[Music] [Applause] we are made from very small things and we live in a very very big universe and the small things are so small and the big things are so big that you might think we have no hope of ever understanding them but I'm going to argue that in fact we already understand them quite well it's the world in between the big and the small the world we live in that we don't understand and in fact that world is becoming harder and harder to understand because we keep discovering more complexity and creating more complexity and
that's something we have to face if we want to solve our biggest challenges but let's start in the beginning I want to tell you how we came to understand the big that's my background I studied physics and cosmology and it also has to do with where I grew up I grew up in a town called IESA in Finland where you get about 4 hours of daylight uh during the day so when whenever I walked home from school it would be dark and I would look at the stars and it's the stars that really tell you
how big the universe is stars are very big as big or bigger as our sun only very very far away and there are so many of them even with the naked eye you can see 10,000 stars now 10,000 is a big number but it's still a comprehensible number if each star was a grain of sand 10,000 would be about three teaspoons of sand so that's not so bad but of course we don't look at the stars with the naked eye anymore we use telescopes and already 100 years ago around 1900 astronomers had good telescopes and
they could see over a million stars now a million stars is a lot but it's still a comprehensible number it's about a bucket of sand and in fact uh those astronomers were pretty sure that that was it that there were about a million stars in the Universe um except for these funny smudges they kept seeing in their photographs and they called them spiral nebula and nobody knew what those were and it took a computer to figure out what those actually were a human computer called Henry at the lit because back then a computer was what
you called a woman doing calculations for scientists now lit was paid $10 a week to analyze photo phaps of stars and she was deaf but she had a very very good eye and she spotted a pattern in the brightness of stars that gave her a new way to actually figure out how far away stars were and she died of cancer very young but was able to publish her finding uh but uh couldn't see it applied and it was Edwin Hubble who later said that levit should have really won the Nobel Prize who used her method
to look at those spiral nebuli and what he found was that they were much much much further away millions of times further away than any anyone had ever thought in fact they were galaxies galaxies just like our Milk Way systems of hundreds of billions of stars and we now know that the visible Universe has hundreds of billions of galaxies so it's not just a bucket of sand it's not a million stars it's 7 * 10 to the power of 22 stars now again if each star was a grain of sand that would be all the
sand in all the deserts and beaches and sand boxes on Earth times 10,000 10,000 Wells of sand so in less than 100 years that's how much our understanding of the universe has grown from three teaspoons to 10,000 Wells of sand and actually it's even worse because Hubble showed that the universe is getting bigger and bigger all those galaxies are moving away from each other at tremendous speed so you may wonder how could we ever figure out what was going on and what what what where all those stars came from now fortunately Einstein came along and
and Einstein came up with a theory of relativity that says that space is really just distances between points and those distances change depending on what you have between those points he came up with equations that tell us how space itself changes when matter and energy move around in it and these equations work extremely well so well that all the phones uh in your phones use GPS which is based on Einstein's equations and Einstein's equations predicted an expanding unit universe and at first he thought uh he'd made a mistake but then he found out about Hubble's
Discovery and we now know that the Universe has been expanding for 13.8 billion years that means it actually started out very very small smaller than an atom and we call the moment the expansion started the Big Bang now we still don't know exactly what happened at the very instant of the Big Bang but thanks to Einstein we do know how the universe got to be so big and we know that little ripples tiny little ripples in that early Universe grew with the universe into seeds that became stars and galaxies so we do know where stars
came from now one of Einstein's equations had really big implications not just for big things but also for small things and that's his most famous equations E equals mc^ s what does it mean well e means energy m is mass and C squ is speed of FL squared light travels very very fast so c^ squ is an enormous number almost as big as the number of all the grains of sand in the world and that means that even the tiniest amount of matter even an atom has a tremendous amount of energy so let's talk about
atoms and let's talk about small things how small are atoms now if you remember that tremendous number of stars in the universe we have the same number of atoms in just three drops of water so it's quite amazing that we can understand them all and for a long time we thought atoms were the smallest thing there was but in 1898 Mary C discovered an element called radium and radium was constantly radiating so much energy that it couldn't possibly come from reactions between atoms and people got really excited about radium science fiction writer HD Wells thought
that it could be a source of infinite power for a utopian society some people got maybe a little bit too excited and too carried away and started putting radium in products like chocolate and face cream and and other things something we now know wouldn't wouldn't be a good idea now Mary C uh something a bit better she was able to use radium uh to treat cancer so she pioneered radiation therapy but she herself got exposed to so much radiation that she eventually died of anemia and even her cookbook to this day is harmfully radioactive but
she lived long enough to see what was really going on with radium and she suspected that there might be something going on inside atoms something that was converting matter into energy like Einstein's equation implied and she was right in 1911 Ernst rfo took some radium fired some of radium's radiation at a gold leaf very thin gold leaf and saw something really weird the atoms were behaving like there was something much smaller inside something compared to the size of the atom like a grain of sand in the middle of a football field and he had discovered
the nucleus the nucleus of an atom is made out of particles called protons and neutrons orbited by a cloud of electrons and to explain this structure of the atom scientists had to come up with a new Theory called quantum mechanics and quantum mechanics predicts that if you split the atom if you split the nucleus some matter will be converted into energy and that's what was going on with radium but ruford himself didn't think that atomic energy would be of any practical use he famously said that anyone who looks for a s source of power inside
an atom is talking absolute moonshine so of course there was a very stubborn Hungarian who decided that it had to be made to work and he was called Leo card and he was born right here in Budapest as a young man he did a lot of work with Einstein and they became close friends what did they work on quantum mechanics thermodynamics theoretical physics and they also invented a new type of fridge uh oldfashioned fridges used very poisonous gases and a family in Berlin died of of fumes coming coming from those gases and Einstein got really
upset about it and he was certain that there had be had to be a better way to build fridges so he asked seart for help to to invent a better one so they did um it was a genius design obviously um but uh too expensive and and too noisy to be actually practical but in the end they made some money by selling their patents to Electrolux but sard kept inventing and his next invention was something much much bigger in 1933 one morning in London he was crossing the street at this spot and just the moment
when the traffic light changed in a Flash he had a really beautiful and a really terrible idea and he called it the Chain Reaction if you could split just one atom that would release neutrons that would split more atoms that release more neutrons that would split more atoms and so on and so on you could make Atomic power work and you could also make a really terrible weapon and that's exactly what happened in Hiroshima and Nagasaki 12 years later now sard himself was horrified he spent the rest of his life campaigning against nuclear weapons and
he switched fields from physics to biology and the atomic bomb is a terrible thing it shows that there is a dark side to our understanding of the big in the small but actually that same understanding triggered an even bigger explosion that's still going on on today and the trigger for that explosion was this this is the first transistor it's a device about this big it was built by a team led by William shley in Bell labs in 1947 and what it is is the simplest building block of a digital computer it can store a zero
or a one and like the atomic bomb it's based on quantum mechanics in fact on equations worked out by another Hungarian uh called Eugene wigner who was one of zil Art's friends as well and wigner showed that there are some materials that can be made to sometimes conduct electricity and sometimes not so that gives you the one and zero and one of those materials is silicon and silicon is basically sand so we make transistors out of sand and we are now very very very very very good at it here's a modern transistor it's about 20
nanometers in size and to give you an idea of how small that is all the two billion transistors in an iPhone 6 can be made from just two grains of sand so in 1947 there was just one trans transistor today there are 3 * 10 to the power of 21 transistors that's thousand times all the sand grains in the world and in just in 10 years there will be more transistors than there are stars in the known universe so we really have started another big bang now think about that for a minute that's a number
that applies not to atoms but machines that we have made what does it mean it means we can see things that we could never see before the Henry at the lits of today don't have to do it all by hand computers are storing data and analyzing it for us and just like telescopes revealed a much much much bigger Universe computers are revealing a world that is much more complex than we thought and that world is around us and inside us let me give you an example this is a human skin cell so it looks pretty
complicated but thanks to computers we can now read the code that runs it we can read its DNA and for a long time scientists thought that only about 2% of that DNA did anything useful and the rest was junk but recently we got much better at reading DNA and now we know that that 98% is actually the control system for the cell so in just a few years we found out that the cell is actually at least 50 times more complex than we thought now to give you an idea of what how big a leap
that is let's think about it in terms of computer programs a small iPhone app like like Candy Crush is about 50,000 lines of code so what 50 times more code give you it would give you the control system for cern's large hadrin collider the most complicated science instrument in the world so basically we thought a cell was like Candy Crush but it turns out to be more like the large hatn collider in terms of complexity so that means it's much harder to fix if something goes wrong so it's no wonder that we are really far
still from curing cancer and maybe that's because we've been looking at that 2% we thought we understood and to fix that we really need to tackle the cell's full complexity it's not just that we're just using transistors to discover complexity we're using them to build complexity we're putting them in every single device we build and connec them all together now look at the internet in 1977 and then look at it in 2007 it's like a chain reaction the more complex things we built the more complex things they allow us to build and now our transport
networks our financial systems our energy systems are much much more complex than ever before and there's a problem with that because very complex systems can become fragile adding a single grain of sand to a sand pile can trigger an avalanche and those Avalanches are happening faster and faster we're all familiar with 2008 financial crisis but in 2010 competing trading algorithms got locked into a feedback loop that created a trillion dollar stock market crash in 45 seconds was called the flash crash of 2:45 p.m. connections also mean that problems spread very very quickly three billion people
fly every year and that means that the next pandemic we're going to have is going to be truly Global in a very complex system you can also get cascading failures one thing failing after another this is the electricity grid of India and in 2012 just one power line being overloaded crashed the entire grid and left 600 million people without power for 3 days and sometimes connections can be very very hard to see imagine a forest fire in Russia what does it have to do with the Arab Spring well forest fires in Russia led to the
a grain export ban which caused massive Financial speculation on food prices which caused food riots in North Africa and ultimately to people deciding they finally had enough our most difficult problem s like climate change involve both the complexity of Nature and the complexity we're creating to fix CL climate change we need to understand Finance we need to understand energy we need need to understand soil and biology and the atmosphere and and the oceans and Quantum Mechanics for carbon and light all of those things at the same time so we live in a world where most
of what we think we know is wrong small things breaking means that big things break and when things break they break very quickly everything is connected and we can't see those connections and to understand anything you have to understand everything so that's a little bit scary but there's no reason to Panic it's actually also quite exciting for for me looking at all these complexity is like looking at those Stars again and that's why I did what SAR did and switched from physics to biology there are amazing New Opportunities if we can learn to live with
complexity and I think we can and actually we now have the means to make a lot of things much simpler a lot of our systems like finance and energy are fragile because they have Central nodes like Banks and power plants that are connected to everything else so what if we took those away think about Technologies like solar power or Tesla's power wall again both powered by transistors maybe we can have power systems that are much less centralized and much more resilient we might be able to do the same thing for finance Bitcoin is an example
of a platform that allows to have trusted transactions without a central Authority like a bank that verifies them but what about the complexity of nature now cancer and climate change are so difficult problem that they might be too much even for an Einstein but what about a million Einstein all working together where could we find those Einstein well the chances are that a lot of those Einstein are now playing computer games and just all the hours spent on playing Angry Birds actually would translate into 12 wikipedias every year and actually the best way to find
the shape of a biological molecule is already a computer game called folded with 15 million players there are other platforms like that like Z universe that mean that anyone can now try to find cancer mutations or new kinds of galaxies in huge sets of data and we might even be able to apply that approach to politics Iceland recently tried to crowdsource the drafting of the Constitution via social media now you might think that was a terrible idea but actually worked out quite well uh so there there are ways to make democracy more transparent and have
more brains working on problems that no single politician could ever understand it may be that we have to give up some ideas about systems that we have like the fact that we we may not need to be able to understand them nature evolves systems without understanding them that might my company Helix Nano we're trying to build molecular machines that make writing genetic code easier using machines that we've evolved in a test tube and not designed so in a way we can tackle complexity by accepting it and embracing it and maybe ultimately the systems we build
will merge with the systems of nature until we can no longer tell where one ends and one begins Einstein said that things should be as simple as possible but no simpler and that's a good rule for us to follow both as a species and in our lives so let's Embrace complexity where we must but find Simplicity where we can and this is a thought I'd like to leave you with there's a name for the time in our lives where everything we think we know turns out to be wrong where everything is too complex everything is
too overwhelming and we don't know what to do and it's called growing up and that's when our adventures really begin thank you very much [Music] [Applause]
