Ethan Siegel

Ethan Siegel

Theoretical astrophysicist and science writer

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.

black hole
All of the matter that we measure today originated in the hot Big Bang. But even before that, and far into the future, it'll never be empty.
planck temperature polarization
The hot Big Bang is often touted as the beginning of the Universe. But there's one piece of evidence we can't ignore that shows otherwise.
As we gain new knowledge, our scientific picture of how the Universe works must evolve. This is a feature of the Big Bang, not a bug.
most distant
The universe is filled with unlikely events, but it is also full of ways to fool ourselves.
A woman sits at a desk covered with tall stacks of papers, reviewing and pointing to documents as she conducts a purpose-driven peer review in a busy office setting.
Just because a paper passes peer review doesn't mean that what's written, or what the author asserts, is true. Here's why it still matters.
Multiplication table from 1 to 20, featuring pythagorean runs and perfect squares highlighted in yellow along the diagonal from top left (1) to bottom right (400).
It's not just an odd quirk of numbers that makes it true, but a deep mathematical insight that dates all the way back to Pythagoras.
LIGO Livingston
10 years ago, LIGO first began directly detecting gravitational waves. Now better than ever, it's revealing previously unreachable features.
ESO milky way
Questions about our origins, biologically, chemically, and cosmically, are the most profound ones we can ask. Here are today's best answers.
Two large Martian rocks with circular drill holes and light-colored dust are shown on a sandy, rocky surface. Part of a rover’s equipment, searching for traces of organics or signs of Mars life, is visible at the bottom of the image.
The red planet, Mars, may once have been teeming with life, just as Earth is today. Finding "organics" on Mars, however, doesn't mean life.
A dense star field with dark, irregular dust clouds—where cosmic dust come from—obscures parts of the glowing stars in the Milky Way.
Dust is ubiquitous in the modern Universe, appearing in nearly all galaxies. But our cosmos was born dust-free. So where does it originate?
It's the origin of our entire observable Universe, but it's still not the very beginning of everything.
A dark, rocky planet orbits in space with the sun illuminating its edge, surrounded by stars and distant cosmic clouds.
The most common type of exoplanet is neither Earth-sized nor Neptune-sized, but in between. Could these haze-rich worlds house alien life?
Two identical, intricate, circular geometric patterns with symmetrical, multicolored lines and shapes are displayed side by side on a white background—each subtly reflecting the argument against theory of everything’s promise of perfect symmetry.
The Holy Grail of physics is a Theory of Everything: where a single equation describes the whole Universe. But maybe there simply isn't one?
Side-by-side comparison of the Pismis 24 nebula as seen by Hubble (top left) and JWST (bottom right), with an overlay highlighting image differences.
JWST isn't the first telescope to peer into this factory of star-birth some 5500 light-years away, but its views are the most educational.
A bright, circular blue and white object is centered against a black background, with a smaller red object to the lower left.
Going back to 1990, we hadn't even found one planet outside of our Solar System. As we close in on 6000, we now see many of them directly.
Abstract 3D geometric surface with intersecting translucent orange and brown planes, inspired by the amplituhedron theory of everything, set against a blurred orange background with white network lines.
Since even before Einstein, physicists have sought a theory of everything to explain the Universe. Can positive geometry lead us there?
Compton gamma-ray observatory deployment
Across all wavelengths of light, the Sun is brighter than the Moon. Until we went to the highest energies and saw a gamma-ray surprise.
An artist's rendering of the nasa jupiter spacecraft.
The Juno spacecraft, orbiting and imaging Jupiter since 2016, is still succeeding. Without a further extension, the mission now faces death.
An artist's impression of a cluster of stars.
With several seemingly incompatible observations, cosmology faces many puzzles. Could early, supermassive stars be the unified solution?
As we look to larger cosmic scales, we get a broader view of the expansive cosmic forest, eventually revealing the grandest views of all.