Ep. 137: Large Scale Structure of the Universe

Evolution of the large scale structure of the Universe. Image credit: NASA

This week we’re going to think big. Bigger than big. We’re going to consider the biggest things in the Universe. If you could pull way back, and examine regions of space billions of light-years across, what would you see? How is the Universe arranged at the largest scale? And more importantly… why?

Ep. 137: Large Scale Structure of the Universe

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Ep. 135: X-Ray Astronomy

Supernova remnant W49B, seen in X-rays and visible light.

We continue our journey through the electromagnetic spectrum with X-rays.  If you've ever broken a bone, you probably know how X-rays are most commonly used.  While doctors use X-rays to study the human body, and astronomers use X-rays to study some of the hottest places in the Universe. So let's put on our X-ray specs, and see what we can see.

Ep. 135: X-Ray Astronomy

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Ep. 134: Ultraviolet Astronomy

M81 in ultraviolet. Image credit: NASA

Our next visit in this tour through the electromagnetic spectrum is the ultraviolet. You can't see it, but anyone who's spent a day out in the hot sun without sunblock has sure experienced its effects. Ultraviolet radiation is associated with the birth of stars and some of the hottest places in the Universe.

Ep. 134: Ultraviolet Astronomy

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Ep. 123: Homogeneity

Hubble Deep Field.

As astronomers discovered that we live in a great big universe, they considered a fundamental question: is the universe the same everywhere? Imagine if gravity was stronger billions of light years away… Or in the past. It sounds like a simple question, but the answer has been tricky to unravel.

Ep. 123: Homogeneity
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Ep. 122: How Old is the Universe?

WMAP image of the Cosmic Microwave Background Radiation.

We did a wildly popular three part series about the center, size and shape of the Universe. But every good trilogy needs a 4th episode. This week we look at age of the Universe. How old is the Universe, and how do we know? And how has this number changed over time as astronomers have gotten better tools and techniques?      

Ep. 122: How Old is the Universe?

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Ep. 87: The End of the Universe Part 2: The End of Everything

Hopefully you've all recovered from part 1 of this set, where we make you sad about the future of the humanity, the Earth, the Sun and the Solar System. But hang on, we're really going to bring you down. Today we'll look far far forward into the distant future of the Universe, at timescales that we can barely comprehend.

Episode 87: The End of the Universe Part 2: The End of Everything
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Ep. 86: The End of the Universe Part 1: The End of the Solar System

This is a show we wanted to do since we started Astronomy Cast but we always thought it was too early. We wanted you to know that we're positive, happy people with enthusiasm for astronomy and the future. It's time for some sadness. It's time for a grim look to see what the future holds for the Universe. This week we stay close to home and consider the end of humanity, the Earth, the Sun, and the entire Solar System. Next week we'll extend out to the very end of the Universe.

Episode 86: The End of the Universe Part 1: The End of the Solar System
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Ep. 81: Questions on the Shape, Size and Centre of the Universe

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 at astronomycast dot com.

Episode 81: Questions on the Shape, Size and Centre of the Universe (14.7MB)
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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?

Episode 79: How Big is the Universe? (14.7MB)

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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?

Episode 78: What is the Shape of the Universe? (13.4MB)
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