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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Is there a pattern to the universe?

By Paul Sutter

For decades, cosmologists have wondered if the large-scale structure of the universe is a fractal — that is, if it looks the same no matter how large the scale.

Theoretical physicist and science popularizer Brian Greene presenting at the World Science Festival.

Black holes, string theory and more: Q&A with physicist Brian Greene

By Mike Wall

Space.com caught up with Greene to discuss the importance of science education, why black holes are so interesting and whether a "theory of everything" breakthrough could be on the horizon.

A top view of the equipment used in the g-2 experiment at Fermilab. The experiment uses a muon beamline, electronic racks and superconducting magnetic storage ring cooled to minus 450 degrees Fahrenheit (minus 267 degrees Celsius) to study the wobble of muons.

A tiny, wobbling muon just shook particle physics to its core

By Ben Turner

But this may not be the end of the story.

Artist impression of the Big Bang, with particles firing away from a bright core.

The 1st few seconds of the Big Bang: What we know and what we don't

By Paul Sutter

Believe it or not, physicists are attempting to understand the universe when it was only a handful of seconds old.

Diagram of the evolution of the universe from the inflation (left) to the present (right). The reconstruction method winds back the evolution from right to left on this illustration to reproduce the primordial density fluctuations from the current galaxy distribution.

Cosmologists create 4,000 virtual universes to solve Big Bang mystery

By Stephanie Pappas

Cosmologists simulated 4,000 versions of the universe in order to understand what its structure today tells us about its origins.

Scientists have found the first evidence for a rare type of Higgs boson decay.

Scientists find first evidence of rare Higgs boson decay

By Chelsea Gohd

Scientists have spotted the first evidence of a rare Higgs boson decay, expanding our understanding of the strange quantum universe.

In this all-sky map from Planck, a European Space Agency mission, the towers of fiery colors represent dust in the galaxy and beyond that has been polarized.

Twisted light from the beginning of time could reveal brand-new physics

By Mara Johnson-Groh

A new study on the rotation of the universe's first light could suggest physicists need new rule-breaking subatomic particles

Mysterious 'kick' just after the Big Bang may have created dark matter

By Paul Sutter

A mysterious "kick" in the early universe may have produced more matter than antimatter. And that imbalance may have also led to the creation of dark matter, researchers now say.

Scientists have taken a fresh look at the universe to determine its age, settling old debates.

Astronomers reevaluate the age of the universe

By Chelsea Gohd

Scientists have taken a fresh look at the observable (expanding) universe and have estimated that it is 13.77 billion years old (plus or minus 40 million years).

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.