SGU Episode 356
I'm going to work on this one backwards, as usual, in the hope that someone else will work on it from the start. -- Rwh86 (talk) 17:51, 12 May 2012 (UTC)
Introduction
You're listening to the Skeptics' Guide to the Universe, your escape to reality.
This Day in Skepticism (0:28)
May 12, 1910 Today is the birthday of Dorothy Hodgkin
News Items
Dinosaur Farts (3:05)
http://www.rawstory.com/rs/2012/05/07/study-dinosaurs-may-have-caused-extinction-with-flatulence/
Aura Reading (9:46)
http://theness.com/neurologicablog/index.php/is-aura-reading-synaesthesia-probably-not/
48 Frames per Second (22:13)
http://phys.org/news/2012-05-high-cinema-booed.html
Baby Powder (36:00)
Killing Bigfoot (45:12)
http://io9.com/5907846/its-officially-legal-to-kill-bigfoot-in-texas
SGU Dinner at TAM 2012 (52:36)
http://www.amazingmeeting.com/TAM2012/program
Who's That Noisy? (55:11)
Answer to last week: Steve Spangler
Science or Fiction (61:54)
S: Let's move on to Science or fiction.
Iszi Lawrence: It's time for Science or Fiction.
S: Each week I come up with three science news items or facts, two real and one fictitious, and I challenge my panel of skeptics to tell me which one is the fake. We have a theme this week too.
R: Daah.
B: Yay.
S: You know, my themes are usually opportunistic, it's like whatever's there.
R: I was hoping to disabuse you of the theme habit.
S: No. This one, the theme this week is planetary astronomy. Phil Plait is going to be on our show next week, so I'm getting all the astronomy Science or Fiction out this week while he's not on the show.
R: Mmm.
S: OK, here we go. Item number one. Astronomers have demonstrated the ability to detect the composition of expolanet atmospheres by viewing massive lightening discharges. Item number two. Astronomers find that solar systems with so-called hot Jupiters do not have any other detectable planets in their system. And item number three. Astronomers plan to view the upcoming transit of Venus across the sun with the Hubble telescope by using the moon as a giant mirror. Jay, you're sounding sleepy so we'll get yours out of the way first.
J: So the one about the astronomers being able to tell things about an exoplanet's atmosphere by viewing the lightning, that is really cool and it makes sense because the lightning is going to interact with the atmosphere. So that makes sense, and I think that that is a very cool technique if indeed that's happening. So the one about the solar systems with hot Jupiters not having any other detectable planets in their system. Steve, would you care to tell me what a hot Jupiter is?
S: Yeah, a hot Jupiter is a Jupiter-sized planet that is very close to its parent star.
B: Bizarrely close.
J: That's interesting, I would think from my information that this one is fake because it's very rare, or I've never even heard of a solar system only having one planet. I wonder if the hot Jupiter is the result of say, all the planets colliding with each other or something like that, I have no idea, so. And then the last one. The one about using the moon as a giant mirror. Now we know that the moon is made of cheese, and if they use it as a mirror it could melt that cheese, and that could be delicious. I clearly don't know anything about that as well, I didn't read that, using the moon as a mirror, that sounds like Steve throwing a curve ball at us. OK, so I think that using the moon as a mirror is ridiculous, and I know that one is not the fake, so I'm going to pick the Jupiter one as the fake.
S: OK. Evan.
E: Demonstrate the ability to detect the composition of exoplanet atmospheres by viewing massive lightning discharges. Sure, I think they could actually do that. How the lightning discharges react to the elements in the atmospheres of those planets probably gives off specific readings. So I think that one's correct. Jay, you went with the hot Jupiters being the fictions. Don't have other detectable planets in their system. None? Seems extreme. So they ate up all the debris that would have otherwise turned into the planets? Boy I just don't know about that. It seems extreme. So I might be leaning with Jay in that regard. The last one, yeah I've heard about the upcoming transit of Venus, but they're going to point Hubble at it using the moon as a giant mirror. I think so. So I'm leaning towards that one being science as well. Oh, I might be leaning with Jay about the Jupiters, the hot Jupiters, but there's something about the giant mirror that I have no idea how they would really accurately do that. And why would they do that, wouldn't there be, don't they have other telescopes that they can do this with, do they have to really use Hubble specifically or is this just an exercise of some sort? Maybe they're going to use it as an exercise. Oh crud, I have to guess. I'll say Hubble telescope as a giant mirror. I'm going to guess that one's fiction.
S: OK, Rebecca.
R: Uh yeah, we've been talking about trying to film something about the transit of Venus, and not we you guys and I, but my partner and I. And we've been talking about the difficulty of doing that because you can't just point a camera at the sun. Um, which yeah I assume is the problem with Hubble, so using the Moon as a giant mirror sounds like a really cool way for them at least to get around that. We can't use it, but that makes sense to me, it seems like a really great idea. So I was torn between hot Jupiter and exoplanet atmospheres, and hot Jupiter thing makes sense like Evan mentioned, maybe it collects all the mass that would have otherwise formed planets, it could collect all the mass into the hot Jupiter and then any moons that planet might have, I don't know. Um, I like the idea of detecting the composition of an atmosphere by looking at the lightning discharges. My question is whether or not we would be able to get a clear view of those storms. You know, we can see the storms on our actual Jupiter, but can we see the storms on exoplanets? I'm not really sure about that. So I'm thinking maybe that one is that astronomers have suggested that that is a thing that they could do in the future but I don't know that they've actually managed to view storms yet. So, I was thinking that's the fiction. So I'm going to go with that one then at the very least Steve doesn't have a sweep this week.
S: Nice.
R: And that's what really matters.
E: All right, Bob give us the reveal.
S: I prefer the even spreads, means I did a good job. Yep, three-way tie bob, you're the tie-breaker.
B: The transit of Venus across the moon. Yeah, I can kind of see that. I would think that you would need a very very accurate mapping of the moon so that you could predict the paths of the reflected light so that you could then reconstruct the image. I don't know what resolution you would need in order to do that, but it seems feasible. The second one, the hot Jupiters, this one makes sense to me as well because I believe the theory is that for these hot Jupiters to get so close to the sun it's going to have to traverse through the solar system to get down there somehow and I would think it would kind of make sense that, if I'm remembering correctly, that if it did do that then I could see how it would potentially disrupt other planetary orbits, possibly eject them or merge with them, so that kid of makes sense. Plus they're saying detectable planets. There could be small planets that we can't detect yet. So that can kind of make that work out in my mind too. The first one, I just totally agree with Rebecca on that, yeah we could determine if exoplanets have atmospheres, what temperature possibly the planet is, but detecting lightning discharges on an exoplanet? I don't think we could do that yet, I mean it's just so far away. For that reason, I'm going to say that that is fiction.
R: Woop!
S: OK.
R: GWR, that's right.
S: Got two people on number one, we'll take them in reverse order.
B: You went with me in my mind.
R: So awkward.
S: Astronomers plan to view the upcoming transit of Venus across the sun with the Hubble telescope by using the moon as a giant mirror. Evan, you think that one is the fiction.
E: Not any more.
S: And that one is... science.
R: Aw. Yay!
E: See, I got it right.
S: This one is science.
J: Oh, awesome.
S: Yeah, they recently pointed the Hubble at the Tycho crater, not because they were interested in Tycho, even though it's cool.
B: Oh, just using a crater, sweet.
S: Yeah, but using it as a mirror to look at the transit of Venus which is coming up on June 5th or 6th and Bob and Rebecca made a lot of interesting points that are correct, that you know obviously you can't point the Hubble at the sun, it will fry it. You have to look at it indirectly. Do you guys know why they're doing this?
E: To see if they cab.
B: Uuum.
S: Yeah, pretty much. But they want...
R: Probably to learn more about Venus I assume.
S: No. It's not to learn more about Venus, really.
B: How about the test, to test transit method technologies, for detecting exoplanets.
S: Exactly, exactly.
R: Aaah.
S: They're doing this to test methods for looking at the atmosphere of exoplanets as they transit, so they're essentially using Venus as an example of an exoplanet transiting its sun, its star. And they want to see if they can tell, they want to see what the chemical make-up is of Venus', we know what the chemical make-up is of Venus' atmosphere.
B: Confirm it.
S: But what they specifically want to see, if they look at Venus with this technique, will it show signs of life? Now we know there are no signs of life on Venus so if it shows features that we would otherwise attribute to life that would make us more cautious about that interpretation if we get the same, similar results from exoplanets. So this is just informing us, it's like a control, so we know how to interpret using a similar technique, we could look at the starlight shining through the atmosphere of an exoplanet as it transits, as it passes in front of its star and then because of spectroscopy we could see the chemical make-up of the atmosphere and but you know, it's just refining that technique so that we know how to interpret it when we do it on exoplanets.
B: Great idea.
S: Yeah, is that cool?
R: Yeah, very cool.
S: Let's go back to number two. Astronomers find that solar systems with so-called hot Jupiters do not have any other detectable planets in their system. Jay, you think this one is the fiction and this one is also science.
J: Hey!
R: Woo Bob, high five.
(clap)
R: A little off, but that's all right.
B: Yay.
S: Yeah, this one's also interesting, I had to track down the original article again because I wanted to see exactly what did they determine here and how did they determine it? But what astronomers did was very interesting. This hypothesis has been out for a while, in fact I remember when I first heard it. This is like in the early days of detecting all of the exoplanets that we've been detecting. Some of the first worlds that we discovered were these hot Jupiters, you know Jovian-sized planets very close to their star. And even at the time astronomers were hypothesizing that, well probably what's happening is they're forming farther out from the star like where our own Jupiter is and then because of interactions among the planets, they're spiralling in to this very, very close orbit and on their way they'd kick out all the other planets. And so, if most systems, if this were typical, it might be that most systems out there would consist of just Jovian planets close to their suns and no other planets. And I was like, oh if that's true that would suck, that would really tank the Drake Equation in terms of the probability of there being life out there. But it turns out this is a rare situation. Something like one percent of stars that we've investigated so far have this configuration, just this one solitary hot Jupiter very close to the sun. So that's good.
B: Luckily our Jupiter didn't do it.
R: Yeah, suck it Jupiter.
S: Exactly. So what the astronomers think is that the hot Jupiters started out in a very elliptical orbit and then the tidal forces as they pass close to their star dragged them into a more and more circular and very close orbit and over the millions of years where that happens they interact with the other planets that would be in the inner solar system, especially Earth-like worlds in the Goldilocks zone, and they kick them out. But this isn't just theoretical, and that's the thing I was interested in. They actually looked over data of exoplanets and they found that in all of the systems that we have discovered so far with a hot Jupiter, they found no evidence of any other planets in the system. Then as controls they looked at systems that had warm Jupiters, Jupiters that are farther out from the sun and about 10% of them had evidence for other planets, and they looked at hot Neptunes, so smaller planets, still gas giants but much smaller than Jupiter, close to the sun, and 30% of them had signs of planets, other planets in the system. So they think that their techniques are working, that they would detect planets if they were there, but the systems with hot Jupiters just don't have them. Now of course, this doesn't tell us anything about planets beyond the orbit of the Jovian worlds, so there could still be Plutos out there whether they are planets or dwarf planets. But it does mean in a system with a hot Jupiter, there is no Earth in the Goldilocks zone, probably. That's what that means. Sounds interesting, it's observational not just theoretical. All of this means that astronomers have demonstrated the ability to detect the composition of exoplanet atmospheres by viewing massive lightening discharges is fiction. And everybody in fact was correct, just Jay and Evan, you focussed on the wrong thing. Yes, this technique should work, the lightning is interacting with the atmosphere and we can tell what chemicals are in the atmosphere like oxygen or methane or carbon dioxide by examining the interaction with the lightning. But astronomers are talking about looking at lightning in the atmosphere of planets in our own solar system from probes in orbit around those planets, so very close. Doing this sort of analysis in planets, in exoplanets you know, around other stars is hopeless, I mean they're so far away that they're not even talking about that. They're talking about close-up images of worlds in our own solar system. So good work Bob and Rebecca.
R: Thank you.
B: Thank you.
Skeptical Quote of the Week (76:21)
S: So Jay, do you have a quote this week?
J: I have a quote sent in by a listener named Ulrich Fisher from Surrey, B.C. Canada.
E: From the Northern Realms.
J: The quote is:
Skepticism is the highest duty and blind faith the one unpardonable sin.
J: Who was that written by, Steve?
S: I believe that's a quote from T. H. Huxley, my fave...
J: Thomas Henry Huxley!
(laughter)
E: That's what the T. H. stands for.
S: My favourite philosopher. Darwin's bulldog.
B: Yeah.
J: T. H. Huxley is going to be at TAM this year.
S: (laughing) I wish. All right, well thanks Jay, that's a good one this week, and thank you guys for joining me this week.
B: Yeah, it's a good episode.
J: Thanks, Steve.
R: Thank you, Steve.
E: Hey, it's good to be back at the computer.
S: And until next week, this is your Skeptics' Guide to the Universe.
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