Remembering Stephen Hawking

11:48 minutes

Theoretical physicist and cosmologist Stephen Hawking died this week at the age of 76. Known for his research into gravity, his popular books such as A Brief History of Time, and his cameo appearances on popular television shows like “The Simpsons,” Hawking challenged and inspired a generation of physicists. Hawking spoke with us in 2013, and now Amy Nordrum, news editor at IEEE Spectrum, joins guest host Flora Lichtman to talk about Hawking’s life and legacy.

[Did you know that the first ice skates were made of bones?]

They also take a tour of some other stories from the week in science, including a rogue satellite launch, what information can be conveyed in the call of a hungry raven, and an experimental hair dye based on the carbon wonder-material graphene.

Segment Guests

Amy Nordrum

Amy Nordrum is an executive editor at MIT Technology Review. Previously, she was News Editor at IEEE Spectrum in New York City.

Segment Transcript

FLORA LICHTMAN: This is Science Friday. I’m Flora Lichtman. Ira Flatow is away. A bit later in the hour we’ll be talking about how women are breaking into the male dominated world of blockchain and cryptocurrencies.

But first, this week astrophysicist Steven Hawking passed away. Joining me now to talk about that, and other science news from the week, is Amy Nordrum, news editor at IEEE Spectrum. She’s here in our New York studios. Welcome back Amy.


FLORA LICHTMAN: Hey. So, I feel like most of us know Stephen Hawking’s name, but what was he famous for scientifically?

AMY NORDRUM: Yeah. Stephen Hawking is a renowned physicist. And he’s perhaps best known for his contributions to our understanding of black holes. So, black holes are these swirls of mass and energy with a big gravitational pull. So strong that not even light can escape them. And Hawking’s contribution was primarily to show that these black holes actually do emit some things.

So they can emit radiation, they can actually emit particles. And this is now termed Hawking radiation among physicists. And it’s led to a lot of new questions around black holes, and new paths for people to continue to explore in physics.

FLORA LICHTMAN: I think I remember– I was reading the obituaries this week. And people called his paper on exploding black holes, like, the most beautiful physics paper ever written.

AMY NORDRUM: That’s right. I actually tried to read it. It was published in Nature, and I couldn’t understand it. But it’s full of equations, and obviously physicists are still thinking a lot about it, and continuing to work on the theories that he’s put forward.

FLORA LICHTMAN: OK. So if I want to read some Hawking, where should I start?

AMY NORDRUM: Yeah. Hawking is also a beloved popularizer of science. So in the 1980s he published a book called, A Brief History of Time. And that book has sold more than 10 million copies since its publication. So a lot of people look at that book. He attempts to take on a very difficult role for an author, which is explain the history of the universe. But you know, a lot of people have found it useful, and very accessible for his interpretation of it.

FLORA LICHTMAN: So Dr. Hawking was on Science Friday, we have a clip from a recording of Dr. Hawking made for Science Friday back in 2013. He suffered from a neurodegenerative illness, and he spoke using a speech synthesizer. And here’s what he said when we asked him about the limits of science.

“I believe there are no questions that science can’t answer about the physical universe. Although we don’t yet have a full understanding of the laws of nature, I think we will eventually find a complete unified theory. Some people would claim that things like love, joy, and beauty belong to a different category from science, and can’t be described in scientific terms. But I think they can all be explained by the theory of evolution.”

So moving.

AMY NORDRUM: Yeah. I think a lot of his greatness comes from his ability to kind of combine and blend different areas of science, and different theories. So his work on black holes was combining Einstein’s theory of relativity– and what it says about how massive objects produce a gravitational force– with quantum mechanics, which is really concerned with the tiniest particles that we know of. And so, his ability to bridge these fields– and like you said, try to come up with a theory of everything– is a really powerful concept. And he wasn’t able to ever formulize that himself, but obviously work will continue on that. And it’s a really grand idea to think about.

FLORA LICHTMAN: He will certainly be missed. In other news this week, you have a story– this is really tantalizing, I think– about rogue satellites.

AMY NORDRUM: That’s right. There’s a lot of action in the private space world right now. There’s all kinds of startups that are throwing up satellites for lots of different reasons and purposes. New business models being formed around these lower cost, cheaper satellite launches. And there’s one company in particular that one of our contributors, Mark Harris, took a look at.

So this company is called Swarm Technologies, and they’re based in Silicon Valley. And they had this innovative experimental satellite concept. So these satellites that they proposed to launch were about a fourth the size of the smallest satellites that are going up into orbit today.

FLORA LICHTMAN: How big are they?

AMY NORDRUM: They’re about the size of a hardback book, you could say.

FLORA LICHTMAN: Smaller than a breadbox.

AMY NORDRUM: Smaller than a CubeSat, which is what the breadbox-sized satellites are that you always hear about. So they’re going to launch these tinier satellites up into space, and they’re going to use them to form this communications network. So they have this idea that we’re going to need more and more things connected down here on Earth, and companies will pay to track devices that are being attached to trucks, and other goods, as they move around the world.

FLORA LICHTMAN: Is this like internet of things?

AMY NORDRUM: Yeah, exactly. So they would be supplying the backhaul– the data transmission capabilities that these tiny little IoT devices would be sending up to space. So Swarm had this big idea, and they applied for an FCC license to launch these tiny satellites. And the FCC actually denied their license last year, because they were worried. The satellites were too small, they’d be tough to track. And they’d be tough for other spacecraft and satellites to detect, and stay out of the way of.

So it appears now, based on Mark Harris’s work, that the company has gone forward and launched these satellites anyway. So Swarm appears to have launched the satellites in January on a rocket that was launched by the Indian space agency. And the FCC is not too happy about this, as you can imagine.

FLORA LICHTMAN: So what is the recourse for the FCC though? Like, they’re there, right?

AMY NORDRUM: Well they’re up there. Yeah. They’re in orbit. So far as we can tell. On about the same path that Swarm had originally proposed sending them on. And the FCC’s response has been to issue a very strongly worded letter that– Swarm had applied for another license to launch some more satellites on a rocket this April. And so, now the FCC is taking a look again at that application they had already granted, and possibly going to revoke it.

FLORA LICHTMAN: Does the FCC– I can’t understand the jurisdiction though. Because the FCC, they obviously don’t regulate what goes onto an Indian rocket for example, right?

AMY NORDRUM: Yeah. I mean, the FCC has authority over these US startups, and it was an unauthorized launch. They were concerned about the safety of it. And there’s at least three federal agencies– the FCC, the FAA, and then the NOAA– that have some jurisdiction over space launches. And making sure that space is as safe for everyone, that these satellite launches go well. But it’s tricky, because obviously there are more and more opportunities to launch all around the world for these startups to take advantage of. And Swarm may have found a loophole in this process.

FLORA LICHTMAN: This feels like a classic ask forgiveness, not permission.

AMY NORDRUM: That may be what’s happening here. And Swarm has not said anything about it. And the FCC so far hasn’t commented beyond what we are able to read in their letter. So we’re going to be watching this story and seeing how it plays out.

FLORA LICHTMAN: Oh, interesting. OK. Closer to home, there was a story this week about a snow melting blanket. Tell me more.

AMY NORDRUM: Yeah, this researcher at Virginia Tech. He was driving around campus one day and it had snowed recently, and he was late to a meeting. And so he was kind of panicking trying to find a parking spot. And the parking lot he was in, he realized, like a third of the spaces were full of snow, and these massive snow banks that the plows had created when they had tried to clear the parking lot.

FLORA LICHTMAN: I’m familiar with this as a New Yorker.

AMY NORDRUM: Yeah. This is a chronic problem a lot of people in northern climates can relate to. So he started thinking about it, and he realized, this is like a problem that we create for ourselves. Because we’re the ones that pile up snow into these big banks, and snow is highly reflective. And so it’s tough for the middle of those snow banks to melt away, and then they last for a really long time.

This was bothering him so much that he’s come up with this solution to it, like many great scientists do. And he’s conceived of this thermal blanket. And he says, if we had a thermal blanket that we could throw over these snow banks and help the snow melt faster, that would be super useful. And so far he’s made it as far as to do a lab experiment in which he just spray painted aluminum foil black, and then put that over some snow that he made with like a snow cone maker.

But this is how things start, right? So the snow blanket– or the thermal blanket, which is really a piece of aluminum foil– he tested it in the lab, and it effectively melted snow three times faster than if the snow had just been left on its own.

FLORA LICHTMAN: So you put this blanket over a snow bank. It’s black, so it absorbs heat from the sun.


FLORA LICHTMAN: And then it transfers it to the snow, and melts it

AMY NORDRUM: Yeah. That’s why it’s important that it’s metal too. So it can conduct the heat from the outer surface to the inner surface. And so, yeah. That’s his idea, and he’s hoping, you know, it worked in the lab three times faster. So he’s thinking that maybe this could be a commercial product someday.

FLORA LICHTMAN: Or / a DIY project.

AMY NORDRUM: Yeah. I mean, you could try this at home, absolutely. It’s something that– you know– low material costs, so low investment. And he thinks there could be some environmental and cost savings here. I mean, cities pay tons of money to have snow removal every year, and use a lot of salt and chemicals to get rid of it too. So this could be a better way.

FLORA LICHTMAN: All right. Next up, I want you to listen to this.


Amy, what are we listening to?

AMY NORDRUM: Those are Ravens. And they are doing what’s known as food calls. So this is a call that they would do when they’re around some food that they can’t get to, basically. They want to get to the food, but there’s a problem. The problem could be a predator, or it could be that there’s another territorial pair of Ravens that are kind of defending it.

FLORA LICHTMAN: It’s like a hangry call.

AMY NORDRUM: Yeah, you could definitely characterize it as a hangry call. So the Ravens are basically asking for help. I mean, they’re putting these calls out trying to get reinforcements, trying to get other Ravens to join them. And some new research out this week showed that that Raven call, it contains more than just information. It’s not just communicating that they see food, and they want to go get it, it also contains particular characteristics to each individual.

So it’s possible to distinguish the age of the Raven, and the sex of the Raven, based on these calls. And that’s not unlike humans, where you can maybe guess whether someone’s young or old based on the frequency and amplitude of their voice. So now we know that the same thing happens in Ravens.

FLORA LICHTMAN: That makes sense. OK. We have time for one more I think. And this is like the most fun application of graphene that I’ve heard about. So remind us what graphene is.

AMY NORDRUM: Yeah, graphene is a material that has an almost comical reputation for being applied for all kinds of solutions and ideas, within electronics mainly, but also other fields. It’s a single layer of carbon atoms. And it’s very strong, it’s highly conductive, it has a lot of cool properties. It’s the thinnest material we’ve ever been able to find.

And this is a very peculiar idea for how to use graphene. There’s some researchers at Northwestern University who have proposed a way to dye hair with graphene. Which I’d never heard of before.

FLORA LICHTMAN: It wraps around the individual hairs, do I have that right?

AMY NORDRUM: Yeah. It’s kind of cool when you think about it, because a lot of hair dyes– they actually pull up the cuticle, or outer covering of the hair strand. And there’s a chemical combination that occurs within the hair to dye the strand. And this one more just wraps around the outside, so it’s more of like a coating.

And they did test it. I guess the minimum number of washes you need to get a hair dye to be considered permanent is 30. And this lasts longer than 30 washes. It dyes your hair deep black, by the way. They’re also able to get shades of brown too.

FLORA LICHTMAN: But that’s it?

AMY NORDRUM: Yeah. I mean, you wouldn’t go blond with graphene, I don’t think.

FLORA LICHTMAN: I have this vision of the lab of just, like, tons of wigs. Or like mice with interesting new hair colors.

AMY NORDRUM: Yeah. I mean, they did some cool frizz tests too, in terms of static electricity. Because graphene is so conductive. The idea is that actually putting this hair dye in your hair can remove static electricity, because it helps it get rid of built up charges more easily.

FLORA LICHTMAN: It’s a frizzies as well?

AMY NORDRUM: Yeah. De-frizz.


AMY NORDRUM: Not yet. It’s definitely still in the lab stages, maybe someday.

FLORA LICHTMAN: Thank you, Amy.


FLORA LICHTMAN: Amy Nordrum is the news editor at IEEE Spectrum.

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