Welcome to Astronomy Cast, the most popular astronomy-related podcast. Just look at what listeners have to say about it: Astronomy Cast is out of this world! It's hard to believe that it's free! This is an absolute must for any amateur astronomer or anyone interested in astronomy or cosmology. The...

Caffeine atom with 3D electron orbitals. Image credit: Ivan S. Ufimtsev, Stanford University We've talked about the biggest of the big, now let's focus in on the smallest of the small. Let's see what's inside that basic building block of matter: the atom. You probably know the basics, but...

Artist's impression of an experiment to test entanglement One of the most amazing aspects of quantum mechanics is quantum entanglement. This is the strange behavior where particles can become entangled, so they're somehow connected to one another – no matter the distance between them. Interact...

Stellar Spectra. Image credit: NOAO Last week we took a peek into the tiny world of quantum mechanics, and its unintuitive, but very accurate mathematical predictions. And although we all appreciate the physics lesson, you're probably wondering what this all has to do with astronomy. Well, today we...

Einstein, one of the founders of quantum mechanics Quantum mechanics is the study of the very tiny; the nature of reality at the smallest scale. It's a science that defies common sense, and delivers no helpful analogies. And yet it delivers the goods, making scientific predictions with incredible...

Ancient Chinese sundial and observatory. Today, time rules our lives. We live each day with the moments broken up into hours, minutes and seconds. We never seem to have enough time. But can you imagine not being able to tell time at all, where the movements of the Sun and the stars was the only way to know...

Another week, another roundup of your questions. This week listeners asked: will reaching light speed destroy the Universe? When is Andromeda going to look really, really cool with the unaided eye? Why didn't dark matter all turn into black holes? And there's even more. If you've got a...

Look around you. Breathe in some air. Everything you can see and feel was formed in a star. Today we'll examine that long journey that matter has gone through, forged and re-forged in the hearts of stars. In fact, the device you're using to listen to this podcast has some elements formed in a...

At the earliest moments of the Universe, there were no separate forces, energy or matter. It was all just the same stuff. And then the different forces froze out, differentiating into electromagnetism, the strong force and the weak force. Today we'll look at the problem that has puzzled physicists for...

After a quick Dragon*Con break, we're back to our tour through the fundamental forces of the Universe. We've covered gravity and electromagnetism, and now we're moving onto the strong and weak nuclear forces. We didn't think they'd really need to be separate episodes, so we're...