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Scientists & Engineers On Sofas (And Other Furnishings): Black Holes And Coffee

8 minutes

(Describer) In an animation, two people carry a sofa, then drop it. Two legs on one side of it break. The people walk away. Title: Scientists and Engineers on Sofas and Other Furnishings. A chain and hook from the first E in “Engineers” lifts the fallen side of the sofa.

(female) Sometimes you can't know a scientist until you sit down with him. I'm Ivy Kupec. I work for the National Science Foundation. A cool astronomer named Dan Evans is a Program Officer here from the Smithsonian Institution, where he normally studies black holes. I've wanted to know more about black holes, so who better to ask?

(Describer) She enters his office.

Hey, Dan. Hey, Ivy, how's it going? You want to go get coffee or tea? Yes, sure.

(Describer) They leave.

How's your daughter? Been building any forts lately? Yes, she's a Lego genius.

(Describer) Soon after, they get take-out coffee.

(Kupec) I had this dream the other night, I don't know if I told you.

(Describer) They head down a hallway.

I was on the edge of the earth because we were about to fall into a worm hole.

(Describer) On a sofa...

The whole planet was. It seemed funny because I was thinking earlier about your black hole research. What is a black hole exactly? If they're black, how do you see them? A black hole is a region of space and time that is so infinitely dense that nothing, not even light, can escape it. That means that black holes, by their definition, are black. Although black holes are black, they're simple objects. They glow like fireworks in x-ray light when a material falls down them. Imagine watching water go down a drain. The water starts by swirling very slowly. As it approaches the center of the drain, it rapidly spins. Very similar in a black hole. As material falls down, it rubs together so ferociously, with so much viscosity and magnetic fields, that giant bursts of x-ray flares are released just as the material takes its death plunge into the hole. How do black holes come to be made?

I knew you were going to ask me that. [Kupec laughs]

Tough question. There are different theories. There are two different types of black holes-- stellar-mass and supermassive. The stellar-mass ones have pretty small masses, between 4 and 20 times that of our sun. The supermassive are billion to million solar-mass beasts. They probably have very different origins. The stellar-mass black holes, we think they originated when a star exploded into a supernova and the resulting collapse created the black hole. For the supermassive ones, it's anybody's guess. The best theories are in the infinite universe, there were massive halos of dark matter that collapsed underneath their own weight, and because the densities were so high, the black hole formed at the center. Do they bump into or merge with each other?

(Evans) They merge often, we think. They spiral around each other in a cosmic dance before coming together and merging with a ferocious release of gravitational radiation, which we're trying to detect. Are there a lot of them in the universe? Yes, every single galaxy that we know of hosts a supermassive black hole at its heart. The mass of that black hole is between a million and a billion times that of our sun. We know easily of 300 billion galaxies. That's just the fraction we've observed. There are probably infinite numbers of galaxies and, therefore, infinite numbers of black holes at their hearts. You had a picture of your daughter during a talk. Young children, through their eyes, it's best to think about things like black holes. Am I recounting correctly? What I always say is that our children make great astronomers because they view the world with such simplicity. It's actually true. She's 2 1/2, and she'll point at something and say, "Big truck." It's wonderful. You get two parameters. Black holes aren't much more complicated. They're probably the simplest objects in the universe. Then why don't we understand them? The devil's in the details. Black holes are fully and completely described by just three quantities: their mass, their spin-- their angular momentum, and their charge--that's it. You try describing anything with just three parameters. You can't do it. What is some of your research, specifically, with black holes? What I've tried to do is understand how the black holes are spinning. This is a fundamental test of Einstein's general theory of relativity. If we can measure the spin of a black hole, compare to his predictions, then we can begin to understand whether general relativity is correct or whether we need a modification. I've also spent a lot of time investigating jets. Jets are awesome. Material falls into the black hole, and at the vicinity of the black hole giant jets are shot off. They race outwards at almost the speed of light. They can go out many millions of light years. What's on the horizon for black hole research. It's interesting you use that word, "horizon." The next big thing with black holes is to image one. Oh, of course. It might seem like a flight of fancy to construct a telescope the size of the earth, but teams of astronomers are planning just that. Obviously, they're not going to cover the globe with concrete, but they can link together, digitally, different telescopes across the world to synthesize one giant telescope with a diameter that's equivalent to that of the earth. The idea behind it is that you need such a massive diameter to have such sharp resolution that you can image the actual sillhouette of a black hole. It's gonna happen. I'm convinced of it. It'll probably happen within the decade. We've made a massive award within our division to enable one such telescope called the Event Horizon Telescope. We are completely excited about what it's gonna do. We're kind of giddy over it.

(Describer) Later, they carry their coffees out of an elevator.

(Evans) This was fun. (Kupec) We should do this more.

(Describer) They shake hands.

All the best. Take care.

(Describer) He walks off through a lobby to a pair of glass doors, one of them open.

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Over a cup of coffee, astrophysicist Dan Evans chats about black holes, his current research in space sciences, and what he thinks the future holds. Part of the Scientists and Engineers On Sofas Series.

Media Details

Runtime: 8 minutes

Scientists & Engineers On Sofas (And Other Furnishings)
Episode 1
8 minutes
Grade Level: 10 - 12
Scientists & Engineers On Sofas (And Other Furnishings)
Episode 2
9 minutes
Grade Level: 10 - 12
Scientists & Engineers On Sofas (And Other Furnishings)
Episode 3
6 minutes
Grade Level: 10 - 12
Scientists & Engineers On Sofas (And Other Furnishings)
Episode 4
6 minutes
Grade Level: 10 - 12
Scientists & Engineers On Sofas (And Other Furnishings)
Episode 5
7 minutes
Grade Level: 9 - 12
Scientists & Engineers On Sofas (And Other Furnishings)
Episode 6
8 minutes
Grade Level: 10 - 12