Ethan Siegel
A theoretical astrophysicist and science writer, host of popular podcast "Starts with a Bang!"
Ethan Siegel is a Ph.D. astrophysicist and author of "Starts with a Bang!" He is a science communicator, who professes physics and astronomy at various colleges. He has won numerous awards for science writing since 2008 for his blog, including the award for best science blog by the Institute of Physics. His two books "Treknology: The Science of Star Trek from Tricorders to Warp Drive" and "Beyond the Galaxy: How humanity looked beyond our Milky Way and discovered the entire Universe" are available for purchase at Amazon. Follow him on Twitter @startswithabang.

Astronomers claim to have found structures so large, they shouldn’t exist. With such biased, incomplete observations, perhaps they don’t.
Here in our Solar System, we only have one star: a singlet. For many systems, including the highest-mass ones, that’s anything but the norm.
The pattern 1, 1, 2, 3, 5, 8, 13, etc., is the Fibonacci sequence. It shows up all over nature. But what’s the full explanation behind it?
Life became a possibility in the Universe as soon as the raw ingredients were present. But living, inhabited worlds required a bit more.
Today, supermassive black holes and their host galaxies tell a specific story in terms of mass. But JWST reveals a different story early on.
The most celebrated genius in human history didn’t just revolutionize physics, but taught many valuable lessons about living a better life.
Our cosmic home, planet Earth, has been through a lot over the past 4.5 billion years. Here are some of its most spectacular changes
For every proton, there were over a billion others that annihilated away with an antimatter counterpart. So where did all that energy go?
One newly discovered, ancient star has a composition unlike any other. Explaining its existence is already blowing astronomers’ minds.
Planets can be Earth-like or Neptune-like, but only rarely are in between. This hot, Saturn-like planet hints at a solution to this puzzle.
Finding it at all was a happy accident. Examining it further may help unlock the secrets hiding within the earliest galaxies of all.
Each time you fold a piece of paper, you double the paper’s thickness. It doesn’t take all that long to even reach the Moon.
Here in the 21st century, quantum computing is quickly going from a dream to a reality. But what’s hype, and what’s actually true?
The cosmic scales governing the Universe are almost unbelievably large. What if we shrunk the Sun down to be just a grain of sand?
Figuring out the answer involved a prism, a pail of water, and a 50 year effort by the most famous father-son astronomer duo ever.
With the invention of the leap year, the Julian calendar was used worldwide for over 1500 years. Over time, it led only to catastrophe.
Today, the star-formation rate across the Universe is a mere trickle: just 3% of what it was at its peak. Here’s what it was like back then.
Earth wasn’t created until more than 9 billion years after the Big Bang. In some lucky places, life could have arisen almost right away.
As early as we’ve been able to identify them, the youngest galaxies seem to have large supermassive black holes. Here’s how they were made.
For 550 million years, neutral atoms blocked the light made in stars from traveling freely through the Universe. Here’s how it then changed.
Even after the first stars form, those overdense regions gravitationally attract matter and also merge. Here’s how they grow into galaxies.
The first stars in the Universe were made of pristine material: hydrogen and helium alone. Once they die, nothing escapes their pollution.
The first stars took tens or even hundreds of millions of years to form, and then died in the cosmic blink of an eye. Here’s how.
The Big Bang’s hot glow faded away after only a few million years, leaving the Universe dark until the first stars formed. Oh, the changes!
The Universe is an amazing place. Under the incredible, infrared gaze of JWST, it’s coming into focus better than ever before.
As Uranus approaches its solstice, its polar caps, rings, and moons come into their best focus ever under JWST’s watchful eye. See it now!
Misinformation was extremely popular in 2023, as bad science often made global headlines. Learn the truth behind these 10 dubious stories.
In our Universe, matter is made of particles, while antimatter is made of antiparticles. But sometimes, the physical lines get real blurry.
Atomic nuclei form in minutes. Atoms form in hundreds of thousands of years. But the “dark ages” rule thereafter, until stars finally form.
With any occupation comes a risk of health and safety hazards. When it comes to being Santa Claus, the challenges are unique.