I'd like to introduce you to an emerging area of science.
One that is still speculative, but hugely exciting.
It's certainly one that's growing very rapidly.
Quantum biology asks a very simple question.
Does quantum mechanics, that weird and wonderful, and powerful theory
of the subatomic world of atoms and molecules
that underpins so much of modern physics and chemistry, also play
a role inside the living cell?
In other words, are there processes, mechanisms, phenomena in living organisms
that can only be explained with a helping hand from quantum mechanics.
Now, quantum biology isn't new. It's been around since the early 1930s.
But its only in the last decade or so, that careful experiments
in biochemistry labs, using spectroscopy that have shown clear, firm evidence
that there are certain specific mechanisms that require quantum mechanics
to explain them.
Quantum biology brings together quantum physicists, biochemists,
molecular biologists.
It's a very interdisciplinary field.
I come from quantum physics. So, I'm a nuclear physicist.
I've spent more than three decades trying to get my head around quantum mechanics.
One of the founders of quantum mechanics, Neil Bohr said,
If you're not astonished by it, then you haven't understood it.
So, I sort of feel happy that I'm still astonished by it and that's a good thing.
But it means I study the very smallest structures in the universe.
The building blocks of reality.
If we think about the scale of size, start with something, an everyday object
like the tennis ball, and just go down orders of magnitude and size.
From the eye of a needle, down to a cell, down to a bacterium, down to an enzyme.
You eventually reach the nano world.
Now, nanotechnology may be a term you've heard of.
A nanometer is a billionth of a meter.
My area is the atomic nucleus, which is the tiny dot inside an atom.
It's even smaller in scale.
This is the domain of quantum mechanics, and physicists and chemists have had
a long time to get used to it.
Biologists on the other hand have got off lightly, in my view.
They are very happy with their balls-and-sticks models of molecules.
(Laughter)
The balls are the atoms, the sticks are the bonds between the atoms
and when they can't build them physically in the lab,
nowadays they have very powerful computers that will simulate a huge model.
This is a protein made up of 100,000 atoms.
It doesn't really require much in the way of quantum mechanics to explain it.
Quantum mechanics was developed in the 1920s.
It is a set of beautiful and powerful mathematical rules and ideas
that explain the world of the very small.
And it's a world that very different from our everyday world
made up of trillions of atoms.
It's a world built on probability and chance.
It's a fuzzy world.
It's a world of phantoms, where particles can also behave like spread out waves.
If we imagine quantum mechanics or quantum physics, then as
the fundamental foundation of reality itself.
That's not really surprising that we say quantum physics
underpins organic chemistry.
After all, it gives us the rules that tells us the rules that tell us
how the atoms fit together to make organic molecules.
Organic chemistry, scaled up in complexity gives us molecular biology,
which of course leads to life itself.
So, in a way, it's sort of not surprising.
It's almost trivial.
Say, well of course life ultimately must depend of quantum mechanics
-- so does everything else.
So does all inanimate matter, made up of trillions of atoms.
Ultimately, there's a quantum level that we know where we have to delve
into this weridness.
But in everyday life, we can forget about it.
Because once you put together trillions of atoms, that quantum weirdness
just dissolves away.
Quantum biology isn't about this. Quantum biology isn't this obvious.
Of course quantum mechanics underpins life at some molecular level.
Quantum biology is about looking for the non-trivial, the counterintuitive
ideas in quantum mechanics and to see if they do indeed play an important role
in describing the processes of life.
Here is my perfect example of the counterintuitiveness
of the quantum world.
This is the quantum skiier.
He seems to be intact, he seems to be perfectly healthy.
And yet, he seems to have gone around both sides of that tree at the same time.
Well, if you saw some tracks like that you'd guess some sort of stunts of course.
But in the quantum world, this happens all the time.
Particles can multitask, they can be in two places at once.
They can do more than one thing at the same time.
Particles can behave like spread out waves.
It's almost like magic.
Physicists and chemists have had nearly a century of trying
to get used to this weirdness.
I don't blame the biologists for not having or wanting to learn
quantum mechanics.
You see, this weirdness is very delicate and we physicists work very hard
to maintain it on our labs.
We sort of cool our system down to near absolute zero,
We carry out our experiments in vacuums, we try and isolate it
from any external disturbance.
That's very different from the warm, messy, noisy environment of a living cell.
Biology itself, if you think of molecular biology, seems to have done very well
in describing all the processes of life, in terms of chemistry.
Chemical reactions!
And these are reductionist, deterministic chemical reactions showing that
essentially life, is made of the same stuff as everything else,
and if we can forget about quantum mechanics in the macro world,
then we should be able to forget about it in biology, as well.
Well, one man begged to differ with this idea.
Erwin Schrödinger, he of Schrödinger's Cat fame, an Austrian physicist.
He was one of the founders of quantum mechanics in the 1920s.
In 1944, he wrote a book called "What is Life?"
It was tremendously influential.
It influenced Francis Crick and James Watson,
the discoverer's of the double helix structure of DNA.
To paraphrase a description in the book, he says, at the molecular level,
living organism have a certain order, a structure to them that's very
different from the random thermodynamic jostling of atoms and molecules
in inanimate matter of the same complexity.
In fact, living matter seems to behave in its order, in its structure
just like inanimate matter cooled down to near absolute zero,
where quantum effects play a very important role.
There's something special about the structure, the order
inside of living cell.
So, Schrödinger speculated that maybe quantum mechanics plays a role in life.
It's a very speculative, sort of far-reaching idea and it didn't
really go very far.
But, as I mentioned at the start, in the last 10 years
there have been experiment emerging, showing where some of these certain
phenomena in biology, do seem to require quantum mechanics.
Now, I want to share with you just a few of the exciting ones.
This is one of the best known phenomena in the quantum world.
Quantum tunneling.
The box on the left, shows the wavelike spread out distribution of quantum entity.
A particle, like an electron.
Which is not a little ball bouncing off a wall.
It's a wave that has a certain probability of being able to permeate through
a solid wall, like a phantom leaping through to the other side.
You can see a faint smudge of light in the right hand box.
Quantum tunneling suggests that a particle can hit an impenetrable barrier and yet,
somehow, as if by magic, disappear from one side and reappear on the other.
The nicest way of explaining it, is if you want to throw a ball
over a wall, you have to give it enough energy to get over the top of the wall.
In the quantum world, you don't have to throw it over the wall.
You can throw it at the wall and three's a certain non-zero probability that it'll
disappear on one side, and reappear on the other.
This isn't speculation, by the way, we're happy
-- i'm sorry, happy is not the right word.
(Laughter)
We are familiar with this.
(Laughter)
Quantum tunneling takes place all the time, in fact
it's the reason our sun shines.
The particles fuse together and the sun is turning hydrogen into helium
through quantum tunneling.
Back in the 70s and 80s, it was discovered that quantum tunneling also takes place
inside living cells.
Enzymes, those workhorses of life, the catalysts of chemical reaction.
Enzymes are biomolecules that speed up chemical reactions in living cells.
By many, many orders of magnitude.
And it's always been a mystery how they do this.
Well, it was discovered that one of the tricks that enzymes have evolved
to make use of, is by transferring subatomic particles, like electrons
and indeed protons, from one part of a molecule to another via
quantum tunneling.
It's efficient, it's fast, it can disappear
-- a proton can disappear from one place and a reappear on the other.
Enzymes help this take place.
This is research that's been carried out back in the 80s, particularly by a group
Berkeley, Judith Klinman.
Other groups in the UK have now also confirmed that enzymes really do this.
Research carried out by my group -- so I mentioned I'm a nuclear physicist,
but I realize I've got these tools of using quantum mechanics
in atomic nuclei and so can apply those tools in other areas, as well.
One question we asked was, whether quantum tunneling plays a role
in mutations in DNA.
Again, this is not a new idea. It goes all the way back to the early 60s.
The two strands of DNA, the double helix structure are held together by rungs,
it's like a twisted ladder.
And those rungs of the ladder are hydrogen bonds.