SGU Episode 526

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SGU Episode 526
August 8th 2015
(brief caption for the episode icon)

SGU 525                      SGU 527

Skeptical Rogues
S: Steven Novella

B: Bob Novella

C: Cara Santa Maria

J: Jay Novella

E: Evan Bernstein

Quote of the Week

The truth, especially when painful, can wake us from the slumber of self-deception.

Baroness La Valette - Witcher 2

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Show Notes
Forum Discussion


You're listening to the Skeptics' Guide to the Universe, your escape to reality.

Forgotten Superheroes of Science (1:39)[edit]

  • Inge Lehmann: Was a Danish Seismologist who revolutionized our understanding of earth's interior when she discovered that it has a solid inner core

S: But first, Bob, we have a Forgotten Superhero of Science for this week?

B: Yeah, this week, for Forgotten Superheroes of Science, I will talk about Inge Lehmann, who was a Danish seismologist who forever changed our conception of Earth's interior when she figured out that our core was not all molten.

S: Hollow?

B: No, not at all.


S: No?

E: Made of cheese?

S: But some cartoonists told me that it was hollow!

B: She figured out that our core was not all molten, but it had a solid inner core. Ever hear of her?

S: Nope

B: Inge was born in 1888, and died in 1993. Yes,

E: Wow!

B: she was a hundred and five years old.

S: Wow

C: Wow!

B: It's a hell of a good run. She actually had an atypical early education for her time period. She went to a very progressive school, where boys and girls were treated exactly the same.

E: What! In the 1890's?

B: Yeah, right?

E: Dear god!

B: That's incredible. But it's funny, because that made her career later on all that more jarring when she saw the disparity between men and women in the mathematical and scientific community. But, as I said, her magnum opus of her career was her discovery of Earth's core. Seismology, which studies the propagation of energies with the Earth, caused by earthquakes or explosions, can give us clues to the internal structure of the Earth. And those clues, up to that time, had indicated that the core was all molten, and that's what everybody believed. That was the consensus.

But she saw something different though. She was looking at the waves that are most important for determining what our planet's interior is like. And you may have heard of these: These are P-waves and S-waves. And these are very important. The P-waves are, they're the primary wave, they're the fastest. And they're compression waves, like sound, compression and rarefaction. They vibrate in a direction of movement. And they can go through solid and liquid, whatever. But they are refracted a bit at boundaries.

The S-waves though, are also produced. They're secondary waves, they're slower, and they have this up and down motion, kind of like ocean waves. And these waves do not go through a liquid at all. So, because of how these waves act, there are shadow zones on the other side of the planet. So if there was an earthquake right here, right now, at the other side of the planet, there would be a shadow zone, where the P-waves and S-waves should not appear, if you have your little seismographs planted everywhere, you would not see them.

But sometimes, scientists did see some very faint P-waves where they should not have appeared. And they assumed that that was just instrument error. But Inge refused to make that assumption. She didn't believe it, and she treated it like a mystery that needed solving. So after a really notable earthquake in New Zealand, in the late 1930's, she looked at the P-waves that showed up where they shouldn't, and she realized that the only way to really explain it, or the best way to explain it, was that there had to be a solid inner core within the molten, outer core. And the boundary between those two materials would be refracting the P-waves, and changing their course, and sending them into the areas where the seismographs were, where they shouldn't go, if it was all liquid.

And she was correct. She basically made history. And after a few years, pretty much everybody believed her. And I think it was in 1970 that it was absolutely shown for certain that she was exactly right. So, an amazing discovery. So, remember Inge Lehmann; mention her to your friends, perhaps when discussing the refraction of body waves in seismic tomography.

S: Yeah, it's

B: Very cool.

S: neat, because it's one of those things where it's like, how do we know what the center of the Earth looks like? You always see those cut-away diagrams, and you just accept, that is the Earth, that's what it looks like. But it is interesting how scientists pieced together that that's what the interior of our planet is actually

B: Oh yeah!

S: like.

B: I was explaining it to a friend at work, about the core, and she was like, “What's the core made of? Unobtanium?” And I laughed, and I said, “Oh, actually, in a sense, it is. Because we will never see it, or sample anything down that far. But like a lot of science, you can infer incredible detail about something, by looking at it indirectly, and trying to find other ways to figure out what's down there, or what it's made of.

S: But wait a minute, Bob. I saw that movie, The Core, (Bob laughs) where they just drilled through the center of the Earth. That's not real?

C: I thought that's how you get to China, right?

E: That's one way.

B: No comment.

S: All right, thanks, Bob.

B: That movie, I actually saw – that movie was actually better than anticipated. It was still kind of crap, but

S: Well, you must have thought it was really good. It sucked.

(Bob laughs)

E: Oh my god! It went from unwatchable to terrible.

B: It was goofy, and, you know, of course, I had no expectations.

S: (Chuckles) All right.

E: Based on a true myth.

News Items[edit]

Mystery Booms Solved (6:32)[edit]

Convincing Antivaxxers (12:26)[edit]

Needle Exchange Efficacy (25:00)[edit]

S: Speaking of which, Cara, this is kind of related, in a way.

C: Yeah!

S: You're gonna tell us a little bit about the science behind needle exchange programs.

C: Just like you said, speaking of people being reasonable, we're seeing a recent uptick in reason, in Indiana, actually, of all places. But also in Kentucky, and even potentially in West Virginia. So, based on a really great story in Scientific American that actually cites a Reuters story; recently, like, within the last year, there's this county in Indiana called Scott County. And they had a massive increase in HIV cases. Like, it went from something like five in a year, to a hundred seventy-five. And they were like, “Oh god!

B: Whoa

C: What's going on?” Yeah, and so they did a little research, they realized that it really seemed to be linked to IV drug usage. And so, they said, “You know what? We're gonna try this. We're gonna do a needle exchange program here, and we're gonna see what happens.” And it worked!

B: Wow!

C: Because we know that they work! And this is not new. If you research, if you go online, and you start researching needle exchanges, and what's the efficacy behind them, what do we know about them? I mean, this research dates back to kind of like, the late eighties, when these things first started coming about.

S: Actually, Cara, can I tell you, it goes back even farther than that, because we have evidence from needle exchange programs for other

C: Oh!

S: blood-borne illnesses,

C: Sure!

S: like Hepatitis

C: Hepatitis!

S: Yeah,

C: Yeah

S: before, so even before HIV, we knew that needle exchange programs worked.

C: And so, part of the kind of, the detractors of these programs are the people like - I'm going to cite one here – Kentucky State representative Stan Lee. I love that his name is Stan Lee!

(Evan laughs)

C: He says quote, “Really? You're encouraging drug use.” Endquote. And I'll tell you that study after study after study shows that

S: So there were three studies.

C: There were three, on top of three, on top of three. They show over and over that injection drug users, HIV, and actually Hepatitis, and other types of IV-borne pathogens are less likely to spread through needle exchanges, and they have no effect on over all drug use.

B: Wow!

C: No effect. If you provide needles, you are not gonna have more heroin addicts. It just doesn't work that way.

E: Let's see, data versus the opinion of someone who has no idea what they're talking about. Hmm...

C: Exactly.

E: You decide who (inaudible)

C: Also,

J: I can understand why people say things like that, and come up with their own conclusions, because it's not really intuitive.

C: Yeah! It sounds kind of reasonable, right, that if you offer needles for free, to people who use drugs, more people are gonna want to stick those needles in their arms. But the truth is, it's not that they don't have access to needles; it's that they don't have access to fresh, clean needles. People will reuse needles. It happens all the time.

And so, there was a World Health Organization, that kind of talks about the effects of a lot of different studies, sort of a meta analysis. And they found kind of certain, like a handful of certain recommendations for a lot of different countries. So, the first one, is they said, there is compelling evidence that increasing the availability in utilization of sterile injecting equipment by injection drug users reduces HIV infection substantially. Again, all those three studies – study after study after study – say yes, this reduces HIV.

There is no convincing evidence of any major unintended negative consequences, like increased drug use. They also say that needle-syringe programs are cost-effective. And of course, this makes sense. Even though it takes an investment by the federal government, or the state governments, to have these fresh, clean needles available, these sterile needles, it still is going to be significantly less money than how much it costs to actually treat an HIV-infected person over the lifetime, which is something (I had the number pulled up recently), I think it was something like a hundred ninety-eight thousand dollars.

Another one is that needle-syringe programs have additional and worthwhile benefits apart from reducing HIV infection. So, having a needle exchange program can actually catch some people in the community who aren't already in treatment. And so you actually will see an uptick in the number of people who go to drug rehab, because they can go to these needle-exchange programs, and there can be counselors present. And you'll see more people signing up for that.

Another interesting thing that I wouldn't have thought of, bleach, and other forms of disinfection are not supported by good evidence of effectiveness for reducing HIV infection. So, anybody, you know, any, sometimes you'll see these politicians who say, “We can't provide these drug users needles. We're just encouraging drug use. Just, let's teach them that they should be cleaning their needles, or maybe let's give them bleach.” Um, no. It actually does not reduce the risk of HIV infection.

And another one: Pharmacies and vending machines increase the availability and the probability of utilization of sterile injecting equipment. So just having these needles available readily in pharmacies, no questions asked. “Can I buy some clean needles?” Actually, we do see an improvement in HIV outcomes there.

Injecting paraphernalia legislation is a barrier to effective HIV control. This makes sense, right? So, when you have these politicians saying, “Not only are we trying to, we have these clean needles available. We're telling drug users 'It's okay to use drugs.'” But they sometimes will go a step further, and say, “We should arrest somebody if they have a dirty needle on them, or if we find them carrying needles.” That's not going to help. It's not going to help prevent the spread of HIV.

And then, lastly, and I think this is an important one, and it's always a hedge our bets kind of thing, that the World Health Organization does: Neelde syringe programs on their own are not enough to control HIV infection among intravenous drug users. So, of course, even though needle-exchange programs work, they're not a cure-all. And we have to remember that, that we still need good treatment strategies, and good community support available.

But, going back to this first story that I was reading about in Scientific American, it's a really great example of kind of legislators on both sides of the aisle looking at the evidence, realizing that these programs work. They can significantly reduce the number of HIV infections in their regions, and adopting these policies. And we're seeing it happen throughout the country, even in very conservative areas.

S: What amazes me more is when a politician stands up in front of cameras, and makes a factual claim that they could easily find out is dead wrong.

C: Yeah!

S: You know? Like, this

C: Like Stan Lee!

S: Yeah, “This is going to encourage people to use drugs.” No, that's a factual claim, and we know that it's wrong! There have been – as you say – the evidence is quite clear. People are -

C: For decades!

S: Yeah, people aren't gonna start doing IV drugs because there's a needle-exchange program. That's not the barrier to them starting to use IV drugs. It's ridiculous. And the empirical evidence doesn't show it. So, I mean, don't these people have staff that could check this out for them, before they get up there and make an ass of themselves? But I suspect they don't care. I mean,

C: No, I think it's both, honestly.

S: Yeah

C: I think it's that truthiness thing that Colbert talks about,

S: Yeah

C: you know? It's that legislating by our guts. And I think that this is why the skeptical movement is so important in politics and public policy. You know, we talk about it a lot when it comes to science-based medicine. We talk about it a lot when it comes to people not being taken advantage o by charlatans, and by hucksters.

But I think we need to be pushing our politicians more and more to look at the evidence, and start legislating based on evidence!

S: Yeah, evidence-based government.

C: Not – yes!

S: Exactly.

C: It's so important! And it's, for whatever reason, we're just really bad at it here in the US. We kind of have a system that celebrates legislating based on emotion.

S: Right

C: And I have a big problem with that. And there are other countries, especially in the west, you know, other European countries who do this so much better than us.

Life on Earth's "Cousin" (33:32)[edit]

Who's That Noisy (41:02)[edit]

  • Artificial singer

(Commercial at 44:13)

(Membership drive at 45:32)

Interview with Jamy Ian Swiss (46:12)[edit]

Science or Fiction (1:08:05)[edit]

Item #1: New research finds that romantic kissing (lip-to-lip contact) occurs in less than half of human cultures surveyed. Item #2: Recent historical analysis finds that medieval alchemists were often practical chemists, but disguised their recipes with fanciful code to protect their intellectual property. Item #3: Scientists have found that horses have as many “discrete facial movements” used in expressing emotions and social cues as do chimps and humans.

Skeptical Quote of the Week (1:27:59)[edit]

'The truth, especially when painful, can wake us from the slumber of self-deception.'Witcher 2 - Baroness La Valette

Announcements (1:29:01)[edit]

  • Live show at Long Island Convention next week

S: The Skeptics' Guide to the Universe is produced by SGU Productions, dedicated to promoting science and critical thinking. For more information on this and other episodes, please visit our website at, where you will find the show notes as well as links to our blogs, videos, online forum, and other content. You can send us feedback or questions to Also, please consider supporting the SGU by visiting the store page on our website, where you will find merchandise, premium content, and subscription information. Our listeners are what make SGU possible.


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