SGU Episode 524

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SGU Episode 524
July 25th 2015
(brief caption for the episode icon)

SGU 523                      SGU 525

Skeptical Rogues
S: Steven Novella

B: Bob Novella

C: Cara Santa Maria

J: Jay Novella

E: Evan Bernstein


GH: George Hrab

JR: James Randi

RH: Ray Hyman

Quote of the Week

'It's OK to fool people, as long as you're doing that to teach them a lesson which will better their knowledge about how the real world works. No matter how smart or well educated you are you can be deceived.'

James Randi

Download Podcast
Show Notes
Forum Discussion


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

Announcement (0:58)[edit]

S: But you know, for a while now, many of you have noticed that there's just been four of us on the show. And there's been, some have said, a hole, or at least room to expand our awesomeness is how I like to think about it.

(Jay chuckles)

S: So, we do have an announcement to make: We have added our fifth, permanent rogue to the SGU. And we are going to reveal them to you live, here on stage at TAM 13. Now, to honor James Randi, we're going to do the reveal as a magic trick.

(Audience laughs)

S: Gentlemen, if you will.

GH: Swell

(Long applause)

S: For those of you who don't recognize this awesome skeptic and science communicator to my right, this is Cara Santa Maria. Cara, welcome to the Skeptic's Guide!

C: Hey everyone!


S: So, a lot of people pointed out that the SGU could stand a little bit more diversity on the panel, which we agree with. So we decided that we really had to get somebody with tattoos.


S: So we now have covered the tattoo contingent. We're all set to go. Cara, tell everybody a little bit about yourself.

C: Ah, first of all, I have to say that I am thrilled. I'm honored. I'm just over the Moon, and really emotional about this exciting opportunity. I'm so happy that the reveal got to happen right here in front of all of you. My friends, the skeptic community. Hi, I'm Cara. I am now the fifth rogue. That's something about me. I also host another podcast called Talk Nerdy. And I work full time – oh thanks!


C: I work full time as a freelance science communicator, trying to kind of translate science to the public across a lot of different media platforms. Television, the web, podcasting, any place I can.

S: Any place you can.

C: Yeah

S: And you're doing a great job.

C: Thank you so much!

S: We've conducted an exhaustive search – a really (unintelligible – east year?) You know, six months, really, carefully considering all of our options. And we had Cara on for a stealth interview earlier in the year. We had her on as a guest rogue, if you recall – it was in January, right?

J: Yep!

S: But we didn't tell her that she was on our short list for the permanent position. But the chemistry was, I think, pretty instantaneous.

E: Right

S: Like, I knew that, yep, this is – which basically means that she could keep up with us, right?


S: That …

C: No, that means you guys can keep up with me.

S: That's what I meant.


S: All right, so, we do have a great show for you. We're gonna go ahead and go right to our show.

Best Slot Machines According to Poll (4:03)[edit]

GMO Political Correctness ()[edit]

Forgotten Superheroes of Science (8:42)[edit]

  • Henrietta Leavitt: Astronomer who discovered the property of Cepheid variables

S: Bob, you're gonna do your Forgotten Superhero of Science.

B: Henrietta Leavitt. Henrietta

S: Bob, talk into the mike.


E: Running gag on our show.

B: Should'a seen that coming. Um, Henrietta Swan Levitt (1868 to 1921). She was an astronomer who was the first person to have a key insight into the creation of the first standard candle of astronomy, that essentially opened up the universe to us, made us appreciate the true, at least a better approximation of the scale of the universe, and the distance to very remote galaxies, which we were not able to do before her work.

Now, Levitt investigated a lot of variable stars in the Magellenic Clouds – I think seventeen hundred stars. She found, forty seven of them that was cepheid variables, that's a very special class of variable star. They pulsate. They have a period where they pulsate, increasing their diameter and their luminosity over a period of time.

Now, she was looking at their light curves, and she had this incredible insight. She realized that there was a direct relationship between the period of the pulsation, and the luminosity of that star. This is the period-luminosity relationship. Now, this is what helped establish the standard candle.

So this is how it works: You're looking at a star. You know what the period is. You can follow the light curve. You can see it getting brighter and then dimmer. But we have no idea how far away that is. But, if you know the period, that means you can determine what the absolute magnitude of that star, the intrinsic magnitude.

J: Yeah

B: If you were really close to it.

S: But you know how bright it is.

B: Right

S: You know how it looks. You can calculate how far away it is.

B: Exactly. You see how dim it is, you see how bright it should be, if you were really close. And from there, it's a simple step, just figuring out exactly how far away it is. Now that one insight led to a host of amazing discoveries. We learned the size, and the shape of the Milky Way. We learned that spiral nebulae were actually, like Andromeda, were actually not in the Milky Way, but were galaxies in their own rights, many millions of light years away.

Also, Edwin Hubble, you know, he's that guy that telescope is named after. He actually used her insight, and some others, to actually determine that the universe is expanding. I mean, pretty amazing stuff. So, remember Henrietta Levitt; mention her to your friends, perhaps when you're discussing the cappa mechanism, and non-abiobatic stellar pulsation.

S: That just came up the other day.

B: Yeah.

E: Over drinks.

B: It happens.

S: All right.


B: Thank you.

News Items[edit]

Pluto Close Approach (11:26)[edit]

Village on the Moon (15:17)[edit]

Giant Fighting Robots (21:13)[edit]

Depression App (26:40)[edit]

We Are Teaching Science Wrong (33:24)[edit]

New Winged Dinosaur (39:43)[edit]

Scientists Discover Pentaquark (41:40)[edit]

(Commercial at 44:33)

James Randi and Ray Hyman (45:23)[edit]

  • Discuss the origin of the skeptical movement.

(Commercial at 1:07:50)

Science or Fiction (1:09:07)[edit]

Item #1: Scientists have used meta material to create a prototype 'perfect lens,' 1,000 times smaller than conventional lenses with the same magnification. Item #2: Researchers have developed a light metal foam alloy that blocks gamma rays better than solid steel and X-rays almost as well as lead. Item #3: Researchers have used nanowires to increase the yield of a solar fuel cell 10 fold using 10,000 times less precious metal.

Skeptical Quote of the Week (1:23:17)[edit]

'It's OK to fool people, as long as you're doing that to teach them a lesson which will better their knowledge about how the real world works. No matter how smart or well educated you are you can be deceived.'- James Randi

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.

Today I Learned[edit]

  • At the end of the episode, Steve says that the wives and daughters of the rogues were “manning the tables” at the event, and helping to run the show behind the scenes.


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