Ethan Siegel
A theoretical astrophysicist and science writer, host of popular podcast "Starts with a Bang!"
Ethan Siegel is a Ph.D. astrophysicist and author of "Starts with a Bang!" He is a science communicator, who professes physics and astronomy at various colleges. He has won numerous awards for science writing since 2008 for his blog, including the award for best science blog by the Institute of Physics. His two books "Treknology: The Science of Star Trek from Tricorders to Warp Drive" and "Beyond the Galaxy: How humanity looked beyond our Milky Way and discovered the entire Universe" are available for purchase at Amazon. Follow him on Twitter @startswithabang.
The big question isn’t whether the Universe is expanding at 67 or 73 km/s/Mpc. It’s why different methods yield such different answers.
The original principle of relativity, proposed by Galileo way back in the early 1600s, remains true in its unchanged form even today.
Most stars in the Universe are located in big, massive, Milky Way-like galaxies. But most galaxies aren’t like ours at all.
The largest particle accelerator and collider ever built is the Large Hadron Collider at CERN. Why not go much, much bigger?
More than any other equation in physics, E = mc² is recognizable and profound. But what do we actually learn about reality from it?
The Michelson-Morley experiment of 1887, despite expectations, revealed a null result: no effect. The implications were revolutionary.
For centuries, Newton’s inverse square law of gravity worked beautifully, but no one knew why. Here’s how Einstein finally explained it.
From size to mass to density and more, each world in our Solar System is unique. When we compare them, the results are truly shocking.
Today, the Large Hadron Collider is the most powerful particle physics experiment in history. What would a new, successor collider teach us?
Dark matter’s hallmark is that it gravitates, but shows no sign of interacting under any other force. Does that mean we’ll never detect it?
Peaking on the night of August 11/12, up to 100 bright meteors per hour will be visible. Here’s how to make the most of it.
Earth, the only rocky planet with a large, massive satellite, is greatly affected by the Moon. Destroying it would cause 7 major changes.
Straddling the bounds of science and religion, Newton wondered who set the planets in motion. Astrophysics reveals the answer.
How do normal matter and dark matter separate by so much when galaxy clusters collide? Astronomers find the surprising, unexpected answer.
Even in the very early Universe, there were heavy, supermassive black holes at the centers of galaxies. How did they get so big so fast?
Often viewed as a purely theoretical, calculational tool only, direct observation of the Lamb Shift proved their very real existence.
In July of 2022, the first science images from JWST were unveiled. Two years later, it’s changed our view of the Universe.
A longstanding mismatch between theory and experiment motivated an exquisite muon measurement. At last, a theoretical solution has arrived.
The all-time record is Usain Bolt’s 9.58 seconds, set in 2009. What is the fastest time, ultimately, for an ideal human body?
The passage of time is something we all experience, as it takes us from one moment to the next. But could it all just be an illusion?
From inside our Solar System, zodiacal light prevents us from seeing true darkness. From billions of miles away, New Horizons finally can.
Adams was infamously scooped when Neptune was discovered in 1846. His failure wasn’t the end, but a prelude to a world-changing discovery.
It’s knowledgeable, confident, and behaves human-like in many ways. But it’s not magic that powers AI though; it’s just math and data.
For its 2-year science anniversary, JWST has revealed unprecedented details in “the Penguin and the Egg.” Here are the surprises inside.
As the Sun ages, it loses mass, causing Earth to spiral outward in its orbit. Will that cool the Earth down, or will other effects win out?
Just 13.8 billion years after the hot Big Bang, we can see objects up to 46.1 billion light-years away. No, this doesn’t violate relativity.
We know of stellar mass and supermassive black holes, but intermediate mass ones have long proved elusive. Until now.
The Bullet Cluster has, for nearly 20 years, been hailed as an empirical “proof” of dark matter. Can their detractors explain it away?
On a cosmic scale, our existence seems insignificant and inconsequential. But from another perspective, humans are completely remarkable.
The standard picture of our Universe is that it’s dominated by dark matter and dark energy. But this alternative is also worth considering.