As predicted we got a lot of questions from people about our trilogy of shows on the size, shape and centre of the universe. Today we’ll do our best to clear them all up.As always, if you’re still confused drop us an email to info@astronomycast.com
Ep. 80: Craters
Pamela’s attending the 39th Lunar and Planetary Sciences Conference, and you know what that means: the Moon… and planets! When you think of the Moon, you think of craters. In fact, that’s a big theme this week at the conference, so Pamela took it as inspiration. Here you go, the week we drove the show into a crater. Wait… there’s got to be a better way to describe this.
Ep. 79: How Big is the Universe?
We’re ready to complete our trilogy of discovery about the universe. We’ve learned that it has no center; rather everywhere is its center and nowhere. We discovered that the universe seems to be flat. It’s not open, it’s not closed, it’s flat. If that doesn’t make any sense, you need to listen to the previous show because there’s no way I could give that an explanation.
So now we want to know: How big is it? Does it go on forever or is it finite in scale? How much of it can we see?
Ep. 78: What is the Shape of the Universe?
Some of the biggest questions in the universe depend on its shape. Is it curved? Is it flat? Is it open? Those may not make that much sense to you, but in fact it’s very important for astronomers. So which is it? How do we know? How did we figure it out? Why does it matter?
Ep. 77: Where is the Centre of the Universe?
There are some people – I’m not naming names – who think the universe revolves around them. In fact, for most of humankind, everybody thought that. It’s only been in the last few hundred years that scientists finally puzzled out that the Earth isn’t the centre of the universe at all. That begs the question: where is the centre?
Ep. 76: Lagrange Points
Gravity is always pulling you down, but there are places in the solar system where gravity balances out. These are called Lagrange points and space agencies use them as stable places to put spacecraft. Nature is on to them and has already been using them for billions of years.
Ep. 75: Stellar Populations
After the big bang, all we had was hydrogen, a little bit of helium, and a few other trace elements. Today, we’ve a whole periodic table of elements to enjoy, from oxygen we breathe to the aluminium cans we drink from to the uranium that powers some people’s homes. How did we get from plain old hydrogen to our current diversity? It came from stars, in fact successive generations of stars.
Ep. 74: Antimatter
Sometimes, we don’t get to decide what our show’s about. So many threads come together at the same time driving the decision for us. This is one of those situations. We’ve gotten so many questions from listeners in just the last week about antimatter that our show had just been chosen for it. You command, we obey. Let’s talk about antimatter.
Ep. 73: Questions Show #8
We’ve been so crazy following our own whims through the universe that we’ve neglected your questions. That ends today. It’s time to dig deep into our overflowing email box to retrieve the puzzling questions our listeners have sent in.
Ep. 72: Cosmic Rays
We’re going to return back to a long series of episodes we like to call: Radiation that Will Turn You Into a Superhero. This time we’re going to look at cosmic rays, which everyone knows made the Fantastic Four. These high-energy particles are streaming from the Sun and even intergalactic space, and do a wonderful job of destroying our DNA, giving us radiation sickness, and maybe (hopefully!) turning us into superheroes.
Ep. 71: Gravitational Waves
When he put together his theories of relativity, Einstein made a series of predictions. Some were confirmed just a few years later, but scientists are still working to confirm others. And one of the most fascinating is the concept of gravitational waves. As massive objects move in space, they send out ripples across the Universe that actually distort the shape of matter. Experiments are in place and in the works to detect these gravitational waves as they sweep past the Earth.
Ep. 70: How To Win a Nobel Prize
Now that you’ve got your career in astronomy, obviously the next goal is to win a Nobel prize. We’re here at the American Astronomical Society meeting in Austin, which is just one tiny step that a person has to take before you get that Nobel prize. Before you get that call in the middle of the night from Sweden, you’re going to need to come with an idea, do some experiments, write a paper, get published and a bunch of other stuff. This week, we’ll tell you all about it.
Ep. 68: Globular Clusters
This week we’re going to study some of the most ancient objects in the entire Universe; globular clusters. These relics of the early Universe contain hundreds of thousands of stars, held together by their mutual gravity. Since they formed together, they give astronomers a unique way to test various theories of stellar evolution.
Ep. 67: Building a Career in Astronomy
With all the enthusiasm that’s being generated with astronomy, it’s had a bit of a strange side-effect. We’ve been causing some of our listeners to have midlife crises about their careers. We’ve had other people who just want advice – they’re moving into college for the first time and they want to direct the courses they’re going to be taking into astronomy. Some other people already have skills that are very useful and have wondered how they can help up or even change their career to be working in the field. We thought we’d try and answer everyone’s questions all at once and just run through the major career paths you can take that relate to astronomy and space, and the kinds of things you’ll need to do to actually make yourself a good candidate for that field.
Ep. 66: How Amateurs Can Contribute to Astronomy
Astronomy is one of the few sciences where amateurs make meaningful contributions to discoveries. Many professional researchers work hand-in-hand with teams of amateurs to make discoveries that just wouldn’t be possible without this kind of collaboration. In fact, Pamela regularly relies on dedicated enthusiasts for her data on variable stars.
Ep. 65: The End of Our Tour Through the Solar System
All good things come to an end – we now find ourselves in the outer reaches of the solar system where our Sun is hard to distinguish from the other bright stars in the sky. But we’re not done with the solar system, there’s some stuff that’s leftover. This week, we look at the outer reaches of the solar system and how it interacts with the rest of the universe.
Ep. 64: Pluto and the Icy Outer Solar System
It’s been a long journey, 64 episodes, but now we’re back where we began: Pluto. Last time we talked about how Pluto lost its planethood status, so we won’t go over all that again. This time we’re going to talk about Pluto, its moons, the Kuiper belt, and the other icy objects that inhabit the outer Solar System.
Ep. 63: Neptune
We’ve reached Neptune, the final planet in our tour through the solar system – but don’t worry! The tour’s not over, but after this week we’ll be all out of planets. Neptune has a controversial story about its discovery, some of the strongest winds in the solar system and some weird moons.
Ep. 62: Uranus
This week, we’re on to the next planet in the solar system. We don’t know a whole lot about this blue gas planet, but today we’ll cover some of the neat stuff we do know, including it’s faint rings, sideways axis of rotation and its rocky core – a first in the gas planets we’ve encountered so far in our tour.
Ep. 61: Saturn's Moons
We know that delaying this show one more week would be too dangerous, so here you go: Saturn’s moons. These are some of the most interesting objects in the Solar System, from the spongy Hyperion, to the geysers on Enceladus, to the rainy, misty, oceany Titan. They’ve kept Cassini busy for years, and scientists will likely be pondering them for decades.
Ep. 60: Questions Show #7
It’s about time for a question show again, so we’ll have one last interruption to our planetary tour, to deal with the questions that arose from our inflation show (episode 58).
So if you still don’t understand inflation, take a listen to this week’s show and as always, send us your questions.
Ep. 59: Saturn
Returning to our tour of the solar system, let’s voyage away from the largest planet to the second largest, Saturn. Once again, we’ll break up our visit because there’s lots to talk about. This week, we talk about Saturn and its famous rings. Next week, we’ll discuss its many moons.
Ep. 58: Inflation
We interrupt this tour through the solar system to bring you a special show to deal with one of our most complicated subjects: the big bang. Specifically, how it’s possible that the universe could have expanded faster than the speed of light. The theory is called the inflationary theory, and the evidence is mounting to support it. Einstein said that nothing can move faster than the speed of light, and yet astronomers think the universe expanded from a microscopic spec to become larger than the solar system, in a fraction of a second.
Ep. 57: Jupiter's Moons
Last week we talked about Jupiter and we could sense right away it would be too much to handle. This week, we’ll talk about Jupiter’s moons – how many are there? What makes them so interesting? Is it true that the most likely place in the solar system to find life (other than Earth) is actually on one of Jupiter’s moons? Hang on tight. We’re going to cover a lot.
Ep. 56: Jupiter
Last week we talked about rubble, this week we’re going to dig into the largest planet in the Solar System: Jupiter, but will it all just be hot gas? There’s so much to talk about, we’ve decided to break this up into two shows. This week we’re going to just talk about Jupiter, and then next week, we’re going to cover its moons.