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00:11PIANO PLAYS
00:57PIANO PLAYS
01:02PIANO PLAYS
01:19The final check is completed, it's clear to land.
01:46I tell you, no matter how much you may like to go Swiss air, one thing you can't call the
01:52experience is a flight of fancy.
01:54Nothing so irrational, but efficient, yes.
01:57You know their boast, you want the right time, you set your watch by one of their touchdowns.
02:03Still, what would you expect from a nation of clockmakers?
02:32Even the trams run on time. They're a tick-tock lot, the Swiss.
02:35I mean, look around. Life here is logical, orderly, efficient.
02:39They obey the law because the discipline it imposes on the community makes it organized enough to achieve one of
02:45the highest standards of living in the entire world.
02:48All you need here is money.
02:52The view they take here, though, is, if you think about it, the epitome of what the modern scientific world
02:59we live in is supposed to be about.
03:00Cool, rational, common sense.
03:03With science to explain everything, because ultimately everything is knowable, there's nowhere to go but onwards and upwards.
03:14It's an attitude we inherited and nobody took to it more enthusiastically than the Swiss, about 300 years ago, from
03:20Newton.
03:20You know that the universe and everything in it runs like a giant clock.
03:24With God, the great timekeeper in the sky.
03:44It's 1801, and in Geneva, a visiting Italian is, although he doesn't know it, about to trigger the destruction of
03:52the universe.
03:53With a box, he's taking to a party.
04:09Being a Swiss party, of course, it's a hair-raisingly serious affair.
04:13Today's a shocking display, ho-ho, all you ever wanted to know about electricity.
04:25All they know about electricity, of course, is not much.
04:28A mystery force that goes through people who hold hands and makes sparks.
04:51Electricity also attracts some things and repels others, and apparently the way electrically charged things do attract and repel each
04:58other happens in straight lines and depends on how far apart they are.
05:02Just like Newton said everything should.
05:04Good old Newton. Always right.
05:17Meanwhile, enter our Italian Giuseppe Volta with his pal Brugnatelli on their way to see Napoleon after a brief stopover
05:25to galvanise Geneva society with this.
05:27Volta's pile of copper and wet pasteboard disks that would you believe it makes non-stop electricity as long as
05:34you keep it damp.
05:36And the destruction of the universe? The pile would spark that off.
05:59Volta's pile caused sparks in more ways than one because it immediately set the public and the scientists off in
06:04that direction, with the public heading for the wonder technology it has mistakenly taken science to be ever since.
06:09Like arcing for instance. The same year as that demo back in Geneva, Humphrey Davy in England was sparking current
06:17between two carbon rods producing a brilliant white flash and turning the world on to electric light.
06:23Military gents started exploding mines remotely and medical quacks gave shock treatment for everything from infertility to drowning.
06:31Volta's pal Brugnatelli explored the mysteries of electrolysis, put the leads from a pile into a solution, say, of salt,
06:39sodium chloride, and it splits into sodium metal and chlorine gas.
06:44Great technique for extracting metals, or in Brugnatelli's case, who was coining it, depositing gold from a solution onto medallions.
06:53Electroplating that turned out great for the table setting business.
06:58Meanwhile, the scientists were going off the rails. Mysterious things were happening because although chemistry could be caused by electricity,
07:06electrolysis, it could also happen the other way round.
07:22A solution, like lead acid, could produce a current. So, was there some connection between electricity and chemistry? Interesting train
07:33of thought, that.
07:36And it fitted the romantic ideas of the time with social misfits like Byron and Shelley fetching up here at
07:43the castle of Chillon to write second-rate poems about the lonely grandeur of the Alps and all that back
07:48-to-nature stuff.
07:49Because the philosophy behind their efforts was called nature philosophy.
07:57It had to do with everything in existence being the product of two conflicting forces that resolved themselves into a
08:04higher unity after conflicting first, you understand.
08:12All very mystic stuff. But you can see how that kind of thinking would leap at any new example of
08:18a force like electricity to see if it would conflict with anything else around.
08:21And one thing those loony romantics had noticed was how very easy it was to get lost in these parts
08:28as lightning caused your compass needle to go haywire while you wandered lonely as a cloud, getting totally sodden in
08:36alpine storms.
08:37Speaking of which...
08:47Speaking of which, as I said, in 1820, an immensely boring Dane called Ørsted, during a lecture in Copenhagen, applied
08:57the basic nature philosophy idea of conflicting forces and decided that if he forced the force, electricity, by shoving it
09:05down a high resistance wire,
09:06the wire, the wire, with all the effort, would go incandescent, like lightning was.
09:17And since lightning made compass needles go funny, he thought if he brought a needle close to his wire, something
09:24philosophically meaningful should happen, shouldn't it?
09:30Sure enough, something did. The compass needle went, so to speak, wild.
09:36And it did it, even when separated from the wire by wood, water, glass, metal, anything Friend Ørsted could think
09:43of.
09:44And it did it all round the wire in a uniform, circular manner, even though Newton said everything acted in
09:52straight lines.
09:53The electricity in the wire was obviously giving off something strange that affected the magnetic needle.
09:59Electricity was setting up some kind of magnetic field.
10:03Now, there was only one minor awkwardness about that. It was supposed to be impossible. For a start, what was
10:10the field? And for a finish, how did it work? And for a second finish, in what?
10:31One year later, another intense nature philosophy person called Faraday was trying to answer the questions Ørsted had left in
10:38the air.
10:38An electric wire. An electric wire would generate a magnetic force that actually made a floating magnet circle it. So
10:44Faraday reckoned the opposite ought to happen.
10:46Sure enough, it did.
11:01Faraday got turned on by the thought that if an electric current made a magnetic field, maybe a magnetic field
11:07would make an electric current.
11:10He set up a compass needle to detect the current if it was there.
11:15It wasn't. Except when he switched the magnetic field on and off.
11:21So it was a changing field, did it?
11:29Well, there was an easier way to put a changing magnetic field near a wire. Push a magnet in and
11:34out of a coil.
11:35So that was it. Just moving the magnet made surges of current in the wire.
11:40You could see the current. The needle swung.
11:43But why had moving a magnet made electricity?
11:49Then he got it. When you moved the magnet, the wire cut through its magnetic force lines.
11:57In 1831, Faraday was cutting magnetic force lines with a spinning copper disc and making electricity happen in the disc
12:04as long as you cared to turn the handle.
12:09Well, before the public could begin to ponder the philosophic implications of Faraday's deeply meaningful discoveries, here in the United
12:18States they had once again been hijacked by the glitter of technology.
12:22As assorted American blacksmiths, travelling dentists, civil servants and other such riff-raff dazzled the eye and numbed the brain
12:31with the latest mechanical marvels.
12:46Basically, this avalanche of electromagnetic gizmos, as seen here in model form, came in two types.
12:52This lot used the ability to switch on and off the magnetic effect of a current to attract a piece
12:57of metal up and down or back and forth.
13:03Most of them linked the movement to a flywheel.
13:08And this one drove machine belts in a factory.
13:12And so on.
13:15The other wonder machine in this electromagnetic extravaganza used the other effect, the way a moving magnet will make current
13:22in a wire.
13:23Here's the moving magnet.
13:27Here's the power.
13:31This beautiful-looking thing would one day lead to electricity generators.
13:36And these little whizzers, as you will already have guessed, did pave the way to real electric motors.
13:42All good knockout stuff.
13:51Here we go.
13:58But for sending the public right off on the wrong track about science, in 1844 nothing equaled this magic sound.
14:12The Morse key interrupted the current going down a wire and made a magnet turn on and off at the
14:18other end.
14:22Morse code united the United States.
14:43Meanwhile, back in Cambridge, the study of how electromagnetism actually worked seemed to be leading scientists right up the creek.
14:58You see, for 200 years Newton's version of the universe had explained absolutely everything.
15:03According to him, the universe was made up of bits of matter surrounded by empty space.
15:09And force interacted between the bits, like gravity.
15:13And the force was supposed to go in straight lines, you remember, and act instantaneously through empty space from one
15:19bit to another.
15:21Well, electricity wasn't doing any of that.
15:23The force lines were curved.
15:25It was in space and not in the wire or the magnets.
15:29And as for going instantaneously through empty space, was it empty?
15:34Not according to a guy called Young, who'd looked at light and found that it acted like this.
15:42Like ripples.
15:43Two sets of ripples moving outwards, here they are, meet and interact like this, don't they?
15:49Some waves meet and boost each other, the light bands, others cancel each other out, the dark bands.
15:56So, did light act like ripples?
16:03If you try it with light, going through two holes, and then meeting and interacting, you get the same effect.
16:12You see those light and dark bands?
16:15Interfering waves of light.
16:18Now, the reason Young's idea was dynamite was that if light did travel in waves, it wasn't instantaneous.
16:24It took time.
16:26And it had to be waves in something.
16:29He called the something, ether.
16:36Out there, in here, everywhere in the universe, invisible stuff making waves.
16:43And maybe also carrying electricity and magnetism.
16:47It would certainly give Faraday's lines of force a place to be.
16:51But it would also blow Newton's idea of empty space right out the window.
16:56So the fellow who did that in 1861, a Scottish Faraday fan called Maxwell,
17:02here in Trinity College, Cambridge, began with caution.
17:06First, he made himself a mental model of these mysterious ether forces,
17:10and imagined them to act like fluids, because you could measure what fluids did.
17:15A cross-section of what was in Maxwell's mind might have looked something like this.
17:21The idea, and it was pretty weird, was
17:24tubes of invisible magnetic force surrounded by spinning cylinders of ether.
17:28The faster the ether spins, the more intense the magnetism.
17:32Well, I said it was weird.
17:35Electricity?
17:36He made that little balls of ether.
17:39A current would be moving balls.
17:41And magnetism could move balls and make electricity, or vice versa.
17:46Typically complicated bit of Victoriana.
17:49Now, the figures Maxwell got from his mental model told him that if, when the lines of force first came
17:55into existence, say in a live wire,
17:58and then radiated out to take up position around it, they should radiate at a certain speed.
18:04Almost exactly the speed of light.
18:06Although he had no proof, Maxwell jumped in with both feet.
18:09You'll see, he said, electricity, magnetism and light are all one wave moving through the ether.
18:16Goodbye, Newton.
18:18Well, nobody could test Maxwell's theory.
18:20So now the scientists were going that way.
18:27By now, the public had the bit between its teeth about the wonders of electricity, as the first regular transatlantic
18:33telegraph started in 1866.
18:37Science was indubitably progressed. There were no two ways about that.
18:41And what scientists did was obvious enough.
18:43They turned out gadgets, didn't they?
18:47To a public whose knowledge of science was rising to zero, one man, more than any other,
18:54was to stamp the image of the tireless scientific genius at work for the betterment of mankind on their consciousness
18:59forever.
19:00Because he made sure of his PR.
19:04Thomas A. Edison, inventor extraordinaire.
19:07In this laboratory here, he filed no less than 1,039 patents.
19:13You're looking at the world's first inventions factory.
19:15Well, more of a shrine, really.
19:18Henry Ford was so taken with Edison that he moved this lot, lock, stock and the tree outside,
19:24all the way from New Jersey to this museum here outside Detroit,
19:28all to the memory of a man who must have been absolutely insufferable.
19:33Edison used to say,
19:35I can never pick something up without wanting to improve it.
19:39Except he didn't.
19:40Fifteen loyal and very unknown specialists worked very behind the scenes to obey his pleasant little rule of life.
19:48There's a better way.
19:51Find it.
19:51He himself worked to a set of rules.
19:54One, get the money first.
19:56Two, find the market.
19:58Three, only after one and two, produce the goods.
20:03He reckoned to turn out a minor invention every ten days and something big every six months.
20:09Modest, no?
20:10But, the stuff in this hallowed spot did somewhat knock the world for six, it must be said.
20:15Like, the phonograph.
20:18Mary had a little lamb that speaks quite as slow, and everywhere that Mary went, the lamb was cured at
20:24all.
20:25The repeating telegraph.
20:28The electric sewing machine.
20:33The electric pen.
20:41And perhaps the most illuminating example of why the public was led by the nose into taking technology to be
20:46science.
20:47The light bulb.
20:49Bingo!
20:50Well, it would have been bingo if you'd never seen it before, wouldn't it?
20:53It took him two years and six thousand tries to get the right filament inside that bulb.
20:58Well, it took his loyal sidekicks two years and six thousand tries, etc.
21:03Now, by itself, that isn't gonna exactly roll him in the aisles, is it?
21:08But then, Edison didn't just switch on.
21:11Edison switched on!
21:13Didn't see it almost, spectra-yel Quite the same quotas of some kind because of his pitch on this for
21:17me.
21:21It's onochoon, Martin!
21:22How did he say the vet paranormal?
21:23Oh, you're not happy about you...
21:34Theitting pan, Owen.
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21:48Typically, Edison did it on the grand scale,
21:51producing everything needed from switches to cables to generating plants.
22:00He strung lights up all around the laboratory
22:03and in 1879 invited a few people, 3,000, in a special train,
22:09to see this, street lighting.
22:12Boffo, success! Wasn't science wonderful?
22:19Science wasn't here.
22:20It was having a bad time with electromagnetic radiation elsewhere.
22:27Hello? I'd like to call England, please.
22:30Another one of his inventions.
22:34Hello?
22:53The year after Edison lit up, an American living in London
22:57was to show an amazing discovery concerning electromagnetic force
23:00to local scientific bigwigs.
23:02This clockwork bit automatically breaks an electric circuit
23:06for a split second at regular intervals.
23:09Several hundred yards away from the clockwork, out in the garden,
23:12the American, a music professor called Hughes.
23:18Well, you're back right there.
23:21This is Hughes, and this is his discovery.
23:30When the circuit back in the house gets broken,
23:32you can hear a noise in a telephone receiver
23:35if it's attached to a battery via a loose contact,
23:38because Hughes reckons the loose contact is being zapped
23:41by waves of electromagnetic energy
23:43coming from the short-circuiting spark indoors.
23:45But the waves aren't coming through a wire.
23:49They're wireless waves, get it?
23:51Well, the bumbling British boffin doesn't.
24:04Oh, they are on the far side of the lake, sir.
24:09Yes, I see.
24:13Alas for poor old Hughes.
24:14The demonstration was a flop.
24:16All the credit went to a German seven years later.
24:19The English just couldn't believe what they were hearing.
24:23Mysterious airwaves travelling hundreds of yards.
24:26A rumpf.
24:27Induction, Mr. Hughes.
24:29Induction.
24:31This is nothing new.
24:38This summer, the Cleveland in line.
24:41We're not alone.
24:43It's a universal problem.
24:44Oh, but I think the...
24:49Well, the technology freaks really had a field day a bit later on
24:52when the transmission range went up to 4,000 miles
24:55because of a fellow called Marconi,
24:57who also found a way to use the mysterious waves
25:00called radio.
25:03The trouble was, now everybody was happily making waves,
25:07the question still remained, what were the waves travelling in?
25:10What was the so-called ether?
25:13And why couldn't anybody ever find it to answer that question?
25:19Well, in 1887, a couple of people here in America decided to have a crack at finding out
25:24by shooting light beams through the ether in different directions.
25:28Let me give you the reasoning.
25:29Suppose this boat I'm on is the Earth, travelling through the ether of space, say, at 5 miles an hour.
25:35If I shoot a light beam ahead at 6 miles an hour, let's say the beam's that boat there.
25:42It'll creep ahead and leave me behind, at 1 mile an hour, the difference in our speeds.
25:47So it'll take quite a while to get, say, half a mile ahead.
25:49At that point, when it turns round, of course, our combined speeds will bring us back together again fast.
25:56But if at the same time I send another light beam, that boat, at the same speed as the other
26:02one,
26:026 miles an hour, sideways to me, the same distance out and back,
26:06he will get back sooner.
26:07Look! Go!
26:14See how the sideways beam is moving off quite fast relative to me,
26:19getting to the half-mile point quickly?
26:21And the beam pushing out ahead is going to take longer,
26:24because relative to me, it's only doing 1 mile an hour.
26:29The sideways beam's already turning back.
26:34Now, if real light beams did that, it would be too much better.
26:37It would be proof that the ether existed.
26:39And you could measure the ether through what it was doing to the light beams.
26:44Those two Americans I was talking about, Michelson and Morley,
26:47did this great experiment here, at Cleveland, at the university.
26:51Do you remember Young and the light waves and stuff,
26:53and those interference patterns you get when light waves mix when they're out of phase?
26:57There's these light and dark bands here.
26:59This is the trick they used to see one light beam returning sooner than the other.
27:05Come on, I'll show you.
27:13OK, let's take it that this lecture hall and the Earth are going through space.
27:17Well, they'd better be that way.
27:20So, that's straight ahead.
27:23Here's the light source.
27:25Send the beam out and split it with this half-mirror.
27:28One half of the beam goes that way.
27:30You remember that's the straight ahead direction.
27:32And the other half of the beam goes this way out to the side.
27:35Now, you give the beams a nice long trip by bouncing them back and forward
27:39between these mirrors for one beam and these mirrors for another beam.
27:43And when they finish the trip, you recombine them here and bring them back out here.
27:49I'll show you better with a laser beam and better still with some smoke.
27:54Now, since the straight ahead beam will be slowed down more than the sideways beam,
27:58the two beams will recombine here out of phase,
28:02with the straight ahead beam lagging behind, right?
28:05All mixing light beams make interference patterns.
28:08So, that's what you get to start with here.
28:10I'll show you.
28:11On this card.
28:13See?
28:14Michelson and Morley reckoned that if the ether existed,
28:17this pattern should be altered when you changed the angle the beams were being shot through it.
28:22So, to do that, they rotated the entire experiment
28:26and took 16 readings on no less than 36 rotations.
28:37Just to be sure they were seeing what they were seeing,
28:39which was...
28:41No change in the interference fringe at all.
28:46And you know what that meant.
28:48No shift, no ether.
28:50No ether, no anything.
28:53You could hear the stunned silence all the way to Ireland.
29:19Here, in Ireland, was a Dublin physics professor called George Fitzgerald,
29:24with two ambitions.
29:25To get off the ground and to explain the light beam failure.
29:28So, while he has yet another go at the former,
29:31here are his thoughts on the latter.
29:34Electromagnetic waves travel in ether, so ether has to be everywhere.
29:37No?
29:38Oh, hang on a minute.
29:57Where was I?
29:58Oh yeah.
29:59If ether is everywhere, then it's kind of the universal absolute thing to measure everything against.
30:04If you can't even find the ether, measurement isn't possible.
30:08That's why the American experiment was such a disaster.
30:11Except to a nimble Irish mind like this one.
30:14And Fitzgerald's solution was beautifully Irish.
30:18Moving through ether shrank things.
30:20So the bit of the American light beam instrument that had pointed forward
30:23had been shrunk by just enough to shorten the forward light beam trip
30:27and make it equal to the sideways unshrunk bit.
30:30But you couldn't measure the shrink,
30:32because the ether would shrink your measuring equipment.
30:37Right, away you go, Professor.
30:40God bless your honour.
30:42Sadly for this last imaginative defender of the Newton and common sense view of things,
30:47thanks to a Viennese philosophy teacher,
30:49everything Fitzgerald and the other people were trying to do to explain how the ether worked
30:53was to crash in ruins.
31:17The Viennese genius who turned everything upside down was called Ernst Mach.
31:32I'm ready here.
31:50I'm ready here.
31:58Mark turned everything upside down because that's what he spent his time doing.
32:02Turning people upside down, or sideways, or round and round.
32:13By 1895, Mach had spent years investigating what happened to people's senses
32:18when they were put into every position he could conceive of.
32:21He'd blindfold them, for instance, and then tilt them in an environment that was also moving,
32:26and test their sense of direction.
32:32Mach came up with some of the basic ideas of modern perceptual science.
32:36He was really trying to find out how much of what you observed was affected by your senses.
32:41The way, for example, you could be in something that was moving up or down,
32:44and yet feel as if you weren't.
32:46Mach became convinced that much of what you sensed about the world was in your mind,
32:50and that everything you could ever say about reality was subjective,
32:54altered by conditions like temperature or sound, acceleration, pressure, even mood.
32:59There was nothing out there that you could be certain of
33:02unless you were in direct contact with it.
33:08Were you going down here, or was Vienna going up?
33:14No.
33:24But it was how Mach used his work on perception
33:27that made him such a big wheel among the scientific thinkers of the time,
33:30because he argued that it showed all a scientist could be sure of
33:34was what his own personal experience, his five senses, showed him.
33:40Take movement, for instance.
33:41Force is on you acting up or down or from side to side.
33:45You might invent some scientific law to explain those forces,
33:49but you should always remember that it was you that invented the law.
33:52For Mach, there was no reason why the rest of the cosmos
33:55should be doing what your little bit was doing,
33:57so science should only describe, not try to explain.
34:03And even description is relative.
34:05I mean, am I moving, or is the background moving?
34:08Or take the position of a star.
34:10It depends on where you see it from, which depends on the date and time,
34:13which depends on the position of the Earth in solar orbit,
34:16in a solar system moving round and round at the edge of the galaxy,
34:19which itself might be drifting away from some other galaxy, and so on and so on.
34:23So, say you've decided that I'm moving and the background's standing still.
34:27How do you know the background isn't moving relative to something else, hmm?
34:36That's why there was no point in playing around with light beams
34:38to try and find some theoretical universal absolute.
34:41There were no absolutes you could ever know anything about.
34:44They couldn't find the ether, said Mach, because there was no ether to find.
34:48Well, you can guess what that did to Newton.
34:54Quite.
34:55And it was worse to come from people working on these things.
34:58Well, these things.
35:00Cathode ray tubes.
35:16Another mystery force, cathode rays.
35:19Anything they hit glowed.
35:21And you could make the glow move with a magnet.
35:23Electricity was affected by magnetism.
35:25So, were the cathode rays electric?
35:31Well, if you took some cathode rays and used a magnet to aim them at two little gold foil leaves,
35:37the leaves separated, which they only did if they were getting electrified.
35:41A positively charged rod would cancel that effect, so that meant the cathode rays were making negative electricity.
35:49In 1897, an Englishman called Thompson, who thought cathode rays were really particles, worked out a technique for weighing them.
35:57He changed the direction of the stream of particles with a magnetic field, and then saw how much of an
36:03electrical field was needed to straighten it out again.
36:11Sure enough, they turned out to be particles of negative electricity.
36:15We call them electrons, that were a thousand times smaller than the smallest atom.
36:20Thompson reckoned he had the basic unit of electricity there in his measuring tube.
36:24But the big shock was this.
36:28Ultraviolet light waves would knock negative electrons out of metal.
36:31Look, the gold leaves collapse.
36:42By the turn of the century, what with waves of the mysterious force rippling out through ether nobody could find,
36:50an incredible shrinking Irish instrument, and Marx saying it was all meaningless anyway,
36:55and Thomson's light rays knocking subatomic particles out of metal.
37:00Well, poor old Newton's universe had more holes in it than this bit of Gruyere.
37:04And the physicists were, to put it mildly, cheesed off with the whole affair.
37:11Until, fittingly, a Swiss government bureaucrat called Einstein simply invented a new universe.
37:17And the reason I'm telling you this on board a Concorde flight is because Concorde goes at over Mark II.
37:23That's the Mark you know and who gave Einstein the idea.
37:27Two stands for twice the speed of sound which Mark identified,
37:31which means I'm going at quite a lick, which makes my point for me.
37:35Because Einstein's cosmic rewrite of the laws of nature just said that everything in the universe was relative,
37:41and everything you observed about it depended on the frame of reference you were in at the time.
37:46Like this Concorde cabin, where I'm standing still, dropping my pen in comfort.
37:49In this cabin, I'm not going at 1,400 miles an hour, am I?
37:56Yes, I'm Buck, I'm D at 155.
37:5855, 62, 65.
37:59And everything works like that, conditioned by its frame of reference.
38:02All the electrics and all the instruments on board this plane obey the same laws they would if they were
38:09standing still.
38:10Because inside this frame, like me, they are not going at Mark II.
38:14And all the laws of nature behave the same way.
38:18That's the Q and H, I advise on those to complete the check.
38:24This beam of light is going out in all directions at 186,000 miles a second.
38:30And being on Concorde makes no difference to its speed, forwards, backwards, or sideways.
38:35That's why the way the Earth was moving made no difference to the Michelson and Morley light beam.
38:40It never could have.
38:41It could never measure the speed of light except relative to your frame of reference.
38:45And like Mark said, you could never measure it against anything outside your frame of reference
38:50because you would never know what it was doing relative to you.
38:53There was no absolute because you could never know anything was absolute.
39:00So, that sorted out the light beam and the ether business.
39:03As for Thomson's light knocking electrons out of metal,
39:07Einstein said, obviously, light came in bits and knocked bits out of the metal.
39:11And the more intense the light, the more bits it knocked out.
39:16However, this moving moment in the study of light went almost entirely unnoticed
39:20in the light of another moving moment in the study of light.
39:25The movies.
39:26Another great example of the triumph of technology.
39:38It was probably the movies above all that convinced the millions that in this new 20th century,
39:44fortune and success would come only to the kind of fellow who kept up with science.
40:09The modern hero would be the man who could change with the times.
40:13Taking advantage of the latest technology was going to be the way to get ahead.
40:36The movies showed that without science, life was no fun at all.
40:46The music, of course, wasn't really there.
40:48It still had to be played by somebody in the movie theatre watching the film.
40:59Until somebody used the light going through the film to hit metal,
41:03to produce electrons, to make electricity for a loudspeaker.
41:06And the public's love affair with technology really took off.
41:10With the talkies.
41:13Georgie Portie is a guy who is very bashful and so shy.
41:16The ladies prize him. They idolize him.
41:19You can find...
41:20Let's not knock it.
41:22I'd be out of work without it.
41:23But it did all ignore the awful implications of what Einstein had said.
41:33If the more intense the light was, the more electrons it knocked out of the wall,
41:37that sounded as if light wasn't a wave at all.
41:39More like a stream of particles.
41:41Einstein said, sure.
41:42And called them photons.
41:45That's how something like this works.
41:46When I remove the card, the stream of light particles can hit a metal target.
41:51That gives off electrons.
41:53That makes electricity.
41:55And that closes the door.
42:01Well, if light wasn't a wave, that blew the last hundred years' work right away, didn't it?
42:06But then what about Young?
42:08And the way light interfered with itself to produce those light and dark ripples the way only waves can.
42:13What about that?
42:15In 1923, the same year that movie you saw, a Frenchman called de Broglie muddied the waters by coming at
42:21it the other way round.
42:23If waves could be particles, could particles be waves?
42:26Because if they could, they'd make patterns like waves, wouldn't they?
42:29Now, this was getting out of hand.
42:31A wave is a wave, and a particle is a particle.
42:35Right?
42:36Wrong.
42:37And in 1927, an accident proved it.
42:41Two Americans called Davison and Germer were quietly shooting electrons from an electron gun at a nickel target to see
42:48how the electrons bounced off.
42:50When the vacuum tube in which their whole gizmo worked cracked.
42:54Disaster.
42:55The air coming in had contaminated the target.
42:58Having heated it up and so on to clean it, back to work.
43:01Only this time, when they moved their little electron collector around the target to catch the electrons, no electrons.
43:07Then lots, then none, then lots, and so on.
43:12Big investigation.
43:14Turned out, the reheat on the target had produced big crystals on its surface.
43:18Now, in crystals, atoms are neatly spaced, like that.
43:23So now the electrons were coming in and bouncing off, but in a series.
43:29Like that.
43:30Now just supposing those electrons were waves, they'd do this, wouldn't they?
43:35And those waves would interact like waves do, building up or cancelling out.
43:40So you'd get lots, none, lots, none, lots, none, interference ripples.
43:48Don't believe me?
43:49Look.
43:51Modern equipment.
43:53Vacuum tube inside, electron gun and target.
43:56The electrons scatter out here.
43:57I'll fire the gun.
44:02See?
44:04Interference reports.
44:06Particles are waves.
44:11Now, if you're getting a bit worried about how things can be two things at once, hold on to your
44:16subatomic hats because the bottom is about to drop out of everything.
44:20I'll go slow because I won't understand it if I don't.
44:23In 1927, a fellow called Heisenberg decided to take a look at what these particle electrons and the waves they
44:29seem to go with were up to.
44:31And he announced that you could either say where an electron was by examining an individual intense wave crest, the
44:39electron would be in there somewhere,
44:40or how fast it was going by looking at a whole group of waves moving, getting the general speed.
44:46But then you wouldn't know which wave crest had the electron.
44:48So, position or speed, but not both.
44:53And worse, to look, you had to shine a light to see, no?
44:58And the light particles would hit the electrons.
45:01So you could never be sure that the electrons were where they were, doing what they were doing naturally, or
45:07because you'd hit them.
45:09Get it?
45:11Heisenberg called this drain down which everything went the uncertainty principle.
45:15Now we know, he said, that we shall never know.
45:19He said that because you can't know if it's a particle or a wave.
45:23There's nothing at the fundamental level of existence that you can see as it is, because in seeing it, you
45:29do something to it.
45:31There's no true basic reality to find beyond the one you yourself make by looking, if there's any reality at
45:38all.
45:39And in that case, which way is up, for God's sake?
45:44Yeah, this is the moon event.
45:46It does not have very much energy in the calorimeters.
45:51The size is about 100 kilobytes, you said.
45:54We're in the countdown now.
45:56We wait two cycles.
45:58Here at the high energy physics laboratory outside Geneva, for scientists, the truth is you can only talk about the
46:05universe in terms of probabilities.
46:07You can never, by definition, be certain about it.
46:11Well, this depends on the trigger rate as well, I guess.
46:14But the reading time is slow.
46:19You see what that implies.
46:22The comfortable certainty science is supposed to provide isn't there anymore.
46:26But we ignore that fact, we only see the technology.
46:29The electron that caused all the trouble makes a digital watch work.
46:34And all that electronics, and that's good enough.
46:37As far as we're concerned, the world is still the same as it was at the beginning of this programme.
46:41Newton's world, when there was a true reality, final certainty, order, with everything knowable.
46:48A Swiss clockwork type world.
46:51But as you've seen in science, that world is long gone.
46:56We talk about living with uncertainty, but it's this kind of uncertainty.
47:00War, crime, disaster, famine.
47:02Uncertainty about how tomorrow will turn out.
47:06But in some form or other, it will turn out.
47:11That's not the kind of uncertainty those guys back down that hole live with.
47:15Where ultimately, reality itself is only what you say it is.
47:19Because it's only there, when you and your amazing technology decide it is,
47:23in the form your instruments give it.
47:26So, time, for instance, is only what your clock says.
47:29Or when your plane takes off.
47:31Nothing more.
47:33Which is okay, as long as you don't pretend it's some kind of real reality, the one we create.
47:38If you accept it as we rush headlong into the future, it's a future already defined as the only one
47:44our instruments will take us to.
47:46Truck's away.
47:47Request it.
47:49Check normal.
47:52So, is there any direction to our journey into knowledge?
47:56Or do we make up the route as we go along?
47:59And if that's the case, what is knowledge?
48:03The next and final program, we'll see where that question leads.
48:09The next one is the best for us to achieve and truly achieve the success.
48:38bragging back in front.
48:56ORGAN PLAYS
49:24ORGAN PLAYS
49:39ORGAN PLAYS
49:39ORGAN PLAYS
49:39ORGAN PLAYS
49:40ORGAN PLAYS
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