地球轨道上的第一个动物是什么?Quizzing the Experts!

Plant scientist Beverley Glover from Cambridge University, tech expert and Angel investor Peter Cowley, Imperial College London physicist Jess Wade and mathematician James Grime from Numberphile are all put to the test by Chris Smith...

Chris - Question one, this is for Beverley and James. The light bulb was invented by Thomas Edison. Is that a science fact or is that a science fiction, do you think?

James - I believe I could answer this one, yeah. That sounds like nonsense to me.

Beverley - Oh dear!

James - I'm thinking it might have been one of the early people who profited from electricity and the light bulb, but I do not think it is correct to say that he invented the light bulb.

[Bing!]

Chris - Yup! You're on the money. It’s now generally accepted that British physicist Joseph Swan was the inventor of the modern light bulb. Edison developed a commercially viable and practical electric light bulb for the mass markets. So, well done to you two. Okay, over to Jess and Peter. Radiation was discovered by Marie Curie. Science fact or science fiction, do you think?

Peter - I suspect, not. I think, it’s probably the same that she was named for it, but not – was the one. Do you know, Jess?

Jess - I have never worked with – I mean, she has the big name, right? so, I'm assuming in the same way to the other one. She probably was the first one to measure it maybe, but…

Peter - Sorry, yeah. I was looking for…

Jess - I want to come up with a great answer about who actually did discover it, but maybe they died too quickly.

Chris - Are we going fact or fiction?

Jess - We’re going fiction.

Peter - Fiction, yeah.

[Bing!]

Chris - Well, my mouse button wouldn’t work. You're both on 1 point each. This has been quite tense this week. Normally, by this time, we’ve already got a lead. Sorry, James.

James - Discovery of radiation, was that?

Chris - I will answer. I’ll tell you. So, Marie Curie is often credited with the discovery of radiation but she actually coined the term ‘radioactivity’ but it was actually her doctoral supervisor who was Henri Becquerel who first discovered its existence. He was the one who famously showed that uranium salts, if you put them on a hard piece of paper or card that you had wrapped around a photographic plate could fog the photographic plate. So there was some invisible ray that was going through the card and hitting the photo plate.

James - Isn’t light radiation?

Chris - Yes, it is and Rontgen had invented x-rays before that and used his wife’s hand to produce some of the first x-rays. But actually, radiation, in terms of radioactivity that we’re talking about here was invented, not by Curie but by Becquerel.

Jess - We measure it in Becquerel, right? So, he does get some credit.

Chris - So, he gets his credit. He gets his name on the unit, that’s right. now, we’re on to round 2 which is firsts. We’re calling this round ‘firsts’. Now, what Beverley and James, was the first animal to orbit the earth?

James - That sounds like fun.

Beverley - It was a dog, wasn’t it?

James - Yeah.

Beverley - A Russian dog.

James - Dog sounds like a good answer. You think I think of chimpanzees.

Beverley - I think it was a dog.

James - But I think it might be rats or mice. I think it might be something simpler. Do you want to go for dog or rats or mice?

Beverley - I want to go dog.

James - Okay, we’ll go dog.

[Bing!]

Chris - The Soviet Union led the way on this one. They were the first to send an animal into orbit and Laika who was formerly a stray dog on the streets of Moscow, she was the first animal officially to orbit the earth when she successfully blasted into space aboard Sputnik 2 in November 1957. We do have to acknowledge though that she didn’t come back and there was no way to retrieve her from space with the technology they had at that time. So unfortunately, she went up. She was a pioneer, but she also died up there. Now question four – this is for you guys, what came first, Jess and Peter, a genetically modified plant or a genetically modified animal?

Peter - I don’t know.

Jess - I think it was a plant.

Peter - Yes, so it would be more likely to be a plant, isn’t it?

Jess - It’s easier, maybe. Oh, sorry. Don’t want to get in there with that. I have a feeling that an animal came much later. Okay, I'm going to say something stupid about Dolly the sheep that wasn’t the first time they genetically modified an animal. Let’s go with plant.

Peter - Yup!

[Bong!]

Chris - Did you know that one Beverley?

Beverley - I think I did.

克里斯-是的。事实上,答案是在1974年, Rudolf Jaenisch made the first genetically modified mouse. We’ve heard of Jaenisch on this program. He’s actually one of the scientists who invented or co-invented the IPS, the Induced Pluripotent Stem Cell, where they reprogram an adult cell to become a stem cell. But he produced the first genetically modified mouse in 1974. It was until 1983 that the first GM plant which was actually a strain of tobacco got produced by Michael Bevan, Richard Flavell, and Mary-Dell Chilton. Now why do people assume plants are easier than animals because it would appear from this discovery that they're not, Beverley?

Beverley - I think it’s about whether where the effort had gone in actually. So plants probably are easier because the trick about any kind of genetic modification is you modify a single cell and then you want to generate a whole organism back from that. And as we know with animals, that means either taking a stem cell and modifying that or taking a cell that’s already committed to on a fate and de-differentiating it back to a stage where it can create anything. That’s really tricky. That’s why there's so much research on stem cells whereas with plants, actually all cells are pluripotent and you can persuade pretty much any cell in a plant to regenerate a whole new plant if you give it the right hormones and the right sugars.

Chris - So, why did it take so long to do a plant compared to a mouse?

Beverley - There's an awful lot less plant scientists out there than there are animal scientists.

克里斯——这将是原因。对的,好吧。Beverley and James, in one second, we want to know what’s larger. So this is all about size or scale. In one second, what's larger, the number of dead skin cells that drop off your body or the number of laps of a 27-kilometer long Large Hadron Collider circuit that’s made by a packet of protons? So, what's more, dead skin cells falling off your body every second or the number of laps done by a packet of protons in the 27-kilometer long loop of the Large Hadron Collider?

James - What do you think? Do you think…

Beverley - I think skin cells.

James - You think skin cells. It sounds like you want to say Hadron Collider and so, I'm going to say – yeah, you think that they're trying to trick us?

Beverley - Okay.

James - I’d say skin cells, yeah.

[Bong!]

James - Too clever!

Chris - No. The answer is the proton laps actually. Scientists estimate, the average person sheds about 500 million skin cells in a day. So that’s about 6,000 dead skin cells dropping off you every second. But traveling at just 3 meters per second slower than the speed of light, CERN reckon that the protons accelerated in their LHC complete over 11,000 laps of the 27-kilometer long ring every second. So the protons currently clinch it. Right, it is ought to play for, okay. So, it’s level pegging so you’ve got to save your reputation here, Jess and Peter. Okay, here we go. The weight of all humans on earth or the weight of all ants on earth. Which is bigger, the humans or the ants, do you think?

Peter - I would guess, ants. The number of ants on this globe must be astronomical.

Jess - Yeah.

Peter - Astronomically more, must be.

Jess - I'm with you on that. They're underneath as well. They win.

Peter - Yeah.

[Bong!]

Chris - No, I'm sorry. Actually, it’s the humans, okay.

Jess - How different is it?

Chris - Ants weigh…

Jess - What if we take out China?

Chris - Ants weigh about 5 milligrams and we think, although we don’t know but scientists think there are 10,000 trillion ants on earth. So a likely estimate for their combined mass would be about 40 billion kilos or so. There are over 7 billion humans though and their combined weight is more than 300 billion kilos if you take everyone over the age of about 15. So, we outweigh the ants by almost an order of magnitude. But historically, if we’ve been doing this quiz in the 18th century, you probably would’ve been right because scientists also extrapolated backwards and suggests that around the time of the industrial revolution, so the 1700s, ants did probably outweigh us because there were fewer people around.

Peter - Can I challenge the 5 milligrams per ant?

Chris - You can certainly challenge. I'm not going to give you a point.

Peter - It seems remarkably low.

Chris - Well, no. Ants range between about 1 milligram and about 50 milligrams for some really big ones.

Peter - Is that right?

Chris - So actually, yes. And if you look at the… Beverley, do you know about ants?

Beverley - Yeah and you even get variation on that kind of order of magnitude within a single ant species. So, within a colony, you’ve got worker ants, soldier ants, and different types of ants, and you can have enormous variations in size. Scientists actually use them to try and understand how body mass and things like claw sharpness scale with size because they're such variable group.

Chris - Now, isn’t that wonderful? We’ve ended with both teams scoring the same. So your level pegging and you depart with your reputation intact.