030514 01:01 UT NOTE: A better formatted script is coming soon.. Black Hole In the Corner Pocket Episode #1 Written by: Aaron Price Aaron: (in distant background): Okay, this is our last take. If you don't get it right this time I'm going to pull the plug on the whole show and go back to training helper monkeys for a living. 3-2-1-cue music (music) Pamela: Welcome to Episode #1 of Slacker Astronomy, a podcast about astronomy and just about anything else that floats over our heads. Travis: Every week or so we will bring you a summary of a recent news event from the realm of astronomy. And during slow news weeks, we will prank call astrologers. Pamela: This week's show is about a new discovery involving black holes, one of the sexiest objects in astronomy. Without black holes, and their imaginary white hole cousins, many a science fiction writer would be out of a job. Travis: Also, many of the most powerful, exciting and exotic phenomena in the Universe wouldn't occur. Objects such as hyper-novae, gamma-ray bursts and quasars all owe their existence to black holes. Pamela: One of the most interesting effects caused by some black holes and other objects in gravitational lensing. With this effect, the gravity of a black hole acts like a giant lens, focusing light from the Universe beyond. Travis: Say you are looking at something very, very far away. Pamela: Like a democrat winning an election? Travis: Not that far. Like something 5 billion light-years away. Now imagine a supermassive black hole is between that object and us. The light from that object would normally spread out in all directions, going to visit all the many corners of the universe, but in some cases, the gravitational pull from some âbig ol € ™ object like a black hole my force that light to bend toward us rather than going where it would normally go. Pamela: This strong-armed light is modified in various ways as its path is bent. Sometimes it is spread out into a beautiful arc. Other times, the object appears cloned in space so we see 4 of identical images in a diamond pattern, instead of just one. We have pictures and diagrams of this in the show notes on our site. Travis: Any object with a lot of mass can cause gravitational lensing. In fact, some objects, like dark matter and very dim stars, can only be detected when they are gravitationally lensed. Pamela: Our Sun can act as a gravitational lens. This was a lucky thing for Einstein, whose theory of General Relativity predicted gravitational lens. During a 1919 solar eclipse, Eddington observed our Sun gravitational lensing background stars. Travis: So you should just tell anyone who doubts Relativity to just go stare at the Sun to see Relativity in action. Pamela: Although you may want to tell them to use safety glasses. Travis: Or not. Pamela: Or not. The former head of NASA, Dan Goldin, even talked about creating a space telescope that uses the Sun as its lens. Travis: A camera would be flown way out of our solar system, ten times further out than Pluto and 500 times further out from the Sun than the Earth. At that distance the Sun would be appear as bright as other nearby stars, but it would act as a gravitational lens for objects behind it. Pamela: But that is truly a high concept proposal that we likely won't see in our lifetime. But maybe in Dick Clarks! Travis: Astronomers have known about Gravitational Lensing for a while and lenses to make many pretty pictures to sell as posters. They have to pay for their telescopes somehow! Pamela: They should use credit cards like the rest of us. Travis: You can't run up 200 million dollars on a credit card! Pamela: Tell my ex-husband that! Travis: You mean he's still alive? (You left him alive?) Pamela: Only if you consider a vegetative state as living. Aaron: Hey, guys â € ¦ uh back to the show? âTravis: Okay, slave driver- I mean Aaron. Aaron: That's € śMr. Slave Driver â € ť to you. Pamela: Better than â € śMy Liege â € ť as it was last week. Aaron: I'm feeling charitable, now back to work. (whip sound) Travis: Okay, I've figured out how to cut this show short. Want to know what a black hole is? Look in Aaron's heart! (your heart is empty hole, mr grinch - cue at 00m:39s ) Pamela: Since it seems I'm the only professional here, I'll get the show rolling again. Where were we? Oh yeah, black holes and gravitational lensing. So astronomers have known about gravitational lensing for a while and have been taking looking for them, and for ways to use them when doing studies of distant objects. Travis: But this week some mathematicians announced that black holes can throw some curve balls almost as well as Randy Johnson. Pamela: It began four years ago when physicists discovered that some materials negatively refract light. Imagine looking at a pencil in a glass of tap water. Travis: In Boston water you wouldn't be able to see the pencil. Pamela: Okay, imagine using bottled water instead. The pencil looks like it is broken at the water line. The bottom part of the pencil does not line up with the top. This is refraction at work. In negative refraction the submerged part of the pencil may look like it is pointing at a different angle, maybe even sideways. Travis: This month, Dr. Akhlesh Lakhtakia at Penn State and Tom G. Mackay at the University of Edinburgh published a paper in the New Journal of Physics predicting that massive spinning supermassive black holes can do the same thing to light that passes at a certain angle. Pamela: So now, not only do we have black holes bending light toward them, they can now also bounce light away from them. Now what happens if the bounced light of a distant quasar reaches the Earth? Travis: We see it as a normal quasar. Pamela: So then what about all the quasars we see in the sky? How can we tell which ones are really there and which ones just look like they are there because they have been bounced? Travis: Exactly. This means that when astronomers look at objects that are very far away, they now have to somehow take into consideration that they may be looking at a reflection and not the real deal. Pamela: This could be a big deal because quasars are fundamental distance markers. Our knowledge of them affects many key areas of astronomy. So now the theorists will have to find a way to detect if a distant light source, such as a quasar, has been effected by an intervening black hole or not. Then the observational astronomers will have to look for the effect. Travis: But there is some debate about just how significant this may be. The Universe is huge and contains many black holes. At one point in the very distant future there will be nothing left BUT black holes, neutron stars and cold black white dwarfs. But the black holes we â € ™re worried about have to be supermassive, spinning and just happen to be in the right position to bounce the light off that object to us. They also can â € ™t be associated with a lot of other matter that might distort the light from the background object. Pamela: Some scientists think this will probably never be positively detected by us while others, including the authors of the paper, think that so many supermassive black holes exist that we'll never be able to see to the positions of things at the earliest days of the Universe because eventually everything gets its light bounced by a black hole. This means we can â € ™t trust our measurement of the position of anything that is far away. Travis: The key will be to find some a tell tale signature in the way an object looks if it has been bounced by a black hole. Surely there has to be some effect on its spectra or something. Slacker Astronomy will keep an eye on the papers and give you updates as they come along. Pamela: For a price, of course. This isn't a free service. Travis: It's not? Then we can no longer claim people get what they pay for! Pamela: What we ask is that you let your friends know about this show. If you like it, that is. Travis: Why did you have to go and add that? Now no one will say anything to anyone. Pamela: Honestly though, we have been overwhelmed by the response we have received from all you kind folks out in cyber land. The letters you have sent us have really meant a lot. Thank you. Travis: Although we sometimes wonder if they are being sent to the wrong show. They're just too darn nice! Pamela: The best way we can make this show a success is through positive word of mouth. So if you like it, mention it on your blog, to your friends, on an e-mail list, etc. We would really appreciate it. Travis: You'll be doing a good deed for Boston too. Recording this show keeps us off the streets for one night a week, much to the rejoicing of every singles dive bar in town. Aaron: You know guys, I'm sorry I've been cranky and a jerk this week. But, it €â ™s just that when writing about black holes I get so depressed. I think of what Nietzche said, "take care not to become a monster too, for if you stare long enough into the Abyss, the Abyss stares also into you." I think black holes were having an effect on me. Now that the show is over, I just wanted to say to both of you... I love you guys! Travis/Pamela: No you can't have our bud light! Travis: This is Travie Searle, Pamela: Pamela Gay, Aaron: and Aaron Price, the imperial slacker astronomy Slave Driver. Pamela: Thanks for listening, and remember, we want you to Spam! Travis: Clear Skies and Clear Bandwidth. This has been the first official episode of Slacker Astronomy, a volunteer collaboration for you, for fun, for the voices in our heads. (mr grinch 01:10--01:51)