Under the Big Rip scenario, dark energy becomes strong enough to tear atoms apart

The universe's expansion is accelerating due to a mysterious force called dark energy

Astronomers discovered in the late 1990s that galaxies move apart faster over time, contradicting expectations that gravity should slow cosmic expansion. This prompted the revival of the "cosmological constant," a form of repulsive gravity first proposed by Albert Einstein.

Dark energy dominance represents the final era of the universe

As the universe expanded after the Big Bang, matter and energy diluted at different rates, with light once the most dense substance in the cosmos, followed by a period when matter was the most dense component. About five billion years ago, the density of dark energy was higher than that of both light and matter, which will continue to dilute.

If dark energy is weakening, the universe may collapse under its own gravity

Scientists using the Dark Energy Spectroscopic Instrument (DESI) analyzed light from 15 million galaxies and quasars to identify that the universe's accelerated expansion is diminishing. If this continues, the universe might reverse course and collapse in as little as 20 billion years.

Under a model of quintessence, the strength of dark energy should change over time

The theory suggests that dark energy permeates space and may drive the universe to expand or contract throughout its history. The model's flexibility allows it to fit every possible observed behavior of the universe's expansion, rendering it unfalsifiable and untestable.

Dark matter and dark energy make up 95% of the universe

Dark matter holds galaxies and other large-scale structures together through gravity, and dark energy drives the universe's accelerating expansion. While scientists do not know what either is made of, they see how these dark components affect the normal matter in the universe.

Due to dark energy, the universe is expected to end as a dark, sparse place

While the sun is expected to continue shining for another five billion years, the expansion of the universe will cause nearby stars and galaxies to become ever more distant, until they are too far to observe. Once the last old, red, dim stars cool into darkness after trillions of years, the universe will settle into a state of eternal, dark emptiness.

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.

Universes with stronger dark energy may be more common than ours

Research shows that while universes with slightly weaker dark energy form stars more efficiently, universes with stronger dark energy are statistically more common and can still support star formation. This challenges the anthropic logic that our universe must have ideal conditions for life because we exist to observe them.

The cosmic dark ages: before stars existed

The theories behind the Big Bang suggest the process of the universe beginning to the creation of stable, neutral atoms took just half a million years. But the transition from such atoms to star formation took surprisingly much longer, upwards of 100 million years. Why? This deep dive explores the science behind the unique physical composition of the so-called cosmic dark ages.

Collisions between cosmic rays and atmospheric particles dwarf particle accelerators

According to Einstein's model of gravity, confining immense energy into a sufficiently small region would warp space-time enough to create a black hole. If accelerators actually did create black holes, then trillions more would be produced daily in the atmosphere, where collisions are millions of times more energetic.

The heat death of the universe will mark the perceptive end of time

Under this scenario, all matter and energy will be scattered as far out as possible, with no stars left to produce measurable light between objects. With no way of observing changes or increasing the disorder of the universe further, events could not be distinguished from one another, and time would lose meaning.

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.

The theory of axiogenesis may explain the matter-antimatter asymmetry in our universe

Axiogenesis suggests that a theoretical particle field that evolved after the Big Bang may have spun like a marble around a wobbly “Mexican hat” energy landscape, producing excess matter over antimatter. This theoretical particle—the axion—may also make up dark matter, solving an additional mystery in astronomy.

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.

Why most atoms do not spontaneously break apart, despite protons repelling one another

At small scales, the strong nuclear force overwhelms electromagnetic repulsion between positively charged particles, keeping the nucleus intact. However, because the force's range is limited, it cannot provide the attraction needed to hold onto protons that are spread out across very large atomic nuclei.

Black holes can disrupt the formation of galaxies

A team of astronomers in Munich detected a gas cloud being stretched and torn apart by the supermassive black hole at the center of the Milky Way, preventing matter from coalescing into new stars. Energy released from siphoned gas produced warm winds that may also prevent surrounding gas from coalescing.

Our solar system is currently traveling through a 'dark matter hurricane'

The phenomenon refers to a stream of cosmic debris, including stars and dark matter, leftover from a small galaxy that passed too close to the Milky Way and was torn apart. There are over 30 such streams known in our galaxy, and the stream intersecting the solar system is predicted to continue to do so for millions of years.

Through gravitational redshift, light loses energy as it leaves a massive object

Just as one becomes exhausted as they walk up a flight of stairs against gravity, light is predicted to lose energy as it travels out of a gravitational well created by an object warping spacetime. This is observable through a decrease in the frequency of light toward longer, redder wavelengths.

Falling into a black hole would stretch and shred your body beyond recognition

As you approach a black hole, you initially feel weightless. Eventually, the difference in gravity between your feet and head would create a powerful stretching force that overcomes the molecular bonds in your body and pulls you apart.

Simulate the distribution of dark matter within a galaxy

By modifying the dark matter density at different distances from the center of a simulated galaxy, you can plot the resulting orbital speed of stars. Preset data enables you to replicate astrophysicists' work in determining the dark matter concentration that best fits observed structures.

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.

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

Differential rotation and density waves create the arms of spiral galaxies

Stars and gas near the galaxy's center complete an orbit in less time than objects farther out. Pressure waves cause material to bunch, lagging behind stars and gas that orbit closer to the center and forming the arms.

Hawking radiation shows black holes slowly evaporate through quantum effects.

Hawking radiation is Stephen Hawking's theoretical prediction that black holes emit radiation and eventually evaporate. Applied to known black holes, their radiation is so weak that it would take vastly longer than the current age of the universe for them to disappear.

How string theory explains gravity on the quantum scale, but may be untestable

Combining the general theory of relativity with quantum field theory creates nonsensical mathematical outcomes, such as probabilities of infinity. These are resolved by treating particles as vibrating strings rather than points of matter. However, probing the scale of these strings to validate the theory requires technology equivalent to a particle accelerator the size of the solar system.

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.

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

Earth is constantly bombarded by material from space

Most of this matter is composed of small particles, with any smaller than 33 feet in diameter burning up in the atmosphere. Larger asteroids can reach the ground, and those larger than several thousand feet cause global damage, including earthquakes and tsunamis.

According to the physics of black holes, our 4D reality may be a hologram—a projection of information coded on a 2D surface on the edge of the universe.

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

While the sun's gravity keeps the planets in orbit, their gravity also pulls on the sun, causing it and everything else in the solar system to orbit around a mutual balance point called the barycenter—the true center of the solar system.

Stars appear to twinkle because turbulence in the motion of molecules in Earth's atmosphere causes light to bend and wiggle rapidly on its way to the surface—a phenomenon called scintillation.

After NASA's Voyager 1 captured Earth as a single pixel as it left the solar system in 1990, astronomer Carl Sagan used the image to reflect on humanity's fragility and the responsibility to protect 'the only world we've ever known.'

Larger animals like giraffes, elephants, and blue whales have developed a unique defense against cancer, a phenomenon known as Peto's Paradox

Discover the catastrophic consequences of a failure of the US electrical grid—something that is more likely than many Americans think.

Explore chaos in this simulation of two double pendulums, where small differences in the release angles produce wildly different outcomes.

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.

Astronauts have repaired genetic damage in space using CRISPR—a molecular tool that can make precise changes to DNA and is used in single-celled organisms to attack invasive viruses.

Apeirophobia is an overwhelming fear of living forever, perhaps stemming from the brain's inability to conceptualize an infinite life.

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.

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.

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.

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

A 2019 Facebook event called on attendees to "Storm Area 51, They Can't Stop All of Us," resulting in countless memes, the creation of a music festival, and eventually the arrests of those who did try to approach the area.

A vending machine run with Anthropic's AI went out of business after it was convinced to give away items for free and sell a video game console.

Poison ivy will likely become both larger and more resilient due to climate change.

Massive 3D printers have been used to build homes by stacking layers of 'concrete toothpaste,' a fire-resistant material that effectively insulates against outside noise.

For centuries, Niagara Falls has been a magnet for daredevils seeking to conquer one of nature's most powerful wonders, with its 200-foot drop and water rushing at 32 feet per second with 280 tons of force.

To reduce wrinkles in clothing, research recommends gentle wash cycles with more water and tumble drying with smaller loads and longer times.

Iran's Revolutionary Guard Corps is independent of Iran's regular army and is one of the most powerful and influential military-political organizations in the Middle East.