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.
gravity probe b
We first measured G, the gravitational constant, back in the 18th century. As the least well-known fundamental constant, can it be improved?
In 2017, a kilonova sent light and gravitational waves across the Universe. Here on Earth, there was a 1.7 second signal arrival delay. Why?
A detailed image of the Eta Carinae star system could trick science headlines with its bright, colorful clouds of gas and dust in blue, red, and purple hues swirling around a luminous central region.
Dark matter, dark energy, and the Big Bang are all part of a solid scientific foundation. Here's why popular media often claims otherwise.
A bright, circular object with concentric rings and a surrounding halo set against a dark background, resembling a gap-clearing planet or other astronomical phenomena.
Planets grow from protostellar material in disks, leading to full-grown planetary systems in time. At last, the final gap has been filled.
A wavy line, one meter long, transitions from dark red to bright yellow above a ruler, set against a magenta oval with a blue background featuring drawn human figures.
Until the late 20th century, there wasn't a truly universal standard. Under our current definition, everyone agrees on what "one meter" is.
Book cover of "Do Aliens Speak Physics?" by Daniel Whiteson and Andy Warner, featuring a blue background, yellow and white text, and an illustration of a robot and people interacting.
Do aliens speak the same physics that we do, with similar laws, observables, and underlying mathematics. Maybe not, argues Daniel Whiteson.
gravitational wave effects on spacetime
We've now detected hundreds of gravitational waves with LIGO, Virgo, and KAGRA. What if we tried Weber's original method in the modern day?
terraforming
The first world beyond Earth for human habitability should be the Moon, not Mars. This is why we should terraform our lunar neighbor first.
two particles different wavelength speed of light
Times dilate and lengths contract near the speed of light. Bizarre and confusing? Sure. But under relativity, it can't be any other way.
A field of galaxies in deep space, featuring a bright spiral galaxy at the lower right with a stellar stream escaping the galaxy, and a large, bright red star at the upper left.
Stellar streams are faint trails of stars that appear to "stream" out of galaxies. A new one, escaping galaxy M61, may point to many others.
Three side-by-side images show different views of the Red Spider Nebula in space, captured by JWST, with a bright center and colorful gases in orange, green, and blue against a backdrop of stars.
When dying, Sun-like stars have binary companions, spectacular sights arise from the ionization. JWST spots the Red Spider Nebula in action!
big crunch
There's some, but not overwhelming, evidence that dark energy is evolving. What would it take for a "Big Crunch" to be our cosmic fate?
solar system model
Scientists are notoriously resistant to new ideas. Are they falling prey to groupthink? Or are our current theories just that successful?
ufo lights liverpool
Physicist Daniel Whiteson challenges the notion that all intelligent species would eventually uncover the same laws of nature. Do you agree?
DUNE neutrino detectors
Nearly 100 years after being theorized, the strange behavior of the neutrino still mystifies us. They could be even stranger than we know.
An image of El Gordo, a massive galaxy cluster captured by Hubble
The planet, the Solar System, and the galaxy aren't expanding. But the whole Universe is. So where does the dividing line begin?
big bang
For 13.8 billion years, the Universe has been expanding. But that couldn't have been the case for an eternity, and science has proven it.
dark matter
Dark matter has never been directly detected, but the astronomical evidence for its existence is overwhelming. Here's what to know.
A dense cluster of differently sized red, blue, and green spheres overlaps against a black background, evoking the biggest mysteries surrounding the origin of the universe.
We've long known we can't go back to infinite temperatures and densities. But the hottest part of the hot Big Bang remains a cosmic mystery.
star vs planet vs brown dwarf
Red dwarfs are the Universe's most common star type. Their flaring now makes potentially Earth-like worlds uninhabitable, but just you wait.