Search
Our mission is to answer the biggest questions of all, scientifically.
What is the Universe made of? How did it become the way it is today? Where did everything come from? What is the ultimate fate of the cosmos?
For most of human history, these questions had no clear answers. Today, they do. Starts With a Bang, written by Dr. Ethan Siegel, explores what we know about the universe and how we came to know it, bringing the latest discoveries in cosmology and astrophysics directly to you.
Read Less
with
Full Profile
Ethan Siegel is an award-winning PhD astrophysicist and the author of four books, including The Grand Cosmic Story, published by National Geographic.
Ask Ethan: What sets the size of the observable Universe?
For all we know, the cosmos could truly be infinite in scale. But the observable part of our Universe? It's finite, and its size is known.
The LIGO facilities in the U.S. are the most sensitive gravitational wave detectors in the world. Their future remains uncertain.
We used to think the Big Bang started it all. Then we realized that something else came before it, erasing everything that existed prior.
At "only" 25 meters in diameter, the Giant Magellan Telescope is the smallest of three current projects. That might make all the difference.
Using the newest large-scale structure data, a team of researchers announced a huge cosmic anisotropy in Nature. Too bad it's wrong.
Over 800,000 fireworks explode in under an hour in the world's largest fireworks shows. How do natural auroral displays compare in energy?
65 million years ago, a massive asteroid struck Earth, causing a mass extinction. Without advance warning, could anyone have spotted it?
With ~400 billion stars in the Milky Way and 6-20 trillion galaxies overall, that makes for a lot of stars. But not as many as you'd think.
The first one, NGC 1052-DF2, was mired in controversy. With four examples now, there only remains one possible escape. What does nature say?
Over 10 billion years in the past, an ultra-massive galaxy cluster lenses objects behind it. That has big implications for dark matter.
At 240 million light-years away, galaxy NGC 1277 hasn't formed new stars in over 10 billion years. Could it contain the first stars' ashes?
We live on Earth, orbiting the Sun, part of our Solar System, within the Milky Way. But what's our membership status on even larger scales?
Einstein's most famous equation is E = mc², which describes the rest mass energy inherent to particles. But motion matters for energy, too.
When it comes to the big question of our cosmic origins, inflation is our leading theory. But did string theory ultimately cause inflation?
Interstellar comet 3I/ATLAS has an ancient age, but not for the reason most commonly touted. These three lines of evidence are far stronger.
Globular clusters are some of the most ancient cosmic relics that still survive in our Milky Way today. Famed Terzan 5 isn't one of them.
With targets from all across the Universe, focusing a space telescope — with so many moving parts — is challenging, but doable. Here's how.
By probing the Universe on atomic scales and smaller, we can reveal the entirety of the Standard Model, and with it, the quantum Universe.
Despite their rarity, boron and beryllium can both be detected within white dwarf atmospheres. What does their presence and abundance imply?
When JWST opened its eyes, it spied a huge number of Little Red Dots. What we saw inside was a puzzle, but what's missing could solve it.
After a period of cosmic inflation came to an end, the hot Big Bang commenced. 13.8 billion years later, we arrived. Here's how we got here.