Ethan Siegel

Ethan Siegel

A theoretical astrophysicist and science writer, host of popular podcast “Starts with a Bang!”

Ethan Siegel 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.

A dense field of stars and galaxies is visible against a black background, with some bright stars showing lens flares.
The COSMOS-Web survey is now complete, combining JWST and Hubble infrared data. Its spectacular views show us the Universe as never before.
Visualization of a section through the large-scale structure of the universe highlighting cosmic web patterns and distributions.
Since 1998, we've known our Universe isn't just expanding, but the expansion is accelerating. Could the Big Bang itself be the reason why?
graphene atoms
For millennia, diamonds were the hardest known material, but they only rank at #7 on the current list. Can you guess which material is #1?
A man in a suit holds up a Hurricane Dorian forecast map in an office, tracing the storm’s projected path and intensity over several southeastern U.S. states and the Bahamas—echoing the urgent clarity of a 1938 science manifesto defending democracy.
As democracy recedes and fascism rises in the USA and around the world in 2025, history provides a lesson in how science can fight fascism.
Illustration of a large particle accelerator facility underground, with scientists working and a city landscape above ground.
The laws of nature are almost perfectly symmetric between matter and antimatter, and yet our Universe is made ~100% of matter only. But why?
A repeating pattern of wireframe 3D geometric shapes intersected by diagonal yellow lines on a black background, evoking a physics break down of forms at the Planck scale.
There are limits to where physics makes meaningful predictions: beyond the Planck length, time, or energy. Here's why we can't go further.
Bright star at the center of a blue nebula radiates mass energy, surrounded by numerous smaller stars, with diffraction spikes visible from the brightest stars.
All stars shine due to an internal source of energy. Usually, it's nuclear fusion: converting mass into energy. What makes them most bright?
Photons come in every wavelength you can imagine. But one particular quantum transition makes light at precisely 21 cm, and it's magical.
You don't need to be a scientist or a philosopher for facts, reality, and the truth to matter. The alternative is simply known as bullshit.
An artist's rendering of an alien planet and a red star.
A Cambridge-based team claims to find molecules on an exoplanet that are only produced by life on Earth. Don't fall for the unfounded hype.
According to Stephen Hawking, spontaneously emitted radiation should cause all black holes to decay. But we've never seen it: not even once.
In all the known Universe, Earth is the only planet known to have native life. What should guide us in expanding humanity beyond our world?
particle physics destroy universe
Empty space itself, the quantum vacuum, could be in either a true, stable state or a false, unstable state. Our fate depends on the answer.
An astronaut stands proudly on the moon's surface near scientific equipment and a lunar lander, as the American flag waves in the background, symbolizing a pioneering USA nation.
After drastic cuts to the NIH, the FDA, the NSF, and the DOE, NASA science faces down its smallest budget ever. All of society will suffer.
black hole baby universe
Perhaps no existential question looms larger than that of our ultimate cosmic origins. At long last, science has provided the answers.
A vast view of deep space, captured in one of NASA's most important images, displays numerous galaxies of varying shapes and colors against a dark backdrop scattered with distant stars.
The Hubble Space Telescope, launched in 1990, was originally seen as a colossal mistake. This one image, taken in 1995, changed everything.
A person sits in front of a white backdrop, surrounded by a cosmic map with galaxies and celestial objects.
2hr 18mins
"Asking the question of, "Where did the entire universe come from?" is no longer a question for poets and theologians and philosophers. This is a question for scientists, and we have some amazing scientific answers to this question."
lab leak SARS-CoV-2
In theory, scientists could've produced a deadly virus that accidentally infected lab workers. In practice, we know that didn't happen.
uranium oxide oklo nuclear reactor
Planets can create nuclear power on their own, naturally, without any intelligence or technology. Earth already did: 1.7 billion years ago.
The spiral galaxy, surrounded by dim stars and interstellar dust, stands out against a dark background, shining brighter than astronomers once imagined.
The most famous Hubble images show glittering stars and galaxies amidst the black backdrop of space. But more was captured than we realized.