Starts With A Bang

A field of stars and colorful cosmic dust clouds scattered across the dark expanse of space.
The Universe is out there, waiting to be discovered

Our mission is to answer the biggest questions of all, scientifically.

What is the Universe made of? How did it become the way it is today? Where did everything come from? What is the ultimate fate of the cosmos?

For most of human history, these questions had no clear answers. Today, they do. Starts With a Bang, written by Dr. Ethan Siegel, explores what we know about the universe and how we came to know it, bringing the latest discoveries in cosmology and astrophysics directly to you.

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Ethan Siegel is an award-winning PhD astrophysicist and the author of four books, including The Grand Cosmic Story, published by National Geographic.

Full Profile
A bald man with a long beard and handlebar mustache gestures with his hands against a backdrop of an upside-down cityscape wearing a purple shirt.
Ask Ethan: What’s the biggest misconception in astronomy?
Many facts are well-known to professionals, but are unappreciated or even rejected outright by the public. "How stars work" takes the cake.

Ethan Siegel

A colorful nebula with a bright center and symmetrical, wing-like clouds of gas and dust extends outward in space, as seen in a JWST reveal that uncovers stars and galaxies in the universe beyond.
laniakea
On the largest scales, galaxies don't simply clump together, but form superclusters. Too bad they don't remain bound together.
Abstract digital artwork featuring concentric blue circles, lines, and green geometric shapes over a dark blue and black textured background, evoking a sense of vibe physics within its captivating composition.
The conversation you're having with an LLM about groundbreaking new ideas in theoretical physics is completely meritless. Here's why.
5000 exoplanets
Somewhere, at some point in the history of our Universe, life arose. We're evidence of that here on Earth, but many big puzzles remain.
Full moon over a city skyline at night, high-rise buildings aglow and lights reflecting on the calm water—a scene that inspires 5 science lessons about the moon's impact on our world.
Even just by examining the Moon with the unaided eye, we can learn an incredible amount about the Moon, Earth, and more.
The Big Bang was hot, dense, uniform, and filled with matter and energy. Before that? There was nothing. Here's how that's possible.
quantum particles
Realizing that matter and energy are quantized is important, but quantum particles aren't the full story; quantum fields are needed, too.
levitation
With the right material at the right temperature and a magnetic track, physics really does allow perpetual motion without energy loss.
bounce ball
Whether you run the clock forward or backward, most of us expect the laws of physics to be the same. A 2012 experiment showed otherwise.
every square degree
When the Hubble Space Telescope first launched in 1990, there was so much we didn't know. Here's how far we've come.
Green abstract image with floating, glowing funnel-shaped objects and spherical wireframe shapes evokes a black hole universe, all set against a misty green background with ethereal light streaks.
Once you cross a black hole's event horizon, there's no going back. But inside, could creating a singularity give birth to a new Universe?
F = ma fall up
From high school through the professional ranks, physicists still take incredible lessons away from Newton's second law.
A colorful, abstract scientific illustration with a central glowing sphere, circular patterns, and various lines and circles suggesting quantum connections or uncertainty data points, on a dark background with blue accents.
No matter what it is that we discover about reality, the fact that reality itself can be understood remains the most amazing fact of all.
gravitational wave effects on spacetime
With over 300 high-significance gravitational wave detections, we now have a huge unsolved puzzle. Will we invest in finding the solution?
Two glowing spheres, one red and one green, face each other in space with a wavy line of light—like a particle physics collision—connecting them against a speckled dark background reminiscent of the last collider’s discoveries.
Will we build a successor collider to the LHC? Someday, we'll reach the true limit of what experiments can probe. But that won't be the end.
A visual simulation of two objects orbiting and merging, distorting a red-orange grid representing spacetime—illustrating gravitational waves once thought to be the worst prediction in science.
The measured value of the cosmological constant is 120 orders of magnitude smaller than what's predicted. How can this paradox be resolved?
comet collide with earth
65 million years ago, a massive asteroid struck Earth. Not only did Jupiter not stop it, but it most likely caused the impact itself.
Two colorful, semi-transparent spheres, one blue and one red, represent a possible top quark bound state, toponium, surrounded by small particles inside a cloudy, circular enclosure.
Can the top quark, the shortest-lived particle of all, bind with anything else? Yes it can! New results at the LHC demonstrate toponium exists.
Black and white image of a star field with one bright object in the center, indicated by a red arrow, believed to be the third interstellar object detected passing through our solar system.
First 'Oumuamua, then Borisov, and now ATLAS have shown us that interstellar interlopers are real. Here's what the newest one teaches us.
Side-by-side images of the Ring Nebula show its structure in different colors, each with a white dotted oval highlighting the central region.
Our nearby Ring Nebula, with JWST's eyes, shows evidence for planet formation. Will the Sun eventually destroy, and then replace, the Earth?
A crane lifts a large metal structure onto a white building at a construction site in a mountainous, arid area under clear blue sky.
The relic signal that first proved the Big Bang has been known and analyzed for 60 years. Join us at the frontiers of modern cosmology!