An inventory of the invisible | John Lloyd

75,642 views ・ 2009-09-18

TED


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00:12
So the question is, what is invisible?
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There is more of it than you think, actually.
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Everything, I would say. Everything that matters
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except every thing and except matter.
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We can see matter. But we can't see what's the matter.
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As in this cryptic sentence I found in The Guardian recently:
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"The marriage suffered a setback in 1965,
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when the husband was killed by the wife."
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(Laughter)
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There's a world of invisibility there, isn't there?
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(Laughter)
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So, we can see the stars and the planets,
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but we can't see what holds them apart
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or what draws them together.
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With matter, as with people, we see only the skin of things.
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We can't see into the engine room.
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We can't see what makes people tick, at least not without difficulty.
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And the closer we look at anything, the more it disappears.
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In fact, if you look really closely at stuff,
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if you look at the basic substructure of matter,
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there isn't anything there.
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Electrons disappear in a kind of fuzz,
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and there is only energy. And you can't see energy.
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So everything that matters, that's important, is invisible.
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One slightly silly thing that's invisible
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is this story, which is invisible to you.
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And I'm now going to make it visible to you in your minds.
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01:34
It's about an M.P. called Geoffrey Dickens.
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The late Geoffrey Dickens, M.P. was attending a fete in his constituency.
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Wherever he went, at every stall he stopped he was closely followed
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by a devoted smiling woman of indescribable ugliness.
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(Laughter)
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Try as he might, he couldn't get away from her.
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A few days later he received a letter from a constituent
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saying how much she admired him,
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had met him at a fete and asking for a signed photograph.
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After her name, written in brackets was the apt description, horse face.
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(Laughter)
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"I've misjudged this women," thought Mr. Dickens.
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"Not only is she aware of her physical repulsiveness,
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she turns it to her advantage.
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A photo is not enough."
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So he went out and bought a plastic frame to put the photograph in.
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And on the photograph, he wrote with a flourish,
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"To Horse Face, with love from Geoffrey Dickens, M.P."
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After it had been sent off, his secretary said to him,
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"Did you get that letter from the woman at the fete?
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I wrote Horse Face on her, so you'd remember who she was."
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(Laughter)
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I bet he thought he wished he was invisible, don't you?
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(Laughter)
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So, one of the interesting things about invisibility
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is that things that we can't see
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we also can't understand.
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Gravity is one thing that we can't see
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and which we don't understand.
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It's the least understood of all the four fundamental forces,
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and the weakest.
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And nobody really knows what it is or why it's there.
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For what it's worth, Sir Isaac Newton, the greatest scientist who ever lived,
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he thought Jesus came to Earth specifically to operate the levers of gravity.
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That's what he thought he was there for.
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So, bright guy, could be wrong on that one, I don't know.
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(Laughter)
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Consciousness. I see all your faces.
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I have no idea what any of you are thinking. Isn't that amazing?
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Isn't that incredible that we can't read each other's minds?
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But we can touch each other, taste each other perhaps, if we get close enough.
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But we can't read each other's minds. I find that quite astonishing.
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In the Sufi faith, this great Middle Eastern religion,
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which some claim is the route of all religions,
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Sufi masters are all telepaths, so they say.
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But their main exercise of telepathy
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is to send out powerful signals to the rest of us that it doesn't exist.
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So that's why we don't think it exists,
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the Sufi masters working on us.
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In the question of consciousness
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and artificial intelligence,
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artificial intelligence has really, like the study of consciousness,
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gotten nowhere. We have no idea how consciousness works.
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With artificial intelligence, not only have they not created artificial intelligence,
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they haven't yet created artificial stupidity.
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(Laughter)
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The laws of physics: invisible, eternal, omnipresent, all-powerful.
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Remind you of anyone?
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Interesting. I'm, as you can guess,
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not a materialist, I'm an immaterialist.
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And I've found a very useful new word, ignostic. Okay?
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I'm an ignostic.
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I refuse to be drawn on the question of whether God exists,
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until somebody properly defines the terms.
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(Laughter)
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Another thing we can't see is the human genome.
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And this is increasingly peculiar,
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because about 20 years ago, when they started delving into the genome,
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they thought it would probably contain around 100,000 genes.
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Geneticists will know this, but every year since,
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it's been revised downwards.
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We now think there are likely to be only just over 20,000
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genes in the human genome.
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This is extraordinary. Because rice -- get this --
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rice is known to have 38 thousand genes.
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Potatoes, potatoes have 48 chromosomes. Do you know that?
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Two more than people,
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and the same as a gorilla.
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(Laughter)
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You can't see these things, but they are very strange.
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(Laughter)
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The stars by day. I always think that's fascinating.
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The universe disappears.
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The more light there is, the less you can see.
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Time, nobody can see time.
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I don't know if you know this. Modern physics,
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there is a big movement in modern physics
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to decide that time doesn't really exist,
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because it's too inconvenient for the figures.
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It's much easier if it's not really there.
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You can't see the future, obviously.
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And you can't see the past, except in your memory.
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One of the interesting things about the past is
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you particularly can't see. My son asked me this the other day,
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he said, "Dad, can you remember what I was like when I was two?"
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And I said, "Yes." And he said, "Why can't I?"
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Isn't that extraordinary? You cannot remember
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what happened to you earlier than the age of two or three,
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which is great news for psychoanalysts,
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because otherwise they'd be out of a job.
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Because that's where all the stuff happens
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(Laughter)
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that makes you who you are.
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Another thing you can't see is the grid on which we hang.
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This is fascinating. You probably know, some of you,
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that cells are continually renewed. You can see it in skin and this kind of stuff.
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Skin flakes off, hairs grow, nails, that kind of stuff.
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But every cell in your body is replaced at some point.
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Taste buds, every 10 days or so.
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Livers and internal organs sort of take a bit longer. A spine takes several years.
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But at the end of seven years, not one cell in your body
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remains from what was there seven years ago.
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The question is, who, then, are we?
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What are we? What is this thing that we hang on,
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that is actually us?
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Okay. Atoms, you can't see them.
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Nobody ever will. They're smaller than the wavelength of light.
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Gas, you can't see that.
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Interesting. Somebody mentioned 1600 recently.
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Gas was invented in 1600
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by a Dutch chemist called Van Helmont.
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It's said to be the most successful ever invention
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of a word by a known individual.
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Quite good. He also invented a word called "blas,"
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meaning astral radiation.
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Didn't catch on, unfortunately.
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(Laughter)
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But well done, him.
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(Laughter)
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There is so many things that -- Light.
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You can't see light. When it's dark, in a vacuum,
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if a person shines a beam of light straight across your eyes,
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you won't see it. Slightly technical, some physicists will disagree with this.
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But it's odd that you can't see the beam of light,
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you can only see what it hits.
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I find that extraordinary, not to be able to see light,
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not to be able to see darkness.
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Electricity, you can't see that.
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Don't let anyone tell you they understand electricity.
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They don't. Nobody knows what it is.
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(Laughter)
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You probably think the electrons in an electric wire
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move instantaneously down a wire, don't you, at the speed of light
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when you turn the light on. They don't.
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Electrons bumble down the wire,
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about the speed of spreading honey, they say.
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(Laughter)
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Galaxies, 100 billion of them estimated in the universe.
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100 billion. How many can we see? Five.
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Five out of the 100 billion galaxies, with the naked eye,
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and one of them is quite difficult to see unless you've got very good eyesight.
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Radio waves. There's another thing.
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Heinrich Hertz, when he discovered radio waves in 1887,
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he called them radio waves because they radiated.
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And somebody said to him,
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"Well what's the point of these, Heinrich?
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What's the point of these radio waves that you've found?"
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And he said, "Well, I've no idea.
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But I guess somebody will find a use for them someday."
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And that's what they do, radio. That's what they discovered.
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Anyway, so the biggest thing
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that's invisible to us is what we don't know.
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It is incredible how little we know.
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Thomas Edison once said,
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"We don't know one percent of one millionth
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about anything."
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And I've come to the conclusion --
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because you've asked this other question, "What's another thing you can't see?"
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The point, most of us. What's the point?
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(Laughter)
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(Applause)
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You can't see a point. It's by definition dimensionless,
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like an electron, oddly enough.
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But the point, what I've got it down to,
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is there are only two questions really worth asking.
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"Why are we here?" and "What should we do about it while we are?
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And to help you, I've got two things to leave you with, from two great philosophers,
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perhaps two of the greatest philosopher thinkers of the 20th century,
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one a mathematician and an engineer, and the other a poet.
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The first is Ludwig Wittgenstein who said,
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"I don't know why we are here.
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But I'm pretty sure it's not in order to enjoy ourselves."
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(Laughter)
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He was a cheerful bastard wasn't he?
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(Laughter)
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And secondly and lastly, W.H. Auden,
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one of my favorite poets, who said,
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"We are here on earth
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to help others.
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What the others are here for, I've no idea."
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(Laughter)
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(Applause)
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