Announcer: Welcome to Stuff from the Science Lab from howstuffworks.com.
Allison Loudermilk: This is Allison Loudermilk, the science editor at howstuffworks.com
Robert Lamb: This is Robert Lamb. I'm a writer at howstuffworks.com.
Allison Loudermilk: Today, we have kind of a fun way to start off our podcast about black holes.
Robert Lamb: How many people can you fit into a 1971 Volkswagen Beetle?
Allison Loudermilk: 16?
Robert Lamb: That may have been the record at one point but the record I read was actually 17.
Allison Loudermilk: Seventeen according to what record tracking body? Would this be Guinness?
Robert Lamb: This would be Guinness. They insist that all the people that you cram into the Beetle are neither under 5' tall or younger than 18 years of age. No filling it with midgets or babies because you could probably fit a lot of babies in a Beetle.
Allison Loudermilk: Especially preemies.
Robert Lamb: Yeah, you could really load up on preemies.
Allison Loudermilk: I think that record that you just spouted off is kind of weak actually because I was wondering around online and I came across the international world record breaker's club. This is kind of cool because if you wanna join, you have to be a world record breaker. I like that aspect of it. I was just perusing this record club's knowledge and they said that back in 1989, 354 people, not a single less, not a single more, from the middle school located in Chunet, this is somewhere in the U.K., I'm assuming. Yes, 354 peoples piled into a standard 56-seater London double-decker bus.
Robert Lamb: That's a lot. Of course, that's bigger than a Beetle.
Allison Loudermilk: Yes, it is. It kind of depends on the car. Even more, there was also a British Leyland Metro, a car by the name - have you ever heard of such a car?
Robert Lamb: No, I've never heard that.
Allison Loudermilk: Neither have I. I looked it up; it's a small car. I guess they kind of like this sort of thing in the U.K. There are about 21 members of the Plymouth Young Wives Association who packed themselves into this tiny Leyland Metro. That beats your record.
Robert Lamb: This got me thinking. Have you heard of the dance yet, too many men by Boy Better Know? There's too many man, too many, many man.
Allison Loudermilk: No.
Robert Lamb: Flight of the Conchords did a parody of it that I can't actually say that the title of the song. That got me thinking. This song is basically saying that there are too many men on the dance floor and that they need more women. I was just thinking like how many men is too many men? Apparently, I was looking into the Fabric Nightclub in London has a capacity of 1,800. I think 1,801 would probably be too many men.
Allison Loudermilk: I agree. I agree. Probably all of them are in spandex as well. That's what you have to do to squeeze yourself into a car. I was looking at pictures.
Robert Lamb: And if you allow babies in, like we say, that doubles the capacity.
Allison Loudermilk: Seriously, if you really wanna compress something into a tiny space, you're not gonna look at these babies in spandex or people piling into a car. You're gonna look to the black hole, which is the universal standard.
Robert Lamb: I thought you meant the nightclub, sorry.
Allison Loudermilk: No, not the nightclub but the cosmic phenomena.
Robert Lamb: With the power of a black hole, there's really no limit to the number of college students or dancers or babies or what have you that you could fit into a space. You could get them all into an area no larger than atom's nucleus and still have a few room for say a solar system or two. The key to the black holes is gravitational pull. The same force that holds us on the earth -
Allison Loudermilk: It's the same force that makes us trip and fall on our face occasionally or maybe that's just my clumsiness.
Robert Lamb: Yeah, but with the black hole, this force is infinite; not even light can escape it. It's that heavy. To understand how this happens, we have to start talking about the origins of a black hole.
Allison Loudermilk: Yeah, take us to the stars.
Robert Lamb: A black hole forms when a star dies. Basically what happens is the core of the star runs out of fuel and collapses. This sets off a shock wave. It blows out the outer layer of the star. We call this a supernova, a huge blast, very bright. Then stars' heart collapses when the rest of it explodes. As the core collapses, its gravity increases because it's getting denser. It'll eventually reach the point where the core is massive enough, there's so much mass just crunched down and it reaches a point where it has as much mass as about three suns.
Gravity gets so strong that right at the surface of the collapsing core, the escape velocity increases to the speed of light. Light cannot escape it. When a star burns to the last of its nuclear fuel, its own gravitational pull causes it to cave in on itself. If the core mass is large enough, the enormous star instantly collapses to a subatomic size called a singularity.
Allison Loudermilk: Instantly; we're not talking about say the aging process among humans when some little old lady is just getting smaller and smaller and more wizened by the year. This is instantly.
Robert Lamb: We're talking the estimates are 1/10th of a second to Â½ a second.
Allison Loudermilk: That's crazy. A black hole is some anatomical parts that will take you through. It's not just this massive darkness that's swelling up things wily nilly. It has an event horizon, which is basically signifying the opening or the surface of the black hole.
Robert Lamb: It's important to note that we're not talking about the surface of the singularity. This is the point at which everything speeds up to the speed of light as it approaches the singularity.
Allison Loudermilk: Good point. As Robert was talking about, you have the singularity, which is just this ridiculously tiny points smaller than an atoms nucleus. To which all that dying star stuff is condensed. Then you have the Schwarzschild radius. The idea roughly here is that if you're thinking about the black hole, say you're looking at it top down if that were possible to do, the Schwarzschild radius marks the radius of a sphere past which we can't get light, we can't get particles, we can't get any information. It was thanks to a scientist by the name of Schwarzschild.
Robert Lamb: The Schwarzschild radius is also really important in our ability to determine where a black hole might be located. We're only talking about the suspected black holes because it's physically impossible to see them. We can only look and sort of look at the areas surrounding where this black hole is suspected to be. This includes radiation given off by material rushing towards the event horizon. This includes the bending of light from other stars; we can basically see how the light moves in towards where the black hole would be. The movement of objects around a black hole and light speed jets of ejected material. You have everything surrounding it rushing in. We're able to perceive some of that energy moving.
Allison Loudermilk: Indirect observation.
Robert Lamb: We, of course, have to mention Einstein here because the black hole really comes out of his 1915 theory of general relativity. This is basically involves the idea that gravity and motion can affect the integrals of time and space. The first really good black hole suspect that we found was a Cygnus X-1. It's about 7,000 light years from earth. Ironically, Einstein himself did not believe in the existence of black holes, even though they were predicted by his theory.
Allison Loudermilk: Cygnus isn't the only black hole. Of course, black holes are all over the place, as far as we can indirectly observe. Astronomers have found a small black hole inside a star heavy cluster of space in the elliptical galaxy by the name of NGC 4472. It's an enchanting name if ever there were one. I'd imagine that would be climbing up the social security administration ranks of most popular birth names any day now.
Typically, scientists think that super massive black holes are found in the center of most galaxy. What's a super massive black hole? Black holes are gynormous, gynormous type things. To quantify that, a supper massive black hole is believed to be between 1 million and 1 billion solar masses. The scale of that is almost incomprehensible. Our beloved Milky Way Galaxy may have millions of black holes.
Robert Lamb: These are the questions. What happens to these black holes because it's easy to sort of think of this enormous event occurring, a black hole forming, and it's just going to eat and eat and eat until it just absorbs everything; it starts absorbing other black holes, etc. It doesn't really work like that. On one hand, like you mentioned, we have super massive black holes in the center of vast systems. They haven't eaten everything. They're not even in the process of eating everything. That's because everything sort of stabilizes after a while, I think.
You have a lot of matter falling into these things. It gets very hot. It gives off a lot of light. In the same way that solar wind can move an object. They say that this actually kind of ends up eventually cancelling everything out to where not as much stuff is coming in but the black hole is sort of maintaining and holding its own. Kind of like how Sean Connery stops being in movies though he's still a big star. Even a black hole has a finite life. We owe this to Stephen Hawking, who discovered that black holes should radiate energy due to a quantum mechanical process that we call a Hawking radiation.
However, when we're talking about a black hole eventually dying, we're talking a long, long time in the future. A black hole of the mass of our sun, for instance, would take more than a billion times the age of the universe to evaporate completely. Don't try and wait one out, it's all we're saying. That's the basics on black holes. Our knowledge and our theories regarding them continues to change as we make new observations and discoveries about the observable universe. That's it in a nutshell. A very compact -
Allison Loudermilk: Dense, dark nutshell. There you have it, Mark from Cincinnati. Your wish is our podcast. If you guys have any suggestions or any thoughts about black holes, send us an e-mail at firstname.lastname@example.org.
Robert Lamb: Check out the blogs where we'll keep you guys updated on what we're podcasting about and what's happening in the scientific world around us.
Allison Loudermilk: You can find all that and more on our home page, howstuffworks.com. Thanks for listening.
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