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.

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.
An abstract animation of white, textured patterns symmetrically forming on a blue and black background evokes the mysterious dance of dark energy, subtly hinting at its weakening presence as if guided by the precision of DESI.
The Universe isn't just expanding; the expansion is accelerating. If different methods yield incompatible results, is dark energy evolving?
Two diagrams: the left shows a complex, circular, multicolored network; the right displays a theoretical physics diagram with labeled axes and colored particle symbols, capturing the intricate nature of physics hard concepts.
When you don't have enough clues to bring your detective story to a close, you should expect that your educated guesses will all be wrong.
A chart titled "Masses in the Stellar Graveyard" shows the black holes and neutron stars detected by LIGO-Virgo-KAGRA, plotted on a logarithmic scale in solar masses, highlighting how LIGO triples black hole haul with each new discovery.
10 years ago, LIGO saw its first gravitational wave. After 218 detections, our view of black holes has changed forever. Can this era endure?
A grainy black and white image shows SPHEREx comet 3I/ATLAS gleaming at the center, surrounded by stars appearing as streaks due to long exposure.
Designed to map galaxies, the SPHEREx mission's first science result is instead about interstellar interloper 3I/ATLAS. No, it's not aliens.
Four images of a nebula, sculpted by a dead star, are shown side by side in radio, optical, and X-ray wavelengths; the fourth composite image reveals the so-called "Hand of God." Each is labeled at the bottom.
In our own Milky Way, a recently deceased star creates a ghostly, hand-like shape in X-rays some 150 light-years wide. Here's how it's made.
There could be variables beyond the ones we've identified and know how to measure. But they can't get rid of quantum weirdness.
A man in a suit sits in front of a large NASA logo sign, symbolizing the determination to defy charter limits and push the boundaries of space exploration.
NASA's 1958 charter's top priority was, "the expansion of human knowledge of phenomena in the atmosphere and space." Is this how it ends?
Close-up of a human eye with a digital interface overlay and a red laser beam targeting the pupil, illustrating the science of LASIK and advanced vision correction technology.
For many of us, our imperfect vision compels us to wear corrective lenses to see properly. Here's what everyone should know about LASIK.