Fritz Zwicky predicted the existence of dark matter and neutron stars

Vera Rubin's research into galaxy rotation curves led to the discovery of dark matter

She discovered that stars on the outer edges of galaxies were orbiting much faster than expected based on visible matter alone, implying the presence of unseen mass exerting gravitational force. Without dark matter, the outer stars in galaxies would fly off into space instead of staying in orbit.

Dark stars are hypothetical stars that would have existed in the early universe

Primarily composed of visible matter, this celestial object would also contain a significant amount of dark matter that would annihilate with itself, converting its mass into energy. This energy would prevent the star from collapsing under its own gravity and from triggering nuclear fusion until its dark matter fuel was exhausted.

The hypothetical matter that neutron stars' cores may contain, including strange quarks

Models of the extreme pressures and energies in neutron stars suggest conditions resembling those believed to have existed within a fraction of a second after the Big Bang. In these environments, the quarks that make up protons and neutrons in trios may instead form pairs that combine to form one quantum object. (Some readers may experience a paywall.)

Albert Einstein's equations predicted black holes decades before their discovery

For nearly 50 years, scientists dismissed black holes as implausible oddities, despite solutions to the equations indicating their existence. But the 1970s discovery of intense X-rays from Cygnus X-1 and its massive hidden companion flipped the consensus.

One study suggests that dark matter may have originated from a dark Big Bang

A student-faculty team at Colgate University modeled the event as occurring months after the conventional Big Bang and determined the potential gravitational wave signal that would have been left behind. Future gravitational wave detectors are expected to be sensitive enough to observe this signal, if it exists.

Axions, a hypothetical subatomic particle, are a leading dark matter candidate

Among the possibilities for what makes up dark matter, some physicists champion axions, which could clump into galaxy-scale quantum states. These states would act as massive, unified superparticles that could explain the observational evidence for the universe's missing matter.

The 2011 Nobel Prize in physics was awarded for the discovery of dark energy

Through the use of standard candles—objects whose brightness is well-known—astronomers can determine distances by recognizing that the same phenomena will dim in predictable ways with increasing distance. By observing the same type of bright stellar explosion at various locations, Saul Perlmutter, Brian Schmidt, and Adam Riess identified that the universe's expansion was increasing.

Neutron stars, the remains of some massive stars after they explode in a supernova, are the densest directly observable objects in the universe.

Neutron star collisions may be the universe's gold factories

In his last broadcast interview, Stephen Hawking comments on detecting gravitational waves from the collision of neutron stars. The event may serve as a new means of measuring cosmological distances and help identify revisions to general relativity.

The discovery of antimatter came from addressing a prediction of negative energy

Combining the mathematics of quantum mechanics and special relativity, Paul Dirac came up with an equation that suggested a matter particle, such as an electron, could exist in four quantum states—two of which possessed negative energy. The solution came from realizing that the states referred to positive-energy antiparticles, whose charge is the opposite of that of their normal-matter equivalent.

The structure of the Bullet Cluster cannot be explained without dark matter

In gravitational lensing, mass bends spacetime, deflecting passing light rays. Instead of this deflection being strongest near the gas within galaxies, where visible matter is densest, lensing is strongest in front of the collided galaxies. This suggests the presence of clumps of dark matter that were not slowed by friction during impact.

How Robert Oppenheimer determined when neutron stars become black holes

Building on the work of Richard Tolman and George Volkoff, Oppenheimer reasoned that, once massive enough, a hypothetical, star-sized atomic nucleus would be unable to stave off gravitational collapse with neutron degeneracy—quantum pressure—alone. The mathematical model estimated the maximum mass of a non-rotating neutron star, known as the Tolman-Oppenheimer-Volkoff limit.

Quantum field theory overestimated the value of dark energy by 120 orders of magnitude

Physicists in the 1960s used their most successful theory to determine whether the accelerated expansion of the universe arises from quantum fluctuations in empty space. However, the mismatch between vacuum energy density and dark energy was so severe that it has been referred to as "the worst theoretical prediction in the history of physics."

The discovery of nuclear fission was facilitated by the discovery of the neutron

The discovery of the neutron provided scientists with a particle that could penetrate the nucleus and advance atomic physics. Otto Hahn was the sole Nobel recipient for the discovery of fission, despite collaborating with Lise Meitner and Fritz Strassmann.

The Standard Model reveals an underlying organization to the universe

Using the framework of quantum field theory, it structures all known particles into 12 matter particles, alongside five particles that carry three of the four fundamental forces. Although remarkably precise and predictive, it cannot yet explain gravity, dark matter, or dark energy.

Cecilia Payne-Gaposchkin discovered stars are mostly made of hydrogen and helium

At 25, her doctoral thesis challenged the then-common belief that stars were composed similarly to Earth. Several years later, Henry Norris Russell, who had initially dismissed her findings, independently made the same discovery and received credit for it.

A Belgian Catholic priest was the first to come up with the idea for the Big Bang

In 1931, Georges Lemaître presented his radical idea that the universe came from a “primeval atom,” challenging the long-held belief that the universe had always existed. Einstein initially dismissed Lemaître’s work as having “abominable” physical insight, only to accept it later.

Mapping the universe's 1.3 million quasars

Quasars form the core of active galaxies where supermassive black holes devour unimaginable amounts of matter. You can see a map of all 1.3 million of these objects with this 3D map. It was assembled with data from the Gaia spacecraft and shows how the spread of dark matter across space matches that described by the Cosmic Microwave Background.

Modified Newtonian dynamics revises gravity to eliminate the need for dark matter

Rather than imagining that an undiscovered particle is responsible for discrepancies in the orbits of stars and galaxies, MOND suggests that the mathematics underlying Newton's laws of gravity and force change beyond a certain scale. However, the suggested revisions struggle to explain relativistic effects involving gravity, including gravitational lensing and gravitational waves.

A look at the giants of quantum mechanics

German physicist Max Planck publishes his groundbreaking study of the effect of radiation on a “blackbody” substance, and the quantum theory of modern physics

Fermilab's ICARUS experiment is searching for hypothetical sterile neutrinos

Neutrinos are a group of three chargeless, lightweight particles that can transform into one another via a quantum mechanical phenomenon called neutrino oscillations. The rate of these oscillations can be determined by measuring the amount of each type at different distances, where data inconsistencies would suggest the existence of new physics.

Explaining pulsars, the cosmic clocks and lighthouses of the universe

As of 2023, over 3,000 of these rapidly rotating neutron stars have been discovered, which contain magnetic fields along which energized particles accelerate and emit light, including X-rays, gamma rays, visible light, and, most commonly, radio waves. The fastest of these, PSR J1748–2446ad, rotates 716 times per second, meaning its surface equator moves at about 24% the speed of light.

Italian physicist Enrico Fermi (1901–1954) on the Standard Model

"If I could remember the name of all these particles, I'd be a botanist."

Most of the observable universe's volume consists of voids and supervoids—enormous regions of space with little to no galaxies, stars, or light.

Explaining why solving the solar neutrino problem revealed that neutrinos could transform

Electron neutrinos are byproducts of the nuclear reactions within the sun's core. Based on the sun's energy output, scientists modeled reaction rates and predicted neutrino production, but the observed values were consistently one-third the predicted values. Experiments later showed that these neutrinos could change into other types on their way to Earth, causing the discrepancy.

Delays in the decay of unstable particles provide evidence for time dilation

Physicists used the muon half-life measured in labs to predict how many should reach detectors on Earth's surface after their production in collisions between atmospheric molecules and cosmic rays. Higher detection rates were consistent with a longer half-life due to slower movement through time.

The ultraviolet catastrophe is the infinite energy prediction of classical physics

When scientists first tried calculating the radiation emitted by a heated object, their assumption was that energy was equally distributed across wavelengths and produced infinite energy at low wavelengths. This contradicted observations, which showed near-zero energy intensity at those values.

While atoms are normally made of protons, neutrons, and electrons, exotic ones have been built with antimatter—alternate versions of normal matter that live for fractions of a second and are about a billion times as rare.

How fusion—which releases energy when two lighter atoms combine to form a heavier atom—differs from fission

The first image of a black hole was captured by creating an Earth-sized virtual observatory from a network of eight radio telescopes.

Planeterrellas create artificial auroras that mimic the atmospheric displays of light by setting up an electric field between two metal balls in a jar filled with a small amount of air.

Shooting stars, or meteors, are fragments of asteroids and comets that burn up as they enter Earth's atmosphere, creating streaks in the sky called meteor showers.

Clever Hans was a 1900s horse that was believed to be able to solve math equations, tell time, and read and comprehend German, until a psychology student discovered how he got his answers.

The history of many kitchen appliances involves unexpected discoveries and applications, including wartime radar turned hamster defroster and replacing an 'ice king' with heat-stealing boxes.

The idea for the Federal Reserve was conceived in secret in 1910—with bankers donning duck hunt gear for disguise while traveling to a remote country club on Georgia's Jekyll Island

Against his wishes, Albert Einstein's brain was removed before his cremation, and the pathologist responsible stored it for decades in mason jars within a beer cooler.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

One disco producer saw 'Star Wars' four times on its opening weekend and was so inspired that he recorded the album 'Star Wars and Other Intergalactic Funk,' which produced a chart-topping single.

Sunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil.

Before humans, the Soviet Union and the United States sent animals—including apes, dogs, and cats—to space during the Space Race.

Chaos theory—informally known as the butterfly effect—is the reason why weather forecasts are presented with probabilities rather than certainties.

The first horror movie is believed to be George Méliès' 1986 short 'The Haunted Castle,' which pioneered the use of special effects

The word 'jazz' evolved from 'jasm,' 19th-century American slang for 'energy'

Volcanic activity may have triggered the Black Death by spewing gases that led to crop failures in Europe, thus forcing the import of grain ships with plague-infested fleas.

Netflix profits when you're not watching, and its movies are designed that way—read a detail-rich critical essay exposing lesser-known Netflix takes

When caught in the mouths of cardinal fish, seed shrimp release glowing, bioluminescent chemicals, which alert predators of the cardinal fish, prompting the shrimp's ejection.

Existentialist writer Jean-Paul Sartre coined the famous phrase 'Hell is—other people' in his play 'No Exit'

Researchers believe the brain consolidates memories, processes emotions, and plans for the future during dream states

Georgia O'Keeffe's flower paintings are often assumed to be sexual, though the artist claimed she was simply interested in highlighting the beauty of flowers that most people neglect

Waves off the coast of Nazaré, Portugal, can reach over 100 feet and are caused by the area's deep underwater canyon geography