Ethan Siegel

Ethan Siegel

A theoretical astrophysicist and science writer, host of popular podcast “Starts with a Bang!”

Ethan Siegel 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.

inflation spawn parallel universes
When cosmic inflation came to an end, the hot Big Bang ensued as a result. If our cosmic vacuum state decays, could it all happen again?
An image of a starry sky with numerous lines, depicting the concept of space pollution.
In 1957, humanity launched our first satellite; today's number is nearly 10,000, with 500,000+ more planned. Space is no longer pristine.
A diagram illustrating the earth's orbit around the sun with positions indicating seasonal change, including facts about leap day.
Leap day only comes once every four years, including in 2024. But the reason we have it, including when we do and don't, may surprise you.
Lecturer standing in front of a classroom, teaching college admissions students seated at desks with sunlight casting shadows.
There are many problems with relying on SAT and ACT scores for college admissions. But removing them entirely creates less opportunity.
Illustration of the solar system's planets and their predicted fates, with some being swallowed by the sun as it dies and others stripped of their atmospheres or ejected.
For now, our Solar System's eight planets are all safe, and relatively stable. Billions of years from now, everything will be different.
Planets in varying sizes orbiting around a bright central star in a purple-hued cosmos, where life persists.
There are plenty of life-friendly stellar systems in the Universe today. But at some point in the far future, life's final extinction will occur.
A blue t-shirt with a yellow circle and arrow, representing the universe.
The second law of thermodynamics tells us that entropy always increases. But that doesn't mean it was zero at the start of the Big Bang.