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.

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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
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Ethan Siegel

Millikan Lemaitre and Einstein
Side-by-side images of a nebula in space, showing colorful, wispy gas and dust shells surrounding a bright central region with numerous stars in the background.
Resembling a cosmic brain, the Exposed Cranium Nebula instead shows a dying, massive star, as JWST reveals. Its fate remains uncertain.
Digital illustration of Earth showing a large amount of space debris and satellites orbiting the planet, highlighting the issue of space junk.
What goes up into low-Earth orbit will eventually come down, bringing huge consequences with it. Be informed, not surprised!
warm-hot intergalactic medium sculptor wall
In traveling through the expanding Universe, particles slow down while light and gravitational waves redshift. What degrades and what won't?
particle physics destroy universe
Smashing things together at unprecedented energies sounds dangerous. But it's nothing the Universe hasn't already seen, and survived.
No civilization, no matter how successful, can last forever. What does the non-detection of intelligent aliens mean for our own longevity?
A view of a star-filled night sky with numerous bright stars and distant galaxies, including Hubble-dark galaxy formations, scattered across a dark background.
The discovery of CDG-2, a galaxy that's more than 99.9% dark matter, could reveal a new population of ultra-faint galaxies. But is it real?
Voyager
No human has ever left the Solar System, and only six already-launched spacecraft will ever exit it. Will Voyager 1 remain the most distant?
black hole
Quantum entanglement links information between particles across space and time. So what happens when one of them falls into a black hole?
A radio telescope observes a distant galaxy; insets show a magnified view of the galaxy—home to the most distant laser—and a spectral graph. Illustration attributed to IDIA.
Forget about the terawatt lasers we're making on Earth. The Universe makes natural ones thousands of times more powerful than the Sun.
hubble tension
Even space and time are relative in Einstein's universe. That means our old notions of "where" and "when" no longer apply on cosmic scales.
A satellite with extended accordion-like solar panels or reflectors, possibly supporting AI data centers in space, orbits above Earth, with the planet’s surface visible in the background.
There are plenty of engineering obstacles, and those can be overcome. But you cannot change the laws of physics, and those matter too.
The fundamental building blocks of reality are indivisible: quanta that cannot be split or divided. Our understanding remains incomplete.
White lines intersect around a central, glowing sphere on a black background, creating a complex geometric and abstract pattern that suggests how nothing can persist when the universe dies.
Long after the last star burns out, the Universe will experience its end state: a heat death. Will everything prior then be meaningless?
quark gluon plasma primordial soup
Before we formed stars, atoms, elements, or even got rid of our antimatter, the Big Bang made neutrinos. And we finally found them.
Illustration of ape to human evolution with skeletal figures, labeled amino acids, and colorful dots representing molecular structures, highlighting metabolism and the origin of life on Earth.
A big open question in 21st-century science is how life began here on Earth. The metabolism-first scenario just might be the best one.
From the vastness of space, Earth at night reveals its exo-earth beauty, with illuminated continents showcasing a tapestry of lights across North and South America. Major cities and regions emerge from the glowing darkness, painting a vivid picture against the backdrop of oceans.
One big goal of science is to find an inhabited, Earth-like planet. But if we find an Earth-like world, will we even recognize it?
Stellar explosion
Many reactions emit energy, often in large amounts, but cosmic efficiency is another metric altogether. Here's how to maximize your output.
Visualization of the timeline of the universe, from the beginning big bang to the present.
The Universe is expanding, the expansion is accelerating, and some galaxies even recede faster-than-light. Can we see a change in real time?
einstein
Even the most brilliant mind in history couldn't have achieved all he did without significant help from the minds of others.
A luminous dying sun with jets and swirling clouds appears at the center of a dark background, encircled by concentric patterns—an image reminiscent of Hubble’s stunning cosmic view.
Before Sun-like stars die, they transition from AGB red giants into preplanetary nebulae. Here's how Hubble sees the famous Egg Nebula.