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|
{-# OPTIONS_GHC
-Wall
-Wno-unused-imports
-Wno-unused-top-binds
-Wno-name-shadowing
#-}
{-# language NoImplicitPrelude #-}
{-# language RecordWildCards #-}
{-# language FlexibleContexts #-}
{-# language TemplateHaskell #-}
{-# language ViewPatterns #-}
{-# language OverloadedStrings #-}
{-# language QuasiQuotes #-}
module CosmicCalendar where
import Rebase.Prelude
import qualified Rebase.Prelude as Prelude
import Control.Lens hiding ((<|))
import Data.Foldable (toList)
import Data.Ratio
import Text.Printf
import Data.Time.Calendar.OrdinalDate
import Data.Time.LocalTime
import Control.Monad.RWS
import Data.Time.Calendar.OrdinalDate
import Data.Text.Format.Numbers
import NeatInterpolation
import qualified Data.Text as Text
import Data.Text (Text, pack, unpack)
import Rebase.Data.Map.Strict (Map)
import qualified Rebase.Data.Map.Strict as Map
-- 13.787±0.020 billion years. Source: https://en.wikipedia.org/wiki/Age_of_the_universe#cite_note-Planck_2018-2
ageOfUniverseInYears :: Integer
ageOfUniverseInYears = 13787 * 1000 * 1000
-- The point of the cosmic calendar is to mentally visualize or model the scale
-- of cosmic/geologic/evolutionary events using the existing internal mental
-- model of the year. This internal mental model of the year is NOT a 365.2422
-- day earth rotation, but a 365 day calendar year.
--
-- In order to make the math of the calendar work out, the functions that look
-- up calendary entries (and take as input the LocalTime) must check for leap
-- year, and subtract one day from the input if it is later than February.
daysPerYear :: NominalDiffTime
daysPerYear = 365 -- NOT 365.2422
lengthOfDay :: NominalDiffTime
lengthOfDay = 24 * 60 * 60
lengthOfYear :: NominalDiffTime
lengthOfYear = daysPerYear * lengthOfDay
ageOfUniverse :: NominalDiffTime
ageOfUniverse = fromIntegral ageOfUniverseInYears * lengthOfYear
data CalendarEntry = CalendarEntry {
calBeginTime :: NominalDiffTime,
calEndTime :: Maybe NominalDiffTime,
calTitle :: Text,
calSubtitle :: Text,
calDescription :: Text,
calReferences :: Text
} deriving (Show)
-- TODO: Encode the input times like so:
--
-- data CosmicTime = YearsAgo Rational | YearsAfterBigBang Rational | YearsBCE Rational | YearsCE Rational
--
-- The absolute time values (YearsBCE and YearsCE) will be computed using the
-- year at program start:
currentYear :: Integer
currentYear = unsafePerformIO $ getZonedTime <&> toGregorian . localDay . zonedTimeToLocalTime <&> view _1
theCalendar :: Map NominalDiffTime CalendarEntry
theCalendar = Map.fromList $ map (\x -> (calBeginTime x, x)) theCalendarList
years :: Rational -> NominalDiffTime
years = (* lengthOfYear) . fromRational
yearsAgo :: Rational -> NominalDiffTime
yearsAgo (fromRational -> n) = lengthOfYear * (1 - (n / fromIntegral ageOfUniverseInYears))
afterBigBang :: NominalDiffTime -> NominalDiffTime
afterBigBang = (/ ageOfUniverse) . (* lengthOfYear)
thousandYears :: Rational -> NominalDiffTime
thousandYears = years . (* 1000)
millionYears :: Rational -> NominalDiffTime
millionYears = thousandYearsAgo . (* 1000)
billionYears :: Rational -> NominalDiffTime
billionYears = millionYearsAgo . (* 1000)
thousandYearsAgo :: Rational -> NominalDiffTime
thousandYearsAgo = yearsAgo . (* 1000)
millionYearsAgo :: Rational -> NominalDiffTime
millionYearsAgo = thousandYearsAgo . (* 1000)
billionYearsAgo :: Rational -> NominalDiffTime
billionYearsAgo = millionYearsAgo . (* 1000)
yearStart :: LocalTime -> LocalTime
yearStart (LocalTime d _) = LocalTime d' t'
where
d' = fromGregorian y 1 1
t' = TimeOfDay 0 0 0
(y, _, _) = toGregorian d
localTimeToYearElapsed :: LocalTime -> NominalDiffTime
localTimeToYearElapsed t = t `diffLocalTime` yearStart t
getPreviousCalendarEntry :: LocalTime -> Maybe CalendarEntry
getPreviousCalendarEntry (localTimeToYearElapsed -> t) = snd <$> Map.lookupLT t theCalendar
getCurrentCalendarEntry :: LocalTime -> Maybe CalendarEntry
getCurrentCalendarEntry (localTimeToYearElapsed -> t) = snd <$> Map.lookupLE t theCalendar
getNextCalendarEntry :: LocalTime -> Maybe CalendarEntry
getNextCalendarEntry (localTimeToYearElapsed -> t) = snd <$> Map.lookupGT t theCalendar
unwrap :: CalendarEntry -> CalendarEntry
unwrap x@CalendarEntry{..} = x { calDescription = unwrapText calDescription }
where
unwrapText :: Text -> Text
unwrapText = pack . unlines . map unwords . foldr process [] . lines . unpack
process line [] = [[line]]
process line ((x:xs):ys) | shouldMerge line x = (line:x:xs):ys
process line rest = [line]:rest
shouldMerge :: String -> String -> Bool
shouldMerge "" _ = False
shouldMerge _ "" = False
shouldMerge _ _ = True
theCalendarList :: [CalendarEntry]
theCalendarList = map unwrap
[
CalendarEntry 0 Nothing "The Big Bang" "The universe begins" "" "",
CalendarEntry (370 & thousandYears & afterBigBang)
Nothing
"Recombination"
"The universe becomes transparent"
recombinationDescription
recombinationReferences,
CalendarEntry (13.4 & billionYearsAgo) Nothing
"The first observed star"
""
"First Light Viewed Through the Rich Cluster Abell 2218"
"https://sites.astro.caltech.edu/~rse/firstlight/",
CalendarEntry (4.6 & billionYearsAgo) Nothing
"Formation of the Sun"
"The formation of the solar system begins"
[text|
The formation of the Solar System began about 4.6 billion years ago with the
gravitational collapse of a small part of a giant molecular cloud.[1] Most
of the collapsing mass collected in the center, forming the Sun, while the
rest flattened into a protoplanetary disk out of which the planets, moons,
asteroids, and other small Solar System bodies formed.
|]
"https://en.wikipedia.org/wiki/Formation_and_evolution_of_the_Solar_System",
CalendarEntry (4.54 & billionYearsAgo) Nothing
"Formation of Earth"
""
earthDescription
"https://en.wikipedia.org/wiki/History_of_Earth#Solar_System_formation",
CalendarEntry (2.6 & millionYearsAgo) Nothing
"First Stone Tools"
"Mode I: The Oldowan Industry"
[text|
(Stones with sharp edges.)
The earliest known Oldowan tools yet found date from 2.6 million years ago,
during the Lower Palaeolithic period, and have been uncovered at Gona in
Ethiopia.[16] After this date, the Oldowan Industry subsequently spread
throughout much of Africa, although archaeologists are currently unsure
which Hominan species first developed them, with some speculating that it
was Australopithecus garhi, and others believing that it was in fact Homo
habilis.[17]
Homo habilis was the hominin who used the tools for most of the Oldowan in
Africa, but at about 1.9-1.8 million years ago Homo erectus inherited them.
The Industry flourished in southern and eastern Africa between 2.6 and 1.7
million years ago, but was also spread out of Africa and into Eurasia by
travelling bands of H. erectus, who took it as far east as Java by 1.8
million years ago and Northern China by 1.6 million years ago.
|]
"",
CalendarEntry (1.8 & millionYearsAgo) Nothing
"First major transition in stone tool technology"
"Mode II: The Acheulean Industry"
[text|
From the Konso Formation of Ethiopia, Acheulean hand-axes are dated to about
1.5 million years ago using radiometric dating of deposits containing
volcanic ashes.[6] Acheulean tools in South Asia have also been found to be
dated as far as 1.5 million years ago.[7] However, the earliest accepted
examples of the Acheulean currently known come from the West Turkana region
of Kenya and were first described by a French-led archaeology team.[8] These
particular Acheulean tools were recently dated through the method of
magnetostratigraphy to about 1.76 million years ago, making them the oldest
not only in Africa but the world.[9] The earliest user of Acheulean tools
was Homo ergaster, who first appeared about 1.8 million years ago. Not all
researchers use this formal name, and instead prefer to call these users
early Homo erectus.[3]
|]
"",
CalendarEntry (160 & thousandYearsAgo) Nothing
"Second major transition in stone tool technology"
"Mode III: The Levallois technique; The Mousterian Industry"
[text|
(Stone scrapers, knives, and projectile points)
The technique is first found in the Lower Palaeolithic but is most commonly
associated with the Neanderthal Mousterian industries of the Middle
Palaeolithic. In the Levant, the Levallois technique was also used by
anatomically modern humans during the Middle Stone Age. In North Africa, the
Levallois technique was used in the Middle Stone Age, most notably in the
Aterian industry to produce very small projectile points. While Levallois
cores do display some variability in their platforms, their flake production
surfaces show remarkable uniformity. As the Levallois technique is
counterintuitive, teaching the process is necessary and thus language is a
prerequisite for such technology.[2]
The Mousterian (or Mode III) is a techno-complex (archaeological industry)
of stone tools, associated primarily with the Neanderthals in Europe, and to
a lesser extent the earliest anatomically modern humans in North Africa and
West Asia. The Mousterian largely defines the latter part of the Middle
Paleolithic, the middle of the West Eurasian Old Stone Age. It lasted
roughly from 160,000 to 40,000 BP. If its predecessor, known as Levallois or
Levallois-Mousterian, is included, the range is extended to as early as c.
300,000–200,000 BP.[2] The main following period is the Aurignacian (c.
43,000–28,000 BP) of Homo sapiens.
|]
"",
CalendarEntry (115 & thousandYearsAgo) (Just $ 11.7 & thousandYearsAgo)
"The Ice Age begins"
"The Last Glacial Period"
[text|
The Last Glacial Period (LGP), also known colloquially as the last ice age
or simply ice age,[1] occurred from the end of the Eemian to the end of the
Younger Dryas, encompassing the period c. 115,000 – c. 11,700 years ago. The
LGP is part of a larger sequence of glacial and interglacial periods known
as the Quaternary glaciation which started around 2,588,000 years ago and is
ongoing.[2] The definition of the Quaternary as beginning 2.58 million years
ago (Mya) is based on the formation of the Arctic ice cap. The Antarctic ice
sheet began to form earlier, at about 34 Mya, in the mid-Cenozoic
(Eocene–Oligocene extinction event). The term Late Cenozoic Ice Age is used
to include this early phase.[3]
|]
"https://en.wikipedia.org/wiki/Last_Glacial_Period",
CalendarEntry (50 & thousandYearsAgo) Nothing
"Third major transition in stone tool technology"
"Mode IV: The Aurignacian Industry"
[text|
The widespread use of long blades (rather than flakes) of the Upper
Palaeolithic Mode 4 industries appeared during the Upper Palaeolithic
between 50,000 and 10,000 years ago, although blades were produced in small
quantities much earlier by Neanderthals.[20] The Aurignacian culture seems
to have been the first to rely largely on blades.[21] The use of blades
exponentially increases the efficiency of core usage compared to the
Levallois flake technique, which had a similar advantage over Acheulean
technology which was worked from cores.
|]
"https://en.wikipedia.org/wiki/Stone_tool#Mode_IV:_The_Aurignacian_Industry",
CalendarEntry (35 & thousandYearsAgo) Nothing
"Last major transition in stone tool technology"
"Mode V: The Microlithic Industries"
[text|
Mode 5 stone tools involve the production of microliths, which were
used in composite tools, mainly fastened to a shaft.[22] Examples include
the Magdalenian culture. Such a technology makes much more efficient use of
available materials like flint, although required greater skill in
manufacturing the small flakes. Mounting sharp flint edges in a wood or bone
handle is the key innovation in microliths, essentially because the handle
gives the user protection against the flint and also improves leverage of
the device.
|]
"https://en.wikipedia.org/wiki/Stone_tool#Mode_V:_The_Microlithic_Industries"
,
CalendarEntry (12 & thousandYearsAgo) Nothing
"Agriculture leads to permanent settlements"
"Neolithic age (\"new stone age\")"
[text|
Wild grains were collected and eaten from at least 105,000 years ago.[2]
However, domestication did not occur until much later. The earliest evidence
of small-scale cultivation of edible grasses is from around 21,000 BC with
the Ohalo II people on the shores of the Sea of Galilee.[3] By around 9500
BC, the eight Neolithic founder crops – emmer wheat, einkorn wheat, hulled
barley, peas, lentils, bitter vetch, chickpeas, and flax – were cultivated
in the Levant.[4] Rye may have been cultivated earlier, but this claim
remains controversial.[5] Rice was domesticated in China by 6200 BC[6] with
earliest known cultivation from 5700 BC, followed by mung, soy and azuki
beans. Rice was also independently domesticated in West Africa and
cultivated by 1000 BC.[7][8] Pigs were domesticated in Mesopotamia around
11,000 years ago, followed by sheep. Cattle were domesticated from the wild
aurochs in the areas of modern Turkey and India around 8500 BC. Camels were
domesticated late, perhaps around 3000 BC.
|]
"https://en.wikipedia.org/wiki/History_of_agriculture",
CalendarEntry (6.5 & thousandYearsAgo) Nothing
"First copper tools"
""
""
"",
CalendarEntry (5.3 & thousandYearsAgo) Nothing
"First bronze tools, first written language"
"The Bronze Age"
""
"",
CalendarEntry (3000 & yearsBeforeCommonEra) (Just $ 2350 & yearsBeforeCommonEra)
"Corded Ware culture"
"Indo-European languages spread across Europe and Asia"
[text|
The Corded Ware culture comprises a broad archaeological horizon of Europe
between ca. 3000 BCE – 2350 BCE, thus from the late Neolithic, through the
Copper Age, and ending in the early Bronze Age.[2] Corded Ware culture
encompassed a vast area, from the contact zone between the Yamnaya culture
and the Corded Ware culture in south Central Europe, to the Rhine on the
west and the Volga in the east, occupying parts of Northern Europe, Central
Europe and Eastern Europe.[2][3] The Corded Ware culture is thought to have
originated from the westward migration of Yamnaya-related people from the
steppe-forest zone into the territory of late Neolithic European cultures
such as the Globular Amphora and Funnelbeaker cultures,[4][5][6] and is
considered to be a likely vector for the spread of many of the Indo-European
languages in Europe and Asia.[1][7][8][9]
Corded Ware encompassed most of continental northern Europe from the Rhine
on the west to the Volga in the east, including most of modern-day Germany,
the Netherlands, Denmark, Poland, Lithuania, Latvia, Estonia, Belarus, Czech
Republic, Austria, Hungary, Slovakia, Switzerland, northwestern Romania,
northern Ukraine, and the European part of Russia, as well as coastal Norway
and the southern portions of Sweden and Finland.[2] In the Late
Eneolithic/Early Bronze Age, it encompassed the territory of nearly the
entire Balkan Peninsula, where Corded Ware mixed with other steppe
elements.[11]
Archaeologists note that Corded Ware was not a "unified culture," as Corded
Ware groups inhabiting a vast geographical area from the Rhine to Volga seem
to have regionally specific subsistence strategies and economies.[2]: 226
There are differences in the material culture and in settlements and
society.[2] At the same time, they had several shared elements that are
characteristic of all Corded Ware groups, such as their burial practices,
pottery with "cord" decoration and unique stone-axes.[2]
|]
"",
CalendarEntry (2800 & yearsBeforeCommonEra) (Just $ 1800 & yearsBeforeCommonEra)
"Bell Beaker culture"
[text|
copper daggers, v-perforated buttons, stone wrist-guards
copper, bronze, and gold working
long-distance exchange networks, archery
social stratification and the emergence of regional elites
|]
[text|
The Bell Beaker culture (also described as the Bell Beaker complex or Bell
Beaker phenomenon) is an archaeological culture named after the
inverted-bell beaker drinking vessel used at the very beginning of the
European Bronze Age. Arising from around 2800 BC, it lasted in Britain until
as late as 1800 BC[1][2] but in continental Europe only until 2300 BC, when
it was succeeded by the Unetice culture. The culture was widely dispersed
throughout Western Europe, being present in many regions of Iberia and
stretching eastward to the Danubian plains, and northward to the islands of
Great Britain and Ireland, and was also present in the islands of Sicily and
Sardinia and some small coastal areas in north-western Africa. The Bell
Beaker phenomenon shows substantial regional variation, and a study[3] from
2018 found that it was associated with genetically diverse populations.
In its mature phase, the Bell Beaker culture is understood as not only a
collection of characteristic artefact types, but a complex cultural
phenomenon involving metalwork in copper and gold, long-distance exchange
networks, archery, specific types of ornamentation, and (presumably) shared
ideological, cultural and religious ideas, as well as social stratification
and the emergence of regional elites.[6][7] A wide range of regional
diversity persists within the widespread late Beaker culture, particularly
in local burial styles (including incidences of cremation rather than
burial), housing styles, economic profile, and local ceramic wares
(Begleitkeramik). Nonetheless, according to Lemercier (2018) the mature
phase of the Beaker culture represents "the appearance of a kind of Bell
Beaker civilization of continental scale."[8]
Bell Beaker people took advantage of transport by sea and rivers, creating a
cultural spread extending from Ireland to the Carpathian Basin and south
along the Atlantic coast and along the Rhône valley to Portugal, North
Africa, and Sicily, even penetrating northern and central Italy.[50] Its
remains have been found in what is now Portugal, Spain, France (excluding
the central massif), Ireland and Great Britain, the Low Countries and
Germany between the Elbe and Rhine, with an extension along the upper Danube
into the Vienna Basin (Austria), Hungary and the Czech Republic, with
Mediterranean outposts on Sardinia and Sicily; there is less certain
evidence for direct penetration in the east.
|]
"https://en.wikipedia.org/wiki/Bell_Beaker_culture",
CalendarEntry (11.7 & thousandYearsAgo) Nothing
"Ice Age ends"
""
""
"https://en.wikipedia.org/wiki/Last_Glacial_Period",
CalendarEntry (1600 & yearsBeforeCommonEra) Nothing
"Dynastic China"
"History begins"
[text|
The earliest known written records of the history of China date from as
early as 1250 BC, from the Shang dynasty (c. 1600–1046 BC), during the king
Wu Ding's reign
The state-sponsored Xia–Shang–Zhou Chronology Project dated them from c.
1600 to 1046 BC based on the carbon 14 dates of the Erligang site.
|]
"",
CalendarEntry (theYear 1492) Nothing
"Columbus arrives in America"
""
""
"",
CalendarEntry (theYear 570) Nothing
"Muhammad born"
""
""
"",
CalendarEntry (480 & yearsBeforeCommonEra) Nothing
"Old Testament, Buddha"
""
""
"",
CalendarEntry (8.8 & billionYearsAgo) Nothing
"Thin disk of the Milky Way Galaxy"
"Our galaxy begins to form"
[text|
The age of stars in the galactic thin disk has also been estimated using
nucleocosmochronology. Measurements of thin disk stars yield an estimate
that the thin disk formed 8.8 ± 1.7 billion years ago. These measurements
suggest there was a hiatus of almost 5 billion years between the formation
of the galactic halo and the thin disk.[253] Recent analysis of the chemical
signatures of thousands of stars suggests that stellar formation might have
dropped by an order of magnitude at the time of disk formation, 10 to 8
billion years ago, when interstellar gas was too hot to form new stars at
the same rate as before.[254]
|]
"",
CalendarEntry (3.4 & billionYearsAgo) Nothing
"First photosynthetic bacteria"
"(Still no Oxygen)"
[text|
They absorbed near-infrared rather than visible light and produced sulfur or
sulfate compounds rather than oxygen. Their pigments (possibly
bacteriochlorophylls) were predecessors to chlorophyll.
|]
"https://www.scientificamerican.com/article/timeline-of-photosynthesis-on-earth/",
CalendarEntry (2.7 & billionYearsAgo) Nothing
"Oxygen from photosynthesis"
"Cyanobacteria"
[text|
These ubiquitous bacteria were the first oxygen producers. They absorb
visible light using a mix of pigments: phycobilins, carotenoids and several
forms of chlorophyll.
|]
"https://www.scientificamerican.com/article/timeline-of-photosynthesis-on-earth/",
CalendarEntry (1.2 & billionYearsAgo) Nothing
"Red and brown algae"
""
[text|
These organisms have more complex cellular structures than bacteria do. Like
cyanobacteria, they contain phycobilin pigments as well as various forms of
chlorophyll.
|]
"https://www.scientificamerican.com/article/timeline-of-photosynthesis-on-earth/",
CalendarEntry (0.75 & billionYearsAgo) Nothing
"Green algae"
""
[text|
Green algae do better than red and brown algae in the strong light of
shallow water. They make do without phycobilins.
|]
"https://www.scientificamerican.com/article/timeline-of-photosynthesis-on-earth/",
CalendarEntry (0.475 & billionYearsAgo) Nothing
"First land plants"
""
[text|
Mosses and liverworts descended from green algae. Lacking vascular structure
(stems and roots) to pull water from the soil, they are unable to grow
tall.
|]
"https://www.scientificamerican.com/article/timeline-of-photosynthesis-on-earth/",
CalendarEntry (0.423 & billionYearsAgo) Nothing
"Vascular plants"
""
[text|
These are literally garden-variety plants, such as ferns, grasses, trees and
cacti. They are able to grow tall canopies to capture more light.
|]
"https://www.scientificamerican.com/article/timeline-of-photosynthesis-on-earth/",
CalendarEntry (2.05 & billionYearsAgo) Nothing
"Eukaryotic cells"
"Cells with nucleus (inner membrane holding DNA)"
[text|
Eukaryotes (/juːˈkærioʊts, -əts/) are organisms whose cells have a nucleus
enclosed within a nuclear envelope.[1][2][3] They belong to the group of
organisms Eukaryota or Eukarya; their name comes from the Greek εὖ (eu,
"well" or "good") and κάρυον (karyon, "nut" or "kernel").[4] The domain
Eukaryota makes up one of the three domains of life; bacteria and archaea
(both prokaryotes) make up the other two domains.[5][6] The eukaryotes are
usually now regarded as having emerged in the Archaea or as a sister of the
Asgard archaea.[7][8] This implies that there are only two domains of life,
Bacteria and Archaea, with eukaryotes incorporated among archaea.[9][10]
Eukaryotes represent a small minority of the number of organisms;[11]
however, due to their generally much larger size, their collective global
biomass is estimated to be about equal to that of prokaryotes.[11]
Eukaryotes emerged approximately 2.3–1.8 billion years ago, during the
Proterozoic eon, likely as flagellated phagotrophs.[12][13]
|]
"https://en.wikipedia.org/wiki/Eukaryote",
CalendarEntry (3.77 & billionYearsAgo) Nothing
"Life on Earth"
""
[text|
The earliest time for the origin of life on Earth is at least 3.77 billion
years ago, possibly as early as 4.28 billion years,[2] or even 4.41 billion
years[4][5]—not long after the oceans formed 4.5 billion years ago, and
after the formation of the Earth 4.54 billion years ago.[2][3][6][7]
|]
"https://en.wikipedia.org/wiki/Earliest_known_life_forms",
CalendarEntry (3.42 & billionYearsAgo) Nothing
"Earliest known life on Earth"
""
[text|
The earliest known life forms on Earth are putative fossilized
microorganisms found in hydrothermal vent precipitates, considered to be
about 3.42 billion years old.[1][2] The earliest time for the origin of life
on Earth is at least 3.77 billion years ago, possibly as early as 4.28
billion years,[2] or even 4.41 billion years[4][5]—not long after the oceans
formed 4.5 billion years ago, and after the formation of the Earth 4.54
billion years ago.[2][3][6][7] The earliest direct evidence of life on Earth
is from microfossils of microorganisms permineralized in
3.465-billion-year-old Australian Apex chert rocks.[8][9]
|]
"https://en.wikipedia.org/wiki/Earliest_known_life_forms",
CalendarEntry (750 & millionYearsAgo) Nothing
"Bones and shells"
""
[text|
A series of spectacularly preserved, 750-million-year-old fossils represent
the microscopic origins of biomineralization, or the ability to convert
minerals into hard, physical structures. This process is what makes bones,
shells, teeth and hair possible, literally shaping the animal kingdom and
even Earth itself.
The fossils were pried from ancient rock formations in Canada's Yukon by
earth scientists Francis Macdonald and Phoebe Cohen of Harvard University.
In a June Geology paper, they describe their findings as providing "a unique
window into the diversity of early eukaryotes."
Using molecular clocks and genetic trees to reverse-engineer evolutionary
histories, previous research placed the beginning of biomineralization at
about 750 million years ago. Around that time, the fossil record gets
suggestive, turning up vase-shaped amoebas with something like scales in
their cell walls, algae with cell walls possibly made from calcium carbonate
and sponge-like creatures with seemingly mineralized bodies.
|]
"https://www.wired.com/2011/06/first-shells/",
CalendarEntry (440 & millionYearsAgo) Nothing
"Fish with jaws"
""
[text|
Prehistoric armoured fishes called placoderms were the first fishes to have
jaws. They arose some time in the Silurian Period, about 440 million years
ago, to become the most abundant and diverse fishes of their day.
Placoderms dominated the oceans, rivers and lakes for some 80 million years,
before their sudden extinction around 359 million years ago. This is possibly
due to the depletion of trace elements in our oceans.
|]
"",
CalendarEntry (518 & millionYearsAgo) Nothing
"Vertebrates"
"Animals with backbones"
[text|
Vertebrates (/ˈvɜːrtəbrɪts, -ˌbreɪts/)[3] comprise all animal taxa within
the subphylum Vertebrata (/ˌvɜːrtəˈbreɪtə/)[4] (chordates with backbones),
including all mammals, birds, reptiles, amphibians, and fish. Vertebrates
represent the overwhelming majority of the phylum Chordata, with currently
about 69,963 species described.[5]
|]
"",
CalendarEntry (385 & millionYearsAgo) Nothing
"Insects"
""
[text|
Comprising up to 10 million living species, insects today can be found on
all seven continents and inhabit every terrestrial niche imaginable. But
according to the fossil record, they were scarce before about 325 million
years ago, outnumbered by their arthropod cousins the arachnids (spiders,
scorpions and mites) and myriapods (centipedes and millipedes).
The oldest confirmed insect fossil is that of a wingless, silverfish-like
creature that lived about 385 million years ago. It’s not until about 60
million years later, during a period of the Earth’s history known as the
Pennsylvanian, that insect fossils become abundant.
|]
"https://earth.stanford.edu/news/insects-took-when-they-evolved-wings",
CalendarEntry (368 & millionYearsAgo) Nothing
"Amphibians"
""
[text|
The earliest well-known amphibian, Ichthyostega, was found in Late Devonian
deposits in Greenland, dating back about 363 million years. The earliest
amphibian discovered to date is Elginerpeton, found in Late Devonian rocks
of Scotland dating to approximately 368 million years ago. The later
Paleozoic saw a great diversity of amphibians, ranging from small legless
swimming forms (Aistopoda) to bizarre "horned" forms (Nectridea). Other
Paleozoic amphibians more or less resembled salamanders outwardly but
differed in details of skeletal structure. Exactly how to classify these
fossils, and how they might be related to living amphibians, is still
debated by paleontologists. Shown at the right is Phlegethontia, an aistopod
from the Pennsylvanian.
The familiar frogs, toads, and salamanders have been present since at least
the Jurassic Period. (The fossil frog pictured to the left is much younger,
coming from the Eocene, only 45 to 55 million years ago). Fossil caecilians
are very rare; until recently the oldest known caecilians were Cenozoic in
age (that is, less than 65 million years old), but recent finds have pushed
back the ancestry of the legless caecilians to Jurassic ancestors that had
short legs. The rarity of fossil caecilians is probably due to their
burrowing habitat and reduced skeleton, both of which lessen the chances of
preservation.
|]
"https://ucmp.berkeley.edu/vertebrates/tetrapods/amphibfr.html",
CalendarEntry (320 & millionYearsAgo) Nothing
"Reptiles"
""
[text|
Reptiles, in the traditional sense of the term, are defined as animals that
have scales or scutes, lay land-based hard-shelled eggs, and possess
ectothermic metabolisms.
Though few reptiles today are apex predators, many examples of apex reptiles
have existed in the past. Reptiles have an extremely diverse evolutionary
history that has led to biological successes, such as dinosaurs, pterosaurs,
plesiosaurs, mosasaurs, and ichthyosaurs.
|]
[text|
https://en.wikipedia.org/wiki/Evolution_of_reptiles
https://www.thoughtco.com/the-first-reptiles-1093767
|],
CalendarEntry (335 & millionYearsAgo) Nothing
"Pangea forms"
""
[text|
Pangaea or Pangea (/pænˈdʒiː.ə/)[1] was a supercontinent that existed during
the late Paleozoic and early Mesozoic eras.[2] It assembled from the earlier
continental units of Gondwana, Euramerica and Siberia during the
Carboniferous approximately 335 million years ago, and began to break apart
about 200 million years ago, at the end of the Triassic and beginning of the
Jurassic.[3] In contrast to the present Earth and its distribution of
continental mass, Pangaea was centred on the Equator and surrounded by the
superocean Panthalassa and the Paleo-Tethys and subsequent Tethys Oceans.
Pangaea is the most recent supercontinent to have existed and the first to
be reconstructed by geologists.
|]
"https://en.wikipedia.org/wiki/Pangaea",
CalendarEntry (243 & millionYearsAgo) Nothing
"Dinosaurs"
""
[text|
For the past twenty years, Eoraptor has represented the beginning of the Age
of Dinosaurs. This controversial little creature–found in the roughly
231-million-year-old rock of Argentina–has often been cited as the earliest
known dinosaur. But Eoraptor has either just been stripped of that title, or
soon will be. A newly-described fossil found decades ago in Tanzania extends
the dawn of the dinosaurs more than 10 million years further back in time.
Named Nyasasaurus parringtoni, the roughly 243-million-year-old fossils
represent either the oldest known dinosaur or the closest known relative to
the earliest dinosaurs. The find was announced by University of Washington
paleontologist Sterling Nesbitt and colleagues in Biology Letters, and I
wrote a short news item about the discovery for Nature News. The paper
presents a significant find that is also a tribute to the work of Alan
Charig–who studied and named the animal, but never formally published a
description–but it isn’t just that. The recognition of Nyasasaurus right
near the base of the dinosaur family tree adds to a growing body of evidence
that the ancestors of dinosaurs proliferated in the wake of a catastrophic
mass extinction.
|]
[text|
https://www.smithsonianmag.com/science-nature/scientists-discover-oldest-known-dinosaur-152807497/
|],
CalendarEntry (210 & millionYearsAgo) Nothing
"Mammals"
""
[text|
The earliest known mammals were the morganucodontids, tiny shrew-size
creatures that lived in the shadows of the dinosaurs 210 million years ago.
They were one of several different mammal lineages that emerged around that
time. All living mammals today, including us, descend from the one line that
survived.
|]
"https://www.nationalgeographic.com/science/article/rise-mammals",
CalendarEntry (150 & millionYearsAgo) Nothing
"Birds"
""
[text|
The first birds had sharp teeth, long bony tails and claws on their hands.
The clear distinction we see between living birds and other animals did not
exist with early birds. The first birds were in fact more like small
dinosaurs than they were like any bird today.
The earliest known (from fossils) bird is the 150-million-year-old
Archaeopteryx, but birds had evolved before then. A range of birds with more
advanced features appeared soon after Archaeopteryx. One group gave rise to
modern birds in the Late Cretaceous.
|]
"https://australian.museum/learn/dinosaurs/the-first-birds/",
CalendarEntry (130 & millionYearsAgo) Nothing
"Flowers"
""
[text|
Today, plants with flowers--called angiosperms--dominate the landscape.
Around 80 percent of green plants alive today, from oak trees to grass, are
flowering plants. In all of these plants, flowers are part of the
reproductive system. But 130 million years ago, flowering plants were rare.
Most plants reproduced with spores, found today on ferns, or with seeds and
cones, found today on pine trees. The plant fossils found in Liaoning,
China, show evidence of plants with spores or seeds--and perhaps one of the
first flowering plants.
Researchers have found an ancient plant in Liaoning, Archaefructus, that has
very small, simple flowers and could be one of the first flowering plants.
Archaefructus lived around 130 million years ago and probably grew in or
near the water.
|]
"https://www.amnh.org/exhibitions/dinosaurs-ancient-fossils/liaoning-diorama/when-flowers-first-bloomed",
CalendarEntry (85 & millionYearsAgo) Nothing
"Tyranosaurids"
"The Tyrant Lizards"
[text|
The name says it all. This group of huge carnivores must have tyrannically
ruled the land during the last part of the Cretaceous, 85 to 65 million
years ago. Short but deep jaws with banana-sized sharp teeth, long hind
limbs, small beady eyes, and tiny forelimbs (arms) typify a tyrannosaur. The
Tyrannosauridae included such similar animals (in rough order of increasing
size) as Albertosaurus, Gorgosaurus, Daspletosaurus, Tarbosaurus, and of
course Tyrannosaurus rex.
T. rex was one of the largest terrestrial carnivores of all time. It stood
approximately 15 feet high and was about 40 feet in length, roughly six tons
in weight. In its large mouth were six-inch long, sharp, serrated teeth.
Just about two dozen good specimens of these animals have been found and
these finds are from highly restricted areas in western North America. Henry
Fairfield Osborn, of the American Museum of Natural History in New York
City, first described Tyrannosaurus rex in 1905. This first specimen of
Tyrannosaurus is now on display at the Carnegie Museum of Natural History in
Pittsburgh, Pennsylvania.
|]
"",
CalendarEntry (445 & millionYearsAgo) Nothing
"The first mass extinction"
"Fluctuating sea levels cause mass die-off of marine invertebrates"
[text|
The earliest known mass extinction, the Ordovician Extinction, took place at
a time when most of the life on Earth lived in its seas. Its major
casualties were marine invertebrates including brachiopods, trilobites,
bivalves and corals; many species from each of these groups went extinct
during this time. The cause of this extinction? It’s thought that the main
catalyst was the movement of the supercontinent Gondwana into Earth’s
southern hemisphere, which caused sea levels to rise and fall repeatedly
over a period of millions of years, eliminating habitats and species. The
onset of a late Ordovician ice age and changes in water chemistry may also
have been factors in this extinction.
|]
"https://www.amnh.org/shelf-life/six-extinctions",
CalendarEntry (370 & millionYearsAgo) Nothing
"Late Devonian Extinction"
"The Kellwasser Event and the Hangenberg Event combine to cause an enormous loss in biodiversity"
[text|
Given that it took place over a huge span of time—estimates range from
500,000 to 25 million years—it isn’t possible to point to a single cause for
the Devonian extinction, though some suggest that the amazing spread of
plant life on land during this time may have changed the environment in ways
that made life harder, and eventually impossible, for the species that died
out.
The brunt of this extinction was borne by marine invertebrates. As in the
Ordovician Extinction, many species of corals, trilobites, and brachiopods
vanished. Corals in particular were so hard hit that they were nearly wiped
out, and didn’t recover until the Mesozoic Era, nearly 120 million years
later. Not all vertebrate species were spared, however; the early bony
fishes known as placoderms met their end in this extinction.
|]
"https://www.amnh.org/shelf-life/six-extinctions",
CalendarEntry (252 & millionYearsAgo) Nothing
"The Great Dying"
"Mass extinction kills more than 95 percent of marine species and 70 percent of land-dwelling vertebrates"
[text|
So many species were wiped out by this mass extinction it took more than 10
million years to recover from the huge blow to global biodiversity. This
extinction is thought to be the result of a gradual change in climate,
followed by a sudden catastrophe. Causes including volcanic eruptions,
asteroid impacts, and a sudden release of greenhouse gasses from the
seafloor have been proposed, but the mechanism behind the Great Dying
remains a mystery.
|]
"https://www.amnh.org/shelf-life/six-extinctions",
CalendarEntry (201 & millionYearsAgo) Nothing
"Triassic-Jurassic Extinction"
"Death of more than a third of marine species and of most large amphibians"
[text|
This extinction occurred just a few millennia before the breakup of the
supercontinent of Pangaea. While its causes are not definitively
understood—researchers have suggested climate change, an asteroid impact, or
a spate of enormous volcanic eruptions as possible culprits—its effects are
indisputable.
More than a third of marine species vanished, as did most large amphibians
of the time, as well as many species related to crocodiles and dinosaurs.
|]
"https://www.amnh.org/shelf-life/six-extinctions",
CalendarEntry (66 & millionYearsAgo) Nothing
"Dinosaurs extinct"
"Mammals take over land & sea"
[text|
An asteroid more than 6 miles across strikes the Yucatan Peninsula,
triggering the fifth mass extinction in the world’s history.
Some of the debris thrown into the atmosphere returned to Earth, the
friction turning the air into an oven and sparking forest fires as it landed
all over the world. The intensity of the heat pulse gave way to a prolonged
impact winter, the sky blotted out by soot and ash as temperatures fell.
More than 75 percent of species known from the end of the Cretaceous period,
66 million years ago, didn’t make it to the following Paleogene period. The
geologic break between the two is called the K-Pg boundary, and beaked birds
were the only dinosaurs to survive the disaster.|]
[text|
https://www.smithsonianmag.com/science-nature/why-birds-survived-and-dinosaurs-went-extinct-after-asteroid-hit-earth-180975801/,
https://www.amnh.org/shelf-life/six-extinctions
|],
CalendarEntry (27.5 & millionYearsAgo) Nothing
"Apes and monkeys split"
""
[text|
Studies of clock-like mutations in primate DNA have indicated that the split
between apes and Old World monkeys occurred between 30 million and 25
million years ago.
|]
"https://www.nsf.gov/news/news_summ.jsp?cntn_id=127930",
CalendarEntry (12.1 & millionYearsAgo) Nothing
"Humans and chimpanzees split"
""
[text|
A 2016 study analyzed transitions at CpG sites in genome sequences, which
exhibit a more clocklike behavior than other substitutions, arriving at an
estimate for human and chimpanzee divergence time of 12.1 million years.[20]
|]
[text|
https://en.wikipedia.org/wiki/Chimpanzee%E2%80%93human_last_common_ancestor
|],
CalendarEntry (4.4 & millionYearsAgo) Nothing
"Humans first walk upright"
""
[text|
The earliest hominid with the most extensive evidence for bipedalism is the 4.4-million-year-old Ardipithecus ramidus.
|]
[text|
https://www.smithsonianmag.com/science-nature/becoming-human-the-evolution-of-walking-upright-13837658/
|],
CalendarEntry (300 & thousandYearsAgo) Nothing
"Modern humans evolve"
""
[text|
Among the oldest known remains of Homo sapiens are those found at the
Omo-Kibish I archaeological site in south-western Ethiopia, dating to about
233,000[2] to 196,000 years ago,[3] the Florisbad site in South Africa,
dating to about 259,000 years ago, and the Jebel Irhoud site in Morocco,
dated about 300,000 years ago.
|]
[text|
https://en.wikipedia.org/wiki/Early_modern_human
|],
CalendarEntry (100 & thousandYearsAgo) Nothing
"Human migration out of Africa"
""
[text|
Between 70,000 and 100,000 years ago, Homo sapiens began migrating from the
African continent and populating parts of Europe and Asia. They reached the
Australian continent in canoes sometime between 35,000 and 65,000 years ago.
Map of the world showing the spread of Homo sapiens throughout the Earth
over time.
|]
[text|
https://www.khanacademy.org/humanities/world-history/world-history-beginnings/origin-humans-early-societies/a/where-did-humans-come-from
|],
CalendarEntry (4.4 & billionYearsAgo) Nothing
"Formation of the moon"
"A collision of the planet Theia with Earth creates the moon"
[text|
Astronomers think the collision between Earth and Theia happened at about
4.4 to 4.45 bya; about 0.1 billion years after the Solar System began to
form.[15][16] In astronomical terms, the impact would have been of moderate
velocity. Theia is thought to have struck Earth at an oblique angle when
Earth was nearly fully formed. Computer simulations of this "late-impact"
scenario suggest an initial impactor velocity at infinity below 4 kilometres
per second (2.5 mi/s), increasing as it fell to over 9.3 km/s (5.8 mi/s) at
impact, and an impact angle of about 45°.[17] However, oxygen isotope
abundance in lunar rock suggests "vigorous mixing" of Theia and Earth,
indicating a steep impact angle.[3][18] Theia's iron core would have sunk
into the young Earth's core, and most of Theia's mantle accreted onto
Earth's mantle. However, a significant portion of the mantle material from
both Theia and Earth would have been ejected into orbit around Earth (if
ejected with velocities between orbital velocity and escape velocity) or
into individual orbits around the Sun (if ejected at higher velocities).
Modelling[19] has hypothesised that material in orbit around Earth may have
accreted to form the Moon in three consecutive phases; accreting first from
the bodies initially present outside Earth's Roche limit, which acted to
confine the inner disk material within the Roche limit. The inner disk
slowly and viscously spread back out to Earth's Roche limit, pushing along
outer bodies via resonant interactions. After several tens of years, the
disk spread beyond the Roche limit, and started producing new objects that
continued the growth of the Moon, until the inner disk was depleted in mass
after several hundreds of years.
|]
[text|
https://en.wikipedia.org/wiki/Giant-impact_hypothesis#Basic_model
https://www.psi.edu/epo/moon/moon.html
|],
CalendarEntry (600 & millionYearsAgo) Nothing
"Multicellular life"
""
[text|
|]
""
]
where
theYear = yearsAgo . toRational . (currentYear -)
yearsBeforeCommonEra = yearsAgo . toRational . ((+) (currentYear - 1))
earthDescription = [text|
The standard model for the formation of the Solar System (including the
Earth) is the solar nebula hypothesis.[23] In this model, the Solar System
formed from a large, rotating cloud of interstellar dust and gas called the
solar nebula. It was composed of hydrogen and helium created shortly after
the Big Bang 13.8 Ga (billion years ago) and heavier elements ejected by
supernovae. About 4.5 Ga, the nebula began a contraction that may have been
triggered by the shock wave from a nearby supernova.[24] A shock wave would
have also made the nebula rotate. As the cloud began to accelerate, its
angular momentum, gravity, and inertia flattened it into a protoplanetary
disk perpendicular to its axis of rotation. Small perturbations due to
collisions and the angular momentum of other large debris created the means
by which kilometer-sized protoplanets began to form, orbiting the nebular
center.[25]
The center of the nebula, not having much angular momentum, collapsed
rapidly, the compression heating it until nuclear fusion of hydrogen into
helium began. After more contraction, a T Tauri star ignited and evolved
into the Sun. Meanwhile, in the outer part of the nebula gravity caused
matter to condense around density perturbations and dust particles, and the
rest of the protoplanetary disk began separating into rings. In a process
known as runaway accretion, successively larger fragments of dust and debris
clumped together to form planets.[25] Earth formed in this manner about 4.54
billion years ago (with an uncertainty of 1%)[26][27][4] and was largely
completed within 10–20 million years.[28] The solar wind of the newly formed
T Tauri star cleared out most of the material in the disk that had not
already condensed into larger bodies. The same process is expected to
produce accretion disks around virtually all newly forming stars in the
universe, some of which yield planets.[29]
|]
recombinationDescription = [text|
At about 370,000 years,[3][4][5][6] neutral hydrogen atoms finish forming
("recombination"), and as a result the universe also became transparent for
the first time. The newly formed atoms—mainly hydrogen and helium with
traces of lithium—quickly reach their lowest energy state (ground state) by
releasing photons ("photon decoupling"), and these photons can still be
detected today as the cosmic microwave background (CMB). This is the oldest
direct observation we currently have of the universe.
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recombinationReferences = [text|
https://en.wikipedia.org/wiki/Chronology_of_the_universe#The_very_early_universe
3. Tanabashi, M. 2018, p. 358, chpt. 21.4.1: "Big-Bang Cosmology" (Revised
September 2017) by Keith A. Olive and John A. Peacock.
4. Notes: Edward L. Wright's Javascript Cosmology Calculator (last modified
23 July 2018). With a default H 0 {\displaystyle H_{0}} H_{0} = 69.6 (based
on WMAP9+SPT+ACT+6dFGS+BOSS/DR11+H0/Riess) parameters, the calculated age of
the universe with a redshift of z = 1100 is in agreement with Olive and
Peacock (about 370,000 years).
5. Hinshaw, Weiland & Hill 2009. See PDF: page 45, Table 7, Age at
decoupling, last column. Based on WMAP+BAO+SN parameters, the age of
decoupling occurred 376971+3162−3167 years after the Big Bang.
6. Ryden 2006, pp. 194–195. "Without going into the details of the
non-equilibrium physics, let's content ourselves by saying, in round
numbers, zdec ≈ 1100, corresponding to a temperature Tdec ≈ 3000 K, when the
age of the universe was tdec ≈ 350,000 yr in the Benchmark Model. (...) The
relevant times of various events around the time of recombination are shown
in Table 9.1. (...) Note that all these times are approximate, and are
dependent on the cosmological model you choose. (I have chosen the Benchmark
Model in calculating these numbers.)"
https://en.wikipedia.org/wiki/Recombination_(cosmology)#cite_note-2
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