Speed

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Hello, I'm Robin Inks.

And I'm Brian Cox.

And welcome to the podcast version of the Infinite Monkey Cage, which contains extra material that wasn't considered good enough for the radio.

Enjoy it.

Hello, I'm Robin Inks.

And I'm Brian Cox.

And this is our first show back from America.

Yeah, LA didn't suit you, did it?

LA didn't suit me, actually.

I arrived wearing a duffel coat in 25-degree centigrade heat and managed to get a part in Hollywood as a bear.

Actually, America was great because a lot of the scientists, there was a lovely moment where they kept coming up to go, oh, it's really great.

You must be so happy to live in England because everyone in England is so fascinated by science and philosophy and ideas.

And I thought, should I tell them?

No.

Let them dream of this utopia they've imagined.

Today we are discussing speed.

Or rather, in fact, we should do this properly.

You should do this, which is...

tonight.

We are talking about speed.

Things that go really fast, like cars, reindeer, rockets, but not Mexicans.

They've already given it to Chris Evans.

I thought I would really be in with a chance of presenting Top Gear, even though I can't drive.

But I do own a bicycle that has a small bell.

It's very tiring talking like this, isn't it?

That's what I've found.

Where's my hot meat?

We've never done slapstick on the radio, it may be the last time.

And also, the thing that I like about it is what you meant to do is pretend, but you didn't.

You hit me very hard on the ear, and it's created some form of tinnitus.

So.

Okay.

Today we're talking about land speed records, airspeed records, and the engineering and physics of of speed.

How fast can humans aspire to travel?

Are we restricted by engineering or are the laws of physics the only limit?

As usual we have a panel of experts and they are.

I'm Andy Green, fighter pilot in the Royal Air Force and the fastest thing I've ever seen is a very small flock of birds.

On the 15th of October 1997, when we were breaking the world land speed record, just before we went supersonic, this very small cluster of black objects passed just over my head, doing 700 miles an hour with these huge eyes.

Now, technically, I then saw the measured mile go past slightly faster, but in subjective terms, they were very fast.

Hi, I'm Danielle George.

I'm a radio frequency engineer, professor of radio frequency engineering, I should say, sorry, at the University of Manchester.

And the fastest thing I've ever seen is a movie being beamed from one laptop to another using light bulbs.

Hi, I'm Alexei Sal, I'm a comedian, author, and motoring correspondent.

And the fastest thing I've ever seen is robbing out of the bar when the bill comes.

And this is our panel.

Andy, we'll start with you because you currently hold the land speed record, World Land Speed Record.

And this is that I'm kind of intrigued by, which is why are we still trying to get faster on land?

Because surely there's a point where all it does is just get you quicker to the seaside.

There's, you know, going faster into space, in the air, I can understand, but what are the what's the motivation between you know trying to get up to a thousand miles an hour?

Well, there's a bit of simply because we can, it's a part of human endeavor and doing stuff like climbing Everest, going to the moon, etc.

But there's also another bit that's about bringing science and technology to life in a real sort of wow incredible way for the next generation of young scientists and actually teaching them and inspiring them about the magic of science and technology.

Is it too early to involve the audience at this stage?

Can we go there now?

No.

Right.

Radio 4 audience, this is going to take 60 seconds.

I've got four questions.

You'll answer them all.

And no pressure, Alexi, but if they can't, I'm going to send it to you.

So, first question then: jet-powered car, okay, it's a military jet engine, supersonic military jet engine, in a car.

What's the physical mechanism that makes that car move?

Thrust, okay, go with the thrust.

What is thrust?

How does an engine generate thrust?

Recoil, though,

pressure.

Yeah, okay, so it generates pressure.

What does the pressure do?

Expands.

Yeah, it expands, expands, pushes out.

You know, somebody said fast is high-speed gas coming out the back.

Why does that generate thrust?

Push and recoil.

Action and reaction, exactly.

If you're pushing hard on the air, then it's pushing equally hard on the engine, engine bolt of the car, car moves.

Right, it's a seven-ton car.

And we've got 12 miles to get up to a thousand miles an hour and back to stationary again.

So you're going to, you know, you need to accelerate quickly.

Why do we need a really powerful engine to accelerate quickly?

Overcome inertia.

Yeah, to overcome inertia, keep going with that line.

It's a seven-tonne car.

If you only pushed it very gently, it would accelerate

very slowly.

If you push it hard,

it accelerates quickly.

Correct.

So you need a big engine.

Third thing then, if there was no way of slowing this car, if there was no air brakes, no parachutes, it's a very slippery vehicle.

It's designed to be minimum drag.

As close to zero drag as we can get.

If we had no aerodynamic stopping aids, what would happen?

When we shut it off, the car would just

carry on in a straight line at the same speed.

Okay, last question.

What ties those first three questions together?

What do they all have in common?

Correct, that's Newton's third law, second law, and first law in order.

I rather more deeply knowether's theorem.

You always have to spoil it, don't you?

Someone there goes, oh, it's on it right, and you go, well, it wasn't quite right.

Three minutes into the programme, and I've lost.

Links are symmetries of space and time to conservation laws.

That's obviously.

I love the idea.

You answer your question, it brings science and technology.

Everybody's going to remember that.

Newton's laws about the big engine, the thrust, and the needing parachutes or air braces.

You know, that's a way of getting a 12-year-old excited and then going out to build their own little rocket car and put it in the playground.

And we're now running.

No, seriously.

There must be some.

We are now

a global rocket car challenge.

Brazil's taking part.

South Africa's taking part.

Have a guess what the.

And there's four categories.

They're all Guinness World Records.

The unlimited category is currently held by a British school up near Derby.

Have a guess what that record is.

Anyone want to have a guess?

Alexia, you're looking interested.

Have a guess.

This was set by a bunch of school kids with a rocket-powered car.

100 miles an hour?

Rocket-powered car, school kids.

500 miles.

500 miles an hour.

See, he's much cleverer than you are.

Yeah, 530 miles an hour.

A child got in that.

No, no, it's a

model car.

Just, you know.

Think about speed programs, you've got to keep up with all the words.

Model rocket car.

Sorry, I couldn't resist that.

I suddenly feel like David Attenborough, and as we see the two alpha males, he usurps his Newton's laws.

Daniela,

a beautiful description there of

how these challenges can excite people about engineering.

So is that what you really see that the point of the land speed records really is?

Or is it genuinely this pushing the boundaries of technology?

I would say probably it's a mixture of both, but but I think first and foremost,

getting the next generation really excited about engineering

should be first and foremost in so many people's minds.

So many people go to school and do the sciences, but don't really think that what they're doing is engineering.

And having something like this that's got so many different bits of engineering in it, and having it is such a great thing for kids to get involved in, makes them think, actually, yeah, I can be an engineer and I can change the world.

So I'm really good at maths, I'm really good at physics.

I'm actually going to do engineering when I go to university or when I get a job.

Alexi, you actually were, and I find this quite, I find it unusual that an alternative Marxist comedian would become the Daily Telegraph motoring correspondent

and reforming the system from the inside.

What was it that, how did you end up being, you know, a motoring correspondent?

Well, because my parents being communists, they didn't like cars.

The communists always thought the only only good car was one that was painted green and was armoured

and had a big red star on the front and was preferably putting down a workers' uprising.

So they well my dad worked on the railway, so we got free travel.

So cars just seemed like these magical, rare kind of things to me.

And so I I never thought that I'd ever be able to drive.

So I just became fascinated with them as kind of rare objects.

And so I also think that people talk to each other with cars.

I think like the car that you drive, people choose them because it says volumes about them.

And so, I became fascinated with that, really, the kind of iconography of cars, and all this before I could drive.

And then, finally, I did learn.

I mean, I didn't learn to drive until I was 30.

And so, I think I just have this kind of odd kind of outsider view of automobiles, which

you know, I think means that I can write quite interestingly about them, really.

And that's that's what the Telegraph saw in me was that ability.

And then they didn't, and they sacked me.

They stopped seeing that.

But before then, I don't, you know, because I used to, I actually used to present Top Gear

when it was like really at its worst,

when it was like all about the bootlining and carpeting in a Ford Orion.

And did you, did you, when, so you got into cars at a sort of a late age, started driving, did was it the engineering?

Did you like, do you like the fast cars, the Ferraris, the big engines?

Do you like, what was what was your

sort of about the no, it was more the kind of like clothes again, the kind of the it was about the styling and the way that people,

you know, that if you, I mean, then it was more complex now, but it's you know, the kind of you know, that you've you drove a cultano, you were a corner, you know, all that kind of thing.

And

it was about the kind of philosophical ideas of that were contained within cars.

I think I mean, I mean, Roland Barthes, the French philosopher and writer, said that cars are the modern equivalent of the medieval cathedral, in that they embody both the technological but also the social and kind of philosophical pinnacle of our age.

And I think that that's actually true.

And that's what you know Richard Hammond is striving at, constantly to express

that point.

He's striving for the philosophical.

And Andy, so you began life as a fighter pilot.

So were you always interested in land speed as well, in cars?

Or is that did you come to that from the aircraft just for the speed, really?

That was very much a progression.

I actually started life as a mathematician, so that's very much by training.

I then was lucky enough to get what I still think is the best day job in the world as a fighter pilot in the Royal Air Force, and very lately, then bring those skills both as a mathematician and as a fighter pilot to the world of the land speed record.

Which I agree completely with everything Alexis said about cars and medieval cathedrals.

I hadn't heard that before, that's fascinating.

The land speed record is somewhat different.

It is a pure, the purest form of motorsport.

1898, I'm sorry to tell you, ladies and gentlemen, it was a Frenchman that started this.

39.24 miles an hour in 1898.

For those French, is anybody French in the audience?

Yeah, enjoy this moment.

This is your last mention.

Because

this is a very unusual sport.

This is a sport that Britain is better at than everybody else in the world put together.

We've held it for pretty much most of

the period since 1898.

And it combines the very best of engineering disciplines that we have in the UK.

We've got the world's best motorsport engineers here.

My background, fighter pilot,

we make things like the Eurofighter Typhoon, one of the world's best jet fighters, the Rolls-Royce EJ200 in it, world's best military jet engine.

British expertise through and through.

If we are going to have the next generation of excellence in engineering and technology and everything that makes our world work from high-end technology, from aerospace and motorsport all the way through to transport and infrastructure and other places in the world where you need enough food and water to drink.

If we are going to contribute to that, we are going to need that next generation of engineers and that using the land speed record to create a car which is part Formula One race car and it's part supersonic jet fighter and it's part next generation space rocket and package it all in something to do a thousand miles an hour and then put it in front of a ten year old and go, How cool is that?

And then start having science lessons about what makes it go without them even seeing it coming.

It's like hiding the peas in the mashed potato.

It's a very cunning way, get them to do good things without really seeing it coming.

That's how I actually see the landspeed record.

And how difficult is it?

Because essentially,

you described it, it's a Typhoon jet engine, the EJ200, with four wheels on it.

And you sit on it and press go.

And you go ahead.

I mean, and how.

But how difficult actually is it?

It's obviously slightly more difficult than that.

Well, there are a couple of challenges in this because, of course,

no jet fighter in history has actually done a thousand miles an hour at ground level.

So, we're not only going to set the world's

land speed record, but for the first time in over a hundred years, we're going back to the natural order of things where cars are faster than aeroplanes at ground level.

Just the jet engine won't get there because we're actually going faster than the jet engine was designed to go.

So, we are combining it with this next-generation hybrid rocket technology, which is being developed for the European Space Agency.

You know, all of you in the audience, your kids will be using satellite phones one day.

You won't have a mobile master, you'll be talking to a satellite.

Those satellites will be launched with the sort of technology we're going to use in the car.

The tricky bit is to start off, we've got an engine intake sitting behind my head, which is optimised for about Mach 1.2, about 850 miles an hour.

So we can't put full power on.

But I've got to get as much power on as possible.

So we have got to go to what's called the distortion limit.

The maximum amount of air we can stuff through that tiny hole without it breaking down and choking the engine.

So I've got to drive a very precise thrust profile with the engine screaming away behind me as I'm winding it up very, very precisely on the pedal underneath my right foot.

I've got a jet engine underneath my right foot.

When we get to, and it's going to be about 100, 150 miles an hour, we'll establish exactly what speed.

Once we get to full power, kick it through the detent, full reheat lights one second later, the car is then accelerating at 1G, so 20 miles an hour per second.

It's the equivalent of 0 to 60 in one and a half seconds.

So it's pretty ferocious.

I've then got about six seconds before I start the wind-up process for the rocket, because it's a hybrid rocket.

I need to hit it exactly the right time 20 seconds before we get to the measured mile because it burns for just over 20 seconds need to it to burn out in the measured mile so I've got to hit that at exactly the right point and while I'm doing all of that I've also got to monitor the loads front and rear to check that the the aerodynamic balance of the car is exactly the same as we had the run before and the run before

and At slow speed, slow speed for this car is anything below about 200 miles an hour.

The wheels are basically, they're sort of V-shaped metal wheels, they are using their form, just the actual grip and the V-shape in the dry mud surface in South Africa, to actually keep the car straight.

V-shaped, yes.

You can't put tires on it.

Not round.

Because.

Got a tip for you.

I'm going to have to speak.

I'm going to have to speak more slowly.

The round wheels have a V-shaped profile on the tread.

Were you to cut through them?

The shoulders of that at slow speed give me a little bit of grip.

Medium speed, three, four, five hundred miles an hour.

The wheel is now starting to plane like a speedboat hull, so it's starting to skim across the surface.

We are now down to possibly two or three millimeters of wheel sticking into the surface.

So there is almost no lateral grip.

I'm literally, you know, plus or minus 90 degrees of steering is what we estimate I may have to use to keep the car straight at this stage while firing the rocket and now bumping the acceleration up to 2G.

40 miles an hour per second.

You know, the car is now cracking on at a fair rate and it's like driving on ice.

The aerodynamic stability has yet to kick in because at 300 miles an hour the the aerodynamic force is only about a tenth of what it is at a thousand because it's you know comes up with a square law.

Now jump forward until we're fully supersonic doing eight, nine hundred, thousand miles an hour.

The wheels are still skimming so they're still doing very very little but now the aerodynamics are absolutely doing a huge amount.

The front wheels stick down into supersonic airflow doing Mach 1.3, 1.5 between the front wheels.

So now a tiny change in the steering wheel will produce a huge response in the steering input.

So the car goes from being reasonably predictable at 200 miles an hour hour to three or four hundred miles an hour, it's all over the place to a thousand miles an hour, tiny changes making it dart all over the place.

While I'm controlling the jet engine and the rocket and monitoring the downloads and looking for the measured mile so that we can actually get the car up to speed, and then there's the slowing down bit, which is like what I've described, but in reverse involving air brakes and parachutes and still keeping the car straight.

But apart from that, yeah, it'd be quite easy.

See, about halfway through that, all I saw you was dressed as Batman, and it kind of ruined it.

I suddenly realized I'm very childish that it was that when you went, My day job as a fighter pilot, which was my day job as a fighter pilot, by night, I'm a secret greengrocer.

Tell you what, in terms of engineering, as well as the practical side, would you be drawn to actually going on an adventure like that?

You know, the attempt to try and get to a thousand miles an hour.

Could you see yourself behind the driving, you know, the steering wheel, that the driving wheel?

I don't drive.

I don't know any of the technical terms.

I don't think I could see myself behind the wheel, but more behind the technology.

So, so if Andy's in the car, I could see me being there going, right, the electronics is doing this, the mechanics are doing that, and we need that person doing this.

And so, so being more on the sort of

the engineering side, and Andy can take all the glory.

No, that is actually the story we're trying to tell.

The glory is the how do you get the engineering to come together and make all of that?

You know, I'm part of the engineering team showing off exactly what you've just described.

You start, you worked with, not on engines, but on turbines, but the same on jets.

Can you tell us a bit about that?

I suppose the engineering and the design that goes into a modern jet engine?

Oh, it's just amazing.

I mean, it's absolutely.

So, I was at Rolls-Rice in Derby and very privileged to sort of be near one of their Trent 1000 engines.

And

it's truly beautiful.

You know, you're talking about art, Alexi, and how cars are like that.

An engine is truly beautiful.

And you know, they talk about STEM, and a lot of people are talking about steam now, so bringing the art, the A, into into it.

And it is, they're they're they're such beautiful things to look at as well.

And the engineering behind it is truly amazing.

You can just stand there and they're huge, these things.

You know, you feel so small when you're standing in front of them.

But the amount of engineering that goes in them is is truly amazing.

So they're they're the engines that are on things like triple sevens and that's right, yeah, yeah, yeah.

So the trend.

One of the interesting things, I was watching a f I don't know, know, I was watching a film about Rolls-Royce in Derby, and you know, like if you, you know, like at the BBC, everybody kind of, it's like everybody talks posh, but like there's a variety of regional accents that I noticed there, even in the very senior positions.

I don't know whether,

and you've obviously got like a Geordie accent, I don't know whether you think that that's, I don't know, it just seems something significant in a way that, you know, something like the media seems to be dominated by, because it's not a meritocracy,

dominated by posh people,

whereas engineering, because it is a meritocracy, seems to be that you seem to get a lot of working-class accents or regional accents.

I've never really thought of it, but yeah.

Yeah, it just struck me watching that film.

Just making a bit of a Marxist pointer, you know.

That was the television correspondent still wondering how he lost his job.

Can you work specifically on the electronics around those engines?

Yeah, yeah.

So we were looking at the sort of the RF, the radio frequency, and can you effectively try and get rid of some of the wiring that's in a lot of jets?

So, not when they're actually flying, but when they're either in the sort of test beds or when they're on the aircrafts but on the runways or they're parked in the airports,

you want to communicate with them and it'd be really, really good to get rid of all of the wires.

So, can you do it wirelessly?

But there's a lot of huge infrastructure just in the

just in the engine.

And you imagine if you close the cowl doors on an engine, it's like a Faraday cage, you know, no signals can get in or out.

So, so trying to communicate outside of those cowl doors, because they have to be

there's sort of metal strips in them for lightning protection as well, so there's a lot of metal in them.

So, trying to get wireless communication out or radio waves out of an engine is really, really difficult.

Are they the most complicated things that we mass produce as a civilization?

Aircraft engines?

They probably are, aren't they?

Yeah, they probably are, yeah.

When you look at one, you sort of

think,

yeah, because the amount that goes in is

and they cost as much as the plane, don't they?

Oh, they have, yeah.

And the amazing thing is they monitor them, don't they?

That Rolls-Royce actually monitors every Rolls-Royce engine

as it's flying.

Yeah.

Which is great.

But it is amazing.

We think I mean there are.

And what are the different challenges?

You know, Andy was going through a lot of the challenges in terms of land speed, but when we're talking about going into space, and obviously, you know, we have to find ways of if we're going to manage to travel any distance, you know, into even our own solar system, human beings, we're going to have to find new technology.

What are the challenges, the engineering challenges, of going into space and building up speed?

I think a lot of it is

the sort of human

side in terms of the sort of biomedical side.

So there's a lot of biomedical engineering that needs to be done, or bioengineering that needs to be done.

Making people be able to breathe properly when you're at this sort of very basic functions,

but also size.

I mean, sort of forget cost for now, but but think about the size of things.

If we as humans want to travel into space, we need to take a lot of stuff with us.

And so there has to be a lot of spacecrafts that not only carry humans, a bit like we have now with planes, you know, there are commercial flights, but there is cargo as well.

We need cargo as well, so a lot of nanotechnology, so trying to sort of shrink everything down into as small as possible the technology so that

you can put more in a spacecraft, so you can get more out there at any one time.

And they're doing it now.

So, for the International Space Station, they're trying these

to detect sort of toxic or toxins in the air.

They have these tiny little, they've used nanotechnology and they're tiny little

sort of stamp-size vents

and they're detecting toxins in the air on the International Space Station.

But that has taken a huge amount of engineering to get it right down.

You know, at one point, it would have been this size, where they've got it all the way down to the size of a postage stamp now.

So it's sort of nanotechnology, a lot of sort of bioengineering.

And then, of course, there's the obvious mechanical engineering, the huge amounts of electronics.

I mean, there's this huge amount of, I imagine in the cars now that Andy, you're you're dealing with, there's huge amounts of electronics.

There is in the Formula One cars, much less mechanical engineering and much more electronic engineering.

So we need to think about that as well.

They're going to to be

actually, I know you were saying beforehand about, you know, when you were a motoring correspondent, every now and again you were like about once a month you would have to do something which you found reasonably terrifying.

I mean, in terms of things like land speed records or you know journeys into space, are these are either of these things things that you could imagine doing or is that really beyond your

fear factor?

I don't mind as long as I'm if I can drive it.

I don't, you know, what I hated was like we were talking about before about going up the up the up the what do you call it up the hill, a Goodwood now one up there with a Ferrari, one of their Ferrari drivers in a 458.

And it was just the most terrifying, because I wasn't in control, it was just the most terrifying experience.

And just towards the end, it started to rain, and he didn't, the driver didn't turn on the windscreen wipers.

And I thought, oh, that's what you do when you're a racing driver.

You don't use the windscreen wipers.

And I said afterwards, you didn't turn it on the windscreen wipers.

You see, I didn't know where the switch was.

We're doing 120 coming up to a flintstone wall and he hasn't got the windscreen wipers on.

So I would have been even more frightened.

For me, yeah, it's a question control.

I don't mind going fast as long as I'm driving, but if I'm being driven, I find that really terrifying.

I know, but you were talking, I mean, Brian was talking before about you going up in a typhoon and stuff.

You don't mind that seeding control, too?

No, I tend to think these pilots know what they're doing.

In fact, if they said to me, if they said to me, why don't you land this typhoon?

I'd say, no, you land it.

I'd say, yeah.

I'd say, yeah, I can do that.

I want to follow up with Alexis.

You know, it's all about the control.

Would you really be happy to go into space if they just said, yeah, you're on your own, you can fly it?

Yeah, because I think I could.

I'm a comic.

I think I can do everything.

I did it on the Xbox, so you know, I mean.

How hard can it be?

Yeah, you're right.

How hard can it be?

And Andy,

is there a limit that you see to land speed records?

That's always a very dangerous question to answer because, of course, you know, Malcolm Campbell, very famously,

he was the greatest of our land speed record breaker, nine world land speed records.

He almost made a business out of it.

And he was the first man to get over 300 miles an hour.

1935, Bonneville Salt Flats, he climbs out of his car,

first ever 300 miles an hour run, amazing achievement.

And he climbs out and he says, I don't believe man will ever drive faster than that.

Which was probably a little bit on the ambitious side to say, because of course a few years later, people were doing exactly that.

And you can almost buy a commercial production car, certainly go 200 miles an hour.

Yeah, exactly.

But of course, it also depends on how much you understand the technology.

So it may have seemed like a perfectly reasonable thing to say in 1935.

Because if you jump forward, let's say 10 years to 1945, end of the Second World War, aeroplanes were now getting fast enough that in a power dive, they could actually start to generate shockwaves over the wings.

And they got all the buffeting, and aeroplane was thrown all over the place.

And some of them actually physically broke up.

And they coined the term the sound barrier because it was deemed a physical barrier that you would never get through because the shock waves are piling up.

You could never punch through that because the loads would just be so high, it'd be ridiculous.

And you know, if we were in an audience right now saying, Do you think anybody could ever break the sound barrier?

You'd be like, Of course it's been done.

1945, you would have said, No, that can't be done.

We've got all sorts of evidence.

You get close to that, the airplane will break up.

Well, two years later, of course, they developed the technology, and the likes of Chuck Jaeger, we're actually getting supersonic as part of the demonstrating the ability to manage high speed flight because ultimately what they were looking at is very high speed re-entry into the atmosphere because they were building the technology would ultimately allow the Americans to go to space and come back again.

Now is there a limit to how fast people can travel?

They went pretty fast going to the moon and back, you know, tens of thousands of miles an hour.

Does then the physics of the speed of light come in?

And is that actually a physical limit?

Or is it just that we don't understand, like the sound barrier, we don't don't understand what lives beyond it?

We would ask Danielle to.

Well, I just wanted to go on there.

But in terms of land speed, isn't there going to be just the limitation in terms of the amount of land?

You know,

there's a bit where you go, it's just a little bit too fast, and I keep going over the end of the cliff.

You know, there's kind of, so for instance, I know that in South Africa, the fact that the people who are helping prepare where you're going to drive, they're spending a lot of time picking up every stone.

Is that right?

They have to basically clear the street.

They've actually got our first, you know, their first world record.

these guys have done something which is a proportion you know an achievement of biblical proportions they have hand cleared over the last five years 20 million square meters by hand team of 300 people now if you want to picture what three hundred twenty million square meters looks like if you imagine a three-lane road from outside here broadcasting house if you followed that turn left when you get to central London and all the way to the coast to Dover, three-lane road, through the tunnel, keep going, turn left at Paris, that would take you to Moscow.

And you are clearing that by hand.

they lifted 16,000 tons of stones you know that's 55 tons per person it's just staggering numbers and and they've left us with the world's best prepared and certainly by a long way the largest hand cleared racing surface in history however that's you know it's 12 miles long there is no more land available that's end-to-end on the desert if you needed to go faster you've either got to accelerate quicker which is challenging we're already using the world's best jet engine and the hybrid rocket technology or you need a longer surface now here's the the good news: if you really had to go somewhere longer, there is a salt flat in Bolivia, it's 13,000 feet up, it's at the end of 100 kilometers of gravel track, it's 100 miles long.

So, there's plenty of space out there.

I wouldn't recommend actually going to Bolivia.

I know a couple of people have been there and they have had to make quite sizable contributions to the local economy at gunpoint.

So, there's several reasons we're not going there, that's just one of them.

You can't get away fast enough, surely.

That's

when you get to the other end of the desert, and his mates are waiting for you, and you don't need fuel to get back again.

There is a lot of space left.

So, is there a limit to the land speed record?

And we've run up against several limits.

First of all, the aerodynamics of keeping the car on the ground has been the massive challenge.

The world's leaders in this, Swansea University, who did the aerodynamics for the previous car that we built, and they have developed the science to build a lift-neutral shape from 200 to 1,000 miles an hour.

That's never been done before.

It's an amazing achievement.

And we'll validate that over the next two years.

Then there's the wheel problem.

1,000 miles an hour, the wheels are turning 10,000 times a minute.

These are the round wheels, Alexi, with just the V-shaped profile on the V-Shadows and V-shaped wheels.

10,000 times a minute, that's 170 times a second.

So the wheel rims are experiencing 50,000 times the force of gravity outwards.

Now, that's exactly the same sort of loads that jet engines are exposed to, which is why we've got a company called Castle Precision up in Glasgow, who make the big spinny bits and Rolls-Royce engines to make our wheels to the same standards and with the same technology.

But that, again, is right up at the limit of modern aerospace-grade alloys, even with all of the forging and the heat treating and specialist design that Castle and the consortium can put in.

So you're then going to have to look at ever more exotic materials.

And to go, let's say, 20% faster, you're looking at almost 50% increase in that load.

So now you're up at 75,000 G, or you're way outside what most materials will cope with, pretty much anything.

So very rapidly, small increases start to have massive implications in terms of the aerodynamics, in terms of the wheels, in terms of the power you need.

And then you run into the distance problem because at 1,000 miles an hour, you're using a mile of track every three and a half seconds.

So you've got a limited amount of time, even on a 100-mile track, before you run out of the surface of the earth.

All of which leads me to confidently state: I don't think anybody's going to do more than a thousand miles an hour in the near future, but I'm not going to fall into the Malcolm Campbell trap of we're definitely the fastest.

And Daniel.

If you well know, by the way, where that land, stone-cleared land, is it's next to the tallest rockery in the world.

Danielle, we spoke there about the speed limit, which is surely the speed of light.

So, could you speak about that, the universal speed limit?

Yeah, so the speed of light is finite.

It's around 300 million meters a second, 186,000 miles per second.

So put it in context, if you were a traveler moving at the speed of light and you circumnavigated the equator, you could circumnavigate it seven and a half times in one second.

Pretty fast.

But it is finite, but it wasn't always thought to be finite.

So people thought it was infinite for centuries and centuries.

So Aristotle, the Greek philosopher who is in many ways a sort of godfather of physics, he didn't actually ever do any measurements or experiments.

He just took it to be instantaneous and therefore it was infinite.

So, it wasn't really till

sort of Galileo, 16th, 17th century, that people started to think it's not infinite, it is finite.

So, Galileo had this experiment, which he never actually did, but he wrote about it, saying he never did it because he was under house arrest.

That's his excuse, anyway.

But he said he thinks the speed of light is

finite,

and to prove it, get two guys with lanterns and put them on a hill each, and then one guy opens his lantern, shines the light at the other guy on the other hill.

When the other guy sees the light, he then opens his lantern and the light shines back.

And by measuring that light, you'd be able to measure the speed of light.

So, but like I say, he never actually did it, so it's sort of other people took up the gauntlet later on.

There's a small flaw in that.

The second bloat with the lantern is gonna have to be really quick, really quick, yeah.

It was like the 16th-century version of a Jean-Michel Jar concert.

So, it wasn't it was sort of

Ole Roma in the sort of 17th century, he sort of made some measurements when he was looking at Jupiter.

So he was trying to observe the planet Jupiter, and the planet Jupiter has got many moons.

And he was trying to observe the moons going around Jupiter and going into eclipse.

So the sunlight is blocked when it goes into eclipse.

And he noticed that the timings were out sometimes, so they would fluctuate when he was observing them.

And he was quite a confident guy and thought, well, actually, it's not my measurements, it's not my clock.

Something strange is going on here.

And what he was actually measuring was the fact that Jupiter and its moons are very far away, and it's taken quite a long time for that light to reach us.

So, therefore, that light must be finite, and we must be able to measure it somehow.

So, what are the I mean, there are, there was a while ago, what was it about two years ago, there was the neutrino, rumours that neutrinos went faster than speed light.

And there are some ideas of possible particles, aren't there, or or which may, you know, the idea conjecture that there might be something that goes faster than the speed of light.

Now, can you tell me a little bit about those?

Yeah, yeah, it's hugely theoretical, very Alice in Wonderland type world here.

But um there are a thing called tachyons

and or metaparticles they were called before uh tachyons were termed.

And basically they have no mass.

Uh so if they have no mass then you can effectively travel faster than the speed of light.

So the the reason that they have no mass is because um in mathematics you have a real number and an imaginary number.

So you have have complex numbers.

There's a real number and an imaginary number, and it is deemed that tachyons have imaginary mass, so they don't have real mass, they have imaginary mass.

We should say that so imaginary, that's a square root of minus one, isn't it?

This thing is I.

So the mass is I times something.

I'm now really sorry I started this line of conversation.

Because ten minutes ago, we were talking about 350 meters a second, supersonic driving really fast.

And you know, d now Concorde's out of service.

Anyone that's flown, no, I've driven faster than that.

Now we're up at three hundred million meters a second, not being left way behind.

So, yeah, so the imaginary mass, and then so this is uh but what are the repercussions?

You know, the idea that there would be something that once you have something that can travel faster than the speed of light, how does that change our universe?

So, the the theory is if you can travel faster than the speed of light, you can effectively time travel

in the future.

You can go forward.

So, they don't talk about going in the back in time, but in forward, you can travel forward in time.

That's a cop-out, isn't it?

Because if they said you could travel back in time, there'd be you say, Well, not because there aren't loads of scientists coming back here and bringing their dynamic.

I don't know where I'm going with this, I shouldn't be.

What I'm hoping is another Lengthy Sail is about to walk on.

He goes,

See, I told you,

Yeah, you can travel forward in time, but you can't go back because it would prove you could travel back if because people are tearing up from the future, wouldn't they?

In special relativity, in Einstein's theory of special relativity, the speed of light, the finite speed of light is the thing that protects us from time travel.

Right.

So if you travel faster than the speed of light in Einstein's special theory of relativity, you can you can wander around in time in the same way that you can wander around in space, essentially.

So there's it w what the speed of light does in that theory is prote is protect the past from the future.

It so scientists physicists call that causality.

So So, so what the speed the finite speed of light protects cause and effect as an idea.

And and now these people are saying it's

been repealed.

Tachyons, tachyons, the the trick with tachyons, isn't it Daniel, is that they can go that if they existed, they'd always go faster than light and they wouldn't be able to ever

go slower than light.

Yeah, you'd have to put energy in them to make them slow down.

So, it's complete opposite to what we have now.

So, we need energy to speed up.

So, obviously, for Andy's car, he needs a lot of power, a lot of energy into his car to speed up.

These things, you have to put energy in them theoretically to slow down.

So, they could go.

So, the message I'm getting here is we need a tachyon-powered car

and a very big runway.

Yeah.

So, in terms of what have we sent into space, and I include things like radio waves.

I mean, this is one of the things that you will often see used in films and television shows where they will give this sense of

journeying into space where the idea that extraterrestrials will now be watching for instance I love Lucy somewhere or Alexi Sales stuff whatever it might be that there will be

extraterrestrials Farage will be furious

But so so what would when we are for instance you know radio waves say for instance tele signals when they go but is there a point where during that travel the speed of that travel, that no longer, say, extraterrestrials at certain distant planets around stars, that they will not be able to actually see the picture or hear the sound because there will be fragmentation?

Yes, there'll be huge amounts of fragmentation.

So,

as the radio waves leave the Earth, they'll propagate out, they'll move out into space, and there'll be a lot of noise associated with that.

Well, the first thing actually, they've got to get out of our ionosphere.

So, short waves, so short wave radio doesn't have a chance.

It's FM radio and long wave radio would be able to break through, or television signals as well, would be able to break through our atmosphere and get out there.

But then, once it's out there,

this sort of signal would degrade, and it's an inverse square low that it degrades.

So, if you think about

the signal would be as quarter a great as it was

once it's travelled twice the distance.

So, it's really deteriorating as it goes out and out and out.

So how far can we get then, Brian?

How far would this show get?

Do you know you must be able to do the maths?

Well, you should as well.

I won't be able to.

I know a lot about Bleak House.

So this is.

So how the.

I'll tell you what, it's not a happy place.

It is not a happy place.

Is it a bit.

If you get Bleak House on Monopoly and someone lands on it.

Anyway, so the.

No, so

I want to know exactly what you're doing.

This is not.

You can do.

Look, when I'm on loose ends again, I'll tell you about Bleak House, but that's not our agenda.

So the uh so I mean, in terms of I fast it, how far out could this show get?

And I was gonna say to the point where it starts to fragment and makes no sense, but that's only about as far

as far as our Alderney, I think, possibly.

Maybe to Alderney and back.

Well, I don't know.

I mean, it depends on the power of the transmitter, doesn't it?

Right, okay, then.

So, do you know the power of the transmitter?

Like, if we go for someone like Ali Pally, someone like that?

Do you know what a typical transmitter A typical radio transmitter is?

Kilowatts?

Yeah,

you're in kilowatts.

Is this FM or long wave?

I'll tell you what, because it's radio.

Let's go long wave.

Sorry that Python sketch, and then it gets vaulted out.

Long wave.

Nope.

So long wave is

what, 198?

198 kilohertz.

At kilohertz, yeah.

Oh, there's the signal that says you've only got five seconds left.

So

could you work it out with

because

this is always my favourite bit is when he just looks up at the stars.

If you do, only you can enjoy this,'cause he hasn't got another landmark show for a few months.

So if you if you imagine that it's photons rather than rather than um wa waves by the night special waves, imagine it's photons, then there's a there's a finite number of photons going out from the transmitter'cause there's a finite amount of energy.

And as everyone knows in the audience, the en I can do that with your QA, it's gonna the energy of a photon is Planck's constant multiplied by the

frequency.

Frequency.

E equals H C over lambda, H F.

Frequency.

So so

given the frequency, and we know Planck's constant, you can work out the energy of a photon.

So the energy of the transmitter.

So if it's 200 kilowatts, that's

200,000 joules per

second.

Anyway, but hang on.

The alpha nails are now battling over the

no but it's the point but the point is that so you've got a finite number of photons going out.

So as you said, there's an inverse square law, so they decrease.

So so you get to a point where there's only one photon per

per

cubic light year or something like that if you go that fast.

So so then you would have no signal, would you?

Because you don't have a single photon.

And even the amount of information in this show can't be fitted inside a single photon.

But the person that goes inside the photon, they still have to pay their licence fee.

So so that's a a viewer's question for next week.

So given that there's a 200 kilowatt transmitter, let's say it transmits just for one second, then at 198 kilohertz, then it should be relatively trivial to work out the point at which there's a the the the signal degrade such that there's one one photon per, let's say per square meter on some sphere out from the earth at some distance, and that distance is the answer to Robin's question.

I venture.

And if we do get, if we get for the final episode, if we do get up, I'm at Libby Mathematics and Physics on the radio.

That's what you're known for.

You're the John Sessions of Euclidean geometry.

It is going to be very exciting.

Basically, if anyone does write in

the final show and get that answer right, it's doubly exciting because we're actually recording the last show before this one goes out.

So it will also mean that they've conquered time travel as well.

So

the

you may assume, no, it's not

hence or otherwise really.

So we asked the audience what is the thing that is most likely to make them move the fastest and we have so far we have this is correct F equals MA

Okay, that's very well F equals MATLAB

Christopher Biggins and it's not often that on any Radio 4 show you go straight from F equals MA to Christopher Biggins but there is a link link, do write in.

Seeing Brian Cox at the end of the road, moving towards, obviously, that's Natasha.

Brian Cox running towards

you've got a choice.

Brian Cox running towards you, naked.

That's Emma.

Brian Cox with a bottle of Shiraz.

Happy days.

That's Linda.

Brian Cox dancing wildly, that's Barry.

Brian Cox,

Brian Cox riding naked on a Velociraptor, that's Kathleen.

And

nothing.

The universe revolves around me.

That's Brian.

So thank you very much for listening.

Thank to our panel, Andy Green, Danielle George, and Alexi Sale.

Next week is the final show in the series where we are going to be discussing death and forensics.

So, just in case you've forgotten that your life is finite, we always like to end the series with existential angst and murder.

And while we're on that subject of death, here is the subject that never dies.

It is actually strawberries again.

We haven't had a reply to this for a while.

We've got a letter from Samuel Firce, who wrote, I don't think the strawberries ever lived.

This interpretation is informed by my year eight science work on classification that said that any part of a living thing that never lived but was part of something that had lived.

Other examples include a severed arm and hair.

Follow your hair, though.

However, the strawberry contains seeds, at least some of which may be alive.

So perhaps your question is rather like asking whether a colony of living beings is alive, like an anthill or Manchester.

And the other letter we received was: if you hold a piece of red litmus paper against Jim Al Khalili, does it turn blue?

Thank you very much for listening, hands.

Good night and goodbye.

In the infinite monkey cage.

In the infinite monkey cage.

Without you troubled.

In the infinite monkey cage.

Till now, nice again.

Hello, I'm Greg Jenner, host of You're Dead to Me, the comedy podcast from the BBC that takes history seriously.

Each week, I'm joined by a comedian and an expert historian to learn and laugh about the past.

In our all-new season, we cover unique areas of history that your school lessons may have missed, from getting ready in the Renaissance era to the Kellogg Brothers.

Listen to You're Dead to Me now, wherever you get your podcasts.