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: Can someone possibly see the edge of spacetime?
Our Big Bang could be just one region within an infinite, inflating multiverse. If we were born close to the cosmic edge, what would we see?

Ethan Siegel

black hole merger
The ultimate multi-messenger astronomy event would have gravitational waves, particles, and light arriving all at once. Did that just occur?
Astronomical image of a young star system with labeled features: jet, conical outflow, dark lane, possible spiral, disk, tail, and a scale marking 300 astronomical units.
A young, nearby, massive star, whose protoplanetary disk appears perfectly edge-on, was just viewed by JWST, with staggering implications.
planetary nebula
Historically, astronomers have often named things creatively, bizarrely, and often inaccurately. But which terms are the most egregious?
Five men, immersed in conversation, sit indoors on a blanket, eating from metal bowls. Despite the cloud of ignorance surrounding them about modern science, they share stories and laughter as a red bowl rests prominently at their center.
If we wish to tackle the very real problems society faces, we require expert-level knowledge. Valuing it starts earlier than we realize.
super earth mini neptune transit spectroscopy
Seeking life beyond the Solar System, we first look to the closest star systems with Earth-like planets. Here's why that's not good enough.
A grayscale image captures the moon's surface, featuring numerous craters of varying sizes. The scene is reminiscent of a lunar Grand Canyon, with a highlighted spot drawing the viewer's attention.
Our Moon is full of craters, basins, and ancient lava flows. But two large lunar Grand Canyons have the same origin: a single, giant impact.
A colorful cosmic scene features a bright super star cluster with glowing stars surrounded by swirling red, orange, blue, and gray nebulous clouds.
There are only four super star clusters in all the Local Group: rarities today. Here's what the youngest, the just-discovered N79, shows us.
warm-hot intergalactic medium sculptor wall
Here in our Universe, both normal and dark matter can be measured astrophysically. But only normal matter can collapse. Why is that?
A textured, abstract artwork prominently features the word "CENSORSHIP" in bold black, flanked by stark words like "BEATEN," "DEATHS," and "IRON FIST." The beige backdrop subtly hints at government influence, blending shadows of science with restraint.
With a flurry of threats to scientists, science funding, and health policy, the USA now faces a crisis reminiscent of Soviet-era Lysenkoism.
Diagram showing the cosmic microwave background radiation with satellites COBE, WMAP, and Planck, illustrating improvements in observational detail and resolution.
First discovered in the mid-1960s, no cosmic signal has taught us more about the Universe, or spurred more controversy, than the CMB.
elements
From LIGO, there weren't enough neutron star-neutron star mergers to account for our heavy elements. With a JWST surprise, maybe they can.
A dark nebula with dimming T Tauri stars nestled among dust and gas. The nebula casts a shadowy silhouette against a backdrop of numerous smaller stars in space.
It's the ultimate game of cosmic "cover up," as the dimming occurs when a circumbinary disk from a nearby star passes in front of T Tauri North.
Illustration of the periodic table with a human silhouette reveals how heaviest elements shape us. Elements are color-coded, depicting the percentage composition of the body: 73% oxygen, 16.5% carbon, 9.5% hydrogen, and 1% others.
Matter is made up largely of atoms, where atomic nuclei can contain up to 100 protons or more. But how were the heaviest elements made?
CMB polarization Planck
Cosmic inflation, proposed back in 1980, is a theory that precedes and sets up the hot Big Bang. After thorough testing, is it still valid?
A dense star field with various galaxies and cosmic bodies scattered, showcasing a vibrant and colorful view of space. Among them, an isolated galaxy grows in brilliance, capturing the imagination with its distant allure.
Scientists just viewed one of the tiniest, most isolated, lowest-mass galaxies ever found with JWST. Despite all odds, it's still growing.
A group of satellite dishes under a starry sky, capturing celestial signals from star birth.
New telescopes, radio dishes, and gravitational wave detectors are needed for next-generation science. Will the USA lead the way?
Three images of the Ring Nebula reveal its true shape: visible light (left), infrared (center), and a composite with contour lines (right) showcasing different details of the nebula's intricate structure.
The Ring Nebula, a bright, circular planetary nebula, is created by a dying Sun-like star. After centuries, we finally know its true shape.
JWST MIRI NIRCam SMACS 0723
Since mid-2022, JWST has been showing us how the Universe grows up, from planets to galaxies and more. So, what's its biggest find of all?
proton internal structure
A proton is the only stable example of a particle composed of three quarks. But inside the proton, gluons, not quarks, dominate.
Six mesmerizing images, bathed in red hues, reveal distant galaxies—JWST's little red dots. Each is precisely labeled: CEERS 14448, NGDEEP 4321, PRIMER-COS 10539, CEERS 20320, JADES 9186, and PRIMER-UDS 17818—alongside their corresponding redshift values.
The discovery of ultra-bright, ultra-distant galaxies was JWST's first big surprise. They didn't "break the Universe," and now we know why.