What's invisible? More than you think - John Lloyd

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Gravity. The stars in day. Thoughts. The human genome. Time. Atoms. So much of what really matters in the world is impossible to see. A stunning animation of John Lloyd's classic TEDTalk from 2009, which will make you question what you actually know.

Lesson by John Lloyd, animation by Cognitive Media.

(Circus music)

[Ted N' Ed's Carnival]

[John Lloyd's Inventory of the Invisible]

[Adapted from a TEDTalk
given by John Lloyd in 2009]

June Cohen: Our next speaker
has spent his whole career

eliciting that sense of wonder.

Please welcome John Lloyd.

(Applause)

[Hall of Mirrors]

The question is, "What is invisible?"

There's more of it
than you think, actually.

Everything, I would say --
everything that matters --

Except every thing, and except matter.

We can see matter

but we can't see what's the matter.

We can see the stars and the planets
but we can't see what holds them apart,

or what draws them together.

With matter as with people,
we see only the skin of things,

we can't see into the engine room,
we can't see what makes people tick,

at least not without difficulty,

and the closer we look at anything,
the more it disappears.

In fact, if you look
really closely at stuff,

if you look at the basic
substructure of matter,

there isn't anything there.

Electrons disappear in a kind of fuzz,
and there is only energy.

One of the interesting things
about invisibility is,

the things that we can's see,
we also can't understand.

Gravity is one thing that we can't see,
and which we don't understand.

It's the least understood
of all the four fundamental forces,

and the weakest, and nobody really
knows what it is or why it's there.

For what it's worth, Sir Isaac Newton,
the greatest scientist who ever lived,

he thought Jesus came
to Earth specifically

to operate the levers of gravity.

That's what he thought he was there for.

So, bright guy, could be wrong
on that one, I don't know.

(Laughter)

Consciousness. I see all your faces;
I've no idea what any of you are thinking.

Isn't that amazing?

Isn't it incredible that we can't read
each other's minds,

when we can touch each other,
taste each other,

perhaps, if we get close enough,
but we can't read each other's minds.

I find that quite astonishing.

In the Sufi faith,
this great Middle Eastern religion

which some claim
is the root of all religions,

Sufi masters are
all telepaths, so they say,

but their main exercise of telepathy

is to send out powerful signals
to the rest of us that it doesn't exist.

So that's why we don't think it exists;
the Sufi masters working on us.

In the question of consciousness
and artificial intelligence,

artificial intelligence has really,
like the study of consciousness,

gotten nowhere, we have no idea
how consciousness works.

Not only have they not created
artificial intelligence,

they haven't yet created
artificial stupidity.

(Laughter)

The laws of physics: invisible,
eternal, omnipresent, all powerful.

Remind you of anyone?

Interesting.

I'm, as you can guess,
not a materialist, I'm an immaterialist.

And I've found a very useful
new word -- ignostic.

Okay? I'm an ignostic.

[God?]

I refuse to be drawn on the question
on whether God exists

until somebody properly defines the terms.

Another thing we can't see
is the human genome.

And this is increasingly peculiar,
because about 20 years ago

when they started delving into the genome,
they thought it would probably contain

around 100 thousand genes.

Every year since,
it's been revised downwards.

We now think there are likely
to be just over 20 thousand genes

in the human genome.

This is extraordinary,
because rice -- get this --

rice is known to have 38 thousand genes.

Potatoes have 48 chromosomes,
two more than people,

and the same as a gorilla.

(Laughter)

You can't see these things,
but they are very strange.

The stars by day, I always
think that's fascinating.

The universe disappears.

The more light there is,
the less you can see.

Time. Nobody can see time.

I don't know if you know this.

There's a big movement in modern physics

to decide that time doesn't really exist,

because it's too inconvenient
for the figures.

It's much easier if it's not really there.

You can't see the future, obviously,

and you can't see the past,
except in your memory.

One of the interesting
things about the past

is you particularly can't see --

my son asked me this the other day,

"Dad, can you remember
what I was like when I was two?

And I said, "Yes." He said, "Why can't I?"

Isn't that extraordinary?

You cannot remember what happened to you
earlier than the age of two or three.

Which is great news for psychoanalysts,
because otherwise they'd be out of a job.

Because that's where all the stuff happens

(Laughter)

that makes you who you are.

Another thing you can't see
is the grid on which we hang.

This is fascinating.

You probably know, some of you,
that cells are continually renewed.

Skin flakes off, hairs grow,
nails, that kind of stuff --

but every cell in your body
is replaced at some point.

Taste buds, every ten days or so.

Livers and internal organs
take a bit longer.

Spine takes several years.

But at the end of seven years,
not one cell in your body

remains from what was there
seven years ago.

The question is:
who then are we? What are we?

What is this thing that we hang on?

That is actually us?

Atoms, can't see them. Nobody ever will.

They're smaller
than the wavelength of light.

Gas, can't see that.

Interesting, somebody
mentioned 1600 recently.

Gas was invented in 1600
by a Dutch chemist called van Helmont.

It's said to be the most successful ever
invention of a word by a known individual.

Quite good. He also invented a word
called "blas," meaning astral radiation.

Didn't catch on, unfortunately.

(Laughter)

But well done, him.

Light -- you can't see light.

When it's dark, in a vacuum,

if a person shines a beam of light

straight across your eyes,
you won't see it.

Slightly technical, some physicists
will disagree with this.

But it's odd that you can't see
the beam of light,

you can only see what it hits.

Electricity, can't see that.

Don't let anyone tell you
they understand electricity, they don't.

Nobody knows what it is.

(Laughter)

You probably think the electrons
in an electric wire move instantaneously

down a wire, don't you,
at the speed of light,

when you turn the light on, they don't.

Electrons bumble down the wire,

about the speed of spreading
honey, they say.

Galaxies -- hundred billion of them,

estimated in the universe.
Hundred billion.

How many can we see?

Five. Five, out of a hundred billion
galaxies, with the naked eye.

And one of them is quite difficult to see,
unless you've got very good eyesight.

Radio waves. There's another thing.

Heinrich Hertz, when he discovered
radio waves, in 1887,

he called them radio waves
because they radiated.

Somebody said to him,
"What's the point of these, Heinrich?

What's the point of these radio waves
that you've found?"

And he said, "Well, I've no idea,

but I guess somebody will find
a use for them someday.

The biggest thing that's invisible
to us is what we don't know.

It is incredible how little we know.

Thomas Edison once said,

"We don't know one percent
of one millionth about anything."

And I've come to the conclusion --

because you ask this other question:
"What's another thing we can't see?"

The point, most of us. What's the point?

The point -- what I've got it down to

is there are only two questions
really worth asking.

"Why are we here?",

and "What should
we do about it while we are?"

To help you, I've got two things to leave
you with, from two great philosophers,

perhaps two of the greatest philosopher
thinkers of the 20th century.

One a mathematician and engineer,
and the other a poet.

The first is Ludwig Wittgenstein,

who said, "I don't know why we are here,

but I am pretty sure it's not
in order to enjoy ourselves."

(Laughter)

He was a cheerful bastard, wasn't he?

(Laughter)

And secondly, and lastly,
W.H. Auden, one of my favorite poets,

who said, "We are here
on Earth to help others.

What the others
are here for, I've no idea."

(Laughter)

(Applause)

(Circus music)

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[Continue your journey into the unknown!]

(Circus music)