedia.org/wiki/File:Fl%C3%BBte_pal%C3%A9olithique_(mus%C3%A9e_national_de_Slov%C3%A9nie,_Ljubljana)_(9420310527).jpg
          height: 81.88

      - name: Homo Sapiens conquer all of Europe, Neanderthals become extinct
        actual: 40000
        label: 40,000 years ago
        source: https://en.wikipedia.org/wiki/Neanderthal
        image:
          name: neanderthal.jpg
          link: https://commons.wikimedia.org/wiki/File:Neandertaler_reconst.jpg
          height: 93.25

      - name: Domestication of dogs
        necessary: true
        actual: 40000
        label: 40,000 - 27,000 years ago
        source: https://en.wikipedia.org/wiki/Origin_of_the_domestic_dog
        image:
          name: wolf.jpg
          link: https://commons.wikimedia.org/wiki/File:Gray_wolf_(Canis_Lupis).jpg
          height: 66

      - name: First cave paintings (hands/animals, Spain)
        necessary: true
        actual: 35400
        label: 35,400 years ago
        source: https://en.wikipedia.org/wiki/Cave_painting
        image:
          name: cave-paintings.jpg
          link: https://commons.wikimedia.org/wiki/File:Hands_in_Pettakere_Cave_DYK_crop.jpg
          height: 89

      - name: Invention of weaving
        actual: 27000
        label: 27,000 years ago
        source: https://en.wikipedia.org/wiki/Weaving
        image:
          name: sewing-needle.jpg
          link: https://commons.wikimedia.org/wiki/File:Aiguille_os_246.1_Global.jpg
          height: 57.38

      - name: First fish hook
        actual: 23000
        label: 23,000 years ago
        source: https://en.wikipedia.org/wiki/Fish_hook
        image:
          name: fish-hook.jpg
          link: https://www.nature.com/news/archaeologists-land-world-s-oldest-fish-hook-1.9461
          height: 66.59

      - name: First use of bread (Middle East)
        actual: 23000
        label: 23,000 years ago
        source: http://www.nature.com/news/2009/091217/full/news.2009.1147.html
        image:
          name: early-bread.jpg
          link: https://commons.wikimedia.org/wiki/File:Conical_loaves_of_bread,_Gebelein,_5th_Dynasty_c_2400_BC.jpg
          height: 74.38

      - name: End of ice age, sea levels rise 400 ft over 13,000 years
        actual: 19000
        label: 19,000 - 6,000 years ago
        source: https://en.wikipedia.org/wiki/Holocene
        image:
          name: megatherium.jpg
          link: https://commons.wikimedia.org/wiki/File:Megatherum_DB.jpg
          height: 85.44

  - name: Agriculture
    label: 15,000 years ago
    events:
      - name: Domestication of pigs, beginning of agriculture (Mesopotamia)
        necessary: true
        actual: 15000
        label: 13,000 BC
        source: https://en.wikipedia.org/wiki/History_of_agriculture
        image:
          name: pig.jpg
          link: https://commons.wikimedia.org/wiki/File:Wild_Pig_KSC02pd0873.jpg
          height: 61.13

      - name: Earliest known oil lamps (Lascaux caves, France)
        necessary: true
        actual: 15000
        label: 13,000 BC
        source: https://en.wikipedia.org/wiki/Oil_lamp#History
        image:
          name: oil-lamp.jpg
          link: https://commons.wikimedia.org/wiki/File:Lampe_a_graisse_-_Lascaux.jpg
          width: 800
          height: 580

      - name: First cities, beginning of civilization
        necessary: true
        actual: 14000
        label: 12,000 BC
        source: https://en.wikipedia.org/wiki/Cradle_of_civilization
        image:
          name: fertile-crescent.jpg
          link: https://commons.wikimedia.org/wiki/File:Fertile_Crescent_map.png
          height: 88.83

      - name: Domestication of rice (China)
        actual: 13500
        label: 11,500 BC
        source: https://en.wikipedia.org/wiki/Rice
        image:
          name: rice.jpg
          link: https://commons.wikimedia.org/wiki/File:White,_Brown,_Red_%26_Wild_rice.jpg
          height: 75

      - name: Domestication of sheep (Mesopotamia)
        actual: 13000
        label: 11,000 BC
        source: https://en.wikipedia.org/wiki/History_of_the_domestic_sheep
        image:
          name: sheep.jpg
          link: https://commons.wikimedia.org/wiki/File:Muffelwild12.4.2008_007.jpg
          height: 75

      - name: First homo sapiens in America, extinction of American megafauna
        actual: 12700
        label: 10,700 BC
        source: https://en.wikipedia.org/wiki/Pleistocene_megafauna
        image:
          name: mammoth.jpg
          link: https://commons.wikimedia.org/wiki/File:Woolly_mammoth.jpg
          height: 66.38

      - name: Homo floresiensis becomes extinct, homo sapiens last remaining humanoid species
        actual: 12000
        label: 10,000 BC
        source: https://en.wikipedia.org/wiki/Homo_floresiensis
        image:
          name: homo-floresiensis.jpg
          link: https://commons.wikimedia.org/wiki/File:Homo_floresiensis_v_2-0.jpg
          height: 81

      - name: First bow and arrow (Europe)
        necessary: true
        actual: 11000
        label: 9000 BC
        source: https://en.wikipedia.org/wiki/History_of_archery
        image:
          name: bow-arrow-cave-painting.jpg
          link: https://commons.wikimedia.org/wiki/File:Morella_(combate-de-arquero.png
          height: 79.69

      - name: Domestication of corn (Mexico)
        actual: 11000
        label: 9000 BC
        source: https://en.wikipedia.org/wiki/Maize
        image:
          name: corn.jpg
          link: https://commons.wikimedia.org/wiki/File:Maize-teosinte.jpg
          height: 62

      - name: Domestication of cattle (Turkey)
        actual: 10500
        label: 8500 BC
        source: https://en.wikipedia.org/wiki/Cattle
        image:
          name: cattle.jpg
          link: https://commons.wikimedia.org/wiki/File:Lascaux_painting.jpg
          height: 65.55

      - name: First calendar (Scotland)
        necessary: true
        actual: 10000
        label: 8000 BC
        source: https://en.wikipedia.org/wiki/History_of_calendars
        image:
          name: scotish-calendar.jpg
          link: http://www.bbc.com/news/uk-scotland-north-east-orkney-shetland-23286928
          height: 73.7

      - name: Domestication of cats (possibly to keep rodents out of food stores)
        actual: 9500
        label: 7500 BC
        source: https://en.wikipedia.org/wiki/Cat
        image:
          name: wild-cat.jpg
          link: https://commons.wikimedia.org/wiki/File:Felis_Lybica_Sarda_05.JPG
          height: 56.25

      - name: First cities with over 10,000 people (Turkey)
        actual: 9000
        label: 7000 BC
        source: https://en.wikipedia.org/wiki/%C3%87atalh%C3%B6y%C3%BCk
        image:
          name: turkey-ruins.jpg
          link: https://commons.wikimedia.org/wiki/File:%C3%87atalh%C3%B6y%C3%BCk_with_surroundings..jpg
          height: 66.63

      - name: First use of dairy animals, milk (Southeast Asia)
        actual: 9000
        label: 7000 BC
        source: https://en.wikipedia.org/wiki/Milk
        image:
          name: goat-milk.jpg
          link: https://commons.wikimedia.org/wiki/File:Goat_kid_feeding_on_mothers_milk.jpg
          height: 66.75

      - name: First use of alcoholic drinks (China, Middle East)
        necessary: true
        actual: 9000
        label: 7000 BC
        source: https://en.wikipedia.org/wiki/History_of_alcoholic_drinks
        image:
          name: ancient-alcohol.jpg
          link: https://www.messagetoeagle.com/ancient-civilizations-invented-alcohol-10000-years-ago/
          height: 72.84

  - name: Ancient History
    label: 8,000 years ago
    events:
      - name: Invention of writing, beginning of recorded history
        necessary: true
        actual: 8000
        label: 6000 BC
        source: https://en.wikipedia.org/wiki/History_of_writing
        image:
          name: ancient-writing.jpg
          link: https://www.ancient-code.com/the-earliest-form-of-writing-on-earth-dating-back-to-5500bc-the-incredible-tartaria-tablets/
          height: 50

      - name: Domestication of chickens (China)
        actual: 8000
        label: 6000 BC
        source: https://en.wikipedia.org/wiki/Chicken
        image:
          name: junglefowl.jpg
          link: https://commons.wikimedia.org/wiki/File:Gallus_gallus_male_Kaziranga_0.jpg
          height: 75

      - name: First copper weapons, end of stone age (Serbia)
        necessary: true
        actual: 7500
        label: 5500 BC
        source: https://en.wikipedia.org/wiki/History_of_weapons
        image:
          name: copper-axe.jpg
          link: https://commons.wikimedia.org/wiki/File:ReconstructedOetziAxe.jpg
          height: 89.38

      - name: Horses domesticated (Northern Asia)
        actual: 5500
        label: 3500 BC
        source: https://en.wikipedia.org/wiki/Domestication_of_the_horse
        image:
          name: horse-cave-painting.jpg
          link: https://commons.wikimedia.org/wiki/File:Lascaux_horse_replica.jpg
          height: 71.5

      - name: First man-made glass objects (Mesopotamia)
        actual: 5500
        label: 3500 BC
        source: https://en.wikipedia.org/wiki/History_of_glass
        image:
          name: glass-beads.jpg
          link: https://www.sciencenews.org/article/ancient-egyptian-blue-glass-beads-reached-scandinavia
          height: 56.25

      - name: First written language, first schools (Mesopotamia)
        necessary: true
        actual: 5500
        label: 3500 BC
        source: https://en.wikipedia.org/wiki/History_of_education
        image:
          name: early-language.jpg
          link: https://commons.wikimedia.org/wiki/File:Peribsen.jpg
          height: 78

      - name: First wheeled vehicles, pulled by horses
        necessary: true
        actual: 5350
        label: 3350 BC
        source: https://en.wikipedia.org/wiki/Wheel
        image:
          name: wheel.jpg
          link: https://commons.wikimedia.org/wiki/File:Ur_chariot.jpg
          height: 51

      - name: First metal alloy, bronze (Mesopotamia)
        actual: 5300
        label: 3300 BC
        source: https://en.wikipedia.org/wiki/Ancient_Near_East
        image:
          name: bronze-dagger.jpg
          link: https://commons.wikimedia.org/wiki/File:Poignard_IMG_4977-white.jpg
          height: 88

      - name: Earliest human who's name we know (Egypt)
        actual: 5200
        label: 3200 BC
        source: https://en.wikipedia.org/wiki/Iry-Hor
        image:
          name: iry-hor.jpg
          link: https://commons.wikimedia.org/wiki/File:Iry_Hor_name.jpg
          width: 800
          height: 580

      - name: Invention of indoor plumbing and flush toilet (South Asia)
        actual: 5000
        label: 3000 BC
        source: https://en.wikipedia.org/wiki/History_of_water_supply_and_sanitation
        image:
          name: skara-brae.jpg
          link: https://commons.wikimedia.org/wiki/File:Skara_Brae_house_1_5.jpg
          width: 800
          height: 600

      - name: Decimal mathematics (Egypt)
        actual: 5000
        label: 3000 BC
        source: https://en.wikipedia.org/wiki/Decimal
        image:
          name: egyptian-decimal.jpg
          link: http://www.egykingblog.com/2012/11/can-you-answer-this-questions-about.html
          width: 800
          height: 448

      - name: Invention of candles/torches (Romans/Egyptians)
        actual: 5000
        label: 3000 BC
        source: https://candles.org/history/
        image:
          name: candle.jpg
          link: https://commons.wikimedia.org/wiki/File:Candle_(Slava_celebration).jpg
          width: 600
          height: 600

      - name: Invention of abacus (Middle East)
        actual: 4700
        label: 2700 BC
        source: https://en.wikipedia.org/wiki/Abacus
        image:
          name: abacus.jpg
          link: https://commons.wikimedia.org/wiki/File:Chinese-abacus.jpg
          width: 800
          height: 526

      - name: Great Pyramid of Giza (completed in only 20 years), remained tallest manmade structure for 3,800 years (height of 481 feet), still heaviest building ever made
        actual: 4560
        label: 2560 BC
        source: https://en.wikipedia.org/wiki/Great_Pyramid_of_Giza
        image:
          name: giza-pyramid.jpg
          link: https://commons.wikimedia.org/wiki/File:Kheops-Pyramid.jpg
          width: 800
          height: 491

      - name: First horses used for transporting people, chariot becomes primary branch of the military
        actual: 4000
        label: 2000 BC
        source: https://en.wikipedia.org/wiki/Chariot
        image:
          name: chariot.jpg
          link: https://commons.wikimedia.org/wiki/File:Parade_charriots_Louvre_CA2503.jpg
          width: 800
          height: 450

      - name: First scissors, spring scissors (Mesopotamia)
        actual: 4000
        label: 2000 BC
        source: https://en.wikipedia.org/wiki/Scissors
        image:
          name: spring-scissors.jpg
          link: https://commons.wikimedia.org/wiki/File:Shears_MET_29I_E08R4.jpg
          width: 800
          height: 700

  - name: Iron Age
    label: 3,300 years ago
    events:
      - name: First iron smelting (melting point of 2,800 °F)
        necessary: true
        actual: 3200
        label: 1200 BC
        source: https://en.wikipedia.org/wiki/Smelting
        image:
          name: iron-dagger.jpg
          link: https://www.history.com/news/researchers-say-king-tuts-dagger-was-made-from-a-meteorite
          width: 686
          height: 385

      - name: Major collapse of civilization (Mediterranean, possibly triggered by drought and famine), beginning of Greek dark ages
        actual: 3177
        label: 1177 BC
        source: https://en.wikipedia.org/wiki/Late_Bronze_Age_collapse
        image:
          name: late-bronze-age-collapse.jpg
          link: https://commons.wikimedia.org/wiki/File:Invasions,_destructions_and_possible_population_movements_during_the_Bronze_Age_Collapse,_ca._1200_BC.png
          width: 800
          height: 449

      - name: First standardized coinage (China)
        necessary: true
        actual: 3000
        label: 1000 BC
        source: https://en.wikipedia.org/wiki/History_of_money
        image:
          name: coinage.jpg
          link: https://commons.wikimedia.org/wiki/File:BMC_06.jpg
          width: 500
          height: 275

      - name: First glass lenses (Middle East)
        necessary: true
        actual: 2700
        label: 700 BC
        source: https://en.wikipedia.org/wiki/Lens_(optics)
        image:
          name: nimrud-lense.jpg
          link: https://commons.wikimedia.org/wiki/File:Nimrud_lens_British_Museum.jpg
          width: 800
          height: 600

      - name: Torah written, beginning of Abrahamic religions, currently 54% of world population adheres to an Abrahamic religion (Babylonia)
        actual: 2600
        label: 600 - 400 BC
        source: https://en.wikipedia.org/wiki/Abrahamic_religions
        image:
          name: jehu-obelisk.jpg
          link: https://commons.wikimedia.org/wiki/File:Jehu-Obelisk-cropped.jpg
          width: 800
          height: 513

      - name: Democracy (Cleisthenes, Greece)
        necessary: true
        actual: 2508
        label: 508 BC
        source: https://en.wikipedia.org/wiki/History_of_democracy
        image:
          name: athens.jpg
          link: https://commons.wikimedia.org/wiki/File:The_Acropolis_of_Athens_viewed_from_the_Hill_of_the_Muses_(14220794964).jpg
          width: 800
          height: 530

      - name: Discovery that Earth is round (Pythagoras, Greece)
        necessary: true
        actual: 2500
        label: 500 BC
        source: https://en.wikipedia.org/wiki/Spherical_Earth
        image:
          name: curve-earth-shadow.jpg
          link: https://commons.wikimedia.org/wiki/File:20080816eclipsed2.jpg
          width: 650
          height: 551

      - name: Discovery of the Phythagorean theorem (Pythagoras, Greece)
        actual: 2500
        label: 500 BC
        source: https://en.wikipedia.org/wiki/Pythagorean_theorem
        image:
          name: pythagorean-theorem.jpg
          link: https://commons.wikimedia.org/wiki/File:Pythagorean.svg
          width: 800
          height: 646

      - name: Horses bred large enough to carry men, beginning of cavalry (Middle East)
        necessary: true
        actual: 2490
        label: 490 BC
        source: https://en.wikipedia.org/wiki/Cavalry
        image:
          name: cavalry.jpg
          link: https://commons.wikimedia.org/wiki/File:Assyriancavalry.JPG
          width: 800
          height: 508

      - name: First record of camera obscura phenomenon, light travels in straight lines (Mozi, China)
        actual: 2400
        label: 400 BC
        source: https://en.wikipedia.org/wiki/Camera_obscura
        image:
          name: camera-obscura.jpg
          link: https://evolutionnews.org/2014/04/on_cosmos_neil_/
          width: 500
          height: 281

      - name: First higher learning institution founded, The Academy (Plato, Greece)
        necessary: true
        actual: 2387
        label: 387 BC
        source: https://en.wikipedia.org/wiki/Academy
        image:
          name: athens-academy.jpg
          link: https://commons.wikimedia.org/wiki/File:Raffael_058.jpg
          width: 800
          height: 509

      - name: Foundation of western philosophy, science, western religion, and spirituality (Plato, Greece)
        necessary: true
        actual: 2375
        label: 375 BC
        source: https://en.wikipedia.org/wiki/Plato
        image:
          name: plato.jpg
          link: https://commons.wikimedia.org/wiki/File:Plato_Silanion_Musei_Capitolini_MC1377.jpg
          width: 800
          height: 684

      - name: Development of geometry (Euclid, Greece)
        necessary: true
        actual: 2300
        label: 300 BC
        source: https://en.wikipedia.org/wiki/Euclid%27s_Elements
        image:
          name: euclid-elements.jpg
          link: https://commons.wikimedia.org/wiki/File:Euclid_Vat_ms_no_190_I_prop_47.jpg
          width: 800
          height: 491

      - name: Estimation of pi, invention of exponents (Archimedes, Greece)
        necessary: true
        actual: 2250
        label: 250 BC
        source: https://en.wikipedia.org/wiki/Archimedes
        image:
          name: estimate-pi.jpg
          link: https://commons.wikimedia.org/wiki/File:Archimedes_pi.svg
          width: 800
          height: 480

      - name:
          Accurate measurement of Earth’s circumference, tilt, and distance from the sun;
          development of geography (Eratosthenes, Greece)
        necessary: true
        actual: 2200
        label: 200 BC
        source: https://en.wikipedia.org/wiki/History_of_geodesy
        image:
          name: earth-circumference.jpg
          link: https://commons.wikimedia.org/wiki/File:Eratosthenes_measure_of_Earth_circumference.svg
          width: 800
          height: 533

      - name: Invention of paper (China)
        necessary: true
        actual: 2179
        label: 179 BC
        source: https://en.wikipedia.org/wiki/History_of_paper
        image:
          name: paper.jpg
          link: https://commons.wikimedia.org/wiki/File:Paperbook%2B256.jpg
          width: 800
          height: 700

      - name: Intromission theory - light is not a property of the eye (Lucretius, Roman)
        actual: 2055
        label: 55 BC
        source: https://en.wikipedia.org/wiki/Emission_theory_(vision)
        image:
          name: intromission-light-theory.jpg
          link: https://commons.wikimedia.org/wiki/File:Thesaurus_opticus_Titelblatt.jpg
          width: 800
          height: 640

      - name: Christianity (Jesus)
        actual: 2004
        label: 4 BC
        source: https://en.wikipedia.org/wiki/History_of_Christianity
        image:
          name: last-supper.jpg
          link: https://commons.wikimedia.org/wiki/File:%C3%9Altima_Cena_-_Juan_de_Juanes.jpg
          width: 800
          height: 506

      - name: First cities with population over 1 million (Rome / Alexandria)
        actual: 2001
        label: 1
        source: https://en.wikipedia.org/wiki/List_of_largest_cities_throughout_history
        image:
          name: colosseum.jpg
          link: https://commons.wikimedia.org/wiki/File:Colosseo_2008.jpg
          width: 800
          height: 533

      - name: Invention of glass mirror (Rome)
        actual: 1923
        label: 77
        source: https://en.wikipedia.org/wiki/Mirror
        image:
          name: mirror.jpg
          link: https://commons.wikimedia.org/wiki/File:Naples_National_Archaeological_Museum_(14842094122).jpg
          width: 800
          height: 657

      - name: First modern scissors, pivot scissors (Rome)
        actual: 1900
        label: 100
        source: https://en.wikipedia.org/wiki/Scissors
        image:
          name: pivot-scissors.jpg
          link: https://medium.com/@susiperedo/scissors-b890c78dee08
          width: 500
          height: 340

      - name: First light refraction tables (Claudius Ptolemy)
        actual: 1850
        label: 150
        source: https://en.wikipedia.org/wiki/History_of_optics
        image:
          name: ptolemy.jpg
          link: https://commons.wikimedia.org/wiki/File:Ptolemy_urania.jpg
          width: 500
          height: 367

  - name: Middle Ages
    label: 1,540 years ago
    events:
      - name: Fall of Roman Empire, beginning of middle ages (Europe)
        actual: 1524
        label: 476
        source: https://en.wikipedia.org/wiki/Fall_of_the_Western_Roman_Empire
        image:
          name: roman-invasions.jpg
          link: https://commons.wikimedia.org/wiki/File:Invasions_of_the_Roman_Empire_1.png
          width: 800
          height: 566

      - name: Method to solve quadratic equations, understanding of zero (Brahmagupta, India)
        necessary: true
        actual: 1372
        label: 628
        source: https://en.wikipedia.org/wiki/Br%C4%81hmasphu%E1%B9%ADasiddh%C4%81nta
        image:
          name: zero.jpg
          link: https://commons.wikimedia.org/wiki/File:Khmer_Numerals_-_605_from_the_Sambor_inscriptions.jpg
          width: 244
          height: 157

      - name: First paper currency (China)
        necessary: true
        actual: 1194
        label: 806
        source: http://www.pbs.org/wgbh/nova/ancient/history-money.html
        image:
          name: paper-currency.jpg
          link: https://twitter.com/mashreqtweets/status/640102109942157312
          width: 505
          height: 318

      - name: Development of algebra (Muhammad ibn Musa al-Khwarizmi, Middle East)
        necessary: true
        actual: 1170
        label: 830
        source: https://en.wikipedia.org/wiki/History_of_algebra
        image:
          name: algebra.jpg
          link: https://commons.wikimedia.org/wiki/File:Bodleian_MS._Huntington_214_roll332_frame36.jpg
          width: 800
          height: 578

      - name: Invention of gunpowder (China)
        necessary: true
        actual: 1150
        label: 850
        source: https://en.wikipedia.org/wiki/History_of_gunpowder
        image:
          name: gunpowder.jpg
          link: https://www.grc.nasa.gov/www/k-12/rocket/BottleRocket/13thru16.htm
          width: 242
          height: 186

      - name: Oldest existing university founded (University of Al Quaraouiyine, Morocco)
        actual: 1141
        label: 859
        source: https://en.wikipedia.org/wiki/University_of_Al_Quaraouiyine
        image:
          name: university.jpg
          link: https://commons.wikimedia.org/wiki/File:University_of_Al_Qaraouiyine.jpg
          width: 567
          height: 600

      - name: Experimental evidence for intromission light theory, predicted light has a finite speed (Ibn al-Haytham, Middle East)
        actual: 1000
        label: 1000
        source: https://en.wikipedia.org/wiki/Book_of_Optics
        image:
          name: optics.jpg
          link: https://commons.wikimedia.org/wiki/File:Thesaurus_opticus_Titelblatt.jpg
          width: 545
          height: 600

      - name: Invention of magnetic compass (China)
        necessary: true
        actual: 960
        label: 1040
        source: https://en.wikipedia.org/wiki/History_of_the_compass
        image:
          name: compass.jpg
          link: https://commons.wikimedia.org/wiki/File:Chinese_Geomantic_Compass_c._1760,_National_Maritime_Museum.JPG
          width: 800
          height: 531

      - name: Magna Carta, foundation for individual rights (England)
        actual: 785
        label: 1215
        source: https://en.wikipedia.org/wiki/Magna_Carta
        image:
          name: magna-carta.jpg
          link: https://en.wikipedia.org/wiki/File:Magna_Carta_(British_Library_Cotton_MS_Augustus_II.106).jpg
          width: 800
          height: 533

      - name: First rockets (China)
        actual: 768
        label: 1232
        source: https://en.wikipedia.org/wiki/History_of_rockets
        image:
          name: rocket-arrows.jpg
          link: https://commons.wikimedia.org/wiki/File:Oldest_depiction_of_rocket_arrows.jpg
          width: 465
          height: 578

      - name: First joint-stock company (Bazacle Milling Company, France)
        necessary: true
        actual: 750
        label: 1250
        source: https://en.wikipedia.org/wiki/Joint-stock_company
        image:
          name: joint-stock-company.jpg
          link: https://www.britannica.com/topic/joint-stock-company
          width: 556
          height: 600

      - name: First firearm, cannon (Middle East)
        necessary: true
        actual: 740
        label: 1260
        source: https://en.wikipedia.org/wiki/History_of_the_firearm
        image:
          name: canon.jpg
          link: https://commons.wikimedia.org/wiki/File:Yuan_chinese_gun.jpg
          width: 800
          height: 599

      - name: Invention of eyeglasses (Italy)
        actual: 714
        label: 1286
        source: https://en.wikipedia.org/wiki/Glasses
        image:
          name: reading-stone.jpg
          link: https://commons.wikimedia.org/wiki/File:2015-08_archeon_reading_stone.JPG
          width: 800
          height: 533

      - name: Largest contiguous land empire - 16% of earth, 9 million mi<sup>2</sup> (Mongol Empire)
        actual: 706
        label: 1294
        source: https://en.wikipedia.org/wiki/Mongol_Empire
        image:
          name: mongol-empire.jpg
          link: https://mapsontheweb.zoom-maps.com/post/162235071505/mongol-empire-in-1294-via-reddit
          width: 800
          height: 592

      - name: Lincoln Cathedral surpasses Great Pyramid as tallest manmade structure (height of 525 feet)
        actual: 689
        label: 1311
        source: https://en.wikipedia.org/wiki/List_of_tallest_buildings_and_structures
        image:
          name: lincoln-cathedral.jpg
          link: https://commons.wikimedia.org/wiki/File:Lincoln_Cathedral_viewed_from_Lincoln_Castle.jpg
          width: 800
          height: 600

      - name: First use of coffee drinking - may have replaced alcohol and led to the enlightment (Yemen)
        necessary: true
        actual: 586
        label: 1414
        source: https://en.wikipedia.org/wiki/History_of_coffee
        image:
          name: coffee.jpg
          link: https://www.bbc.com/news/magazine-22190802
          width: 800
          height: 578

      - name: Invention of printing press (Johannes Gutenberg)
        necessary: true
        actual: 560
        label: 1440
        source: https://en.wikipedia.org/wiki/Printing_press
        image:
          name: printing-press.jpg
          link: https://commons.wikimedia.org/wiki/File:Chodowiecki_Basedow_Tafel_21_c_Z.jpg
          width: 793
          height: 600

      - name: Columbus explores America
        actual: 508
        label: 1492
        source: https://en.wikipedia.org/wiki/Voyages_of_Christopher_Columbus
        image:
          name: columbus.jpg
          link: https://commons.wikimedia.org/wiki/File:Eclipse_Christophe_Colomb.jpg
          width: 738
          height: 600

      - name: Realization that America was a new land mass, not Asia (Amerigo Vespucci, Italy)
        actual: 498
        label: 1502
        source: https://en.wikipedia.org/wiki/Amerigo_Vespucci
        image:
          name: america.jpg
          link: https://commons.wikimedia.org/wiki/File:Waldseem%C3%BCller_world_map_1508.jpg
          width: 800
          height: 445

      - name: First global circumnavigation (Magellan, Spain)
        actual: 478
        label: 1522
        source: https://en.wikipedia.org/wiki/Circumnavigation
        image:
          name: magellan.jpg
          link: https://commons.wikimedia.org/wiki/File:ReplicaNaoVictoriaMagallanes.jpg
          width: 595
          height: 397

  - name: Scientific Revolution
    label: 475 years ago
    events:
      - name: Earth revolves around Sun, Copernican Revolution (Nicolaus Copernicus)
        necessary: true
        actual: 457
        label: 1543
        source: https://en.wikipedia.org/wiki/Copernican_Revolution
        image:
          name: heliocentrism.jpg
          link: https://commons.wikimedia.org/wiki/File:Copernican_heliocentrism_diagram-2.jpg
          width: 655
          height: 600

      - name: First published picture of camera obscura (Gemma Frisius)
        actual: 455
        label: 1545
        source: https://en.wikipedia.org/wiki/Camera_obscura
        image:
          name: camera-obscura-picture.jpg
          link: https://commons.wikimedia.org/wiki/File:1545_gemma_frisius_-_camera-obscura-sonnenfinsternis_1545-650x337.jpg
          width: 650
          height: 337

      - name: Invention of microscope (Zacharias Janssen)
        necessary: true
        actual: 410
        label: 1590
        source: https://en.wikipedia.org/wiki/Microscope
        image:
          name: microscope.jpg
          link: https://en.wikipedia.org/wiki/File:Jaansen_Microscope.jpg
          width: 800
          height: 600

      - name: First stock market (Amsterdam Stock Exchange)
        necessary: true
        actual: 398
        label: 1602
        source: https://en.wikipedia.org/wiki/Stock_market
        image:
          name: stock-market.jpg
          link: https://commons.wikimedia.org/wiki/File:VOC_aandeel_9_september_1606.jpg
          width: 800
          height: 582

      - name: Invention of telescope (Hans Lippershey)
        necessary: true
        actual: 392
        label: 1608
        source: https://en.wikipedia.org/wiki/History_of_the_telescope
        image:
          name: telescope.jpg
          link: https://commons.wikimedia.org/wiki/File:Emblemata_1624.jpg
          width: 800
          height: 545

      - name: Discovery of moons of Jupiter (Galileo Galilei)
        actual: 391
        label: 1610
        source: https://en.wikipedia.org/wiki/Galilean_moons
        image:
          name: galilean-moons.jpg
          link: https://commons.wikimedia.org/wiki/File:Jupiter_and_the_Galilean_Satellites.jpg
          width: 800
          height: 561

      - name: Laws of planetary motion (Johannes Kepler)
        actual: 381
        label: 1619
        source: https://en.wikipedia.org/wiki/Kepler%27s_laws_of_planetary_motion
        image:
          name: kepler-laws.jpg
          link: https://commons.wikimedia.org/wiki/File:Kepler_laws_diagram.svg
          width: 559
          height: 600

      - name: First submarine (Cornelis Drebbel, Dutch)
        actual: 380
        label: 1620
        source: https://en.wikipedia.org/wiki/History_of_submarines
        image:
          name: submarine.jpg
          link: https://commons.wikimedia.org/wiki/File:Van_Drebbel.jpg
          width: 584
          height: 400

      - name: First economic bubble (tulip mania, Netherlands)
        actual: 363
        label: 1637
        source: https://en.wikipedia.org/wiki/Economic_bubble
        image:
          name: tulip-mania.jpg
          link: https://commons.wikimedia.org/wiki/File:Jan_Brueghel_the_Younger,_Satire_on_Tulip_Mania,_c._1640.jpg
          width: 800
          height: 511

      - name: Theory of chemical elements (Robert Boyle)
        necessary: true
        actual: 339
        label: 1661
        source: https://en.wikipedia.org/wiki/Chemical_element
        image:
          name: boyles-law.jpg
          link: https://www.britannica.com/science/Boyles-law
          width: 800
          height: 564

      - name: Development of calculus (Gottfried Leibniz and Isaac Newton)
        necessary: true
        actual: 325
        label: 1675
        source: https://en.wikipedia.org/wiki/History_of_calculus
        image:
          name: calculus.jpg
          link: https://commons.wikimedia.org/wiki/File:Integral_as_region_under_curve.svg
          width: 643
          height: 600

      - name: Discovery of bacteria (Antonie van Leeuwenhoek)
        actual: 324
        label: 1676
        source: https://en.wikipedia.org/wiki/Bacteria
        image:
          name: leeuwenhoek-microscope.jpg
          link: https://commons.wikimedia.org/wiki/File:Leeuwenhoek_Microscope.png
          width: 800
          height: 481

      - name: First quantatitive estimate of the speed of light, only 25% off (Ole Rømer)
        necessary: true
        actual: 324
        label: 1676
        source: https://en.wikipedia.org/wiki/Speed_of_light
        image:
          name: ole-romer.jpg
          link: https://commons.wikimedia.org/wiki/File:Ole_R%C3%B8mer_at_work.jpg
          width: 413
          height: 319

      - name: Discovery of gravitational force (Isaac Newton)
        actual: 313
        label: 1687
        source: https://en.wikipedia.org/wiki/Gravity
        image:
          name: gravity.jpg
          link: https://commons.wikimedia.org/wiki/File:NewtonsLawOfUniversalGravitation.svg
          width: 800
          height: 500

      - name: Accurate measurement of speed of sound (William Derham)
        actual: 291
        label: 1709
        source: https://en.wikipedia.org/wiki/Speed_of_sound
        image:
          name: speed-of-sound.jpg
          link: https://www.fineartstorehouse.com/collections/dorling-kindersley-prints/illustration-william-derhams-sound-experiment-13540675.html
          width: 600
          height: 226

      - name: Invention of electrical capacitor (Pieter van Musschenbroek)
        actual: 254
        label: 1746
        source: https://en.wikipedia.org/wiki/Capacitor
        image:
          name: leyden-jar.jpg
          link: https://commons.wikimedia.org/wiki/File:Andreas_Cunaeus_discovering_the_Leyden_jar.png
          width: 800
          height: 582

      - name: Discovery of galaxies (Thomas Wright)
        actual: 250
        label: 1750
        source: https://en.wikipedia.org/wiki/Galaxy
        image:
          name: galaxies.jpg
          link: https://commons.wikimedia.org/wiki/File:Pic_iroberts1.jpg
          width: 569
          height: 371

      - name: Common understanding of electricity (Benjamin Franklin)
        actual: 250
        label: 1750
        source: https://en.wikipedia.org/wiki/History_of_electrical_engineering
        image:
          name: franklin-kite.jpg
          link: https://commons.wikimedia.org/wiki/File:Benjamin_West,_English_(born_America)_-_Benjamin_Franklin_Drawing_Electricity_from_the_Sky_-_Google_Art_Project.jpg
          width: 448
          height: 600

      - name: Discovery of electromagnetism (Franz Aepinus)
        necessary: true
        actual: 241
        label: 1759
        source: https://en.wikipedia.org/wiki/History_of_electromagnetic_theory
        image:
          name: magnetism.jpg
          link: https://commons.wikimedia.org/wiki/File:Lodestone_attracting_nails.png
          width: 668
          height: 532

  - name: Industrial Revolution
    label: 250 years ago
    events:
      - name: Discovery of hydrogen (Henry Cavendish)
        necessary: true
        actual: 234
        label: 1766
        source: https://en.wikipedia.org/wiki/Hydrogen
        image:
          name: cavendish-hydrogen.jpg
          link: https://commons.wikimedia.org/wiki/File:Cavendish_hydrogen.jpg
          width: 495
          height: 343

      - name: First iron-cased rockets (India)
        actual: 220
        label: 1780
        source: https://en.wikipedia.org/wiki/Mysorean_rockets
        image:
          name: mysorean-rockets.jpg
          link: https://commons.wikimedia.org/wiki/File:Rocket_warfare.jpg
          width: 616
          height: 423

      - name: Invention of rotary steam engine (James Watt)
        necessary: true
        actual: 219
        label: 1781
        source: https://en.wikipedia.org/wiki/History_of_the_steam_engine
        image:
          name: steam-engine.jpg
          link: https://commons.wikimedia.org/wiki/File:Maquina_vapor_Watt_ETSIIM.jpg
          width: 800
          height: 594

      - name: Discovery of Uranus (William Herschel)
        actual: 219
        label: 1781
        source: https://en.wikipedia.org/wiki/Uranus
        image:
          name: uranus-telescope.jpg
          link: https://commons.wikimedia.org/wiki/File:HerschelTelescope.jpg
          width: 468
          height: 600

      - name: Theory of black holes (John Michell)
        actual: 217
        label: 1783
        source: https://en.wikipedia.org/wiki/Black_hole
        image:
          name: black-hole.jpg
          link: https://commons.wikimedia.org/wiki/File:BH_LMC.png
          width: 600
          height: 480

      - name: First manned flight, hot-air balloon (Montgolfier brothers)
        actual: 217
        label: 1783
        source: https://en.wikipedia.org/wiki/Hot_air_balloon
        image:
          name: hot-air-balloon.jpg
          link: https://commons.wikimedia.org/wiki/File:1783_balloonj.jpg
          width: 440
          height: 600

      - name:
          Determination of solar apex, the direction the Sun is traveling relative to local stars,
          calculated within 10° of the value accepted today (William Herschel)
        actual: 217
        label: 1783
        source: https://en.wikipedia.org/wiki/Solar_apex
        image:
          name: solar-apex.jpg
          link: https://www.islamicvideos.org/the-quran-and-science-booklet/
          width: 800
          height: 599

      - name: Development of chemistry, first list of elements (Antoine Lavoisier)
        necessary: true
        actual: 213
        label: 1789
        source: https://en.wikipedia.org/wiki/Chemical_revolution
        image:
          name: chemistry.jpg
          link: https://commons.wikimedia.org/wiki/File:Lavoisier_Trait%C3%A9_%C3%A9l%C3%A9mentaire_de_chimie_p192.jpg
          width: 331
          height: 600

      - name: First vaccine, smallpox (Edward Jenner)
        necessary: true
        actual: 204
        label: 1796
        source: https://en.wikipedia.org/wiki/Vaccine
        image:
          name: vaccine.jpg
          link: https://commons.wikimedia.org/wiki/File:Jenner_phipps_01_(cropped).jpg
          width: 574
          height: 379

      - name: Invention of internal combustion engine (John Stevens)
        necessary: true
        actual: 202
        label: 1798
        source: https://en.wikipedia.org/wiki/History_of_the_internal_combustion_engine
        image:
          name: internal-combustion-engine.jpg
          link: https://commons.wikimedia.org/wiki/File:Benz_Patent_Motorwagen_Engine.jpg
          width: 800
          height: 600

      - name: Discovery of Rosetta Stone (origin 196 BC) enabling translation of Egyptian hieroglyphics (Napoleon)
        actual: 201
        label: 1799
        source: https://en.wikipedia.org/wiki/Rosetta_Stone
        image:
          name: rosetta-stone.jpg
          link: https://commons.wikimedia.org/wiki/File:Rosetta_Stone.JPG
          width: 513
          height: 600

      - name: Invention of continuous current electric battery (Alessandro Volta)
        necessary: true
        actual: 201
        label: 1799
        source: https://en.wikipedia.org/wiki/History_of_the_battery
        image:
          name: voltaic-pile.jpg
          link: https://commons.wikimedia.org/wiki/File:VoltaBattery.JPG
          width: 450
          height: 600

      - name: Invention of photography (Thomas Wedgwood)
        necessary: true
        actual: 201
        label: 1800
        source: https://en.wikipedia.org/wiki/History_of_photography
        image:
          name: photography.jpg
          link: https://en.wikipedia.org/wiki/File:Boulevard_du_Temple_by_Daguerre.jpg
          width: 800
          height: 575

      - name: Discovery of infrared radiation (William Herschel)
        actual: 200
        label: 1800
        source: https://en.wikipedia.org/wiki/Infrared
        image:
          name: infrared.jpg
          link: https://web.archive.org/web/20120225094516/http://coolcosmos.ipac.caltech.edu/cosmic_classroom/classroom_activities/herschel_bio.html
          width: 258
          height: 328

      - name: Discovery of ultraviolet light (Johann Wilhelm Ritter)
        actual: 199
        label: 1801
        source: https://en.wikipedia.org/wiki/Ultraviolet
        image:
          name: ultraviolet.jpg
          link: https://timetunnelcollective.tumblr.com/post/618354364201025536/embed
          width: 600
          height: 600

      - name: Atomic theory (John Dalton)
        necessary: true
        actual: 197
        label: 1803
        source: https://en.wikipedia.org/wiki/Atomic_theory
        image:
          name: dalton-elements.jpg
          link: https://commons.wikimedia.org/wiki/File:Dalton%27s_symbols_of_the_elements._1806_Wellcome_M0004592.jpg
          width: 442
          height: 600

      - name: First commercially successful locomotive (Matthew Murray)
        actual: 188
        label: 1812
        source: https://en.wikipedia.org/wiki/History_of_rail_transport
        image:
          name: locomotive.jpg
          link: https://commons.wikimedia.org/wiki/File:Blenkinsop%27s_rack_locomotive,_1812_(British_Railway_Locomotives_1803-1853).jpg
          width: 696
          height: 600

      - name: Invention of electric motor (Michael Faraday)
        necessary: true
        actual: 179
        label: 1821
        source: https://en.wikipedia.org/wiki/Timeline_of_the_electric_motor
        image:
          name: motor.jpg
          link: https://commons.wikimedia.org/wiki/File:Faraday_magnetic_rotation.jpg
          width: 538
          height: 545

      - name: Invention of electric generator (Michael Faraday)
        actual: 169
        label: 1831
        source: https://en.wikipedia.org/wiki/Electric_generator
        image:
          name: generator.jpg
          link: https://commons.wikimedia.org/wiki/File:Faraday_disk_generator.jpg
          width: 768
          height: 600

      - name: Development of glass silvering; affordable glass mirrors (Justus von Liebig)
        actual: 165
        label: 1835
        source: https://en.wikipedia.org/wiki/Silvering
        image:
          name: glass-silvering.jpg
          link: https://commons.wikimedia.org/wiki/File:Johann_Jacob_Kirstein_001.JPG
          width: 667
          height: 600

      - name: First telegram, invention of Morse code (Samuel F.B. Morse)
        necessary: true
        actual: 162
        label: 1838
        source: https://en.wikipedia.org/wiki/Electrical_telegraph
        image:
          name: morse-telegraph.jpg
          link: https://commons.wikimedia.org/wiki/File:Morse_Telegraph_1837.jpg
          width: 800
          height: 600

      - name: First commercially successful camera (Louis Daguerre)
        actual: 161
        label: 1839
        source: https://en.wikipedia.org/wiki/History_of_the_camera
        image:
          name: camera.jpg
          link: https://commons.wikimedia.org/wiki/File:Susse_Fr%C3%A9re_Daguerreotype_camera_1839.jpg
          width: 753
          height: 600

      - name: Correct prediction and discovery of Neptune (Johann Galle)
        actual: 154
        label: 1846
        source: https://en.wikipedia.org/wiki/Neptune
        image:
          name: neptune.jpg
          link: https://commons.wikimedia.org/wiki/File:Neptune_-_Voyager_2_(29347980845)_flatten_crop.jpg
          width: 600
          height: 600

      - name: Germ theory of disease, sterilization (John Snow)
        actual: 151
        label: 1849
        source: https://en.wikipedia.org/wiki/Germ_theory_of_disease
        image:
          name: germ-theory.jpg
          link: https://en.wikipedia.org/wiki/File:Snow-cholera-map-1.jpg
          width: 640
          height: 600

  - name: Technological Revolution
    label: 160 years ago
    events:
      - name: Invention of refrigeration, first commercially successful ice machine (James Harrison)
        necessary: true
        actual: 146
        label: 1854
        source: https://en.wikipedia.org/wiki/Refrigeration
        image:
          name: refrigeration.jpg
          link: https://australianfoodtimeline.com.au/james-harrisons-refrigeration-system/
          width: 688
          height: 600

      - name: First plastic patent (Alexander Parkes)
        necessary: true
        actual: 144
        label: 1856
        source: https://en.wikipedia.org/wiki/Timeline_of_plastic_development
        image:
          name: plastic.jpg
          link: https://dailybritain.wordpress.com/tag/alexander-parkes/
          width: 800
          height: 568

      - name: Discovery of natural selection (Charles Darwin)
        necessary: true
        actual: 142
        label: 1858
        source: https://en.wikipedia.org/wiki/Natural_selection
        image:
          name: darwin.jpg
          link: https://commons.wikimedia.org/wiki/File:Darwin%27s_finches_by_Gould.jpg
          width: 795
          height: 600

      - name: First transatlantic telegraph cable (Atlantic Telegraph Company)
        actual: 142
        label: 1858
        source: https://en.wikipedia.org/wiki/Transatlantic_telegraph_cable
        image:
          name: transatlantic-cable.jpg
          link: https://commons.wikimedia.org/wiki/File:Atlantic_cable_Map.jpg
          width: 800
          height: 322

      - name: Fundamental equations of electromagnetism (James Clerk Maxwell)
        actual: 139
        label: 1861
        source: https://en.wikipedia.org/wiki/Maxwell%27s_equations
        image:
          name: maxwell-equations.jpg
          link: https://commons.wikimedia.org/wiki/File:Maxwell%27sEquations.svg
          width: 800
          height: 596

      - name: Antiseptics - reduced infections from surgery (Joseph Lister)
        actual: 133
        label: 1867
        source: https://en.wikipedia.org/wiki/Antiseptic
        image:
          name: antiseptic.jpg
          link: https://www.sutori.com/en/item/untitled-56a1-7ac7
          width: 437
          height: 587

      - name: First commercially successful typewriter (Sholes, Hall, Glidden, Soule)
        necessary: true
        actual: 132
        label: 1868
        source: https://en.wikipedia.org/wiki/Typewriter
        image:
          name: typewriter.jpg
          link: https://commons.wikimedia.org/wiki/File:Sholes_typewriter.jpg
          width: 531
          height: 600

      - name: Development of periodic table, correct predictions of unknown elements (Dmitri Mendeleev)
        actual: 131
        label: 1869
        source: https://en.wikipedia.org/wiki/Periodic_table
        image:
          name: periodic-table.jpg
          link: https://commons.wikimedia.org/wiki/File:Mendelejevs_periodiska_system_1871.png
          width: 684
          height: 341

      - name: First transcontinental railroad (Pacific Railroad)
        actual: 131
        label: 1869
        source: https://en.wikipedia.org/wiki/First_Transcontinental_Railroad
        image:
          name: transcontinental-railroad.jpg
          link: https://commons.wikimedia.org/wiki/File:East_west_shaking_hands_by_russell.jpg
          width: 791
          height: 600

      - name: Invention of voice telephone (Alexander Graham Bell)
        necessary: true
        actual: 124
        label: 1876
        source: https://en.wikipedia.org/wiki/Telephone
        image:
          name: telephone.jpg
          link: https://americanhistory.si.edu/collections/search/object/nmah_689864
          width: 800
          height: 600

      - name: Invention of phonograph for recording and playing sound (Thomas Edison)
        necessary: true
        actual: 123
        label: 1877
        source: https://en.wikipedia.org/wiki/Phonograph
        image:
          name: phonograph.jpg
          link: https://www.sciencephoto.com/media/808553/view/edison-s-first-phonograph-1877
          width: 800
          height: 431

      - name: First motion picture, galloping horse (Eadweard Muybridge)
        necessary: true
        actual: 122
        label: 1878
        source: https://en.wikipedia.org/wiki/Sallie_Gardner_at_a_Gallop
        image:
          name: motion-picture-horse.jpg
          link: https://commons.wikimedia.org/wiki/File:The_Horse_in_Motion_high_res.jpg
          width: 600
          height: 370

      - name: Modern QWERTY key layout established (Christopher Latham Sholes)
        actual: 122
        label: 1878
        source: https://en.wikipedia.org/wiki/QWERTY
        image:
          name: qwerty.jpg
          link: https://commons.wikimedia.org/wiki/File:QWERTY_1878.png
          width: 330
          height: 211

      - name: Invention of viable light bulb and continuous electrical system (Thomas Edison)
        necessary: true
        actual: 121
        label: 1879
        source: https://www.nps.gov/edis/learn/kidsyouth/the-electric-light-system-phonograph-motion-pictures.htm
        image:
          name: lightbulb.jpg
          link: https://www.worthpoint.com/worthopedia/thomas-edison-1st-electric-light-1880-492768971
          width: 241
          height: 400

      - name: First successful organ transplant, thyroid (Theodor Kocher)
        necessary: true
        actual: 117
        label: 1883
        source: https://en.wikipedia.org/wiki/Organ_transplantation
        image:
          name: thyroid.jpg
          link: https://www.niddk.nih.gov/health-information/diagnostic-tests/thyroid
          width: 300
          height: 342

      - name: Invention of automobile (Karl Benz)
        necessary: true
        actual: 114
        label: 1886
        source: https://en.wikipedia.org/wiki/Car
        image:
          name: automobile.jpg
          link: https://commons.wikimedia.org/wiki/File:1885Benz.jpg
          width: 763
          height: 600

      - name: Discovery of radio waves (Heinrich Hertz)
        necessary: true
        actual: 113
        label: 1887
        source: https://en.wikipedia.org/wiki/History_of_radio
        image:
          name: radio.jpg
          link: https://commons.wikimedia.org/wiki/File:Hertz_spark_radio_transmitter_1887.png
          width: 800
          height: 557

      - name: Invention of kinetoscope, first movie player, standardization of 35mm film (Thomas Edison)
        actual: 107
        label: 1893
        source: https://en.wikipedia.org/wiki/Kinetoscope
        image:
          name: 35mm-film.jpg
          link: https://commons.wikimedia.org/wiki/File:ButterflyDancebis.jpg
          width: 600
          height: 449

      - name: Discovery of electrons (J. J. Thomson)
        actual: 103
        label: 1897
        source: https://en.wikipedia.org/wiki/Electron
        image:
          name: thomson-electron.jpg
          link: https://www.ssplprints.com/image/99169/richardson-claire-thomsons-cathode-ray-tube-1897
          width: 428
          height: 347

      - name: First remote control, boat (Nikola Tesla)
        actual: 102
        label: 1898
        source: https://en.wikipedia.org/wiki/Remote_control
        image:
          name: remote-control.jpg
          link: https://www.engadget.com/2014-01-19-nikola-teslas-remote-control-boat.html
          width: 630
          height: 549

  - name: Petroleum Age
    label: 120 years ago
    events:
      - name: First transmission of voice by radio, invention of amplitude modulation aka AM (Reginald Fessenden)
        actual: 100
        label: 1900
        source: https://en.wikipedia.org/wiki/Amplitude_modulation
        image:
          name: amplitude-modulation.jpg
          link: https://commons.wikimedia.org/wiki/File:Illustration_of_Amplitude_Modulation.png
          width: 797
          height: 310

      - name: First flight of an airplane (Orville and Wilbur Wright)
        necessary: true
        actual: 97
        label: 1903
        source: https://en.wikipedia.org/wiki/Airplane
        image:
          name: flight.jpg
          link: https://en.wikipedia.org/wiki/File:First_flight2.jpg
          width: 800
          height: 519

      - name: Special relativity, spacetime continuum (Albert Einstein)
        necessary: true
        actual: 95
        label: 1905
        source: https://en.wikipedia.org/wiki/Special_relativity
        image:
          name: special-relativity.jpg
          link: https://commons.wikimedia.org/wiki/File:World_line.svg
          width: 588
          height: 600

      - name: First cathode ray tube television (Boris Rosing)
        actual: 93
        label: 1907
        source: https://en.wikipedia.org/wiki/Cathode_ray_tube
        image:
          name: television.jpg
          link: https://www.timetoast.com/timelines/television-timeline-1cfc72b9-86c8-481c-b136-d60299ba32a1
          width: 640
          height: 396

      - name: First affordable automobile (Henry Ford)
        actual: 92
        label: 1908
        source: https://en.wikipedia.org/wiki/Car
        image:
          name: model-t.jpg
          link: https://commons.wikimedia.org/wiki/File:1910Ford-T.jpg
          width: 670
          height: 527

      - name: First expedition to geographic South Pole (Norway)
        actual: 89
        label: 1911
        source: https://en.wikipedia.org/wiki/Amundsen%27s_South_Pole_expedition
        image:
          name: south-pole.jpg
          link: https://en.wikipedia.org/wiki/File:At_the_South_Pole,_December_1911.jpg
          width: 484
          height: 321


      - name: Idea of continental drift formalized - there once was a supercontinent, Pangaea (Alfred Wegener)
        actual: 88
        label: 1912
        source: https://en.wikipedia.org/wiki/Continental_drift
        image:
          name: continental-drift.jpg
          link: https://commons.wikimedia.org/wiki/File:Snider-Pellegrini_Wegener_fossil_map.svg
          width: 780
          height: 600

#      - name: World War I
#        actual: 86
#        label: 1914 - 1918

      - name: First transcontinental telephone call (New York to San Francisco)
        actual: 85
        label: 1915
        source: https://en.wikipedia.org/wiki/First_transcontinental_telephone_call
        image:
          name: transcontinental-phone-call.jpg
          link: https://commons.wikimedia.org/wiki/File:Alexander_Graham_Bell,_first_transcontinental_phone_call,_25_Jan_1915.jpg
          width: 735
          height: 600

      - name: General relativity, gravity curves spacetime (Albert Einstein)
        actual: 84
        label: 1916
        source: https://en.wikipedia.org/wiki/General_relativity
        image:
          name: general-relativity.jpg
          link: https://commons.wikimedia.org/wiki/File:Spacetime_lattice_analogy.svg
          width: 800
          height: 299

      - name: Invention of zipper
        actual: 83
        label: 1917
        source: https://en.wikipedia.org/wiki/Zipper
        image:
          name: zipper.jpg
          link: https://commons.wikimedia.org/wiki/File:Coil_plastic_and_metal_zippers.jpg
          width: 800
          height: 600

      - name: Largest empire by land area - 24% of earth, 13 million mi<sup>2</sup> (Britain)
        actual: 80
        label: 1920
        source: https://en.wikipedia.org/wiki/List_of_largest_empires
        image:
          name: british-empire.jpg
          link: https://commons.wikimedia.org/wiki/File:British_Empire_1921.png
          width: 800
          height: 351

      - name: Discovery of the first antibiotic, penicillin (Sir Alexander Fleming)
        actual: 72
        label: 1928
        source: https://en.wikipedia.org/wiki/Antibiotics
        image:
          name: penicillin.jpg
          link: https://commons.wikimedia.org/wiki/File:Penicillium_notatum.jpg
          width: 624
          height: 600

#      - name: Great Depression, 15% drop in global GDP
#        actual: 71
#        label: 1929 - 1932

      - name: Discovery of expansion of the universe, big bang theory (Georges Lemaître)
        actual: 69
        label: 1931
        source: https://en.wikipedia.org/wiki/Big_Bang
        image:
          name: universe-expansion.jpg
          link: https://commons.wikimedia.org/wiki/File:Universe_expansion-en.svg
          width: 667
          height: 600

      - name: Invention of radio telescope, first search for extraterrestrial intelligence (Grote Reber)
        necessary: true
        actual: 63
        label: 1937
        source: https://en.wikipedia.org/wiki/Radio_telescope
        image:
          name: radio-telescope.jpg
          link: https://commons.wikimedia.org/wiki/File:Grote_Antenna_Wheaton.gif
          width: 476
          height: 600

#      - name: World War II
#        actual: 61
#        label: 1939 - 1945

      - name: First usage of antibiotics to treat infections (Allied military)
        necessary: true
        actual: 58
        label: 1942
        source: https://en.wikipedia.org/wiki/Antibiotics
        image:
          name: antibiotic.jpg
          link: https://commons.wikimedia.org/wiki/File:A_course_of_green_cefalexin_pills.jpg
          width: 800
          height: 533

      - name: DNA identified as genetic transformer (Avery, MacLeod, McCarty)
        necessary: true
        actual: 57
        label: 1943
        source: https://en.wikipedia.org/wiki/Avery%E2%80%93MacLeod%E2%80%93McCarty_experiment
        image:
          name: dna-water.jpg
          link: https://commons.wikimedia.org/wiki/File:DNA_in_water.jpg
          width: 435
          height: 600

      - name: Atomic bomb (Manhattan Project)
        necessary: true
        actual: 55
        label: 1945
        source: https://en.wikipedia.org/wiki/Nuclear_weapon
        image:
          name: trinity-detonation.jpg
          link: https://commons.wikimedia.org/wiki/File:Trinity_Detonation_T%26B.jpg
          width: 800
          height: 471

      - name: Invention of microwave oven (Percy Lebaron Spencer)
        necessary: true
        actual: 55
        label: 1945
        source: https://en.wikipedia.org/wiki/Microwave_oven
        image:
          name: microwave.jpg
          link: https://commons.wikimedia.org/wiki/File:NS_Savannah_microwave_oven_MD8.jpg
          width: 353
          height: 600

      - name: Invention of transistor (Bardeen, Brattain, Shockley)
        necessary: true
        actual: 53
        label: 1947
        source: https://en.wikipedia.org/wiki/Transistor
        image:
          name: transistor.jpg
          link: https://www.computerhistory.org/revolution/digital-logic/12/273/2237
          width: 600
          height: 376

      - name: First manned supersonic flight (Chuck Yeager)
        necessary: true
        actual: 53
        label: 1947
        source: https://en.wikipedia.org/wiki/Sound_barrier
        image:
          name: supersonic.jpg
          link: https://commons.wikimedia.org/wiki/File:Chuck_Yeager.jpg
          width: 800
          height: 500

      - name: First stored-program computer (Victoria University of Manchester)
        necessary: true
        actual: 52
        label: 1948
        source: https://en.wikipedia.org/wiki/Stored-program_computer
        image:
          name: computer-program.jpg
          link: https://www.manchestereveningnews.co.uk/news/greater-manchester-news/bringing-up-baby-how-1948-14819127
          width: 800
          height: 450

      - name: DNA double-helix structure discovered (James Watson and Francis Crick)
        actual: 47
        label: 1953
        source: https://en.wikipedia.org/wiki/DNA
        image:
          name: dna.jpg
          link: https://en.wikipedia.org/wiki/File:DNA_Structure%2BKey%2BLabelled.pn_NoBB.png
          width: 605
          height: 600

      - name: First ascent of Mount Everest, Earth's highest mountain (Britain)
        actual: 47
        label: 1953
        source: https://en.wikipedia.org/wiki/1953_British_Mount_Everest_expedition
        image:
          name: everest.jpg
          link: https://www.worldatlas.com/articles/where-is-mount-everest.html
          width: 729
          height: 425

      - name: First practical solar cell (Bell Labs)
        necessary: true
        actual: 46
        label: 1954
        source: https://en.wikipedia.org/wiki/Solar_cell
        image:
          name: solar-cell.jpg
          link: https://www.nrel.gov/docs/fy04osti/33947.pdf
          width: 736
          height: 600

      - name: First nuclear power plant (England)
        necessary: true
        actual: 44
        label: 1956
        source: https://en.wikipedia.org/wiki/Nuclear_power_plant
        image:
          name: nuclear-power.jpg
          link: https://commons.wikimedia.org/wiki/File:Calder_Hall_nuclear_power_station_(11823864155).jpg
          width: 751
          height: 600

  - name: Space Age
    label: 65 years ago
    events:
      - name: First artificial satellite (Sputnik 1)
        necessary: true
        actual: 43
        label: 1957
        source: https://en.wikipedia.org/wiki/Sputnik_1
        image:
          name: sputnik.jpg
          link: https://en.wikipedia.org/wiki/File:Sputnik_asm.jpg
          width: 733
          height: 600

      - name: First bone marrow transplant (E. Donnall Thomas)
        actual: 44
        label: 1957
        source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4222417/
        image:
          name: bone-marrow-transplant.jpg
          link: https://www.immunology.org/bone-marrow-1957
          width: 800
          height: 450

#      - name: NASA created
#        actual: 42
#        label: 1958

      - name: First Moon flyby, first spacecraft to achieve escape velocity (Luna 1)
        actual: 41
        label: 1959
        source: https://en.wikipedia.org/wiki/Luna_1
        image:
          name: luna-1.jpg
          link: https://commons.wikimedia.org/wiki/File:RIAN_archive_510848_Interplanetary_station_Luna_1_-_blacked.jpg
          width: 760
          height: 600

      - name: First human in orbit (Yuri Gagarin, Vostok 1)
        necessary: true
        actual: 39
        label: 1961
        source: https://en.wikipedia.org/wiki/Vostok_1
        image:
          name: vostok-1.jpg
          link: https://en.wikipedia.org/wiki/File:Vostok1.jpg
          width: 240
          height: 180

      - name: First Venus flyby (Venera 1)
        actual: 39
        label: 1961
        source: https://en.wikipedia.org/wiki/Venera_1
        image:
          name: venera-1.jpg
          link: https://commons.wikimedia.org/wiki/File:Venera_1_(a)_(Memorial_Museum_of_Astronautics).JPG
          width: 400
          height: 600

      - name: Invention of cassette tapes (Philips)
        actual: 38
        label: 1962
        source: https://en.wikipedia.org/wiki/Compact_Cassette
        image:
          name: cassette-tape.jpg
          link: https://commons.wikimedia.org/wiki/File:Compactcassette.jpg
          width: 800
          height: 520

      - name: Invention of liquid crystal displays (George H. Heilmeier)
        necessary: true
        actual: 36
        label: 1964
        source: https://en.wikipedia.org/wiki/Liquid-crystal_display
        image:
          name: lcd-screen.jpg
          link: https://www.nytimes.com/2014/05/06/technology/george-h-heilmeier-an-inventor-of-lcds-dies-at-77.html
          width: 735
          height: 600

      - name: Discovery of cosmic microwave background (Arno Penzias and Robert Wilson)
        actual: 36
        label: 1964
        source: https://en.wikipedia.org/wiki/Cosmic_microwave_background
        image:
          name: cosmic-microwave-background-2.jpg
          link: https://commons.wikimedia.org/wiki/File:Planck_satellite_cmb.jpg
          width: 800
          height: 400

#      - name: First Mars flyby (Mariner 4)
#        actual: 35
#        label: 1965

      - name: First personal computer (Programma 101)
        necessary: true
        actual: 35
        label: 1965
        source: https://en.wikipedia.org/wiki/Programma_101
        image:
          name: programma-101.jpg
          link: https://commons.wikimedia.org/wiki/File:Olivetti_Programma_101_-_Museo_scienza_e_tecnologia_Milano.jpg
          width: 800
          height: 533

      - name: Theory of plate tectonics, solid plates move on top of molten interior, creating earthquakes, mountains, and volcanoes (Dan McKenzie)
        actual: 35
        label: 1965
        source: https://en.wikipedia.org/wiki/Plate_tectonics
        image:
          name: plate-tectonics.jpg
          link: https://commons.wikimedia.org/wiki/File:Plates_tect2_en.svg
          width: 800
          height: 546

      - name: First spacewalk (Alexey Leonov, Voskhod 2)
        necessary: true
        actual: 35
        label: 1965
        source: https://en.wikipedia.org/wiki/Voskhod_2
        image:
          name: spacewalk.jpg
          link: https://en.wikipedia.org/wiki/File:FirstSpaceWalk.png
          width: 374
          height: 267

      - name: First successful heart transplant (Christiaan Barnard)
        actual: 33
        label: 1967
        source: https://en.wikipedia.org/wiki/Heart_transplantation
        image:
          name: heart-transplant.jpg
          link: https://commons.wikimedia.org/wiki/File:Transport_bij%C3%ADc%C3%ADho_srdce.jpg
          width: 800
          height: 597

      - name: First human on the Moon (Neil Armstrong, Apollo 11)
        necessary: true
        actual: 31
        label: 1969
        source: https://en.wikipedia.org/wiki/Apollo_11
        image:
          name: apollo-11.jpg
          link: https://en.wikipedia.org/wiki/File:Aldrin_Apollo_11_original.jpg
          width: 596
          height: 600

#      - name: First Mars orbiter (Mariner 9)
#        actual: 29
#        label: 1971

      - name: First computer virus, Creeper (Bob Thomas)
        necessary: true
        actual: 29
        label: 1971
        source: https://en.wikipedia.org/wiki/Computer_virus
        image:
          name: creeper-virus.jpg
          link: https://www.historyofinformation.com/detail.php?entryid=2860
          width: 555
          height: 182

      - name: First candidate black hole discovered (Charles Thomas Bolton)
        actual: 28
        label: 1972
        source: https://en.wikipedia.org/wiki/Black_hole
        image:
          name: cygnus-x1.jpg
          link: https://commons.wikimedia.org/wiki/File:Cygnus_x1_xray.jpg
          width: 500
          height: 500

      - name: First Jupiter flyby, first spacecraft to achieve escape velocity from solar system, first spacecraft to traverse asteroid belt (Pioneer 10)
        actual: 27
        label: 1973
        source: https://en.wikipedia.org/wiki/Pioneer_10
        image:
          name: jupiter-flyby.jpg
          link: https://commons.wikimedia.org/wiki/File:Pioneer_10_at_Jupiter.jpg
          width: 785
          height: 600

#      - name: First Mercury flyby (Mariner 10)
#        actual: 26
#        label: 1974

      - name: First Mars lander (Viking 1)
        necessary: true
        actual: 24
        label: 1976
        source: https://en.wikipedia.org/wiki/Viking_1
        image:
          name: mars-lander.jpg
          link: https://commons.wikimedia.org/wiki/File:Mars_Viking_12a001.png
          width: 800
          height: 285

      - name: Invention of public key cryptography, algorithm to establish shared secret key over an insecure channel (Diffie, Hellman, Merkle)
        necessary: true
        actual: 24
        label: 1976
        source: https://en.wikipedia.org/wiki/Public-key_cryptography
        image:
          name: diffie-hellman.jpg
          link: https://commons.wikimedia.org/wiki/File:Public_key_shared_secret.svg
          width: 559
          height: 600

      - name: First encryption algorithm with separate public and private keys, also allowing digital signatures (Rivest, Shamir, Adleman)
        actual: 23
        label: 1977
        source: https://en.wikipedia.org/wiki/RSA_(cryptosystem)
        image:
          name: public-key-encryption.jpg
          link: https://commons.wikimedia.org/wiki/File:Public_key_encryption.svg
          width: 614
          height: 600

#      - name: First Saturn flyby (Pioneer 11)
#        actual: 21
#        label: 1979

      - name: First commercial cellular phone network (Japan)
        necessary: true
        actual: 21
        label: 1979
        source: https://en.wikipedia.org/wiki/1G
        image:
          name: cellular-phone.jpg
          link: https://commons.wikimedia.org/wiki/File:DynaTAC8000X.jpg
          width: 500
          height: 600

      - name:
          Smallpox, which killed up to 500 million people in the 20th century alone,
          completely eradicated (WHO)
        actual: 20
        label: 1980
        source: https://en.wikipedia.org/wiki/Smallpox
        image:
          name: smallpox.jpg
          link: https://commons.wikimedia.org/wiki/File:Hemorrhagic_smallpox_2_(cropped).jpg
          width: 362
          height: 295

  - name: Information Age
    label: 40 years ago
    events:
      - name: First window based graphical user interface and mouse (Xerox Parc)
        necessary: true
        actual: 19
        label: 1981
        source: https://en.wikipedia.org/wiki/Xerox_Star
        image:
          name: xerox-star.jpg
          link: https://encyclopedia2.thefreedictionary.com/Xerox+Star
          width: 392
          height: 421

      - name: TCP/IP (Internet Protocol) standardized
        necessary: true
        actual: 18
        label: 1982
        source: https://en.wikipedia.org/wiki/Internet_protocol_suite
        image:
          name: ip-address.jpg
          link: https://commons.wikimedia.org/wiki/File:IPv4_address_structure_and_writing_systems-en.svg
          width: 800
          height: 271

#      - name: First Uranus flyby (Voyager 2)
#        actual: 14
#        label: 1986

#      - name: First Neptune flyby (Voyager 2)
#        actual: 11
#        label: 1989

      - name: First internet search engine (Archie)
        necessary: true
        actual: 10
        label: 1990
        source: https://en.wikipedia.org/wiki/Web_search_engine
        image:
          name: search-engine.jpg
          link: https://www.makeuseof.com/tag/the-archie-search-engine-the-worlds-first-search/
          width: 590
          height: 195

      - name: First exoplanet discovered (Aleksander Wolszczan and Dale Frail)
        necessary: true
        actual: 8
        label: 1992
        source: https://en.wikipedia.org/wiki/Exoplanet
        image:
          name: exoplanet.jpg
          link: https://commons.wikimedia.org/wiki/File:Lich_pulsar.png
          width: 600
          height: 600

      - name: Beginning of widespread Internet adoption
        actual: 5
        label: 1995
        source: https://en.wikipedia.org/wiki/Internet
        image:
          name: america-online.jpg
          link: https://commons.wikimedia.org/wiki/File:America_Online_logo.svg
          width: 685
          height: 600

      - name: First computer to beat best human chess player (Deep Blue)
        necessary: true
        actual: 4
        label: 1996
        source: https://en.wikipedia.org/wiki/Computer_chess
        image:
          name: deep-blue.jpg
          link: https://commons.wikimedia.org/wiki/File:Deep_Blue.jpg
          width: 399
          height: 600

      - name: First major peer-to-peer file sharing network (Napster)
        necessary: true
        actual: 1
        label: 1999
        source: https://en.wikipedia.org/wiki/Peer-to-peer_file_sharing
        image:
          name: napster.jpg
          link: https://en.wikipedia.org/wiki/File:Napster_corporate_logo.svg
          width: 800
          height: 213

      - name: Last time there wasn’t a human in orbit
        necessary: true
        actual: 0
        label: 2000
        source: https://en.wikipedia.org/wiki/International_Space_Station
        image:
          name: space-station.jpg
          link: https://commons.wikimedia.org/wiki/File:The_station_pictured_from_the_SpaceX_Crew_Dragon_5_(cropped).jpg
          width: 800
          height: 461

      - name: Beginning of most popular collaborative general information database (Wikipedia)
        actual: -1
        label: 2001
        source: https://en.wikipedia.org/wiki/Wikipedia
        image:
          name: wikipedia.jpg
          link: https://en.wikipedia.org/wiki/File:Wikipedia-logo-v2.svg
          width: 657
          height: 600

      - name: Complete mapping of human genome (Human Genome Project)
        necessary: true
        actual: -3
        label: 2003
        source: https://en.wikipedia.org/wiki/Human_Genome_Project
        image:
          name: genome.jpg
          link: https://commons.wikimedia.org/wiki/File:Dna-split.png
          width: 202
          height: 397

  - name: Mobile Age
    label: 15 years ago
    events:
      - name: First multi-touch smart phone (iPhone)
        necessary: true
        actual: -7
        label: 2007
        source: https://en.wikipedia.org/wiki/Smartphone
        image:
          name: iphone.jpg
          link: https://www.theiphonewiki.com/wiki/M68AP
          width: 264
          height: 500

      - name: First decentralized digital currency (Bitcoin)
        necessary: true
        actual: -9
        label: 2009
        source: https://en.wikipedia.org/wiki/Cryptocurrency
        image:
          name: bitcoin.jpg
          link: https://ftalphaville.ft.com/2020/03/09/1583742985000/Isn-t-bitcoin-meant-to-be-a-safe-haven-/
          width: 800
          height: 450

      - name: First mainstream tablet computer (iPad)
        actual: -10
        label: 2010
        source: https://en.wikipedia.org/wiki/Tablet_computer
        image:
          name: ipad.jpg
          link: https://commons.wikimedia.org/wiki/File:Steve_Jobs_with_the_Apple_iPad_no_logo_(cropped).jpg
          width: 800
          height: 591

      - name: First computer to beat best Jeopardy player (Watson)
        actual: -11
        label: 2011
        source: https://en.wikipedia.org/wiki/Watson_(computer)
        image:
          name: watson-jeopardy.jpg
          link: https://www.youtube.com/watch?v=P18EdAKuC1U
          width: 800
          height: 450

      - name: First social network with 1 billion monthly active users (Facebook)
        actual: -12
        label: 2012
        source: https://en.wikipedia.org/wiki/Facebook
        image:
          name: facebook-datacenter.jpg
          link: https://www.datacenterknowledge.com/archives/2016/05/24/inside-facebook-data-center-sweden-video
          width: 800
          height: 416

      - name: Discovery of Higgs boson (CERN)
        actual: -12
        label: 2012
        source: https://en.wikipedia.org/wiki/Higgs_boson
        image:
          name: higgs-boson.jpg
          link: https://commons.wikimedia.org/wiki/File:Candidate_Higgs_Events_in_ATLAS_and_CMS.png
          width: 720
          height: 462

      - name: First autonomous cars in public traffic
        necessary: true
        actual: -13
        label: 2013
        image:
          name: self-driving-car.jpg
          link: https://electrek.co/2020/08/14/elon-musk-tesla-full-self-driving-quantum-leap-new-rewrite/
          width: 800
          height: 386

      - name: First lag-free virtual reality headsets
        necessary: true
        actual: -15
        label: 2013
        source: https://en.wikipedia.org/wiki/Virtual_reality
        image:
          name: virtual-reality.jpg
          link: https://commons.wikimedia.org/wiki/File:Reality_check_ESA384313.jpg
          width: 800
          height: 600

      - name: First computer to beat best human Go player (AlphaGo)
        actual: -15
        label: 2015
        source: https://en.wikipedia.org/wiki/AlphaGo
        image:
          name: alphago.jpg
          link: http://opendeeptech.com/alphago-googles-artificial-intelligence
          width: 512
          height: 288

      - name: First cheap, targeted DNA editing (CRISPR)
        necessary: true
        actual: -15
        label: 2015
        source: https://en.wikipedia.org/wiki/Genome_editing
        image:
          name: crispr.jpg
          link: https://commons.wikimedia.org/wiki/File:Genetic_engineering_logo.png
          width: 459
          height: 432

      - name: First rocket to re-enter atmostphere and land vertically
        actual: -15
        label: 2015
        source: https://en.wikipedia.org/wiki/Falcon_9
        image:
          name: reusable-rocket.jpg
          link: https://commons.wikimedia.org/wiki/File:Falcon_Heavy_Side_Boosters_landing_on_LZ1_and_LZ2_-_2018_(25254688767).jpg
          width: 800
          height: 533

      - name: Discovery of gravitational waves (LIGO)
        necessary: true
        actual: -16
        label: 2016
        source: https://en.wikipedia.org/wiki/Gravitational_wave
        image:
          name: gravity-wave.jpg
          link: https://commons.wikimedia.org/wiki/File:Artist%E2%80%99s_impression_of_merging_neutron_stars.jpg
          width: 800
          height: 527

      - name: Discovery of first interstellar object in our solar system, ʻOumuamua (Robert Weryk)
        actual: -17
        label: 2017
        source: https://en.wikipedia.org/wiki/%CA%BBOumuamua
        image:
          name: oumuamua.jpg
          link: https://commons.wikimedia.org/wiki/File:Oumuamua_orbit_at_perihelion.png
          width: 800
          height: 600

      - name: First crewed reusable rocket (SpaceX Falcon 9)
        actual: -20
        label: 2020
        source: https://en.wikipedia.org/wiki/Falcon_9
        image:
          name: reusable-rocket-crew.jpg
          link: https://twitter.com/SpaceX/status/1266798486256676864
          width: 800
          height: 600