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.
Only 5% of the Universe is made of normal “stuff” like we are. Could there be dark matter or dark energy life, or even aliens, out there?
When we divide matter into its fundamental, indivisible components, are those particles truly point-like, or is there a finite minimum size?
The primary causes of global climate change are all due to human activity. Adding aerosols to our atmosphere only exacerbates the problem.
The ultimate multi-messenger astronomy event would have gravitational waves, particles, and light arriving all at once. Did that just occur?
A young, nearby, massive star, whose protoplanetary disk appears perfectly edge-on, was just viewed by JWST, with staggering implications.
If we wish to tackle the very real problems society faces, we require expert-level knowledge. Valuing it starts earlier than we realize.
Seeking life beyond the Solar System, we first look to the closest star systems with Earth-like planets. Here’s why that’s not good enough.
Our Moon is full of craters, basins, and ancient lava flows. But two large lunar Grand Canyons have the same origin: a single, giant impact.
There are only four super star clusters in all the Local Group: rarities today. Here’s what the youngest, the just-discovered N79, shows us.
Here in our Universe, both normal and dark matter can be measured astrophysically. But only normal matter can collapse. Why is that?
With a flurry of threats to scientists, science funding, and health policy, the USA now faces a crisis reminiscent of Soviet-era Lysenkoism.
First discovered in the mid-1960s, no cosmic signal has taught us more about the Universe, or spurred more controversy, than the CMB.
From LIGO, there weren’t enough neutron star-neutron star mergers to account for our heavy elements. With a JWST surprise, maybe they can.
It’s the ultimate game of cosmic “cover up,” as the dimming occurs when a circumbinary disk from a nearby star passes in front of T Tauri North.
Matter is made up largely of atoms, where atomic nuclei can contain up to 100 protons or more. But how were the heaviest elements made?
Cosmic inflation, proposed back in 1980, is a theory that precedes and sets up the hot Big Bang. After thorough testing, is it still valid?
Scientists just viewed one of the tiniest, most isolated, lowest-mass galaxies ever found with JWST. Despite all odds, it’s still growing.
New telescopes, radio dishes, and gravitational wave detectors are needed for next-generation science. Will the USA lead the way?
The Ring Nebula, a bright, circular planetary nebula, is created by a dying Sun-like star. After centuries, we finally know its true shape.
Since mid-2022, JWST has been showing us how the Universe grows up, from planets to galaxies and more. So, what’s its biggest find of all?
A proton is the only stable example of a particle composed of three quarks. But inside the proton, gluons, not quarks, dominate.
The discovery of ultra-bright, ultra-distant galaxies was JWST’s first big surprise. They didn’t “break the Universe,” and now we know why.
Seven years ago, an outburst in a distant galaxy brightened and faded away. Afterward, a new supermassive black hole jet emerged, but how?
Here in our Universe, stars shine brightly, providing light and heat to planets, moons, and more. But some objects get even hotter, by far.
Most stars shine with properties, like brightness, that barely change at all with time. The ones that do vary help us unlock the Universe.
The electromagnetic force can be attractive, repulsive, or “bendy,” but is always mediated by the photon. How does one particle do it all?
Many of us look at black holes as cosmic vacuum cleaners: sucking in everything in their vicinity. But it turns out they don’t suck at all.
There’s no upper limit to how massive galaxies or black holes can be, but the most massive known star is only ~260 solar masses. Here’s why.
In the year 2000, physicists created a list of the ten most important unsolved problems in their field. 25 years later, here’s where we are.
We see objects whose light only arrives just now. But we see them as they were in the past: when that now-arriving light was first emitted.