Starts With A Bang

A dense starfield, with various colored stars shimmering through a dark cloud-like formation, lies against a deep black background in the mysterious zone of avoidance.
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.

with Ethan Siegel
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.
Groupthink in science isn’t a problem; it’s a myth
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Ethan Siegel

solar system model
Infographic illustrating three steps to measure the Hubble Constant, showing Cepheid variable stars, supernovae, and galaxies at increasing distances with redshifted light—highlighting how these methods reveal that the hubble tension is real.
Is the Universe's expansion rate 67 km/s/Mpc, 73 km/s/Mpc, or somewhere in between? The Hubble tension is real and not so easy to resolve.
parallel universe
The ANITA experiment found cosmic rays shooting out of Antarctica. One interpretation claims "parallel Universes," but is that right?
A composite image showing a galaxy with red circles marking stars on the left and multicolored expanding rings with Earth on the right, all set against a grid background, illustrating concepts like Hubble tension studied by Wendy Freedman.
Different methods of measuring the Universe's expansion rate yield high-precision, incompatible answers. But is the problem robustly real?
Circular astronomical image showing constellations and celestial objects labeled against a dark sky, reminiscent of a NASA PUNCH video sun corona visualization, with a timestamp of 2025-06-03 01:52 at the bottom left.
Launched in March, the PUNCH mission has viewed two incredible coronal mass ejections, tracking them farther from the Sun than ever before.
The tiniest galaxies of all are the most severely dominated by dark matter. Could black holes be the cause of the extra gravity instead?
A digital illustration showing a glowing blue particle on the left, evoking cosmic inflation, transitioning into a geometric, grid-like structure on a purple background on the right.
A few physical quantities, in all laboratory experiments, are always conserved: including energy. But for the entire Universe? Not so much.
Timeline of the universe from the Big Bang, as described in cosmology, showing inflation, formation of atoms, stars, galaxies, and expansion to the present day over 13.8 billion years.
If you want to understand the Universe, cosmologically, you just can't do it without the Friedmann equation. With it, the cosmos is yours.