Trillions of neutrinos are produced in our Sun through its nuclear reactions. These particles stream out at nearly the speed of light, and pass right through any matter they encounter. In fact, there are billions of them passing through your body right now. Learn how this elusive particle was first theorized and finally discovered.
Ep. 31: String Theory, Time Travel, White Holes, Warp Speed, Multiple Dimensions, and Before the Big Bang
We get questions every week about string theory and topics popularized by science fiction. Here’s the problem. There’s just no evidence. Each of these is based on wonderful and well-formed mathematical equations, or wishful thinking, but they’re very hard (if not impossible) to test in the real Universe.
Ep. 30: The Sun, Spots and All
It’s Spring in the Northern Hemisphere, and that means the Sun is back. But it’s more than just a free heat lamp for your garden, it’s an incredible, dynamic nuclear reaction complete with flares, coronal mass ejections, twisting magnetic fields and the solar wind. Put in your headphones, head outside and enjoy the sunshine while you listen to this week’s podcast.
Correction: At the beginning of the show I say the Sun has 50 billion years to go. I mentally combined two numbers. In 50 million years life will become untenable or impossible on Earth. In 5 billion years the sun goes off the main sequence. We are very sorry for the mistake. -Pamela
Ep. 29: Asteroids Make Bad Neighbors
This week we’re talking about asteroids. And not just any asteroids, but Near Earth Objects. How do astronomers find these things, why are they buzzing around the Earth, what are the chances we’ll actually get hit, and what would happen if we did get hit? How could we stop them?
Ep. 28: What is the universe expanding into?
Come on, admit it, you’ve had this question. If the Universe is expanding from the Big Bang, what is it expanding into? What’s outside the Universe? Ask any astronomer and you’ll get an unsatisfying answer. We give you the same unsatisfying answer, but really explain it, so your unsatisfaction doesn’t haunt you any more.
Ep. 27: Questions Show #3
The questions are piling up, so it’s time to get through them. We’ve got a great collection this week. How can our eyes collect so many photons? What’s the speed of gravity? Shouldn’t the light from the cosmic microwave background radiation passed us by?
Ep. 26: The Largest Structures in the Universe
This week we continue the story of galaxy formation, learning how groups of galaxies come together to form the biggest structures around – galaxy superclusters. And when you look at the Universe at this scale, environment is everything.
Ep. 25: The Story of Galaxy Evolution
Our Milky Way is a complex and majestic barred spiral galaxy. But 13.7 billion years ago it began, like all galaxies, from the elementary particles formed in the Big Bang. How did our galaxy grow from nothing to the hundreds of billions of stars we see today?
Ep. 24: The Fermi Paradox: Where Are All the Aliens?
We live in a mind bogglingly big Universe filled with countless stars. We know intelligent life evolved here on Earth. It must be common across the Universe, right? But if there’s life out there, how come we haven’t been visited by aliens yet? Why haven’t we even picked up signals from alien television stations? Where’s all the life?
Ep. 23: Counting Aliens With the Drake Equation
If you’re wondering how many extraterrestrials there are in our galaxy, you just have to use a simple equation developed by astronomer Frank Drake in 1961. Just find out how many stars there are, how many support life, how many advanced societies form, and a few other details and we’ll be set.
Ep. 22: Variable Stars
Our Sun has been around for billions of years, and will last for billions more. We’re lucky, it’s pretty stable and regular as stars go, only changing in brightness a little now and then. But there are stars out there that change dramatically; astronomers call them variable stars, and they demonstrate just how bizarre and dangerous the Universe can be.
Ep. 21: Questions Show #2
Our episode on black holes generated many many questions from listeners. We dip into this bottomless pool of questions and start dealing with them. Are really big black holes like the Big Bang? How can black holes evaporate? What would it look like to stand on a black hole? And just how large would a rock have to be before its gravity is so strong that a human can’t escape?
Ep. 20: What We Learned from the American Astronomical Society
It’s astronomical society get together time, and we send Pamela to investigate and record. Hear the latest news that will make your text books out of date. Find out where all the dark matter is collecting, the identity of Kepler’s supernova, and new insights into the closest, brightest supernova in recent memory.
Ep. 19: Comets, Our Icy Friends from the Outer Solar System
The sudden brightening of Comet McNaught has reminded us what a treat it can be to see a comet with the unaided eye. A diffuse ball with a long tail stretching across the sky. There’s nothing else in the night sky that can compare to a bright comet. But what are these objects, where do they come from, and what can they tell us about the formation of the Solar System?
Special Alert: Go See Comet McNaught
There’s a big bright comet visible in the sky right now. Listen to this special alert, and then go outside right at sunset to see Comet McNaught with your very own eyes. You’ve got to move quickly, as it’ll be lost in the glare of the Sun. Don’t worry, it’ll reappear shortly, and could be one of the brightest comets in recent history.
Ep. 18: Black Holes Big and Small
We’re finally ready to deal with the topic you’ve all been waiting for: Schwarzschild swirlers, Chandrasekhar crushers, ol’ matter manglers, sucking singularities… you might know them as black holes. Join as as we examine how black holes form, what they consume, and just how massive they can get.
Ep. 17: Where does the Moon Come From?
We take the Moon for granted, but its effect on the Earth is very important; possibly even critical for the formation of life. But where did it come from? Did the Earth and Moon form together? Or did the Earth capture a wayward Moon? Or was there a more catastrophic cause to this lunar mystery?
Ep. 16: Across the Electromagnetic Spectrum
We see the Universe in visible light with our photon detecting eyes. We can feel infrared heat with our photon detecting hands, and we get sunburns with our ultraviolet photon detecting skin (ouch). But there’s a whole spectrum of photons out there, from radio waves to gamma rays that astronomers use to understand the Universe. It’s time to see the whole picture.
Ep. 15: Questions Show #1
We finally get organized enough deal with several listener questions: isn’t dark matter just regular stuff we can’t see? how can parts of the Universe be expanding faster than the speed of light? what will Betelgeuse look like when it explodes as a supernova? what’s the speed of gravity? All these and more questions are answered.
Ep. 14: We're all Made of Supernovae
No more suspense. This week we blow the biggest stars up. Kaboom. Want more details? Then you’ve got to listen.
Ep. 13: Where Do Stars Go When They Die?
We’ve celebrated the birth of new stars, but the stellar lifecycle doesn’t end there. Stars like our Sun will spend billions of years fusing together hydrogen and pumping out energy. And when the fuel runs out, their death is as interesting as their birth. This week Fraser and Pamela trace out this stellar evolution, and explain what the future holds for stars, large and small.
Ep. 12: Where Do Baby Stars Come From?
Most parents have had that uncomfortable conversation with their children at some point. Mommy, Daddy, where do stars come from? You hem and haw, mumble a few words about angular momentum and primordial hydrogen and then cleverly change the subject. Well, you don’t have to
avoid the subject any longer. Pamela and Fraser describe formation of stars, large and small, in a tasteful manner, using only understandable and scientific language.
iPod Issues Fix
Several of you have reported problems getting your iPods to play our show and other podcasts. Unfortunately, the latest version of iTunes has some new features that are making iPods behave oddly when they try to play podcasts that aren’t in stereo. To fix this problem, go into the Settings menu of your iPod and set EQ to off. Sorry for the inconvenience.
Ep. 10: Measuring Distance in the Universe
You hear distances all the time in astronomy. This star is 10 light-years away; that galaxy is 50 million light-years away; that Big Bang over there happened 13.7 billion years ago. But how did astronomers actually figure out how far away everything is? It’s not a single measuring stick. Instead, astronomers have built up a series of overlapping measuring tools (yes, we’re calling supernovae and variable stars “tools”), which take us from right around the corner to very ends of the Universe. Get out your ruler… no, the bigger one… never mind… just listen.
Ep. 9: Einstein's Theory of Special Relativity
It’s all relative. How many times have you heard that? Well, when you’re traveling close to the speed of light, everything really is relative; especially the passage of time. This week, Fraser and Pamela give you the skinny on Einstein’s Special Theory of Relativity. After listening to a few thought experiments, you too should be able to wrap your head around this amazing theory.