Full text of physicist Prof Russell Cowburn’s talk: ‘Nanotechnology, Creation and God’ at TEDxStHelier conference.
Listen to the MP3 Audio here:
Prof Russell Cowburn – Physicist
I’ve got two ideas I’d like to challenge you with, this morning. Two new ideas. The first is really about how small can we go in science and engineering? And to that end, I’d like to introduce you to the world of nanotechnology. So, both; what is nanotechnology and what’s exciting about nanotechnology?
I’ve been a professional scientist for about 25 years. You may be surprised to know I’ve also been a Christian for 25 years. And so, the second thing I’d like to challenge your thinking about, this morning, is your expectation of what a scientist might think about God.
And so, to that end, having told you about nanotechnology, I then want to ask what does God think about nanotechnology?
Okay, so, what is nanotech? Well, if you think of a size scale, we all know what a meter is. That’s you and me. If we go down a factor of a thousand to a millimeter, again, you still you know what a millimeter is. There’s a paperclip.
If we then go down another factor of 20 or 30, we get to the diameter of a human hair, and that picture there shows you a pinhead with a human hair across it and actually a dust mite, that’s the little pink thing in in the picture.
If we go down a little bit further to a length scale of around 10 microns, where a micron is a millionth of a meter, we get to the individual red blood cells that flow around your body.
Now, let’s go all the way to the bottom of that scale and to the smallest thing we can imagine, which would be a single atom. On this scale, a single atom is 0.1 of a nanometer, where a nanometer is a thousand millionth of a meter. So, a European billionth of a meter.
Nanotechnology is everything that lies in that gap. So, it’s everything that is bigger than a single atom, going up to about a hundred nanometers or so.
And just to give you a little flavor of why we might want to explore in that particular size range, let me just show you a little picture of some of the very early work to come out of IBM on nanotechnology.
They made an abacus but instead of make using wooden beads and a metal pole to make the abacus, they used single atoms and to count from one to ten, they moved the atoms along bit by bit and spelled out the number just like a Chinese counting machine.
Let’s just talk some of the… about some of the techniques of nanotechnology. How is it possible to make things and to see things and manipulate things on such a small scale? Well, one of the most important techniques is called the atomic force microscope, and it’s primarily a microscope but it sees things in the same way that a blind person reads Braille.
So, we make a very, very sharp tip, something which is almost atomically sharp and then we scrape it across a surface and as that very sharp tip goes over the lumps and bumps of the surface, the cantilever that it’s attached to goes up and down just by a very small amount and by bouncing a laser beam off the back of that cantilever, we can actually measure those very small deflections, and from that we can map out the surface with near atomic resolution.
There’s a sister technique to this called scanning tunneling microscopy, which uses a very similar method, and together they allow us to see and to move individual atoms. There’s just an example. This is what you get if you look at a piece of silicon under one of these microscopes. You actually see the individual silicon atoms making these pretty rings on the top surface.
So, the atomic force microscope is both our eyes and our hands for the nano scale. Now, one of the ironies about nanotechnology is that the smaller you go, the bigger the machines you need in order to make stuff. So, my lab in Cambridge is full of enormous stainless steel vacuum chambers and their main purpose is to get rid of any air. We need to work at extremely high levels of vacuum. In some cases, levels that are as clean as outer space, because while you’re making such small things, if even a single air molecule comes along and hits it, it’ll be destroyed.
And so, we need to work inside these pristine environments that have got no influence at all from air. So, those are the some of the techniques.
Let me just share briefly with you some of the materials of nanotechnology. Now, carbon has been very good to us in the nanotech world. When I was at school, I was taught that carbon comes in different forms. It comes in graphite, it comes in diamond.
Well, if we were studying these things today, we would add three other forms of carbon, thanks to what we’ve learnt in nanotech. So, this carbon 60. Now, which a little footballs of 60 carbon atoms arranged as little molecule. The reason this picture shows you stars in the background is that it was actually first discovered in outer space. So, long before we started to make it on earth, astronomers with telescopes could see that it existed out in the stars.
Another form of nano scale carbon is what we call the carbon nanotube, and that’s a little tube of carbon atoms. And if you then take one of those tubes and cut it down the back and fold it out into a sheet, you then get something called graphene, which is a single layer of carbon atoms. And you might think that’s a very fragile thing, especially given what I’ve told you about needing to remove all the air in case that destroys it.
In fact, graphene, relative to its size, is the world’s strongest material. And so, there are some big surprises in the nano scale.
So, why do we bother? We spend a lot of time and effort in trying to go so small. Why do we go small? What’s so great about being small? Well, there’s what we call the Nano advantage. And quite simply, the properties of materials, the laws of science, if you like, are different for such small objects and this is really important. This is not just about miniaturization in order to make things smaller for the sake of it, it’s because by going small, we can do things that have no counterpart in the larger scale. We can get new properties, new physics, new chemistry, that only exists in this new nano world.
And then most importantly, hopefully, we can use these new properties, this new science to build better, cheaper, smarter, cleaner products. It’s all about being useful with the new science that you get when you go small.
Let me give you a few examples. So, if we went back to the 1940s, this is what a transistor looked like. This was the first transistor and it was about that big.
Scroll forward to the 21st century, and this is what a transistor looks like. Similar principle but instead of being that big, it’s 65 nanometers across. Consequently, in a space of this, instead of getting one transistor, I can get billions of transistors and that means that your phone or your tablet or your laptop can begin to interact with you in a way which is more intuitive, which is easier to operate, is smarter, because it’s got all of these transistors to help it think.