Science & Nature
Events · 172
- 13.8 billion years agoThe Universe
The Big Bang
About 13.8 billion years ago the universe began as an unimaginably hot, dense state and started to expand. In a tiny fraction of a second, space, time, matter and energy all came into being.
Reputable source - the first fraction of a secondThe Universe
Cosmic Inflation
A tiny fraction of a second after the Big Bang, the universe underwent 'inflation' — expanding faster than the speed of light, ballooning from smaller than an atom to larger than the visible universe almost instantly.
Reputable source - the first momentsThe Universe
The Matter–Antimatter Asymmetry
In the earliest instants, matter and antimatter were created in almost equal amounts — and wherever they met, they annihilated into pure energy. Yet a tiny excess of matter survived: roughly one extra matter particle for every billion matter–antimatter pairs.
Reputable source - the first secondThe Universe
The First Matter
Within the first second, the searing universe cooled just enough for quarks to bind together into protons and neutrons — the particles that sit at the heart of every atom.
Reputable source - the first few minutesThe Universe
The First Elements: Big Bang Nucleosynthesis
In the first few minutes, protons and neutrons fused to build the lightest atomic nuclei — hydrogen, helium and a trace of lithium. After about five minutes the universe had expanded and cooled too much for any more to form.
Reputable source - ~100,000 years after the Big BangThe Universe
Helium Hydride: The First Molecule
As the young universe cooled, helium and hydrogen joined to form helium hydride (HeH⁺) — the very first molecule. NASA's SOFIA observatory finally detected it in space in 2019, decades after scientists predicted it should exist.
Reputable source - ~380,000 years after the Big BangThe Universe
The Cosmic Microwave Background: First Light
About 380,000 years after the Big Bang, the universe cooled enough for electrons and nuclei to join into the first neutral atoms. Light could finally travel freely, and that ancient glow still fills the sky today as the cosmic microwave background (CMB).
Reputable source - ~380,000 years to a few hundred million years after the Big BangThe Universe
The Cosmic Dark Ages
After the cosmic microwave background was released, the universe entered the 'Dark Ages' — a long, starless era filled with neutral hydrogen gas and no sources of visible light.
Reputable source - ~13.5 billion years agoThe Universe
The First Stars: Cosmic Dawn
A few hundred million years after the Big Bang, the first stars ignited and ended the Dark Ages. Made only of hydrogen and helium, these Population III stars were enormous, brilliant and short-lived.
Reputable source - from ~13.5 billion years agoThe Universe
Heavy Elements Forged in Stars
Stars fuse light elements into heavier ones deep in their cores, then scatter them across space when they die — especially in supernova explosions. Carbon, oxygen, iron and more were all built this way.
Reputable source - ~13.4 billion years agoThe Universe
The First Galaxies
Within a few hundred million years of the Big Bang, gravity pulled gas and early stars together into the first galaxies. The James Webb Space Telescope is now spotting some of the earliest galaxies ever seen.
Reputable source - ~13 billion years agoThe Universe
The Epoch of Reionization
Ultraviolet light from the first stars and galaxies broke the universe's neutral hydrogen back apart into charged particles. This 'reionization' cleared the cosmic fog and made the universe transparent to starlight.
Reputable source - ~13 billion years agoThe Universe
The Birth of the Milky Way
Our own galaxy began forming early in cosmic history. ESA's Gaia mission has found that part of the Milky Way's disc is far older than expected — over 13 billion years old — and that our galaxy grew partly by merging with others.
Reputable source - from ~13 billion years agoThe Universe
Supermassive Black Holes and Quasars
Black holes millions to billions of times the mass of the Sun grew at the centres of early galaxies. Feeding on surrounding gas, they blazed as quasars — among the most luminous objects in the entire universe.
Reputable source - building up over billions of yearsThe Universe
Dark Matter: The Invisible Scaffolding
Most of the universe's matter is invisible 'dark matter' — roughly five times more abundant than ordinary matter and detectable only by its gravity. It forms a vast cosmic web of filaments along which galaxies gather.
Reputable source · 2 sources - throughout cosmic historyThe Universe
Gold Forged in Colliding Neutron Stars
The heaviest elements — gold, platinum and more — are forged when ultra-dense neutron stars collide. In 2017, astronomers observed such a merger for the first time, detecting both its gravitational waves and the light of the 'kilonova' explosion that builds these elements.
Reputable source - ~10 billion years agoThe Universe
Cosmic Noon: The Peak of Star Formation
A few billion years after the Big Bang, the universe formed stars faster than at any time before or since. Galaxies blazed with newborn stars at rates far higher than in the Milky Way today.
Reputable source - ~10 billion years agoThe Universe
The Milky Way's Great Merger
Early in its life, the young Milky Way collided and merged with another large galaxy — an event called Gaia-Enceladus (the 'Sausage'). ESA's Gaia mission found its stars still moving on distinctive paths through our galaxy today.
Reputable source - throughout cosmic historyThe Universe
Gravitational Waves Ripple Through Spacetime
When massive objects such as black holes spiral together and merge, they send ripples through spacetime itself — gravitational waves — spreading outward at the speed of light. Albert Einstein predicted them in 1915; they were first directly detected in 2015.
Reputable source - ~5 billion years agoThe Universe
Dark Energy and the Accelerating Universe
Around 5 billion years ago the expansion of the universe began to speed up rather than slow down, pushed apart by a mysterious 'dark energy' that makes up roughly 68% of the cosmos.
Reputable source - ~4.6 billion years agoThe Universe
The Birth of the Solar System
A giant cloud of gas and dust collapsed under its own gravity, forming the Sun at its centre and a spinning disc of debris that clumped together into the planets, moons, asteroids and comets of our Solar System.
Reputable source - ~4.5 billion years agoThe Universe
Earth and the Moon
Earth formed from the disc of material around the young Sun. Soon after, a Mars-sized body is thought to have collided with the young Earth, and debris flung into orbit came together to form the Moon.
Reputable source - ~4 billion years agoThe Universe
The Late Heavy Bombardment
Around 4 billion years ago, the young Earth and its neighbours may have endured an intense spike of asteroid and comet impacts — possibly triggered when the giant planets' orbits shifted and scattered debris across the inner Solar System.
Reputable source - ~3.8 billion years agoEvolution of Life on Earth
The Origin of Life
Life arose on the early Earth not long after the planet became habitable. The oldest possible traces — microfossils in ancient seafloor rocks of Quebec's Nuvvuagittuq belt and carbon signatures and stromatolite-like structures in Greenland — date to roughly 3.7–3.8 billion years ago, with some claims reaching further back still.
Reputable source · 2 sources - ~3.5 billion years agoEvolution of Life on Earth
Photosynthesis and the First Stromatolites
By about 3.5 billion years ago, communities of microbes were building layered mineral structures called stromatolites — among the oldest fossils of living organisms on Earth. Early photosynthetic microbes had begun capturing the Sun's energy, some releasing oxygen as a by-product.
Reputable source - ~2.4 billion years agoEvolution of Life on Earth
The Great Oxidation Event
Oxygen produced by photosynthesising cyanobacteria built up in the atmosphere around 2.4 billion years ago, rising by orders of magnitude over roughly 200 million years and turning an oxygen-poor world into an oxygen-rich one.
Reputable source - ~2–1.6 billion years agoEvolution of Life on Earth
The First Complex Cells
Complex cells — eukaryotes, with a nucleus and internal compartments — evolved from simpler microbes. A key step was endosymbiosis: one cell engulfed a bacterium that became the mitochondrion, the powerhouse of the cell (and later, in plants, the chloroplast).
Reputable source - ~720–635 million years agoEvolution of Life on Earth
Snowball Earth
During the Cryogenian period, the planet endured at least two extreme global glaciations — the Sturtian and Marinoan — when ice may have reached the equator and average temperatures plunged far below freezing. Life survived in refuges such as meltwater ponds.
Reputable source - ~575 million years agoEvolution of Life on Earth
The First Animals: The Ediacaran Biota
The Ediacaran biota — soft-bodied organisms like the pancake-shaped Dickinsonia, which crept across microbial mats on the seafloor — are the oldest known fossils of large, complex animals, living in the tens of millions of years before the Cambrian.
Reputable source - ~538 million years agoEvolution of Life on Earth
The Cambrian Explosion
In a geologically brief interval beginning about 539 million years ago, animals rapidly diversified into a wide range of body plans. Most of the major animal groups — the phyla we recognise today — first appear in the fossil record during this burst.
Reputable source - ~500 million years agoEvolution of Life on Earth
The First Vertebrates
The first vertebrates — small, jawless fish — appeared in the ancient oceans. Over the following tens of millions of years, fish diversified spectacularly, evolving jaws and bony skeletons and coming to dominate the seas during the Devonian 'Age of Fishes.'
Reputable source - ~470 million years agoEvolution of Life on Earth
Plants Colonize the Land
Plants first moved onto land around 470 million years ago, beginning as small, simple forms and evolving roots, vascular tissue, and eventually towering trees. By the late Devonian, forests tens of metres tall covered parts of the land.
Reputable source - ~375 million years agoEvolution of Life on Earth
The First Tetrapods Step Ashore
During the Devonian, some lobe-finned fish evolved into the first four-limbed vertebrates, the tetrapods. Transitional fossils such as Tiktaalik — with a mix of fish and land-animal features including sturdy limb bones, a mobile neck, and lungs — capture this move from water toward land.
Reputable source - ~360–300 million years agoEvolution of Life on Earth
The Carboniferous: Coal Forests and Giant Insects
Lush, swampy forests spread across the land during the Carboniferous; when they died and were buried, they eventually became coal. High atmospheric oxygen allowed arthropods to grow to enormous size — dragonfly-like griffinflies with wingspans up to 71 centimetres and metre-scale millipedes.
Reputable source - ~252 million years agoThe Age of Dinosaurs
The Great Dying
The Permian period ended in the most severe extinction event in Earth's history. Vast volcanic eruptions in Siberia poured out lava and greenhouse gases, warming the planet and acidifying the oceans. As much as 90% of marine species and most life on land was wiped out.
Reputable source - ~252 million years agoEvolution of Life on Earth
The Great Dying: The Permian Extinction
The largest mass extinction in Earth's history struck about 252 million years ago, wiping out up to 96% of marine species. It is linked to enormous volcanic eruptions in what is now Siberia, which drove global warming, acid rain, and the poisoning of the oceans.
Reputable source - ~250 million years ago (Triassic)The Age of Dinosaurs
Ichthyosaurs Return to the Sea
As life recovered from the Great Dying, some reptiles returned to the water. Ichthyosaurs — sleek, dolphin-shaped 'sea dragons' — became fast marine predators; smaller ichthyosaurs survived until around 90 million years ago.
Reputable source - ~230 million years ago (Late Triassic)The Age of Dinosaurs
The First Dinosaurs
The oldest definitive dinosaurs appear in ~230-million-year-old rocks of the Ischigualasto Formation in Argentina — small, bipedal forms such as Eoraptor and the early carnivore Herrerasaurus. They were still rare members of ecosystems dominated by other archosaurs.
Reputable source - ~230 million years agoEvolution of Life on Earth
The First Dinosaurs
The oldest known dinosaurs — small, agile predators such as Eoraptor and Herrerasaurus — appeared in the Late Triassic, around 230 million years ago, in what is now South America.
Reputable source - ~225 million years ago (Late Triassic)The Age of Dinosaurs
The First Mammals
Tiny, shrew-like mammals and their close relatives appeared alongside the earliest dinosaurs. Brasilodon quadrangularis, from what is now Brazil, shows mammal-like features around 225 million years ago, with Morganucodon following by about 205 million years ago.
Reputable source - ~215 million years ago (Late Triassic)The Age of Dinosaurs
The First Pterosaurs Take Flight
The first pterosaurs appear in the fossil record around 215 million years ago. These flying reptiles were not dinosaurs but close archosaur cousins — and they were the first vertebrates ever to evolve powered flight, tens of millions of years before birds.
Reputable source - ~210 million years agoEvolution of Life on Earth
The First Mammals
Tiny, shrew-like mammals such as Morganucodon evolved from mammal-like reptiles in the Late Triassic and Early Jurassic. Through the long age of the dinosaurs, mammals remained small and mostly nocturnal.
Reputable source - ~201 million years agoThe Age of Dinosaurs
The End-Triassic Extinction
A mass extinction around 201 million years ago — one of the 'big five' — wiped out up to 80% of species. It was probably driven by enormous volcanism (the Central Atlantic Magmatic Province) as the supercontinent Pangaea began to rift apart, and it killed off many of the archosaurs that had competed with dinosaurs.
Reputable source - Early–Middle Jurassic, ~200–170 million years agoThe Age of Dinosaurs
Pangaea Breaks Apart
During the Jurassic, the supercontinent Pangaea broke apart, opening new seaways and separating the land into drifting continents. The climate grew warmer and wetter, and lush vegetation spread across the world.
Reputable source - Jurassic, ~180 million years agoThe Age of Dinosaurs
Plesiosaurs Rule the Seas
Long-necked plesiosaurs became dominant ocean predators through the Jurassic and Cretaceous. Fully adapted to open water, they swam using four large wing-like flippers.
Reputable source - Late Jurassic, 152–145 million years agoThe Age of Dinosaurs
Diplodocus and the Giant Sauropods
In the Late Jurassic, long-necked sauropods reached enormous sizes. Diplodocus, one of the longest dinosaurs ever known, roamed the Morrison Formation of western North America alongside other giant plant-eaters.
Reputable source - ~150 million years agoEvolution of Life on Earth
Archaeopteryx and the First Birds
Archaeopteryx, from the Late Jurassic about 150 million years ago, had feathers and broad wings like a bird, but also teeth, clawed hands, and a long bony tail like a dinosaur. It is a classic transitional fossil.
Reputable source - Late Jurassic, 152–145 million years agoThe Age of Dinosaurs
Stegosaurus, the Plated Dinosaur
Stegosaurus, a large Late Jurassic plant-eater of the Morrison ecosystem, carried two rows of tall bony plates along its back and a spiked tail for defence.
Reputable source - Late Jurassic, 152–145 million years agoThe Age of Dinosaurs
Allosaurus, Apex Predator of the Jurassic
Allosaurus was the top predator of Late Jurassic North America — a powerful bipedal carnivore with a large skull and blade-like teeth. It hunted the same landscapes as Stegosaurus and the giant sauropods.
Reputable source - Late Jurassic, ~149–145 million years agoThe Age of Dinosaurs
Archaeopteryx and the Origin of Birds
Archaeopteryx, a small feathered dinosaur from Late Jurassic Germany, had wings, feathers and a wishbone like a bird, yet also sharp teeth, clawed hands and a long bony tail like other dinosaurs. The first specimen was found in 1861 — just two years after Darwin's On the Origin of Species.
Reputable source - ~130 million years agoEvolution of Life on Earth
The First Flowering Plants
Flowering plants — angiosperms — appeared in the Early Cretaceous, around 130 million years ago, and then radiated with remarkable speed, co-evolving with insect pollinators.
Reputable source - Early Cretaceous, ~130–100 million years agoThe Age of Dinosaurs
The First Flowers Bloom
Flowering plants (angiosperms) appeared and rapidly spread during the Cretaceous, diversifying across the world and transforming ecosystems on land.
Reputable source - Early Cretaceous, ~125 million years agoThe Age of Dinosaurs
Feathered Dinosaurs Revealed
Exceptionally preserved Cretaceous fossils show that many dinosaurs — especially small meat-eaters — were covered in feathers. The finds confirmed that feathers first evolved in dinosaurs long before any animal could fly.
Reputable source - ~101 million years ago (Cretaceous)The Age of Dinosaurs
Patagotitan and the Largest Dinosaurs
Titanosaurs — the last and largest of the sauropods — reached staggering sizes in the Cretaceous. Patagotitan, from ~101-million-year-old rocks of Argentina, measured about 37.5 metres long and weighed an estimated 57 tonnes.
Reputable source - ~99 million years ago (Cretaceous)The Age of Dinosaurs
Spinosaurus, the River Predator
Spinosaurus, a huge sail-backed predator from Cretaceous North Africa, was even longer than Tyrannosaurus rex. A remarkably complete skeleton found in Morocco in 2014 revealed dense bones, paddle-like feet and a fin-shaped tail, suggesting it hunted fish in rivers.
Reputable source - Late Cretaceous, ~80–66 million years agoThe Age of Dinosaurs
Mosasaurs, the Last Sea Monsters
As the ichthyosaurs faded, giant marine lizards called mosasaurs rose to rule the Late Cretaceous oceans. Powerful swimmers related to today's monitor lizards and snakes, they were the top predators of the seas.
Reputable source - Late Cretaceous, 74–70 million years agoThe Age of Dinosaurs
Velociraptor, the Feathered Hunter
Velociraptor, a Late Cretaceous predator from Mongolia, was in reality about the size of a turkey — far smaller than in the movies — and covered in feathers, with a large sickle-shaped claw on each foot.
Reputable source - Late Cretaceous, 68–66 million years agoThe Age of Dinosaurs
Triceratops and the Horned Dinosaurs
Triceratops appeared around 68 million years ago, in the final stretch of the age of dinosaurs. This massive plant-eater bore three facial horns and a large bony frill, and shared its world with Tyrannosaurus rex.
Reputable source - Late Cretaceous, 68–66 million years agoThe Age of Dinosaurs
Tyrannosaurus rex, the Tyrant King
Tyrannosaurus rex, one of the largest land predators of all time, lived in the final couple of million years of the dinosaur age in western North America. It reached around 12 metres long, had up to 60 teeth as long as 20 centimetres, and a bite several times more powerful than a lion's. The first skeleton was found in 1900 by Barnum Brown.
Reputable source - ~66 million years agoThe Age of Dinosaurs
The Deccan Traps Erupt
Around the end of the Cretaceous, one of the largest volcanic events in Earth's history — the Deccan Traps, in what is now India — poured out immense floods of lava over hundreds of thousands of years, releasing climate-altering gases across the boundary.
Reputable source - ~66 million years agoEvolution of Life on Earth
The Asteroid: The End-Cretaceous Extinction
An asteroid roughly 10 kilometres wide struck at Chicxulub, on today's Yucatán Peninsula, about 66 million years ago. The impact darkened the skies for years and caused a global catastrophe that killed around three-quarters of all species, including every non-avian dinosaur.
Reputable source - ~66 million years agoThe Age of Dinosaurs
The Day the Mesozoic Died: The Chicxulub Impact
A city-sized asteroid slammed into what is now the Yucatán Peninsula of Mexico, carving out the vast Chicxulub crater. The impact triggered wildfires, tsunamis and a global 'impact winter' as debris blotted out the Sun. Around three-quarters of all species — including every non-bird dinosaur — died out.
Reputable source · 2 sources - 66 million years ago, and ever sinceThe Age of Dinosaurs
Birds: The Dinosaurs That Survived
One group of small, feathered theropod dinosaurs lived through the mass extinction: the birds. Every bird alive today — from sparrows to ostriches — is a living dinosaur, descended from Cretaceous ancestors.
Reputable source - after 66 million years agoThe Age of Dinosaurs
After the Dinosaurs: The Age of Mammals
With the non-bird dinosaurs gone, mammals — until then mostly small and nocturnal — rapidly diversified to fill the empty ecosystems, growing larger and taking on new roles through the Cenozoic Era.
Reputable source - ~55–25 million years agoEvolution of Life on Earth
The Rise of Primates and Apes
With the dinosaurs gone, mammals diversified explosively in the 'Age of Mammals.' Among them were the primates. The last common ancestor of monkeys and apes lived around 25 million years ago; humans belong to the ape branch of this family tree.
Reputable source - ~7 million years agoEvolution of Life on Earth
The First Hominins
The lineages leading to humans and to chimpanzees split roughly 8 to 6 million years ago. Sahelanthropus tchadensis, from Chad and dated to about 7 million years ago, combines ape-like features (a small brain) with human-like ones (small canines, a skull that may indicate upright posture), and is among the oldest known members of the human family tree.
Reputable source - ~3.2 million years agoEvolution of Life on Earth
Walking Upright: Lucy and Australopithecus
Australopithecus afarensis — including the famous 3.2-million-year-old partial skeleton 'Lucy,' found in Ethiopia — walked upright on two legs, while its curved toes and long arms show it could still climb trees.
Reputable source · 2 sources - ~2.6 million years agoEvolution of Life on Earth
The Genus Homo and the First Stone Tools
The oldest widely accepted stone tools — the simple flakes and cores of the Oldowan toolkit — date to about 2.6 million years ago. They are associated with early members of our own genus, Homo, such as Homo habilis ('handy man'), though other hominins may also have made tools.
Reputable source · 2 sources - ~1.9 million years agoEvolution of Life on Earth
Homo erectus Leaves Africa
Homo erectus, which first appeared in Africa around 2 million years ago, had modern human-like body proportions built for walking and running long distances. It was the first human species to spread widely beyond Africa into Asia, and it made more advanced Acheulean handaxes.
Reputable source - ~400,000 years agoEvolution of Life on Earth
Neanderthals and Other Human Cousins
Homo neanderthalensis evolved in Europe and western Asia. Robust and adapted to cold climates, Neanderthals made tools, used fire, hunted large game, and buried their dead. They lived alongside our own species and interbred with it before going extinct around 40,000 years ago.
Reputable source - ~300,000 years agoEvolution of Life on Earth
The Origin of Homo sapiens
Our own species, Homo sapiens, arose in Africa at least 300,000 years ago. Fossils from Jebel Irhoud in Morocco — showing modern-looking faces alongside more archaic braincases — are the oldest known members of our species, suggesting we evolved across a wide area of the continent.
Reputable source · 2 sources - c. 1800 BCEHistory of Mathematics
Babylonian and Egyptian Mathematics
The earliest advanced mathematics arose in the great river-valley civilizations. Babylonian scribes worked in a sophisticated base-60 (sexagesimal) system, solved quadratic equations, and knew the relationship later called the Pythagorean theorem. Egyptian mathematics, recorded on papyri, mastered fractions and the geometry needed to survey land and raise the pyramids.
Reputable source · 2 sources - antiquity to the presentPandemics Through History
Malaria: Humanity's Oldest Scourge
Long before the great epidemics that struck suddenly and passed, malaria was killing people steadily, year after year. Caused by Plasmodium parasites and spread by the bite of Anopheles mosquitoes, it has afflicted humans since ancient times, shaping where people could live and helping to sap armies and empires. It remains one of the world's deadliest diseases, killing hundreds of thousands of people every year — most of them young children in Africa — though it is both preventable and curable.
Reputable source - 430 BCEPandemics Through History
The Plague of Athens
In the second year of the Peloponnesian War, a devastating epidemic swept through Athens, packed with refugees behind its walls. The historian Thucydides — who caught the disease and survived — left a vivid eyewitness account of its symptoms and of the social breakdown it caused. By its end the epidemic had killed upwards of a third of the population.
Reputable source - c. 300 BCEHistory of Mathematics
Euclid and the Birth of Proof
Working in Alexandria, the Greek mathematician Euclid compiled the Elements — a systematic treatment of geometry and number theory built up from a handful of axioms by rigorous logical proof. It was arguably the most influential textbook ever written, used to teach mathematics for more than two thousand years.
Reputable source - c. 250 BCEHistory of Physics
Archimedes and the Birth of Mechanics
In the 3rd century BCE the Greek mathematician Archimedes of Syracuse brought rigorous mathematics to the physical world. He worked out the law of the lever and the principle of buoyancy — that a body immersed in fluid is buoyed up by the weight of the fluid it displaces — and studied the centre of gravity, designing ingenious machines and war engines along the way.
Reputable source - c. 250 BCEHistory of Mathematics
Archimedes
Archimedes of Syracuse, often ranked among the greatest mathematicians of all time, calculated remarkably accurate approximations of pi, found the areas and volumes of curved shapes using methods that anticipated integral calculus, and laid the foundations of mathematical physics with his work on levers and buoyancy.
Reputable source - 165–180 CEPandemics Through History
The Antonine Plague
Roman legions returning from campaigns in the East carried a terrible sickness — probably smallpox — back to the empire. The Antonine Plague raged for fifteen years, killing an estimated five million people across the Roman world, and struck again a generation later.
Reputable source - 249–262 CEPandemics Through History
The Plague of Cyprian
Beginning around 249 CE, a devastating pestilence swept the Roman Empire for some fifteen to twenty years. Named for St. Cyprian, the bishop of Carthage who described it, the plague at its height reportedly killed as many as 5,000 people a day in Rome. Its cause is uncertain — smallpox, a viral haemorrhagic fever, and pandemic influenza have all been suggested.
Reputable source - 541–549 CEPandemics Through History
The Plague of Justinian
The first recorded outbreak of bubonic plague erupted in the Byzantine Empire during the reign of Emperor Justinian, who caught the disease himself but survived. Spreading along trade routes from Egypt, it may have killed tens of millions of people around the Mediterranean over the following two centuries.
Reputable source - c. 628 CEHistory of Mathematics
The Invention of Zero
In India, mathematicians developed the place-value decimal system and, crucially, treated zero as a number in its own right. Around 628 CE, Brahmagupta set down rules for arithmetic with zero and negative numbers. This complete Hindu numeral system was the ancestor of the digits the whole world uses today.
Reputable source · 2 sources - c. 820 CEHistory of Mathematics
Al-Khwarizmi and Algebra
In the House of Wisdom in Baghdad, during the Islamic Golden Age, Muhammad ibn Musa al-Khwarizmi wrote a foundational treatise on solving equations. Its title gave us the word 'algebra,' and his own Latinized name gave us the word 'algorithm.' Scholars of the Islamic world preserved and extended Greek and Indian mathematics.
Reputable source - c. 1015History of Physics
Ibn al-Haytham and the Science of Optics
Working in Cairo in the early 11th century, the Arab scholar Ibn al-Haytham (known in the West as Alhazen) wrote a great Book of Optics — a rigorous study of light, reflection, refraction, lenses, and vision. He argued that understanding must be built on careful observation and experiment rather than the authority of the ancients.
Reputable source The Hindu-Arabic Numerals Reach Europe
In 1202 the Italian mathematician Leonardo of Pisa — Fibonacci — published Liber Abaci, championing the Hindu-Arabic numeral system he had learned from Arab merchants in North Africa. Over the following centuries these digits (0–9) gradually replaced clumsy Roman numerals across Europe.
Reputable source- 1347–1351Pandemics Through History
The Black Death
Bubonic plague returned to Europe with catastrophic force, arriving on ships from the Black Sea and sweeping across the continent in just a few years. The Black Death killed an estimated one-third or more of Europe's population — tens of millions of people — in the worst pandemic in recorded history.
Reputable source Syphilis: The Great Pox
In 1495 a terrible new disease broke out among the soldiers of Charles VIII of France besieging Naples. As the mercenary armies dispersed, the 'great pox' — syphilis — spread across Europe within a few years. Sexually transmitted and far more virulent then than now, it caused disfiguring sores and could be fatal. Many historians link its sudden appearance to the return of Columbus's crews from the Americas, though the origin is debated.
Reputable source- from 1520Pandemics Through History
Smallpox and the Columbian Exchange
When Europeans reached the Americas, they brought diseases — above all smallpox — to which Indigenous peoples had no immunity. Epidemics raced ahead of the conquerors, killing a huge share of Native American populations, in places 90% or more, and helping a few hundred Spaniards topple great empires.
Reputable source Copernicus and the Heliocentric Universe
In 1543 the Polish astronomer Nicolaus Copernicus published On the Revolutions of the Heavenly Spheres, arguing that the Earth and the planets orbit the Sun rather than the Sun and stars circling a stationary Earth. It overturned the Earth-centred cosmos that had reigned since Ptolemy, 1,400 years earlier.
Reputable source- 1545–1576Pandemics Through History
Cocoliztli: The Great Dying of Mexico
In 1545 a mysterious disease the Aztecs called cocoliztli ('pestilence') erupted in the highlands of Mexico, and struck again in 1576. Together the two epidemics killed an estimated 7 to 18 million people — a huge share of the surviving Indigenous population.
Reputable source - 1609–1619History of Physics
Kepler's Laws of Planetary Motion
Using the remarkably precise observations of Tycho Brahe, Johannes Kepler discovered three mathematical laws of planetary motion: planets move in ellipses with the Sun at one focus; a planet sweeps out equal areas in equal times; and the square of a planet's orbital period is proportional to the cube of its distance from the Sun.
Reputable source - c. 1610–1638History of Physics
Galileo and Experimental Physics
The Italian scientist Galileo Galilei insisted that nature be studied through careful observation and experiment rather than the authority of ancient philosophers. He studied falling bodies and the motion of pendulums, and turned the newly invented telescope on the heavens, discovering moons around Jupiter and the phases of Venus — evidence for a Sun-centered cosmos that brought him into conflict with the Church.
Reputable source Descartes and Analytic Geometry
In an appendix to his Discourse on Method (1637), the French philosopher and mathematician René Descartes fused algebra and geometry. By pinning points to numbers with coordinates — the x and y axes we still call Cartesian — he showed that geometric shapes could be written as equations and equations drawn as curves.
Reputable sourcePascal, Fermat, and the Mathematics of Chance
Asked how to divide the stakes of an interrupted gambling game, the French mathematicians Blaise Pascal and Pierre de Fermat worked out the answer in a famous 1654 exchange of letters — and in doing so laid the foundations of probability theory, a rigorous mathematics of uncertainty where none had existed before.
Reputable source · 2 sources- 1665–1666Pandemics Through History
The Great Plague of London
The last great outbreak of bubonic plague in England struck London in 1665, killing roughly a quarter of the city's population within eighteen months. The wealthy fled to the countryside while the poor bore the brunt; the epidemic finally faded the following year, around the time of the Great Fire of London.
Primary source - 1656–1690History of Physics
Huygens, the Pendulum Clock, and the Wave of Light
The Dutch scientist Christiaan Huygens invented the pendulum clock in 1656, giving the world its first accurate timekeeper, and worked out the mathematics of pendulums and circular motion. In his Treatise on Light he argued that light travels as a wave, explaining reflection and refraction — a direct challenge to Newton's view that light was a stream of particles.
Reputable source - c. 1665–1684History of Mathematics
The Invention of Calculus
In the late 17th century, Isaac Newton in England and Gottfried Leibniz in Germany independently developed the calculus — the mathematics of continuous change, of rates and areas and infinitesimals. A bitter dispute erupted over who had done it first, but the tool they created was the same.
Reputable source Newton's Laws and Universal Gravitation
In his Principia Mathematica (1687), Isaac Newton set out three laws of motion and the law of universal gravitation, showing that the same force that makes an apple fall also holds the Moon and planets in their orbits. Using the calculus he had invented, he unified terrestrial and celestial mechanics into a single system.
Reputable source- 1720–1722Pandemics Through History
The Great Plague of Marseille
In May 1720 a merchant ship from the plague-ridden eastern Mediterranean, the Grand-Saint-Antoine, brought bubonic plague to the great French port of Marseille. Despite quarantine rules its cargo was unloaded, and the disease exploded through the city, killing about 1,000 people a day at its peak — roughly half of Marseille's population, and around 100,000 in the surrounding region.
Reputable source Variolation: The First Inoculation
Long before vaccination, people in Asia, Africa, and the Ottoman world practised 'variolation' — deliberately infecting a healthy person with material from a mild case of smallpox to induce lifelong immunity. In 1721 the practice reached the West on two fronts: Lady Mary Wortley Montagu, who had seen it in Constantinople, had children inoculated in England, while in Boston the enslaved African Onesimus described the technique to Cotton Mather, who promoted it during an outbreak.
Reputable source- 18th centuryHistory of Mathematics
Euler and the Age of Analysis
The Swiss mathematician Leonhard Euler was the most prolific in history, producing work in nearly every field of mathematics even after going blind. He gave us much of the notation still in use — the symbols e, i, and the function notation f(x), and he popularized π — and his identity linking them is often called the most beautiful equation in mathematics.
Reputable source Coulomb's Law of Electric Force
In 1785 the French physicist Charles-Augustin de Coulomb used a delicate torsion balance to measure the force between electric charges. He found that it follows an inverse-square law, just like gravity: the force weakens with the square of the distance between the charges.
Reputable sourceJenner and the First Vaccine
The English physician Edward Jenner tested a folk observation that milkmaids who caught mild cowpox never got smallpox. In 1796 he deliberately inoculated a boy with cowpox and then showed he was immune to smallpox. He called the method 'vaccination,' from the Latin vacca, for cow.
Reputable source- 1796Medicine
Jenner's smallpox vaccine
Edward Jenner showed that inoculation with cowpox protected against smallpox — coining "vaccine" from the Latin for cow.
Reputable source Volta and the Electric Battery
In 1800 the Italian physicist Alessandro Volta built the first electric battery — the 'voltaic pile,' a stack of alternating copper and zinc discs separated by brine-soaked cloth. For the first time it produced a steady, continuous electric current, rather than the fleeting sparks of static electricity.
Reputable source- 1801–1803History of Physics
Young and the Wave Nature of Light
Newton had held that light was a stream of particles, but around 1801 the English polymath Thomas Young challenged him. In his famous double-slit experiment, Young passed light through two narrow slits and saw it form an interference pattern of bright and dark bands — behaviour possible only if light travels as a wave. He even measured the wavelengths of different colours.
Reputable source - the 1820sHistory of Physics
Oersted, Ampère, and Electromagnetism
In 1820 the Danish scientist Hans Christian Oersted noticed that a compass needle twitched near a wire carrying an electric current — the first proof that electricity and magnetism are linked. Within weeks the French physicist André-Marie Ampère worked out the mathematical laws of the forces between currents, founding the science he named 'electrodynamics.'
Reputable source Carnot and the Science of Heat
In 1824 the young French engineer Sadi Carnot, trying to understand why steam engines waste so much of their fuel, worked out the fundamental limits on turning heat into work. His idealized 'Carnot engine' showed that no engine can be perfectly efficient, and that the best possible efficiency depends only on the temperature difference the engine works across.
Reputable source- 1820s–1830sHistory of Mathematics
Non-Euclidean Geometry
For two thousand years mathematicians had tried in vain to prove Euclid's parallel postulate. In the early 19th century, Gauss, Bolyai, and Lobachevsky realized it could not be proved — and that entirely consistent geometries exist in which it is false, describing curved rather than flat space.
Reputable source Faraday and Electromagnetic Induction
A self-taught former bookbinder's apprentice, Michael Faraday became one of the greatest experimenters in history. In 1831 he discovered electromagnetic induction — that a changing magnetic field generates an electric current — and imagined space as filled with invisible lines of 'force,' or fields.
Reputable source- October 16, 1846Medicine
The first public surgery under ether
At Massachusetts General Hospital, dentist William Morton demonstrated ether anesthesia during surgery — later called "Ether Day."
General source - 19th centuryPandemics Through History
Cholera and the Age of Sanitation
As industrial cities swelled with crowded, filthy slums, cholera — a bacterial disease spread through water and food contaminated with human waste — erupted in a series of deadly pandemics that circled the globe from the 1810s onward. It could kill a healthy person within hours through catastrophic dehydration.
Reputable source - 1840s–1850sHistory of Physics
Energy and the Laws of Thermodynamics
As steam power drove industry, physicists worked out the laws governing heat, work, and energy. James Joule showed that heat and mechanical work are interchangeable forms of energy; William Thomson (Lord Kelvin), Rudolf Clausius, and others established that energy is conserved — never created or destroyed — and that heat always flows from hot to cold, a one-way process captured by the new idea of entropy.
Reputable source John Snow and the Birth of Epidemiology
When a violent cholera outbreak killed hundreds in London's Soho in 1854, the physician John Snow mapped the deaths and traced nearly all of them to a single public water pump on Broad Street. Persuading officials to remove the pump handle, he helped end the outbreak — and made his case that cholera spread through contaminated water, not 'bad air.'
Peer-reviewed- 1860sMedicine
Pasteur proves germ theory
Louis Pasteur's experiments showed microorganisms cause fermentation and disease — not spontaneous generation — and led to pasteurization.
General source - the 1860sHistory of Physics
Maxwell's Equations: Light Unified
Building on Faraday's fields, James Clerk Maxwell captured all of electricity and magnetism in a set of elegant equations. They revealed something astonishing: electric and magnetic fields can ripple through space as waves travelling at the speed of light — so light itself is an electromagnetic wave. Maxwell predicted a whole spectrum of such waves beyond the visible.
Reputable source - 1865Medicine
Lister introduces antiseptic surgery
Joseph Lister used carbolic acid to sterilize wounds and instruments, drastically cutting deaths from post-surgical infection.
Primary source - 1860s–1880sPandemics Through History
Germ Theory: Pasteur and Koch
For most of history, disease was blamed on bad air or imbalances in the body. In the 1860s the French chemist Louis Pasteur showed that microscopic organisms cause fermentation and disease, and developed vaccines for anthrax and rabies. In the 1880s the German physician Robert Koch proved that specific microbes cause specific diseases, identifying the bacteria behind anthrax, tuberculosis, and cholera.
Reputable source - 1870s–1890sHistory of Mathematics
Cantor and the Infinite
The German mathematician Georg Cantor dared to treat infinity as a precise mathematical object. Founding set theory, he proved that some infinities are larger than others — that the infinity of the real numbers is greater than the infinity of the counting numbers — a result so startling that many contemporaries rejected it.
Reputable source · 2 sources Tuberculosis: The White Plague
Tuberculosis — the 'white plague' — was the leading cause of death in 19th-century Europe and North America, killing perhaps one in seven people. On 24 March 1882 Robert Koch announced to a Berlin audience that he had identified the bacterium that causes it, Mycobacterium tuberculosis, proving that TB was infectious rather than hereditary.
Reputable sourceThe Michelson–Morley Experiment
Physicists believed light waves travelled through an invisible medium filling all space, the 'ether.' In 1887 Albert Michelson, working with Edward Morley, used the exquisitely sensitive interferometer he had invented to measure the speed of light as the Earth moved through this supposed ether. They found the speed of light unchanged by the Earth's motion — no sign of the ether at all.
Reputable source- 1889–1890Pandemics Through History
The Russian Flu: The First Modern Pandemic
In 1889 a wave of influenza spread out of Central Asia and swept the globe in a matter of months, carried along the new networks of railways and steamships. The 'Russian flu' reached across Europe and the Atlantic to the Americas, killing about a million people and striking down key workers and public figures.
Reputable source - late 19th centuryPandemics Through History
The Cause of Plague Revealed
As a new plague pandemic spread out of Asia, scientists finally identified the culprit behind history's great plagues: the bacterium Yersinia pestis, carried by fleas that live on rats and other rodents. The mystery that had terrified humanity for over a thousand years was solved.
Reputable source Röntgen Discovers X-rays
In 1895 the German physicist Wilhelm Conrad Röntgen, experimenting with electrical discharges in vacuum tubes, noticed a mysterious new kind of radiation that could pass through flesh and photograph the bones of his hand. He called them 'X-rays,' for their unknown nature.
Reputable source- November 1895Medicine
Röntgen discovers X-rays
Wilhelm Röntgen detected a new kind of ray that could image bones through flesh — earning the first Nobel Prize in Physics.
Reputable source - 1896–1898History of Physics
Radioactivity: Becquerel and the Curies
In 1896 Henri Becquerel found that uranium gives off penetrating rays all on its own. Marie and Pierre Curie took up the mystery, coining the word 'radioactivity' and isolating two new radioactive elements, polonium and radium. The rays, they showed, came from within the atom itself.
Reputable source The Discovery of the Electron
Studying the mysterious cathode rays that glowed inside evacuated glass tubes, the British physicist J. J. Thomson showed in 1897 that they were streams of tiny negatively charged particles far smaller than any atom. He had discovered the electron — the first subatomic particle — proving that the atom, long thought indivisible, was not the smallest thing in nature.
Reputable sourceMalaria and the Mosquito
For millennia malaria's cause was a mystery — its very name means 'bad air.' On 20 August 1897, working in India, the British doctor Ronald Ross found malaria parasites inside a mosquito that had fed on an infected patient, proving that the disease is spread by mosquito bites. He won the Nobel Prize in 1902.
Reputable sourcePlanck and the Birth of the Quantum
Trying to explain the colours of light glowing from hot objects, the German physicist Max Planck was forced in 1900 to a radical assumption: that energy is not continuous but comes in tiny discrete packets he called 'quanta.' He thought it a mathematical trick, but it was the seed of a revolution.
Reputable sourceYellow Fever and the Mosquito
Yellow fever terrified port cities and doomed early attempts to build the Panama Canal. In 1900 a U.S. Army board led by Major Walter Reed, testing the theory of the Cuban doctor Carlos Finlay, proved through human experiments that mosquitoes transmit the disease. Mosquito-control campaigns then swiftly cleared yellow fever from Havana and, later, the Panama Canal Zone.
Reputable sourceEinstein and the Photoelectric Effect
In 1905 the young Albert Einstein proposed that light itself comes in quanta — particle-like packets later called photons. This explained the puzzling photoelectric effect, in which light knocks electrons out of metal only if its colour (frequency) is high enough, no matter how bright it is.
Reputable sourceEinstein's Special Relativity
In his 'miracle year' of 1905, Einstein published the special theory of relativity, showing that the speed of light is the same for all observers and that space and time are not absolute but relative to the observer's motion. From it came the most famous equation in science, E = mc², linking mass and energy.
Reputable sourceRutherford and the Nuclear Atom
In 1911, from experiments firing alpha particles at thin gold foil, Ernest Rutherford deduced that the atom is mostly empty space, with nearly all its mass and positive charge packed into a tiny central 'nucleus.' Later he became the first to deliberately split a nucleus, transmuting nitrogen into oxygen.
Reputable sourceBohr's Quantum Atom
In 1913 the Danish physicist Niels Bohr fused Rutherford's nuclear atom with Planck's quanta. He proposed that electrons can orbit the nucleus only in certain fixed energy levels, jumping between them by absorbing or emitting a quantum of light — which explained, at last, the precise colours of light emitted by hydrogen.
Reputable sourceEinstein's General Relativity
In 1915 Einstein completed his general theory of relativity, a radical new theory of gravity. Mass and energy, he showed, curve the very fabric of spacetime, and what we feel as gravity is objects following those curves. When starlight was seen bending around the Sun during a 1919 eclipse, exactly as predicted, Einstein became world-famous overnight.
Reputable source- 1918–1919Pandemics Through History
The 1918 Influenza Pandemic
As the First World War ended, a ferocious strain of H1N1 influenza swept the world in successive waves. Spread by wartime troop movements and censored by governments (giving it the misleading name 'Spanish flu'), it infected about a third of the global population and killed at least 50 million people — unusually, many of them young and healthy adults.
Reputable source - 1921–22Medicine
Insulin saves diabetics
Banting and Macleod's team isolated insulin; a dying diabetic teenager recovered within days of the first injections.
Reputable source - 1925–1927History of Physics
The Quantum Mechanics Revolution
In the mid-1920s a generation of young physicists built quantum mechanics into a full theory. Werner Heisenberg framed it in terms of matrices and his 'uncertainty principle' — that a particle's position and momentum cannot both be known exactly — while Erwin Schrödinger described particles as spreading waves. The new physics was probabilistic: it predicted only the odds of outcomes, and the act of measurement changed what was measured.
Reputable source · 2 sources Penicillin and the Antibiotic Era
In 1928 the Scottish bacteriologist Alexander Fleming returned to his London lab to find that a mould had contaminated a bacterial culture and killed it. The mould, Penicillium, yielded the first true antibiotic — penicillin. Developed into a usable drug by Howard Florey and Ernst Chain in the early 1940s, it began saving lives during the Second World War.
Reputable source- 1928Medicine
Fleming discovers penicillin
Alexander Fleming noticed a mold killing bacteria on a forgotten petri dish — the first antibiotic. Its Nobel came in 1945.
Reputable source The Expanding Universe
Applying Einstein's general relativity to the cosmos, physicists found the universe could not be static. In 1929 the astronomer Edwin Hubble showed that distant galaxies are all rushing away from us, and the farther they are the faster they recede — evidence that space itself is expanding. Run backward, the expansion implied the universe began in a hot, dense state, the idea that became the Big Bang.
Reputable source- 1928–1932History of Physics
Dirac, Antimatter, and the Positron
In 1928 the British physicist Paul Dirac wrote an equation uniting quantum mechanics with special relativity to describe the electron. Strangely, it also predicted a mirror-image particle with opposite charge — antimatter. When the 'positron,' an anti-electron, was found in cosmic rays in 1932, Dirac's prediction was spectacularly confirmed.
Reputable source Gödel's Incompleteness Theorems
As mathematicians sought to place all of mathematics on a complete and certain logical foundation, the young Austrian logician Kurt Gödel proved, in 1931, that this was impossible: in any consistent formal system rich enough for arithmetic, there are true statements that can never be proved within it.
Reputable sourceChadwick Discovers the Neutron
In 1932 the British physicist James Chadwick discovered the neutron — a particle in the atomic nucleus with almost the same mass as a proton but no electric charge. It completed the basic picture of the atom: a nucleus of protons and neutrons surrounded by electrons.
Reputable sourceTuring and the Birth of Computation
In 1936 the English mathematician Alan Turing, tackling a deep problem in logic, devised an abstract 'machine' that could carry out any computation by following simple rules — the Turing machine. In doing so he defined what it means for something to be computable and laid the theoretical foundation of the computer.
Reputable source- 1938–1945History of Physics
Nuclear Fission and the Atomic Age
In late 1938 the chemists Otto Hahn and Fritz Strassmann, with the physicists Lise Meitner and Otto Frisch, showed that bombarding uranium with neutrons splits its nucleus in two — 'nuclear fission' — releasing enormous energy and more neutrons that can split further nuclei in a chain reaction. Within a few years this led to nuclear reactors and the atomic bomb.
Reputable source The Transistor
In 1947 John Bardeen, Walter Brattain, and William Shockley at Bell Labs invented the transistor — a tiny switch and amplifier made from semiconductor crystals, working through the quantum behaviour of electrons in solids. It could do the job of a bulky, hot, fragile vacuum tube in a fraction of the space.
Reputable source- 1940sHistory of Physics
Quantum Electrodynamics
In the late 1940s Richard Feynman, Julian Schwinger, and Shin'ichirō Tomonaga built quantum electrodynamics (QED), a complete quantum theory of how light and matter interact. Feynman's intuitive diagrams tamed its fearsome mathematics, and its predictions matched experiment to more decimal places than any theory before.
Reputable source - April 1953Medicine
The DNA double helix
Watson and Crick published the structure of DNA in Nature — a double helix whose base-pairing suggested how genes copy themselves.
Peer-reviewed Polio and the Vaccine
In the first half of the 20th century, poliomyelitis became a terror of the summer, striking mainly children under five and leaving many with irreversible paralysis; some could breathe only inside mechanical 'iron lungs.' Safe and effective vaccines introduced from the 1950s brought the epidemics under control, and a global eradication campaign launched in 1988 has since cut polio cases by more than 99%, from an estimated 350,000 a year to a mere handful.
Reputable source- 1955Medicine
The polio vaccine
Jonas Salk's inactivated polio vaccine was declared safe and effective after a massive field trial, as epidemics peaked worldwide.
Reputable source · 2 sources - 1957 & 1968Pandemics Through History
The Asian and Hong Kong Flu Pandemics
Two influenza pandemics struck in the mid-20th century. In 1957 a new H2N2 virus — the 'Asian flu' — emerged in East Asia and spread worldwide, killing over a million people. In 1968 a related H3N2 virus, the 'Hong Kong flu,' did much the same. Faster vaccine production and antibiotics for secondary infections helped keep their tolls well below that of 1918.
Peer-reviewed The Laser
In 1960 the first working laser was built, based on the maser–laser principle developed by Charles Townes and others from Einstein's 1917 idea of 'stimulated emission.' A laser makes atoms release light in perfect step, producing an intense, pure, tightly focused beam unlike any natural light.
Reputable sourceMeasles and the Vaccine
Measles is one of the most contagious diseases known, and for most of history it was a near-universal disease of childhood that killed millions. Before a vaccine, major epidemics every few years caused an estimated 2.6 million deaths a year worldwide. A successful vaccine, licensed in 1963, and decades of immunization have since cut measles deaths dramatically.
Reputable sourceThe Cosmic Microwave Background
In 1965 Arno Penzias and Robert Wilson, testing a radio antenna, found a faint hiss of microwaves coming from every direction in the sky. They had detected the cosmic microwave background — the cooled afterglow of the hot, dense early universe, released some 380,000 years after the Big Bang.
Reputable source- December 1967Medicine
The first heart transplant
Christiaan Barnard performed the first human-to-human heart transplant in Cape Town; the patient lived 18 days.
Reputable source - 1960s–1970sHistory of Physics
The Standard Model
Through decades of experiments in giant particle accelerators, physicists discovered that all matter is built from a small set of fundamental particles — quarks and leptons — interacting through forces carried by other particles. This 'Standard Model' of particle physics tied it all together into one of the most tested theories ever devised.
Reputable source The Eradication of Smallpox
Smallpox had killed hundreds of millions of people across history. Beginning in 1967, the World Health Organization led a global campaign of vaccination and case-tracking to hunt down every last outbreak. The final natural case occurred in 1977, and in 1980 the WHO declared smallpox eradicated.
Reputable source- May 8, 1980Medicine
Smallpox is eradicated
The World Health Assembly declared smallpox eradicated — the first and still only human disease wiped out, after a global vaccination campaign.
Reputable source - 1981–presentPandemics Through History
HIV/AIDS
In 1981 U.S. doctors reported clusters of rare infections in previously healthy young men — the first recognized cases of what became known as AIDS, caused by the human immunodeficiency virus (HIV). The virus spread into a global pandemic that has infected more than 80 million people and killed tens of millions.
Reputable source - 2002–2003Pandemics Through History
SARS: The First Epidemic of the 21st Century
In late 2002 a deadly new respiratory disease emerged in southern China. Caused by a coronavirus, SARS — severe acute respiratory syndrome — spread to some thirty countries in early 2003 via air travel, infecting around 8,000 people and killing about 800, roughly one in ten. An unprecedented global response contained it within months.
Reputable source - April 2003Medicine
The Human Genome Project is completed
An international consortium finished sequencing the ~3 billion base pairs of the human genome, two years ahead of schedule.
Reputable source - 2008Medicine
HIV's discoverers win the Nobel
Barré-Sinoussi and Montagnier were recognized for identifying HIV as the cause of AIDS — the basis for the tests and antiretrovirals that turned it treatable.
Reputable source The 2009 Swine Flu Pandemic
In 2009 a new H1N1 influenza virus — a 'swine flu' combining pig, bird, and human strains — emerged in North America and spread worldwide within weeks, prompting the WHO to declare the first flu pandemic in over 40 years. Unusually, it hit children and young adults hardest while largely sparing the elderly, who retained some immunity from older H1N1 strains. Global deaths were estimated in the hundreds of thousands.
Reputable source- 2010Medicine
IVF pioneer honored
Robert Edwards won the Nobel for developing in-vitro fertilization; an estimated millions of "test-tube" babies had been born since Louise Brown in 1978.
Reputable source The Higgs Boson
In 2012, scientists at CERN's Large Hadron Collider — the largest machine ever built — announced the discovery of the Higgs boson, a particle predicted almost 50 years earlier. The Higgs is tied to the field that gives other particles their mass, filling in the last missing piece of the Standard Model.
Reputable source- 2014–2016Pandemics Through History
The West Africa Ebola Epidemic
In 2014 the largest Ebola outbreak in history erupted in West Africa, spreading through Guinea, Liberia, and Sierra Leone. The virus, which causes a severe and often fatal haemorrhagic fever, infected more than 28,000 people and killed over 11,000 before the epidemic was declared over in 2016. Weak health systems and a slow initial response let it spiral.
Reputable source Gravitational Waves Detected
A century after Einstein predicted them, gravitational waves — ripples in spacetime itself — were directly detected for the first time. On 14 September 2015 the twin LIGO observatories caught the faint signal of two black holes colliding more than a billion light-years away, stretching space by less than the width of a proton as the wave passed through Earth.
Reputable source- 2019–presentPandemics Through History
COVID-19
A novel coronavirus, SARS-CoV-2, emerged in late 2019 and spread around the world within months. In March 2020 the WHO declared a pandemic; societies locked down, and the disease killed millions. In a historic scientific feat, safe and effective vaccines — including new mRNA vaccines — were developed and deployed within a year.
Reputable source - 2020Medicine
CRISPR gene editing wins the Nobel
Charpentier and Doudna won the Chemistry Nobel for CRISPR-Cas9, a precise and cheap tool for editing DNA.
Reputable source Mpox Goes Global
In 2022 mpox (formerly called monkeypox), a virus long confined mainly to parts of Africa, spread rapidly around the world for the first time. The WHO declared a global health emergency in July 2022; by the time it was lifted in 2023, more than 87,000 cases had been reported across some 110 countries. Targeted vaccination and behaviour change helped bring it under control.
Reputable source- 2023Medicine
mRNA vaccine science honored
Karikó and Weissman won the Medicine Nobel for the nucleoside-base modifications that made mRNA vaccines possible — deployed at scale against COVID-19.
Reputable source - the present dayThe Universe
The Universe Today
Some 13.8 billion years after the Big Bang, the observable universe holds up to two trillion galaxies and is still expanding — ever faster. We observe it all from a small rocky planet orbiting an ordinary star in one of those galaxies.
Reputable source · 2 sources