Big Bang Theory

Big Bang theory is the leading explanation for how our universe began. According to the theory, the entire universe began as a tiny singularity that went through an explosive expansion 13.8 billion years ago, gradually expanding into the cosmos we see today. Today, astronomers can detect an "echo" from the Big Bang in the cosmic microwave background, a phenomenon that can be detected with radio telescopes. Big Bang Theory is also the name of a popular CBS sitcom about scientists, where several real-life scientists and astronauts have appeared.

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Tracy Slatyer was searching for dark matter when she helped discover the Fermi bubbles, pictured here in an image combining visible light, X-rays and gamma rays.

Dark matter hunter who found unexpected, giant 'Fermi bubbles' wins $100,000 physics prize

By Rafi Letzter

Tracy Slatyer, known for hunting dark matter in our galaxy and discovering evidence of an ancient Milky Way explosion, has won a $100,000 prize funded by tech billionaires.

Astronomers discover South Pole Wall, a gigantic structure stretching 1.4 billion light-years across

By Adam Mann

Strands in the intergalactic web

Observations made with the European Southern Observatory’s Very Large Telescope in Chile have revealed for the first time that a star orbiting the supermassive black hole at the center of the Milky Way moves just as predicted by Einstein's theory of general relativity. Its orbit is shaped like a rosette and not like an ellipse as predicted by Newton's theory of gravity. This effect, known as Schwarzschild precession, had never before been measured for a star around a supermassive black hole. This artist's impression illustrates the precession of the star's orbit, with the effect exaggerated for easier visualization.

What's the most amazing thing about the universe?

By Paul Sutter

A few scant equations can explain a variety of phenomena in our universe, over vast gulfs of space and time. Here's a taste of just how powerful modern physics can be.

New measurements have allowed scientists to alter the Hubble Constant and change our perception of the expanding universe.

'Standard model' of cosmology called into question by new measurements

By Chelsea Gohd

An artist's interpretation of the Big Bang

What happened before the Big Bang?

By Paul Sutter

The Big Bounce theory was once thought impossible. But two physicists have just resurrected it.

A <a href="https://www.wolframphysics.org/visual-summary/img/visual-summary-darkmode-4k.jpg" target="_blank">visual summary of Wolfram's theory</a>.

Physicist Stephen Wolfram thinks he's on to a theory of everything, and wants help simulating the universe

By Tyler Wilde

Could the structure of the universe emerge from the repetition of a simple rule?

A Hubble Space Telescope image shows the Lagoon Nebula, part of the small portion of matter in the Milky Way that isn't made of dark matter.

A huge cloud of invisible particles seems to be missing from the Milky Way

By Rafi Letzter

A key signal for a certain kind of dark matter failed to turn up in a search throughout the Milky Way. Now scientists are disagreeing about what that means.

A view of the Perseus galaxy cluster from NASA's Chandra X-ray Observatory. Scientists studied this galaxy cluster for signs of ultra-low-mass particles that would help support string theory.

Astronomers test string theory using NASA's Chandra X-ray space telescope

By Samantha Mathewson

Astronomers have probed the Perseus galaxy cluster in search of an as-yet undetected particle that would help support string theory.

This radio image shows two jets shooting out of the center of Cygnus A, a galaxy not too far from our own. A new paper reports discovering a similar object in a much more distant, ancient galaxy. That galaxy has a bright, relatavistic jet emanating from its central supermassive black hole pointed at Earth, making it a blazar.

The universe may have been filled with supermassive black holes at the dawn of time

By Rafi Letzter

As the universe cooled in the era after the Big Bang, a supermassive black hole had already formed in the center of a galaxy, forming a giant engine of energy we can still see today.

Inflation stretched the tiny universe into a macroscopic size and turned cosmic energy into matter. But it likely created an equal amount of matter and antimatter. It's not clear why but the authors probe one theory that a phase transition after inflation led to a tiny bit more matter than anti-matter and also created cosmic strings which would produce slight ripples in space-time known as gravitational waves.

Ripples in space-time could explain the mystery of why the universe exists

By Yasemin Saplakoglu

A new study may help answer one of the universe's biggest mysteries.

A visualization of the filaments in the cosmic web. Simulation produced by the EAGLE project.

How dark is the cosmic web?

By Paul Sutter

A dark web ties the universe together. Now, we can see it.

The galaxy cluster Abell 1689 is famous for the way it bends light in a phenomenon called gravitational lensing. Study of the cluster has revealed secrets about how dark energy shapes the universe.

The problems with modern physics

By Paul Sutter

Physicists have certainly achieved a lot, but many mysteries about the universe remain.

An artist's impression of a quasar. New measurements of the universe's expansion have relied on the gravitational lensing of light from six quasars.

No One Can Agree How Fast Universe Is Expanding. New Measure Makes Things Worse.

By Adam Mann

We just might need new physics to get out of this mess.

An abstract image of axion strings, which may have made up the "axiverse."

The Universe May Be Flooded with a Cobweb Network of Invisible Strings

By Paul Sutter

What if I told you that our universe was flooded with hundreds of kinds of nearly invisible particles and that, long ago, these particles formed a network of universe-spanning strings?

There's a Giant Mystery Hiding Inside Every Atom in the Universe

By Rafi Letzter

No one really knows what happens inside an atom.

Mysterious 'Particle X17' Could Carry a Newfound Fifth Force of Nature, But Most Experts Are Skeptical

By Mara Johnson-Groh

It would rewrite the Standard Model of physics.

The Murchison Widefield Array (MWA) — a network of radio telescopes in the Australian outback — is scouring the skies for traces of neutral hydrogen, the last surviving molecule of the cosmic dark ages.

When Did the 'Dark Ages of the Universe' End? This Rare Molecule Holds the Answer.

By Brandon Specktor

Long ago, millions of years before the first star sparked to life, the entire universe was a sea of darkness.

A series of three photographs show a Dutch radio antenna as it unfolded from the Chinese lunar relay satellite, Queqiao.

Radio Telescope Unfurls 3 Antennas Beyond the Far Side of the Moon

By Meghan Bartels

In a quiet orbit around the far side of the moon, three radio antennas are now outstretched, craning for whispers from a mysterious period early in the universe's history.