Full transcript of British complex systems theorist Hannah Fry’s TEDx Talk: Is Life Really That Complex? at TEDxUCL conference.
Listen to the MP3 Audio here: Is life really that complex by Hannah Fry at TEDxUCL
Hannah Fry – British complex systems theorist
Okay, thank you very much. I’m Hannah Fry, the badass, and today I’m asking the question: Is life really that complex?
Now, I’ve only got 9 minutes to provide you with an answer. So, what I’ve done is split this neatly into two parts: Part one – Yes, and later on, part two – No, or, to be more accurate: No?
Okay, so first of all let me try and define what I mean by complex. Now I could give you a host of formal definitions, but, in the simplest terms, any problem and complexity is something that Einstein and his peers can’t do.
So, let’s imagine — if the clicker works, there we go — Einstein is playing the game of snooker. He’s a clever chap, so he knows that when he hits the cue ball he could write you an equation and tell you exactly where the red ball is going to hit the sides, how fast it’s going and where it’s going to end up.
Now, if you scale these snooker balls up to the size of the solar system, Einstein can still help you. Sure, the physics changes, but, if you wanted to know about the path of the Earth around the Sun, Einstein could write you an equation telling you exactly where both objects are at any point in time.
Now, with a surprising increase in difficulty Einstein could include the Moon in his calculations, but, as you add more and more planets, Mars and Jupiter, say, the problem gets too tough for Einstein to solve with a pen and paper.
Now, strangely if instead of having a handful of planets you had millions of objects, or even billions, the problem actually becomes much simpler and Einstein is back in the game.
So let me explain what I mean by this, by scaling these objects back down to a molecular level. Now if you wanted to trace the erratic path of an individual air molecule you’d have absolutely no hope, but when you have millions of air molecules all together they start to act in a way which is quantifiable, predictable and well behaved, and, thank Goodness, air is well behaved because if it wasn’t, planes would fall out of the sky.
Now, on an even bigger scale, across the whole of the world, the idea is exactly the same with all of these air molecules. It’s true that you can’t take an individual rain droplet and say where it’s come from, where it’s going to end up but you can say with pretty good certainty whether it’s going to be cloudy tomorrow. So, that’s it. In Einstein’s time this is how far science had got. We could do really small problems with a few objects, with simple interactions, or you could do huge problems with millions of objects and simple interactions.
But what about everything in the middle? Well, just seven years before Einstein’s death, an American scientist called Warren Weaver made exactly this point. He said that scientific methodology has gone from one extreme to another leaving out an untouched great middle region. Now, this middle region is where complexity science lies and this is what I mean by complex.
Now, unfortunately, almost every single problem you can think of to do with human behavior lies in this middle region. Einstein’s got absolutely no idea how to model the movement of a crowd, there are too many people to look at them all individually and too few to treat them as a gas.