0:00:01.190,0:00:05.718
I'd like to introduce you[br]to an emerging area of science,

0:00:05.742,0:00:09.685
one that is still speculative[br]but hugely exciting,

0:00:09.709,0:00:12.338
and certainly one[br]that's growing very rapidly.

0:00:13.448,0:00:17.496
Quantum biology[br]asks a very simple question:

0:00:17.520,0:00:18.870
Does quantum mechanics --

0:00:18.894,0:00:22.196
that weird and wonderful[br]and powerful theory

0:00:22.220,0:00:24.908
of the subatomic world[br]of atoms and molecules

0:00:24.932,0:00:28.420
that underpins so much[br]of modern physics and chemistry --

0:00:28.444,0:00:31.856
also play a role inside the living cell?

0:00:31.880,0:00:35.959
In other words: Are there processes,[br]mechanisms, phenomena

0:00:35.983,0:00:39.971
in living organisms[br]that can only be explained

0:00:39.995,0:00:42.738
with a helping hand[br]from quantum mechanics?

0:00:43.546,0:00:45.183
Now, quantum biology isn't new;

0:00:45.207,0:00:47.608
it's been around since the early 1930s.

0:00:47.928,0:00:51.643
But it's only in the last decade or so[br]that careful experiments --

0:00:51.667,0:00:55.131
in biochemistry labs,[br]using spectroscopy --

0:00:55.155,0:01:02.018
have shown very clear, firm evidence[br]that there are certain specific mechanisms

0:01:02.042,0:01:04.553
that require quantum mechanics[br]to explain them.

0:01:05.674,0:01:09.003
Quantum biology brings together[br]quantum physicists, biochemists,

0:01:09.027,0:01:12.668
molecular biologists --[br]it's a very interdisciplinary field.

0:01:12.692,0:01:16.621
I come from quantum physics,[br]so I'm a nuclear physicist.

0:01:16.645,0:01:18.910
I've spent more than three decades

0:01:18.934,0:01:21.863
trying to get my head[br]around quantum mechanics.

0:01:21.887,0:01:24.380
One of the founders[br]of quantum mechanics, Niels Bohr,

0:01:24.404,0:01:27.754
said, "If you're not astonished by it,[br]then you haven't understood it."

0:01:28.237,0:01:31.080
So I sort of feel happy[br]that I'm still astonished by it.

0:01:31.104,0:01:32.849
That's a good thing.

0:01:32.873,0:01:39.758
But it means I study the very[br]smallest structures in the universe --

0:01:39.782,0:01:41.857
the building blocks of reality.

0:01:41.881,0:01:45.096
If we think about the scale of size,

0:01:45.120,0:01:48.072
start with an everyday object[br]like the tennis ball,

0:01:48.096,0:01:50.997
and just go down orders[br]of magnitude in size --

0:01:51.021,0:01:56.218
from the eye of a needle down to a cell,[br]down to a bacterium, down to an enzyme --

0:01:56.242,0:01:57.971
you eventually reach the nano-world.

0:01:57.995,0:02:00.490
Now, nanotechnology may be[br]a term you've heard of.

0:02:00.841,0:02:03.694
A nanometer is a billionth of a meter.

0:02:04.560,0:02:08.930
My area is the atomic nucleus,[br]which is the tiny dot inside an atom.

0:02:08.954,0:02:10.886
It's even smaller in scale.

0:02:10.910,0:02:12.828
This is the domain of quantum mechanics,

0:02:12.852,0:02:15.368
and physicists and chemists[br]have had a long time

0:02:15.392,0:02:16.693
to try and get used to it.

0:02:17.248,0:02:21.705
Biologists, on the other hand,[br]have got off lightly, in my view.

0:02:22.071,0:02:26.402
They are very happy with their[br]balls-and-sticks models of molecules.

0:02:26.426,0:02:27.508
(Laughter)

0:02:27.532,0:02:30.730
The balls are the atoms, the sticks[br]are the bonds between the atoms.

0:02:30.754,0:02:33.248
And when they can't build them[br]physically in the lab,

0:02:33.272,0:02:35.664
nowadays, they have[br]very powerful computers

0:02:35.688,0:02:37.655
that will simulate a huge molecule.

0:02:37.679,0:02:41.343
This is a protein made up[br]of 100,000 atoms.

0:02:42.003,0:02:46.338
It doesn't really require much in the way[br]of quantum mechanics to explain it.

0:02:47.695,0:02:50.584
Quantum mechanics[br]was developed in the 1920s.

0:02:50.965,0:02:57.845
It is a set of beautiful and powerful[br]mathematical rules and ideas

0:02:57.869,0:03:00.477
that explain the world of the very small.

0:03:00.501,0:03:03.873
And it's a world that's very different[br]from our everyday world,

0:03:03.897,0:03:05.416
made up of trillions of atoms.

0:03:05.440,0:03:08.997
It's a world built[br]on probability and chance.

0:03:09.818,0:03:11.120
It's a fuzzy world.

0:03:11.144,0:03:12.874
It's a world of phantoms,

0:03:12.898,0:03:16.246
where particles can also behave[br]like spread-out waves.

0:03:18.157,0:03:21.019
If we imagine quantum mechanics[br]or quantum physics, then,

0:03:21.043,0:03:26.257
as the fundamental[br]foundation of reality itself,

0:03:26.281,0:03:28.011
then it's not surprising that we say

0:03:28.035,0:03:30.455
quantum physics underpins[br]organic chemistry.

0:03:30.479,0:03:32.599
After all, it gives us[br]the rules that tell us

0:03:32.623,0:03:35.264
how the atoms fit together[br]to make organic molecules.

0:03:35.288,0:03:38.527
Organic chemistry,[br]scaled up in complexity,

0:03:38.551,0:03:41.873
gives us molecular biology,[br]which of course leads to life itself.

0:03:42.174,0:03:44.151
So in a way, it's sort of not surprising.

0:03:44.175,0:03:45.389
It's almost trivial.

0:03:45.413,0:03:49.633
You say, "Well, of course life ultimately[br]must depend of quantum mechanics."

0:03:50.141,0:03:52.531
But so does everything else.

0:03:52.555,0:03:56.170
So does all inanimate matter,[br]made up of trillions of atoms.

0:03:56.501,0:04:01.379
Ultimately, there's a quantum level

0:04:01.403,0:04:03.586
where we have to delve into[br]this weirdness.

0:04:03.610,0:04:06.026
But in everyday life,[br]we can forget about it.

0:04:06.404,0:04:09.603
Because once you put together[br]trillions of atoms,

0:04:09.627,0:04:12.242
that quantum weirdness[br]just dissolves away.

0:04:15.288,0:04:17.857
Quantum biology isn't about this.

0:04:17.881,0:04:20.437
Quantum biology isn't this obvious.

0:04:20.461,0:04:24.690
Of course quantum mechanics[br]underpins life at some molecular level.

0:04:25.254,0:04:31.258
Quantum biology is about looking[br]for the non-trivial --

0:04:31.282,0:04:35.758
the counterintuitive ideas[br]in quantum mechanics --

0:04:35.782,0:04:38.797
and to see if they do, indeed,[br]play an important role

0:04:38.821,0:04:41.273
in describing the processes of life.

0:04:42.653,0:04:47.873
Here is my perfect example[br]of the counterintuitiveness

0:04:47.897,0:04:49.343
of the quantum world.

0:04:49.367,0:04:50.618
This is the quantum skier.

0:04:50.642,0:04:53.282
He seems to be intact,[br]he seems to be perfectly healthy,

0:04:53.306,0:04:57.433
and yet, he seems to have gone around[br]both sides of that tree at the same time.

0:04:57.457,0:04:59.120
Well, if you saw tracks like that

0:04:59.144,0:05:01.453
you'd guess it was some[br]sort of stunt, of course.

0:05:01.477,0:05:04.068
But in the quantum world,[br]this happens all the time.

0:05:04.864,0:05:07.890
Particles can multitask,[br]they can be in two places at once.

0:05:07.914,0:05:10.242
They can do more than one thing[br]at the same time.

0:05:10.266,0:05:12.909
Particles can behave[br]like spread-out waves.

0:05:13.298,0:05:14.897
It's almost like magic.

0:05:15.538,0:05:18.287
Physicists and chemists have had[br]nearly a century

0:05:18.311,0:05:20.957
of trying to get used to this weirdness.

0:05:21.445,0:05:22.795
I don't blame the biologists

0:05:22.819,0:05:25.454
for not having to or wanting[br]to learn quantum mechanics.

0:05:25.478,0:05:28.676
You see, this weirdness is very delicate;

0:05:28.700,0:05:33.150
and we physicists work very hard[br]to maintain it on our labs.

0:05:33.174,0:05:37.378
We cool our system down[br]to near absolute zero,

0:05:37.402,0:05:39.347
we carry out our experiments in vacuums,

0:05:39.371,0:05:42.898
we try and isolate it[br]from any external disturbance.

0:05:43.602,0:05:48.680
That's very different from the warm,[br]messy, noisy environment of a living cell.

0:05:49.960,0:05:52.747
Biology itself, if you think of[br]molecular biology,

0:05:52.771,0:05:56.228
seems to have done very well[br]in describing all the processes of life

0:05:56.252,0:05:58.738
in terms of chemistry --[br]chemical reactions.

0:05:58.762,0:06:03.612
And these are reductionist,[br]deterministic chemical reactions,

0:06:03.636,0:06:08.750
showing that, essentially, life is made[br]of the same stuff as everything else,

0:06:08.774,0:06:11.834
and if we can forget about quantum[br]mechanics in the macro world,

0:06:11.858,0:06:15.104
then we should be able to forget[br]about it in biology, as well.

0:06:15.706,0:06:19.070
Well, one man begged[br]to differ with this idea.

0:06:20.062,0:06:23.531
Erwin Schrödinger,[br]of Schrödinger's Cat fame,

0:06:23.555,0:06:24.872
was an Austrian physicist.

0:06:24.896,0:06:28.079
He was one of the founders[br]of quantum mechanics in the 1920s.

0:06:28.663,0:06:31.370
In 1944, he wrote a book[br]called "What is Life?"

0:06:31.839,0:06:33.570
It was tremendously influential.

0:06:33.594,0:06:36.475
It influenced Francis Crick[br]and James Watson,

0:06:36.499,0:06:39.022
the discoverers of the double-helix[br]structure of DNA.

0:06:39.343,0:06:43.011
To paraphrase a description[br]in the book, he says:

0:06:43.035,0:06:48.821
At the molecular level,[br]living organisms have a certain order,

0:06:48.845,0:06:52.077
a structure to them that's very different

0:06:52.101,0:06:56.837
from the random thermodynamic jostling[br]of atoms and molecules

0:06:56.861,0:07:00.567
in inanimate matter[br]of the same complexity.

0:07:01.504,0:07:06.518
In fact, living matter seems to behave[br]in this order, in a structure,

0:07:06.542,0:07:10.376
just like inanimate matter[br]cooled down to near absolute zero,

0:07:10.400,0:07:13.433
where quantum effects[br]play a very important role.

0:07:14.280,0:07:18.440
There's something special[br]about the structure -- the order --

0:07:18.464,0:07:20.024
inside a living cell.

0:07:20.048,0:07:25.341
So, Schrödinger speculated that maybe[br]quantum mechanics plays a role in life.

0:07:26.096,0:07:29.521
It's a very speculative,[br]far-reaching idea,

0:07:29.545,0:07:32.418
and it didn't really go very far.

0:07:33.536,0:07:35.069
But as I mentioned at the start,

0:07:35.093,0:07:37.892
in the last 10 years, there have been[br]experiments emerging,

0:07:37.916,0:07:41.971
showing where some of these[br]certain phenomena in biology

0:07:41.995,0:07:43.758
do seem to require quantum mechanics.

0:07:43.782,0:07:46.905
I want to share with you[br]just a few of the exciting ones.

0:07:48.215,0:07:51.922
This is one of the best-known[br]phenomena in the quantum world,

0:07:51.946,0:07:53.647
quantum tunneling.

0:07:53.671,0:07:58.060
The box on the left shows[br]the wavelike, spread-out distribution

0:07:58.084,0:08:00.845
of a quantum entity --[br]a particle, like an electron,

0:08:00.869,0:08:04.506
which is not a little ball[br]bouncing off a wall.

0:08:04.530,0:08:09.269
It's a wave that has a certain probability[br]of being able to permeate

0:08:09.293,0:08:12.699
through a solid wall, like a phantom[br]leaping through to the other side.

0:08:12.723,0:08:16.821
You can see a faint smudge of light[br]in the right-hand box.

0:08:17.773,0:08:22.385
Quantum tunneling suggests that a particle[br]can hit an impenetrable barrier,

0:08:22.409,0:08:24.869
and yet somehow, as though by magic,

0:08:24.893,0:08:27.337
disappear from one side[br]and reappear on the other.

0:08:27.658,0:08:31.909
The nicest way of explaining it is[br]if you want to throw a ball over a wall,

0:08:31.933,0:08:35.510
you have to give it enough energy[br]to get over the top of the wall.

0:08:35.534,0:08:38.592
In the quantum world,[br]you don't have to throw it over the wall,

0:08:38.616,0:08:42.023
you can throw it at the wall,[br]and there's a certain non-zero probability

0:08:42.047,0:08:45.370
that it'll disappear on your side,[br]and reappear on the other.

0:08:45.394,0:08:47.072
This isn't speculation, by the way.

0:08:47.096,0:08:50.492
We're happy -- well, "happy"[br]is not the right word --

0:08:50.516,0:08:52.561
(Laughter)

0:08:52.585,0:08:54.203
We are familiar with this.

0:08:54.227,0:08:56.972
(Laughter)

0:08:56.996,0:08:59.290
Quantum tunneling[br]takes place all the time;

0:08:59.314,0:09:01.981
in fact, it's the reason our sun shines.

0:09:02.655,0:09:04.164
The particles fuse together,

0:09:04.188,0:09:07.886
and the Sun turns hydrogen[br]into helium through quantum tunneling.

0:09:09.464,0:09:14.684
Back in the 70s and 80s, it was discovered[br]that quantum tunneling also takes place

0:09:14.708,0:09:15.900
inside living cells.

0:09:16.290,0:09:22.556
Enzymes, those workhorses of life,[br]the catalysts of chemical reactions --

0:09:22.580,0:09:26.746
enzymes are biomolecules that speed up[br]chemical reactions in living cells,

0:09:26.770,0:09:28.473
by many, many orders of magnitude.

0:09:28.497,0:09:31.281
And it's always been a mystery[br]how they do this.

0:09:31.650,0:09:32.839
Well, it was discovered

0:09:32.863,0:09:37.715
that one of the tricks that enzymes[br]have evolved to make use of,

0:09:37.739,0:09:42.967
is by transferring subatomic particles,[br]like electrons and indeed protons,

0:09:42.991,0:09:47.652
from one part of a molecule[br]to another via quantum tunneling.

0:09:48.333,0:09:51.184
It's efficient, it's fast,[br]it can disappear --

0:09:51.208,0:09:54.319
a proton can disappear from one place,[br]and reappear on the other.

0:09:54.343,0:09:55.972
Enzymes help this take place.

0:09:56.548,0:09:59.231
This is research that's been[br]carried out back in the 80s,

0:09:59.255,0:10:03.292
particularly by a group[br]in Berkeley, Judith Klinman.

0:10:03.316,0:10:05.521
Other groups in the UK[br]have now also confirmed

0:10:05.545,0:10:06.956
that enzymes really do this.

0:10:09.048,0:10:11.597
Research carried out by my group --

0:10:11.621,0:10:14.055
so as I mentioned,[br]I'm a nuclear physicist,

0:10:14.079,0:10:17.134
but I've realized I've got these tools[br]of using quantum mechanics

0:10:17.158,0:10:22.243
in atomic nuclei, and so can apply[br]those tools in other areas as well.

0:10:23.404,0:10:25.214
One question we asked

0:10:25.238,0:10:29.536
is whether quantum tunneling[br]plays a role in mutations in DNA.

0:10:29.843,0:10:33.503
Again, this is not a new idea;[br]it goes all the way back to the early 60s.

0:10:33.527,0:10:36.488
The two strands of DNA,[br]the double-helix structure,

0:10:36.512,0:10:39.335
are held together by rungs;[br]it's like a twisted ladder.

0:10:39.359,0:10:42.866
And those rungs of the ladder[br]are hydrogen bonds --

0:10:42.890,0:10:46.680
protons, that act as the glue[br]between the two strands.

0:10:46.704,0:10:51.454
So if you zoom in, what they're doing[br]is holding these large molecules --

0:10:51.478,0:10:53.085
nucleotides -- together.

0:10:54.130,0:10:55.280
Zoom in a bit more.

0:10:55.304,0:10:57.220
So, this a computer simulation.

0:10:57.855,0:11:01.397
The two white balls[br]in the middle are protons,

0:11:01.421,0:11:03.720
and you can see that[br]it's a double hydrogen bond.

0:11:03.744,0:11:07.058
One prefers to sit on one side;[br]the other, on the other side

0:11:07.082,0:11:11.640
of the two strands of the vertical lines[br]going down, which you can't see.

0:11:12.410,0:11:15.805
It can happen that[br]these two protons can hop over.

0:11:15.829,0:11:17.265
Watch the two white balls.

0:11:17.748,0:11:19.746
They can jump over to the other side.

0:11:20.239,0:11:25.885
If the two strands of DNA then separate,[br]leading to the process of replication,

0:11:25.909,0:11:29.108
and the two protons[br]are in the wrong positions,

0:11:29.132,0:11:30.895
this can lead to a mutation.

0:11:31.204,0:11:33.076
This has been known for half a century.

0:11:33.100,0:11:35.443
The question is: How likely[br]are they to do that,

0:11:35.467,0:11:37.845
and if they do, how do they do it?

0:11:37.869,0:11:40.888
Do they jump across,[br]like the ball going over the wall?

0:11:40.912,0:11:44.414
Or can they quantum-tunnel across,[br]even if they don't have enough energy?

0:11:45.089,0:11:49.341
Early indications suggest that[br]quantum tunneling can play a role here.

0:11:49.365,0:11:51.489
We still don't know yet[br]how important it is;

0:11:51.513,0:11:53.305
this is still an open question.

0:11:54.199,0:11:55.349
It's speculative,

0:11:55.373,0:11:58.016
but it's one of those questions[br]that is so important

0:11:58.040,0:12:00.486
that if quantum mechanics[br]plays a role in mutations,

0:12:00.510,0:12:02.809
surely this must have big implications,

0:12:02.833,0:12:05.527
to understand certain types of mutations,

0:12:05.551,0:12:09.307
possibly even those that lead[br]to turning a cell cancerous.

0:12:10.803,0:12:16.102
Another example of quantum mechanics[br]in biology is quantum coherence,

0:12:16.126,0:12:18.479
in one of the most[br]important processes in biology,

0:12:18.503,0:12:22.444
photosynthesis: plants[br]and bacteria taking sunlight,

0:12:22.468,0:12:25.422
and using that energy to create biomass.

0:12:26.215,0:12:30.367
Quantum coherence is the idea[br]of quantum entities multitasking.

0:12:30.912,0:12:32.516
It's the quantum skier.

0:12:32.540,0:12:35.492
It's an object that behaves like a wave,

0:12:35.516,0:12:38.418
so that it doesn't just move[br]in one direction or the other,

0:12:38.442,0:12:41.762
but can follow multiple pathways[br]at the same time.

0:12:42.708,0:12:46.624
Some years ago,[br]the world of science was shocked

0:12:46.648,0:12:50.232
when a paper was published[br]showing experimental evidence

0:12:50.256,0:12:54.032
that quantum coherence[br]takes place inside bacteria,

0:12:54.056,0:12:55.742
carrying out photosynthesis.

0:12:55.766,0:12:58.830
The idea is that the photon,[br]the particle of light, the sunlight,

0:12:58.854,0:13:02.198
the quantum of light[br]captured by a chlorophyll molecule,

0:13:02.222,0:13:04.813
is then delivered to what's called[br]the reaction center,

0:13:04.837,0:13:06.901
where it can be turned into[br]chemical energy.

0:13:06.925,0:13:09.573
And in getting there,[br]it doesn't just follow one route;

0:13:09.597,0:13:11.812
it follows multiple pathways at once,

0:13:11.836,0:13:16.173
to optimize the most efficient way[br]of reaching the reaction center

0:13:16.197,0:13:17.918
without dissipating as waste heat.

0:13:19.228,0:13:22.537
Quantum coherence taking place[br]inside a living cell.

0:13:22.561,0:13:24.681
A remarkable idea,

0:13:24.705,0:13:30.940
and yet evidence is growing almost weekly,[br]with new papers coming out,

0:13:30.964,0:13:33.176
confirming that this[br]does indeed take place.

0:13:33.555,0:13:38.294
My third and final example[br]is the most beautiful, wonderful idea.

0:13:38.318,0:13:42.381
It's also still very speculative,[br]but I have to share it with you.

0:13:42.405,0:13:47.017
The European robin[br]migrates from Scandinavia

0:13:47.041,0:13:49.676
down to the Mediterranean, every autumn,

0:13:49.700,0:13:53.073
and like a lot of other[br]marine animals and even insects,

0:13:53.097,0:13:57.397
they navigate by sensing[br]the Earth's magnetic field.

0:13:58.968,0:14:01.395
Now, the Earth's magnetic field[br]is very, very weak;

0:14:01.419,0:14:03.499
it's 100 times weaker[br]than a fridge magnet,

0:14:03.523,0:14:09.124
and yet it affects the chemistry --[br]somehow -- within a living organism.

0:14:09.932,0:14:13.738
That's not in doubt --[br]a German couple of ornithologists,

0:14:13.762,0:14:18.022
Wolfgang and Roswitha Wiltschko,[br]in the 1970s, confirmed that indeed,

0:14:18.046,0:14:22.023
the robin does find its way by somehow[br]sensing the Earth's magnetic field,

0:14:22.047,0:14:25.374
to give it directional information --[br]a built-in compass.

0:14:25.398,0:14:27.647
The puzzle, the mystery was:[br]How does it do it?

0:14:28.351,0:14:31.381
Well, the only theory in town --

0:14:31.405,0:14:34.841
we don't know if it's the correct theory,[br]but the only theory in town --

0:14:34.865,0:14:37.849
is that it does it via something[br]called quantum entanglement.

0:14:38.567,0:14:40.941
Inside the robin's retina --

0:14:40.965,0:14:45.197
I kid you not -- inside the robin's retina[br]is a protein called cryptochrome,

0:14:45.221,0:14:46.601
which is light-sensitive.

0:14:46.625,0:14:50.564
Within cryptochrome, a pair of electrons[br]are quantum-entangled.

0:14:50.588,0:14:53.820
Now, quantum entanglement[br]is when two particles are far apart,

0:14:53.844,0:14:56.678
and yet somehow remain[br]in contact with each other.

0:14:56.991,0:14:58.437
Even Einstein hated this idea;

0:14:58.461,0:15:00.500
he called it "spooky action[br]at a distance."

0:15:00.524,0:15:02.405
(Laughter)

0:15:02.429,0:15:05.872
So if Einstein doesn't like it,[br]then we can all be uncomfortable with it.

0:15:05.896,0:15:08.749
Two quantum-entangled electrons[br]within a single molecule

0:15:08.773,0:15:10.244
dance a delicate dance

0:15:10.268,0:15:12.809
that is very sensitive[br]to the direction the bird flies

0:15:12.833,0:15:14.364
in the Earth's magnetic field.

0:15:14.848,0:15:17.458
We don't know if it's[br]the correct explanation,

0:15:17.482,0:15:22.026
but wow, wouldn't it be exciting[br]if quantum mechanics helps birds navigate?

0:15:23.069,0:15:25.790
Quantum biology is still in it infancy.

0:15:25.814,0:15:29.298
It's still speculative.

0:15:29.742,0:15:33.591
But I believe it's built on solid science.

0:15:33.917,0:15:37.726
I also think that[br]in the coming decade or so,

0:15:37.750,0:15:42.591
we're going to start to see[br]that actually, it pervades life --

0:15:42.615,0:15:47.211
that life has evolved tricks[br]that utilize the quantum world.

0:15:48.026,0:15:49.454
Watch this space.

0:15:49.478,0:15:50.635
Thank you.

0:15:50.659,0:15:52.861
(Applause)