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.

Diagram of the expanding universe concept with cosmic inflation, light cone, and time axis.
Almost everyone asserts that the Big Bang was the beginning of everything, followed by inflation. Has everyone gotten the order wrong?
einstein
Many mavericks look to Einstein as a unique figure, whose lone genius revolutionized the Universe. The big problem? It isn't true.
Einstein
Beyond stars, galaxies, and gravity, studying the fundamental workings of nature reveals widely applicable lessons for learners everywhere.
ring nebula hubble jwst nircam miri
More than two years after JWST began science operations, our Universe now looks very different. Here are its biggest science contributions.
A panoramic image of the Milky Way galaxy, with an inset showing a zoomed view of distant galaxies, tells a cosmic story. This region, highlighted in textured detail, echoes the exploration themes of the Euclid mission.
What are dark matter and dark energy? The large-scale structure of the cosmos encodes them both, with ESA's Euclid mission leading the way.
Friedmann equation
The most common visual depictions of the history of the Universe show the Big Bang as a growing tube with an "ignition" point. Why is that?
The fabric of spacetime is four-dimensional, with three for space and only one for time. But wow, time sure is different from space!
Silhouette of NASA's Europa Clipper spacecraft with antennas poised against a colorful planetary surface, sparking dreams of alien life.
Could life be widespread throughout the cosmos, in the subsurface oceans of ice-covered worlds? NASA's Europa Clipper mission investigates.
An image of a cluster of galaxies, meaning science.
An in-depth interview with astronomer Kelsey Johnson, whose new book, Into the Unknown, explores what remains unknown about the Universe.
A starry night sky over a snow-capped mountain, known as one of Earth's best astronomy locations, with bright city lights shimmering in the distance on the horizon.
There are a number of factors to consider when choosing where to build a telescope. These 3 locations, on their merits, surpass all others.
flame nebula infrared spitzer
The Universe changes remarkably over time, with some entities surviving and others simply decaying away. Is this cosmic evolution at work?
hawking radiation black hole decay
Black holes encode information on their surfaces, but evaporate away into Hawking radiation. Is that information preserved, and if so, how?
A glowing, abstract representation of a brain, with intricate patterns and lights reminiscent of the innovative spirit behind the Nobel Prize in Physics 2024, set against a dark backdrop.
Artificial intelligence is much more than image generation and smart-sounding chatbots; it's also a Nobel-worthy endeavor rooted in physics!
Book cover titled "Infinite Cosmos" with a vibrant galaxy and stars. Includes "National Geographic" logo and the text "Visions from the James Webb Space Telescope." Introduction by Brian Greene.
National Geographic's first James Webb Space Telescope book shows us the cosmos like never before.
A starry sky with a magnified view highlights an orange, cloud-like structure representing one of the youngest astronomical objects in the Milky Way, shimmering as it subtly rotates.
The earliest Milky Way-like galaxy, REBELS-25, was spotted rotating about its axis. It's only 700 million years old: 5% of our present age.
Two observatory domes under a starry night sky, with the Milky Way visible, form a stunning backdrop as an optical interferometer captures the universe's secrets.
Interferometry gave us a black hole's event horizon, but that was in the radio. What can we accomplish with a new optical interferometer?
Planck CMB
Today, the deepest depths of intergalactic space aren't at absolute zero, but at a chill 2.73 K. How does that temperature change over time?
A vibrant, high-resolution image of a spiral galaxy with rich clusters of stars and interstellar dust, where most stars formed.
The Universe has been creating stars for nearly all 13.8 billion years of its history. But those photons can't match the Big Bang's light.
A large telescope observatory under construction at dusk with a visible moon and stars in the sky. Cranes and construction equipment are present around the structure.
Comet A3, also known as Comet Tsuchinshan-ATLAS, has sprung to life since 2024's last equinox. Here's how to catch the show for yourself.
dark matter substructure intracluster light
In theory, dark matter is cold, collisionless, and only interacts via gravity. What we see in ultra-diffuse galaxies indicates otherwise.