Transcript:TWIS.ORG Jan 26, 2010

Justin: Disclaimer! Disclaimer! Disclaimer!

How do we judge the quality of life? Some would say it is by whether or not that life is a life lived well. But what is a life lived well? Is it an accomplishment or an affect, a way of being in the world?

This is to say that a life lived well could simply be a life lived in accordance with an individual’s ideals. The life lived well of a painter being very different perhaps in the life lived well of a pro football player or microbiologist.

And there could, by this measure, be as many ways of living the life well-lived as there are people living lives, leaving it up to each of us to decide if the life we’re living is living up to our own standard of wellness.

While equality of life issues, much like the following hour of our programming, do not necessarily represent the views or opinions of the University of California at Davis, KDVS or its sponsors.

The question being interjected into your brain frames at this moment in time is, “Are you living your life the way you, yourself, would judge a life to be well-lived?” Forget about champagne wishes and caviar dreams. I’m talking about you, being the best you. Are you?

If your answer is anything other than, “Hells yeah,” make time this week to invite your ideal you over for a coffee and ask yourself, “What you might do to be more you like?” Just like you, we want to be the best we as we can be, which we couldn’t do without you turning into This Week in Science, coming up next.

Good morning, Kirsten!

Kirsten: Good morning, Justin! We’re here. We made it.

Justin: Whew!

Kirsten: One more week…

Justin: Just barely made it.

Kirsten: …into the year.

Justin: I was almost killed by a cow over the weekend.

Kirsten: A cow?

Justin: Yeah.

Kirsten: Is that one of the perils of…

Justin: Living in the farm land.

Kirsten: …living in the country?

Justin: Yeah. Fifty miles an hour down the dark and rainy farm road, dark shadow jumps out in front of me. I slam on the brakes because there’s like this race show – field mouse runs across the road, you don’t brake. It’s not worth it because there’s (trains or) ditches on either side, you know. It’s not worth the accident you could be putting yourself into by trying to avoid the mouse.

Kirsten: Right.

Justin: Squirrel, you don’t brake. Rabbit, you don’t brake.

Kirsten: Kamikaze squirrel.

Justin: Even rabbit, rabbit is pretty big but you still don’t brake. It’s still not worth it. Coyotes around here, pretty small, yeah I might brake. It’s in the moment kind of decision.

Kirsten: Mm hmm.

Justin: This was like 2500 lbs. cow, darted out in front of my car and was running ahead of me.

Kirsten: I don’t know if I would ever think of cows darting.

Justin: It darted. Oh, it darted in the dark and rainy night. Believe me, that was a darting cow. I slam on the brakes. I got all four of them locked up because I don’t have the anti-lock, I got an older car. And I’m sliding now. I’m sliding and catching up with this cow.

Kirsten: Oh my goodness!

Justin: About two feet off the rear end, the car finally stopped. The cow continued on its way.

Kirsten: Have you ever considered, you know, off road or a special event driving, stunt driving maybe.

Justin: I’m going to – I’m getting a snow plow put on the front.

Kirsten: Cow plow.

Justin: One of those – let me add, one of those cattle movers they put on the front of trains. I’m going to get that put on my little Corolla, absolutely.

Kirsten: And this is all science people.

Justin: Comically, maybe.

Kirsten: Oh my God.

Justin: Maybe being taken out by a cow wouldn’t be completely incorrect but…

Kirsten: There we go. Welcome! It is another wild and wacky week on This Week in Science. We have so much science ahead.

Justin: Woo-ho!

Kirsten: So much science ahead. We’ve got a bunch of how-to’s — how to run faster, how to make a neuron behave and how to melt a moon. Those are stories that I have. Did you bring anything interesting?

Justin: I’ve got some too, yes.

Kirsten: Oh yeah, you’re going to do the how to run faster. We both brought that story.

Justin: We’ve got – yeah.

Kirsten: So it’s up ahead. It’s up ahead. It’s something for you to look forward to.

Justin: I’ve got faster feet. I’ve got – using flying saucers as power sources. I’ve got real physical time travel, both forward and backward.

Kirsten: Flying saucer is a power source. Is that what – is that the magnet levitation story?

Justin: Yeah. Well you gave up the teaser.

Kirsten: What?

Justin: It’s a teaser.

Kirsten: What?

Justin: It’s a floating magnet.

Kirsten: I know.

Justin: And then you could say it looks like the UFO. And so, you can say like, “I’m using UFO as a power source.” And people are like, “Really?” And we’re going to listen long enough – now all the UFO buffs are like, “Oh it’s a magnet, never mind.”

And I’ve got Uranus, might be the new girl’s best friend.

Kirsten: The planet, really?

Justin: Yes Kirsten, the planet.

Kirsten: Interesting. Girl’s best friend?

Justin: Yeah.

Kirsten: I am curious about how this is going to work.

Justin: Mm hmm.

Kirsten: I’m really curious. In the meantime, let’s begin with how to make a neuron behave. Behave neuron, behave. First off, it has to do with how you train the neuron. You have to give it treats. No, you don’t have to give it treats, not at all.

Researchers just published this week in the January 20th issue actually – the Journal of Neuroscience have – published a study in which they have taken embryonic stem cells. So stem cells that are taken from cloned tissue, basically, blastocystic tissue.

Justin: Blastocystic symptoms – okay, that’s different than embryonic.

Kirsten: Yes, blastocystic. So it’s embryonic stem cells. They took the stem cells. And they put them in petri dishes in medium that got the cells to think they were in an environment like the brain or in the part of a forming organism that would become the brain.

And so the neurons, these little embryonic stem cells turned into pre-embryonic, pre-nerve cells. And then they went on to turn into nerve cells. And they actually started to differentiate in this direction.

Okay, this is not new. Researchers have done this much before. The new thing that these researchers have done, these researchers at Stanford Medical School, they implanted these neurons that were grown from embryonic stem cells into the brains of mice.

And then they looked to see what the neurons did historically when we’ve taken stem cells and we’ve put them into brain tissue. It caused all sorts of trouble. The stem cells differentiate and they go all over the place.

Justin: Oh geez!

Kirsten: And they make these random connections everywhere. And they just don’t know what they’re doing. They’re just kind of out of control.

And so, it’s never really been shown that this could be a successful way to treat degenerative brain disease. But it’s been an idea. We’re like, “Oh, maybe we can take the stem cells, put them into Parkinson’s patients and help them out.” Not so much so far. But what we’ve been waiting for is a proof of concept that it might work. And that’s what these Stanford researchers have done.

Justin: Wow.

Kirsten: The Stanford researchers showed that they were able to specifically implant these nerve cells that were grown from embryonic stem cells. And the nerve cells made specific connections based on the area of the brain that they were implanted into and where the nerve cells in that region of the brain normally go.

Justin: Cool.

Kirsten: Yeah. So they didn’t make inappropriate connections. They made appropriate connections. And this is the first time that this has ever been shown. One of the – what an expert in stem cell biology — not affiliated with the study from this article — says that, “The authors show that appropriate connectivity for one important class of projection neurons can be obtained in newborn animals.”

“The authors provide a protocol for how to get the right kind of neurons to show appropriate connectivity. And it’s a huge advance in the practical use of these cells.”

So far, this has still only been tested in the brains of – it’s still only been tested in the brains of newborn mice. This is not – and so, we have two confounding factors here — one, mice.

Justin: Mice brains.

Kirsten: Not anything. I mean it’s related, kind of, but mice brains. Again, we’re curing diseases in mice.

Second confounding factor — newborn mice. Newborn mice are not going to be – not going to have the same developmental environment in the brain as an adult mouse or even an adult human who is experiencing degeneration of any brain tissue.

So there is this, you know, a newborn mouse has all sorts of signaling factors, hormones, control factors that are still being released by cells in the brain because the brain is still developing, right? There’s – I mean, a newborn animal of any kind is making connections, all sorts of connections. Making connections and then pruning connections.

And so, there’s going to be a lot, lot of activity and change in the brain of a newborn animal that might support the implantation of a foreign nerve cell that might not be supported in the brain of an adult animal.

So, this is something that really needs to be checked out later. You know, they don’t know exactly what the mechanism is that allowed these nerve cells to survive and make the right connections. They just know that they made the right connections. There are still a lot to understand about how this works. But it’s really big news.

Justin: Good news.

Kirsten: I want to thank Ali for sending the story.

Justin: Thank you, Ali. Well, feel free to prune the inappropriate connection of this next story. As researchers recently took an in-depth look at Uranus and Neptune in laboratory conditions which simulated atmospheric pressure similar to both planets and found crystals of solid diamond forming like icebergs in a liquid carbon sea they created.

Kirsten: This is like the dream of the bling lovers everywhere.

Justin: Well, it kind of is, yeah. Except that…

Kirsten: If only we could go to these other planets and get these diamonds, it would be great.

Justin: Except, I think it’s one of those things that if like diamonds were…

Kirsten: A girl’s best friend.

Justin: …so super common and then like not worth money, people would devalue them. You know what I mean? Like, well yeah.

Kirsten: Well that’s…

Justin: Yeah, I’ve got – I have replaced my windows with diamond and the…

Kirsten: The only reason that diamonds have any value currently is because they’ve been artificially valued by the companies who control the mines.

Justin: Hoarders, they’re hoarders, diamond hoarders.

Kirsten: And – yeah.

Justin: This is actually pretty common on planet Earth.

Kirsten: Diamonds are quite common on planet Earth.

Justin: Right.

Kirsten: It’s artificial valuation.

Justin: Yeah.

Kirsten: They’re controlling the supply and making them costly.

Justin: Yeah.

Kirsten: So anyway, moot point.

Justin: Anyway this is the first detailed research into the melting point of a diamond. And they found it behaves like water during its melting and freezing with its solid form floating upon the liquid form in the sort of in-between transitional stage.

Further, a large diamond ocean on one or both of the planets could provide an explanation for an oddity that they both share. The two giant gas planets — Uranus and Neptune — unlike Earth, do not have magnetic poles that are matching up with their geographical poles.

As much as 10% of both the planet is made up of carbon. And a liquid diamond ocean could be responsible for deflecting the angle of magnetic field, putting it out of alignment with the planet’s rotation, the researchers believe.

Dr. Jon Eggert of the Laser Shock Equation of State — it’s such a strange name for a group — in the Department of Physics and Life Sciences at the Lawrence Livermore National Laboratory in California says, “The idea of significant quantities of pure carbon existing in giant planets such as Uranus and Neptune has gained both experimental and theoretical support. An ocean of diamond could help explain the orientation of Uranus and Neptune’s magnetic field.”

Researchers took a half-millimeter wide diamond, a tenth of a carat in weight and blasted it with lasers at high pressure, similar to what would be found on the planets Uranus and Neptune. The diamond was liquefied at pressures 40 million-times greater than at sea level on Earth.

Kirsten: That’s pretty – that’s a lot.

Justin: And from there, the scientists slowly reduced the temperature and pressure. When the pressure fell to only 11 million-times Earth’s sea level — only — and temperatures dipped to a mere 50,000 degrees Celsius…

Kirsten: Oh nothing.

Justin: …solid chunks of diamond.

Kirsten: (Bond) me.

Justin: Yeah, solid chunks of diamond began to appear in the liquid.

Kirsten: Interesting.

Justin: As the pressure continued to drop more and more chunks, larger chunks, formed in liquid and were not sinking. They were forming a new…

Kirsten: Floating in the sea of diamond juice.

Justin: That’s wild. With most materials – as with most materials, the solid state is more dense than liquid – with most materials, the solid state is the more dense than the liquid state, with water as one of the few exceptions and now diamond is added to that list of few exceptions. Article is published and viewable in the journal Nature Physics.

Kirsten: Cool.

Justin: A whole planet of diamonds.

Kirsten: Diamonds.

Justin: That gives me an idea.

Kirsten: I just – it’s just fascinating to think of these seas of carbon liquid where the carbon – the pressure allows the carbon to line up in a particular way so that diamonds can form and, you know, the liquid soon becomes solid. And it’s just fascinating.

Justin: Yeah.

Kirsten: It’s fascinating.

Justin: Yeah.

Kirsten: It’s kind of mind-bending a little bit.

Justin: Huh?

Kirsten: No, it’s just not something you normally expect, you know. It’s not like water.

Justin: It doesn’t bend my mind.

Kirsten: Okay, fine!

Justin: My mind is rigid, unbending.

Kirsten: Right, hard as a diamond.

Justin: Yes.

Kirsten: Okay.

Justin: I have a very densely oriented – great.

Kirsten: Yes. Okay, in other space news, everyone out there you’re listening to This Week in Science with me and Justin. Yay! How is it that you can melt a moon? Can you melt a moon? Well, yes, you can. All you need is a late bombardment. That’s all you need.

Justin: Mm hmm.

Kirsten: But how big of a late bombardment? Well, researchers decided that they would take a look at a couple of moons within our solar system. Ganymede and Callisto — two of Jupiter’s four moons — they were discovered by Galileo. Well, yeah, they’re discovered by Galileo.

And looking at the four moons, Callisto and Ganymede are similar in size but they are in different places in their orbits around Jupiter. Looking at them — according to this article from Ars Technica by Mr. Timmer — the Callisto looks as though it was frozen as it formed. And Ganymede is a little bit different. Doesn’t – they don’t really know exactly what happened. It appears to have melted.

Justin: Yeah.

Kirsten: And so, you’re like, “What?” Okay, we got one moon that looks like it was frozen. Another Moon that looks like it was melted. How did this happen? How did these two very similar in density, similar in size moons have these differences in the way that they appear?

So, they started to take a look at the craters on the moons. Callisto has a lot of impact craters, not very much – doesn’t look as though it’s very tectonically or geologically active. Ganymede looks like it’s got lots of geologic activity. It’s got huge rocky areas, icy areas. It’s all – it’s completely different from the surface of Callisto.

The moons themselves, they took a look at them. And this new paper that’s recently out in Nature Geoscience, they consider this period called the “Late Heavy Bombardment” in which there were tons of asteroids coming through, which we’re kind of afraid of right now in the United States. I think it’s the national – there’s some group who’s calling for an international asteroid committee.

Justin: Mm hmm.

Kirsten: The National Research Council, the U.S. National Research Council, an international asteroid defense agency is what they’re looking for.

Justin: Sweet, sign me up.

Kirsten: Yeah. I know. Don’t you want to work there?

Justin: Yeah.

Kirsten: I want to be able to say that I worked for the International Asteroid Defense Agency.

Okay. So, we know that asteroids, they’re a huge problem.

Justin: I think it’s just a desk with a backdrop so that you can go up there and be like, “People of Earth, cling to your loved ones as time draws near.”

Kirsten: Time.

Justin: “And there’s a bit of doom in this fair universe.”

Kirsten: Yes.

Justin: That’s the whole gig. You just wait for that day.

Kirsten: Yeah. Well, currently, we’re in a pretty light period of bombardment. I mean we are bombarded regularly but, you know, kind of small things. Well it’s not that big a deal. We should call this like the really light bombardment.

But there was a period during the development of our solar system when there was all sorts of material from the outer solar system coming in, the Late Heavy Bombardment, “Ah! Our moon!” The impact craters on our noon suggest there was.

Justin: Soon we lost – then we lost the planet Atlantis.

Kirsten: That’s right.

Justin: Well, the Kuiper belt, right, where our planet is supposed to be. Yeah, they may think about that.

Kirsten: I know. I think that it’s more likely that there was not a planet there. And it…

Justin: Planets everywhere else. I think there was a planet. And they got – with planet Atlantis, we were all came from there.

Kirsten: It’s very – it’s great. Right. Okay, go.

Justin: We’re around in spaceships and had universal health care.

Kirsten: Okay. So, the author is considering this Late Heavy Bombardment. They’re thinking that this bombardment would have been striking both Callisto and Ganymede. But looking at them both, they’re like, “Hey! Well, maybe Ganymede got the worse part of the deal here. And maybe it was more impacted than Callisto.”

So, what they think is that Ganymede was struck with about 80 times more mass than Callisto. It was hit with over the period of the Late Heavy Bombardment. And that this period of time in which the asteroids are coming in and they’re striking. Ganymede, they’re striking Callisto. The difference…

Justin: Heated it out?

Kirsten: Yeah. And so, it would have taken the ice and it would have taken the – any rock that was on the surface of Ganymede and pushed it into the inner sphere, the inner sanctum of Ganymede. And as it was pushed in by the impact that it would have heated up and caused this melting, and that over time, with enough impacts, it would have just sustained the melting much more.

Justin: Wild.

Kirsten: Yeah, it would have just kept going.

Justin: But that is – if it’s – I don’t know how big this is. How big is this moon?

Kirsten: I don’t remember the number.

Justin: Because I think – I mean our moon is mostly made up of like lava rock.

Kirsten: This is also further out than we are.

Justin: Of course.

Kirsten: So, you know, the Jupiter and Jupiter’s moons were most likely being hit with more bombarding material than our own moon.

Justin: They’re further away.

Kirsten: Right?

Justin: Yeah.

Kirsten: It’s possible.

Justin: But our Moon is also – I mean the size of our Moon, at least, is one reason why our Moon would have cooled to the point of not being able to maintain. Once that heat was built up in a core, it will just dissipate at some point. It wouldn’t stick around.

Kirsten: Mm hmm. Yeah, it would end up dissipating over time. Mm hmm.

Justin: So, if this was something big enough, it could have sustained it a lot longer except that it’s further away from the sun. So maybe it’s a lot colder and I don’t know how that works.

Kirsten: Right. So, looking at the amount of material that – like our own Moon, the impacts at our own Moon suggest that there were about 1.6 times 10 to the 22 grams in material that impacted the surface of our Moon. And this was probably – scientists think it was divided fairly evenly between comets and asteroids. And…

Justin: When you’re getting bombarded, you don’t even care. It’s all the same to you, really.

Kirsten: Mm hmm. Yeah. And according to this article, it implies the disruption of a planetesimal disk that it contained about 20 times the Earth’s mass and most likely via gravitational interactions with the gas giants.

So Jupiter, huge amount of gravitational pull, it’s going to be sucking in a lot more of these little comets and asteroids. And so, Ganymede smacked up a little bit.

And the main point is that this all happened, the author’s modeled how this happened. And they suggest that it happened over time and that it was, you know, one impact hit, another impact hit. But it’s just the rate of impacts over time was enough to sustain this constant melting.

And that the cool thing that they’ve done here though is figuring out how much energy was imparted into Callisto and Ganymede have potentially given them a limit — upper and lower limits on how much mass came into the inner solar system during the Late Heavy Bombardment.

And so, we’re able to compare the amount that – of material that potentially bombarded…

Justin: Interesting.

Kirsten: …Jupiter with ideas with other numbers that we’ve come up with for how much – how many asteroids and comets potentially bombarded the Earth and the Moon.

And the number actually turns out to agree. So we have these two completely different measurements that…

Justin: Data sets that are…

Kirsten: …data sets but they’re in agreement. And they both work out the numbers between – this is a wide range, but between six and 23 times the mass of Earth, of material and that is very similar to the estimate based on the craters of the Moon.

Justin: Cool.

Kirsten: That’s kind of cool. Yeah.

Justin: Quick experiment before we hit to the break. All right, listen close and listen tight. Pay attention to this. I want you to think back to what you were doing five years ago — whatever your job was, whatever your school was, whatever your day was like. Think back five years ago. Everybody think back five years. Here we go. Here we go.

Okay. Now, I want you to think about what you’d like to be doing in five years. What would you like to be doing five years from now? Okay, okay. You have just time traveled.

Kirsten: Mentally.

Justin: Mentally. It turns out, when we think of the past or future, we also engage in a sort of metaphoraphysical time travel tango as was just illustrated by Ali over here. When you think back into your past, you tend to lean backwards physically.

Kirsten: Really?

Justin: When you think about the future, you tend to lean forward a little bit.

Kirsten: Did Ali do that?

Justin: Ali, when she was thinking about five years ago, she did, she leaned right back. I think it’s a big movement forward but when she was thinking backwards, there was definitely a leaning going on there.

So yeah, some researchers were looking into how mental time travel is represented in sensory motor systems that regulate human movement and found that our perception of space and time are coupled.

University of Aberdeen psychological scientists Lynden Miles, Louise Nind, and Neil Macrae conducted a study and measured it in the lab. They fitted participants with motion sensors while they imagined either future or past events engaging in the mental time travelling, a.k.a. chronesthesia — chronesthesia, that’s cool — resulted in physical movements corresponding to the metaphorical direction of time. Those who thought of the past swayed backwards while those who thought of the future moved a little forward.

Findings are reported in the online Psychological Science, a journal of the Association for Psychological Science. And it suggests that chronesthesia may be grounded in processes that link spatial and temporal metaphors to our system of perception and action. “The embodiment of time and space yields an overt behavioral marker of an otherwise invisible mental operation,” they explain.

That’s cool.

Kirsten: Crazy.

Justin: It’s not crazy, Kirsten.

Kirsten: It’s interesting. I don’t know.

Justin: It’s science.

Kirsten: I don’t know.

Justin: Why don’t you know? What’s not to know? But then the question is what came first, the analogy of backward and forward or – and is that what we’re playing out as our analogy of how we’ve learned to this linear time?

Kirsten: Exactly.

Justin: Or is it something more innate? That’s what they figured out. It’s there anyway.

Kirsten: Yeah. There’s – I think there’s not an easy way for them to actually separate those two things, I mean…

Justin: What do you mean? They did in a lab. They just, “Think about the future,” and people lean forward a little.

Kirsten: But they’re not separating.

Justin: “Remember about the past,” and people lean back a little.

Kirsten: They’re not – right. So how old are these people? How – you know, what are their – are you looking at people from different cultures? You know, there’s a lot that could potentially be teased out here. And I think they’re – there’s this broad reaching conclusion that doesn’t necessarily…

Justin: You’d be a great Grant writer. “We need to look at every potential angle. We must study every human being on planet Earth before we come to any conclusion. It’s going to take us about $14 billion to finish the project but at the end — the result.”

Kirsten: That is absolutely not… It’s not how science works, Justin. It’s about sample sets – sample sizes. You have to do a power test.

Justin: There probably is – there’s a link somewhere that probably got a sample size in all the rest of that. I didn’t look into.

Kirsten: Yeah. It wasn’t big enough, I’m sure.

Justin: That’s probably possible.

Kirsten: This is This Week in Science. We will be back in just a few moments with more science for your ears. I think we’ve got some running to do. We have a few minutes here.

Justin: Thank you for listening to TWIS. If you rely on this show for weekly science-y updates, please understand that we rely on your support to keep bringing those to you. Donate. Keep the science-y goodness on the air.

We’ve made it very easy for you. Go to our website, Click on the button that will allow you to donate $2, $5, $10 or if you like you can donate any amount of money you choose, as many times as you like. Again, just go to and donate today. We need your support. And we thank you in advance for it.

Kirsten: Be a part of the magic. Make some science music. Be heard on This Week in Science. We’re using your science music for our annual science music compilation.

If you’re a musician or know somebody who is, why don’t you write us a song or get your friend to write us a song, sciencey goodness in the form of music?

For more information, email

Justin: And we’re back with more of This Week in Science.

Kirsten: That’s right. We are back in the second half of our show. Let’s get running. Let’s get off the ground running.

Justin: Physiology of a faster foot found in fleeting force of feet on floor, published in The Journal of Applied Physiology. The study of biological limits to running speeds are imposed from the ground up, identifies the critical variable imposed on a biological limit to the top running speed of humans. That would be us.

Kirsten: Mm hmm.

Justin: At least most of us listening. The prevailing view is that speed is limited by the force with which the limbs can strike the running surface and that’s a pretty reasonable idea that, you know, it’s some sort of like, you can only hit the ground so hard with your leg as to not do it damage and so the body is designed around that.

Kirsten: Right. And there is a certain limit to the number of connections that act in (mice) can make when they’re contracting.

Justin: You’re getting out of yourself.

Kirsten: Oh, sorry.

Justin: If one considers that elite sprinters can apply peak force of 800 to 1000 pounds with a single limb during each sprinting step, it is easy to believe that runners are probably operating at or near the force limits of their muscles and limbs.

Kirsten: Right, contractile force. Yes.

Justin: Yeah. However…

Kirsten: So there’s damage force. There’s contractile force. And there is this – the length of time…

Justin: Yes.

Kirsten: …that the foot is on the ground.

Justin: Yes. This is Professor Weyand of Applied Physiological and Biomechanics at SMU in Dallas. He’s saying that, “However, our new data clearly show that this is not the case. Despite how large the running forces can be, we found that the limbs are capable of applying much greater force to the ground than those present during top-speed forward running.”

Kirsten: Which would, I guess, make sense because – I mean, you look at how much people who say they can suddenly, you know, lift a car or you have deadlifters who are like, you know, squatting and lifting, you know, hundreds and so much weight.

Justin: Well, but even if you deadlift 1000 pounds, you’re just doing what a typical sprinter does, 800 to 1000 pounds per foot, right?

Kirsten: Sure. Sure.

Justin: It’s actually you’re doing even less perhaps because you’re splitting up the feet – right?

Kirsten: Because you got both feet.

Justin: So, this is…

Kirsten: Both legs.

Justin: …they did this really kind of a fun test where they put people on a treadmill. And they had this high speed treadmill that could go up 40 miles an hour. And they put people on there and they’re running. And then they have them do stuff like hop at your top hopping speed.

Kirsten: Not at 40 miles an hour. It’s just at the top hopping speed.

Justin: No, you’re going to get – the number you got is 40 miles an hour. But then they also have them turn around and run backwards.

Kirsten: Mm hmm.

Justin: And see what – which I would have been questioning if I was the, you know, I had volunteered to be on the treadmill.

Kirsten: Yeah.

Justin: I’m like, “Are you really doing this for the study or is this just you getting a laugh watching me run backwards on the treadmill?” like I’d be totally suspicious.

Kirsten: But, yeah, the whole point is to be able to compare top running speed forward, top running speed backward, length of footfall forward, length of footfall backward and the amount of pressure that’s departed by the legs.

Justin: Right. This could also measure – this could measure that amount of pressure.

Kirsten: Mm hmm.

Justin: And what they found was that when the subjects were hopping on one leg, they were actually applying much greater force on the treadmill than when they were running at top speed.

Kirsten: Right.

Justin: So it wasn’t the limit of the amount of force that was preventing a faster top speed in running. And what they found was, it wasn’t the force limit but it was – researchers found that the critical biological limit was imposed by time. There’s a very brief period of time available for foot to apply force to the ground when you’re sprinting.

And the weak sprinters that foot ground contact time is less than one tenth of one second. Wow! And the peak ground force occurs within less than one twentieth of one second in that first instant that foot hits the ground. Boom! That’s it. That’s your power. It’s actually probably faster than I can snap my…

Kirsten: As you think about how fast the muscle has to be contracting and ready to contract.

Justin: Bam! Bam! Bam! Bam!

Kirsten: And if it’s happening in such a short period of time.

Justin: Yeah.

Kirsten: One – so one twentieth of one second of the first instant of foot ground contact is when the muscle has to contract to be able to get peak force to be able to get peak speed.

Justin: And that’s exactly what it turns out to be is the limit. It’s not so much the amount of force applied, but it’s the amount of time that the foot is in contact and the amount of time the muscles have to react to it.

Kirsten: To be ready.

Justin: Right.

Kirsten: Yeah. So the idea is that potentially if we could reach the peak, you know, the hopping force, the force that we’re able to create through the single leg hopping which they found…

Justin: Well, we don’t need more force.

Kirsten: …no, what they found was much faster – they found that the force was much greater hopping on a single leg than it is running at full speed forward.

Justin: Right.

Kirsten: So, the idea is that, okay, the muscles can produce more force…

Justin: Oh, absolutely. Absolutely.

Kirsten: …than they are currently producing at top speed in running. So, somehow you can get the muscles to contract with that greater amount of force within that limited amount of time. The potential speed that people could go is probably greater than 40 miles an hour.

Justin: Yeah. That’s what they said.

Kirsten: If we can reach that limit.

Justin: They said that if they – well, looking at the limits of muscle tissue in calculating that forward, how much we could push our muscle to actually contract based on the muscle fibers as they are in that amount of time that we have. Because this is the other interesting thing they found was that when running backward, even though our running backward speed was much less…

Kirsten: Slower, yeah.

Justin: …the amount of time we were contacting the ground was the same as when we were running full speed forward. So what they did was they looked at the actual structure of our muscle fibers and said, “Okay, what’s the maximum amount of contraction that we could be putting out in that amount of time?”

Kirsten: Mm hmm.

Justin: And the number they came up with would be permit us to go in speeds 35-40 miles per hour conceivably.

Kirsten: I know.

Justin: This is amazing since out the…

Kirsten: So, hey sprinters out there.

Justin: …fastest man ever recorded has been clocked at just under 28 miles per hour. That would be Usain Bolt.

Kirsten: Mm hmm.

Justin: So, the fact is he’s at 28 miles an hour and the researchers are saying, “Yeah, you know, he’s…

Kirsten: We can go faster. Go faster.

Justin: …he’s probably still holding back.” This is what it sounds like. He’s waiting.

Kirsten: That’s right.

Justin: He’s just going to keep breaking records for the night.

Kirsten: All the sprinters out there, we know it now. You’re just holding back so that you can break more records later.

Justin: And you know, I always wonder if there is sort of a mental block because as we go forward in time, maybe it is just our training methods are better or athletes are better prepared for their sports. With every record that’s broken, I wonder if, you know, if that wasn’t the record ten years ago — the new record — if the new record wasn’t there ten years ago, well, it might have been broken by now.

Kirsten: Mm hmm. Yeah.

Justin: And I always wonder if it’s like a mental block like that’s the fastest we can go. That’s the highest we can pole vault. That’s the quickest we can swim it.

Kirsten: Right.

Justin: Until somebody does it better and then they go, “Oh, okay. Now, we got to target something a little,” like I don’t know.

Kirsten: Dolphins and bats. Dolphins and bats are kind of similar, right.

Justin: Huh?

Kirsten: They both echolocate. They both rely on a sonar picture of their environment. They create very high pitched, high frequency sounds that then bounce off of objects and then return to them which they are able to use to navigate through their environment to be able to hunt fish or moths, insects, whatever their preference might be.

But you wouldn’t think that the underlying machinery would be that similar. Not necessarily, I mean you got bats that are rodents. And then you have dolphins that are a water mammal. And they divided.

Justin: A little while ago.

Kirsten: They split off from each other long time ago. And as far as I can tell, common ancestor we all share, I don’t have echolocating abilities. So, I’m…

Justin: Have you ever tried?

Kirsten: I’ve never tried.

Justin: Well, there you go. How do you know?

Kirsten: There you go. Maybe I need to try it. So, researchers at Queen Mary University of London have published in Current Biology a study of the inner ear hair cells that have been specialized to enable the echolocation in both bats and dolphins.

It turns out that there is a protein, a gene for a protein that is pretty common across the animal kingdom and this – it’s called the Prestin gene. It’s very common in all the hair cells – inner ear hair cells of mammals which are very – these inner ear hair cells vibrate in response to sound waves. And then they are connected to nerves that transmit that vibrational energy as electrical signals to your brain where they can interpreted as sound.

So, they teamed up with some – with East China’s Normal University and researchers there to sequence the gene, the Prestin gene, that controls this protein that creates the inner ear hair cells.

They found that in bats and dolphins looking at the gene comparatively that the same mutations exist in both bats and dolphins. So they’re thinking that the mutations that had to occur — the changes in the genetic code that had to occur — were really, engineering-wise, the only way that the mutations could occur to allow echolocation that maybe…

Justin: It’s a very, very unique trait.

Kirsten: Right. It’s a unique trait and maybe there are limitations to the behavior such that any different changes to the gene…

Justin: It wouldn’t work.

Kirsten: … just would not work.

Justin: Right.

Kirsten: And so, even though you have this common trait in these two disparate animals, I mean they’re in the same part of the family tree generally, I mean they’re mammals. But the fact that they’re so separated from each other evolutionarily but have the same trait with the same underlying mutations in the same gene that just – it indicates to the scientists that there’s a very limited number of evolutionary pathways to this high frequency hearing in mammals.

It’s very cool.

Justin: Yeah.

Kirsten: I think it’s really neat. So, you know, it indicates that maybe we need to look at, you know, limitations that maybe there are certain – even though there are all these possibilities, so many different genes, so many different mutations that could occur maybe because of the environments that we live in. There are only very few possible solutions to the problems.

Justin: Right, which is going to beg for me to get into some sort of a Lamarckian argument about mutations, but I’m going to avoid it for the moment and say that…

Kirsten: I don’t think that has anything to do with Lamarckism, no.

Justin: It kind of…

Kirsten: No, it doesn’t.

Justin: There’s something about the fact that you can – yeah, there’s a system through your genes that can get feedback in only one way and it can only be used in one way. And once it’s being used and once it’s in that getting feedback and being operating something like an echolocation that the genes don’t continue to go past it. They don’t tweak the system so that it doesn’t work. But they seem to maintain it. I mean for something that is that’s…

Kirsten: No, because if they were to mutate any different way, that individual, that bat that relies on echolocation suddenly wouldn’t be able to hear and it would be a deaf bat not able to find the moth in the night.

Justin: Right, but I’m talking about the development. You got to go back to the – not towards the end where they’ve already got echolocation that will require, you know, relying on it for feeding, but when it first is developed.

When it’s first developed and it’s come upon this echolocation is being developed as a sense that’s getting feedback, that’s getting responses being used or is at least getting some sort of feedback in that part of the work.

Kirsten: It’s called natural selection.

Justin: Not necessarily.

Kirsten: It’s called natural selection.

Justin: There are other possibilities, Kirsten. It could be an epigenetic thing. I think it just comes to like have a genetic system that’s getting some sort of feedback. It doesn’t know what to do with it first. It doesn’t find moths with echolocation right off the bat just like, “Oh, I got echolocation. Oh, I’m going to go hunt at night.” No, it’s just a slow development process.

And the other thing I like is that the North Chinese University that’s called Normal.

Kirsten: East China Normal University, yes.

Justin: Come get your average education at Normal University.

Kirsten: Yes.

Justin: There is an experiment that is reproducing magnetic fields of Earth and other planets has yielded some significant results.

Kirsten: Which – okay, you just like glossed over one of the coolest aspects of this story…

Justin: Oh, sorry. I didn’t hear it.

Kirsten: …is the fact that it’s like they – okay, researchers looking for clean energy. So we have the National Ignition Facility that’s over in Livermore National Lab area, they are using – they’re trying to create fusion with lasers, you know, impact lasers firing on a target and atoms smashing into each other fusion based on this huge heat and impact situation.

These researchers at MIT are trying to create…

Justin: Not a normal or average university.

Kirsten: No. But they were like, “How does – let’s look at how plasma interacts with things and how it all works. Oh look! Our own atmosphere has interactions with plasma and space and oh, if we look at ourselves as a giant – the planet as a giant magnet, and then try to mimic that in the laboratory.”

So they levitated this magnet trying to make it perform like a planet in space. It’s just brilliant. Brilliant!

Justin: See, I think you’re the one that’s sort of glossing over the fact that this magnet that they levitated is a half ton.

Kirsten: I know it’s a half ton magnet.

Justin: It’s a half ton magnet which carries a current of 1 million amperes.

Kirsten: Yeah, okay. This has never…

Justin: That’s the cool part. The whole plasma might turn into fusion someday and be a source of electricity throughout the world. It’s free and it doesn’t create carbon. That’s nice.

Kirsten: That’s like blah, blah, blah, way down the line, right?

Justin: But they’re floating a half a ton magnet. That’s awesome.

Kirsten: And they got the idea from thinking about planets in space.

Justin: Yeah.

Kirsten: Oh, planet floating in space. The planet is a giant magnet. You – I mean, think about it. Our planet is a giant magnet. We have a North Pole, a South Pole. We are a dipole. We’re a body of rock with a core of molten iron that’s a dynamo creating a dipole in space.

Justin: Yeah.

Kirsten: And that dipole in space, the magnetic field that is emanating from the dipole is interacting with energetic components of space, of the universe. And so, this plasma, when plasma comes into contact with our magnetic field, it interacts in a very special way that they wanted to create. They’re like, “Let’s see if we can do that. Nobody else has done it.”

Justin: And they did.

Kirsten: “And let’s levitate a half ton magnet.”

Justin: And this is leading to ways to control plasma. This is – one of the concepts here is this could be a way of controlling fusion reaction so that we could use it as a power source. Although the senior scientist at MIT, Jay Kesner says, “Likely, this isn’t going to be the first.” What is it called the – I forgot the name of it. The way that they are attempting to do it now…

Kirsten: Well, they think that things like the National Ignition Facility, which is already online, or there are other types of fusion reactors that are coming online. And so, they think that those are probably going to be…

Justin: Tokamaks.

Kirsten: Yeah, Tokamaks are already online. They contain plasma inside of a bunch of magnets.

Justin: Right.

Kirsten: So the way the Tokamak is built it’s like a sphere with a bunch of magnets around the outside that contain plasma.

Justin: Which is cool, you know, but it’s not half ton of floating magnet. But what the researchers says that – actually that research is probably going to produce a fusion reactor first. And that, what they’re working on is already – they’re tracking is the second generation of those.

Kirsten: Yeah, next generation. We’re looking at the future.

Justin: So more ways away but proof of concept.

Kirsten: We’re looking at the future right now folks.

Justin: So, they work on those.

Kirsten: In other levitating news, you can use levitation for household chores. Got some dust bunnies you want to clean up your solar panels?

Justin: What?

Kirsten: What?

Justin: Yeah.

Kirsten: Yeah. Some researchers at the Department of Physics and Material Science program – which university are we talking about here?

Justin: So basically, I think…

Kirsten: Wait, wait, wait, I’m trying to find the university.

Justin: One of the places they want is on the Moon, right, because…

Kirsten: Anyway, it’s published – on the Moon or on Mars.

Justin: …you got Moon and Mars dust all over your solar panels.

Kirsten: Yes.

Justin: There goes your energy source. And you’re going to wait for a windy day which on the Moon could be a really long wait.

Kirsten: Yes.

Justin: Mars at least have a shot of having a Martian winter, winds and dust.

Kirsten: Right. So, what they did is they focused acoustic energy, high pitched standing wave of sound, 13.8 kilohertz at 128 decibels emitted from a 3 cm aperture tweeter and focused on to a reflector, 9 cm away dusted the reflector and made it able to reflect light.

Once again, the idea is that this high frequency sound overcomes the van der waals adhesive forces. So these are the very, very small electro – electrical forces that allow certain things to stick together – adhesive forces. Van der waals forces are what allow geckos to stick to walls actually.

So I’m wondering if you could – if you have a gecko problem, if you could just, you know, shoot a tweeter at your geckos, watch them fall off the wall.

Justin: Oh my goodness.

Kirsten: That’s what I’m wondering. If you got a gecko problem, get me a speaker.

Justin: So the next generation of Martian Rovers is going to have a kicking stereo system.

Kirsten: It will have a kicking stereo system.

Justin: Nice.

Kirsten: One of problems with this though is very limited in places like the Moon. They don’t really have an atmosphere. You need an atmosphere to carry sound waves. So, that’s a necessary aspect of this. So, it may only be implemented inside of a space hotels or research lodgings on the Moon. Who knows?

Justin: I guess you could create a little bubble or a bubble around your solar panel and then be like boom boxing the dust off the surface if the vibration carries to the material like you bubble this off then.

Kirsten: Right, if you could carry it off. Yeah.

Justin: Yeah. Yeah.

Kirsten: It’s a new levitating dust via sound waves. Let’s do it.

Justin: NASA’s of analysis – Analysis of NASA scientist.

Kirsten: Let’s go to the Mailbag. Are you – okay.

Justin: Okay, now we can do Mailbag.

Kirsten: What’s in the Mailbag? We have only like nine minutes.

Justin: Yeah, NASA says we’re still getting warmer – global warming.

Kirsten: We have eight minutes to the end of our show.

Justin: Okay. This is a Minion Mailbag.

Kirsten: Minion Mailbag.

Justin: This is from Minion Daniel. “Hey Justin, I have a question concerning the economy and science. With all the job shortages around the US, I’m hesitating to decide what I want to do and going to – applying for school. I’m a senior in high school and I really am fascinated with science. But if I go through all the college and graduate, will there be jobs in the scientific community? I mean…” blah, blah, blah.”

Okay. So, he’s looking for a job with a career path or some job security.

Kirsten: That’s pretty – that’s a smart way to look at it. Where are things going to be in four years, five years when you get out of school?

Justin: Yeah.

Kirsten: What do we think is going to be the situation?

Justin: This is also something I thought about retrospectively. What an amazingly difficult question is to confront at the age of high school graduation? It’s like as a child we are asked, “What do you want to be when you grow up?” And we can say fireman, ballet dancer, astronaut, unicorn. It doesn’t really matter. Anything we say is fine. It’s all acceptable.

Kirsten: Oh how cute, you want to be a unicorn. That’s so cute.

Justin: So then we go through our early education, it’s sort of a wide hodgepodge assortment of general education stuff. At the end of which we’re asked by a load of question. “Okay, now the time has come.”

Kirsten: “Now, what do you want to do?

Justin: “What do you want to do for the rest of your life?” That’s what it feels like, right?

Kirsten: Yeah. Yeah. Yeah.

Justin: And there are some – I remember, you know, there were kids who knew really we’re already on track for something, usually from their parents probably, right? And a lot of us who had no idea.

So, after this college admission begins well before graduation and requires you to write some sort of essay, explaining why this is your life-long passion that you probably came up with last semester.

Kirsten: Maybe.

Justin: Figuring out what you want to do.

Kirsten: Maybe.

Justin: So here’s my advice then on this. If you’re 18 years old-ish, look back five years and you will see that you are not the same person that you were five years ago. What may be surprising to you is that this will hold true probably for every five years span of the rest of your entire life. Okay.

Kirsten: Mm hmm. This is the Justin Theme for the show today.

Justin: Yeah. So, here’s what I would suggest, Daniel. I would suggest ignore the idea that what you study for initially will be your life’s work entirely that you will be in any way stuck or that you will be in any way all consumed by this decision that you’re about to make.

Instead, focus a little bit on what it is you’re good at and interested in like science. You’re fascinated in it. That’s the great thing to study. There’s nothing better to study than something you’re fascinated in because…

Kirsten: Mm hmm. Because you’ll be into it and you want to study.

Justin: …you’ll be interested and so you’ll do well. Right, you would want to read the material.

Kirsten: That’s great.

Justin: So simply start there. The wonderful thing about choosing science as a major is that within the scientist, there is every possible avenue of interesting stuff for you to delve into at some point.

Kirsten: Mm hmm.

Justin: So like Daniel though asked a very specific question. And if I was to suggest just off carte blanche, I would say start with Physics. Physics is applied to everything. Physics is…

Kirsten: Yeah. Engineering, it’s…

Justin: Engineering and Biochemistry and, you know, Life Sciences…

Kirsten: You can go big or you can go small with Physics, yeah.

Justin: All of mathematics is based on Physics. Theoretical…

Kirsten: Physics is based on math.

Justin: I’d say it’s completely the other way. All mathematics is based on Physics.

Kirsten: Mm hmm.

Justin: If it wasn’t for Physics being the way it is, math will be totally different. Yeah. So Daniel though asked a very specific question. “Will there be jobs available?”

If I was to predict — and hey I’ve got some pretty good predictions underway already this year — if I was to predict I would say the most versatile thing I would go into right now, aside from learning starting Physics first, will be Microbiology.

From that platform, you could do public health, pharmaceuticals, quality control for food and beverage. You could do fuel and energy sector now. Consumer gets a list, they’re just continuous. So a good mix of Physics…

Kirsten: Yeah and Computer Science. Get some Computer Programming in there because with Microbiology and Physics, you’re going to need Computer Programming to run a lot of the things that you’re going to do. So computer classes probably a good idea.

Justin: And five years from now with degree in hand, you decide you’ll be doing – rather be doing something completely different than what you ended up doing…

Kirsten: Yeah, start there.

Justin: …you can pursue a new path with, you know, knowing that you’re a Microbiologist or have a Physics degree and looking to change careers as opposed to being uneducated and not being able to choose another career.

Kirsten: There we go. (Stu Soto Saki Leech) wrote a couple of weeks ago, “(Gods), I hope the idea that gravity is relative or an emergent property pans out. My question then is what would it mean to all the dark matter mumbo-jumbo?” In my humble opinion, which is only backed-up with Philosophy degree, the whole, “You can’t see it. You can’t touch it or measure it but it’s there.” Explanatory powers of the dark matter pseudo sciences no better than the phlogiston of the 18th century.

(Judy Heights) writes in.

Justin: It’s not pseudo science but it’s bigger than you think.

Kirsten: (Judy Heights) writes in. “It seems to me that orcas having different sizes and having different wear on teeth may have more to do with their environment than speciation.” Gene genius.

Look at the brown bear and the grizzly bear. Brown bear is larger, darker, stronger because of high protein diet of fish. Grizzlies are on the (horse) but they are still Urkus arctos. Urus? It’s not Urus. Ursus arctos, there we go.

Your opinion, yes. I think she has a very good point there. We had a couple of people write in in response to the osteopenia story. Unfortunately, we’re running out of time. So I’m going to have to save these emails yet again for next week. I’m going to probably try and get to them at the very top because I’m tired of saving them.

(Ed Brydon) writes in, “I had an error that I needed to correct. I said that the 8% of a human genome last week is made up of Borna virus. I should have said just retrovirus in general, called the human endogenous retroviruses or HERVs.” And he’s got some links that I will put on the show’s website.

On next week’s show we will bring lots more science. And I’d like to give a shout-out to Hugh Love, the former president of the Hoof Trimmers Association who writes in, “I listen on an iPod every week while I work. I have a different occupation. I trim cow’s feet for a living.”

And he lets us know that, “You will find Dr. Steven Berry here at UC Davis, one of the top authorities on lame cows. And there’s a lot of science involved with treating cow’s feet — if they don’t walk, they don’t eat, drink or breed, something that’s somewhat necessary for the dairy industry.” Yeah.

Justin: Yeah. I wonder what happens when you mix a Corolla, Toyota. Yes, the dark matter is there but it’s not what you think. No, Kirsten is giving me the…

Kirsten: Finish it up.

Justin: I can’t. Oh, thank you for listening for today’s show. We really enjoyed having you come over and give a listen on your radio or via the podcast which you can find us at if you go to the iTune’s directory and look for This Week in Science.

Kirsten: That’s right. And you can also go to our website, and find more information on anything you’ve heard here today. There’ll be lots of links to the original stories that we sourced and some other Show Notes written by our wonderful intern, Ali. Thank you very much. And we want to hear from you. So email us at or

Justin: Yes. And…

Kirsten: Put TWIS in the subject line or…

Justin: …because otherwise you will get completely spam filtered.

Kirsten: So let us know if there’s anything you’d like us to address. Any errors you found in our reporting or a suggestion for an interview, we’ll try and follow things up if we can. And we’ll be back here on KDVS next Tuesday at 8:30 AM Pacific Time. And we hope you’ll join us again for more great science news.

Justin: But if you learned anything from today’s show, remember…

Kirsten: It’s all in your head.