Summer Science Fair

At the end of most science conferences there is a strange ritual known as the poster display (this is inferred from my grand total conference attendances of one). This surreal session involves everyone wandering around a selection of research summaries, cup of tea in hand, pretending to understand what each display says. The posters are usually filled with bold titles, questionable colour choices and incomprehensible words. And much the same could be said of the scientists reading them.

And it is this realm of incomprehensible research and monotonous graphs that I expected as I walked into the Royal Society’s Summer Science exhibition in Piccadilly today. Instead, the scientists put on a sublime show that was both interesting and accessible to anyone.

The first thing that strikes you, as you walk into the exhibition, is not the displays themselves but the people standing with them. Before you even have a chance to read the exhibit's title, an enthusiastic scientist has rushed over to you and explained the intricacies of a butterfly’s wing or the earth’s aurora. And they all do so in such an understandable way, with the help of great hands-on demonstrations that allow you to ‘play’ with science.

By the end of the first room I have poured ethanol onto a butterfly’s wing to watch how the iridescent colours change, played scalectrics to show how traffic lights might sense cars before they arrive and rubbed a metal plate to see how much static is generated. All in the name of science.

As I leave I have collected a top-trumps pack of physicists, more pencils than I can shake a... well, a pencil at and a great deal of knowledge about physics, maths, biology and engineering. And all this with no sign of the invisible barrier that I found myself behind in the conference poster session. (I'm also thankful to say the garish colour schemes and umpteen scientific terms had disappeared too) I'm sure that places like the Summer Science Fair will help inspire everyone, children especially, to think about science in a new light and, with any luck, get more people into science degrees.

How to win the Nobel Prize in Physics.

The discovery of graphene has for many years been heralded by engineers as the start of a technological revolution. These single-atom thick sheets of carbon could improve everything from the detection of gas molecules in sensors to the transistors and electrodes in the smallest electrical circuits. It is this expectation that led the team that discovered it to receive the 2010 Nobel prize for physics. But what exactly is graphene?

Well, graphene is a two dimensional plane of carbon atoms, with each one bonded to three others in a honeycomb pattern. In graphite, the familiar form of carbon that is found in most pencils, these honeycomb sheets of graphene are stacked up thousands of layers thick. Unusually for a non-metal, graphite is able to conduct electricity due to so-called pi-bonds between each plane, and it is this that means graphene is a perfect component in electrical circuits. Graphene can be produced in the lab by peeling single-atom-thick layers of graphite away from thicker sections.

While this may sound like a complex process, a member of Andre Geim’s award-winning team that discovered graphene helped me produce this revolutionary material... with just sticky tape and graphite. But a Nobel Prize cannot be that simple can it? ‘Yes’, he says. ‘Finding out how to make graphene was the hard part - once we had the material, discovering its properties and how it behaved was a pretty simple process.’

So despite an origin that would be more at home in a stationary cupboard than a world-class laboratory, graphene will almost certainly have a big part to play in future technology. So if, like me, you would also quite like the Nobel Prize in physics, remember that sometimes it’s not always the complicated methods that get results. 

Why The Universe Isn't Green

Despite how it may seem, our night sky is not a black canvas. If we stare at the stars long enough, our eyes adjust to the gloom and more and more stars appear as if from nowhere. If our eyes were sensitive enough, like the Hubble’s huge camera, we would see a view filled with bright stars, vast clouds of gas and incredibly distant galaxies. Every single patch of the universe our eyes could resolve would be burning with light. But this leads to the question: what colour is our universe?

The light from a star begins in nuclear reactions in the stars core, usually where hydrogen is fused to larger helium atoms. The particles of light, known as photons, that are released may take millions of years to tunnel their way to the surface, as they bounce around between densely-packed atoms within the star. When they escape, they give the star a distinctive colour that depends on the amount of energy being released across each square meter of its surface. The coolest stars glow red-hot, like a horseshoe fresh from a blacksmith’s furnace. Hotter stars produce colour across the entire visible spectrum of light and glow white-hot, like Tungsten light bulbs. Some of the biggest stars in the universe are so incredibly hot that they glow blue.

But there is no such thing as a green star. No matter how deep you stare into the universe, none will have the green hue we are so used to here on Earth. This is not some sort of cosmic coincidence, but is instead due to how the eyes of animals have evolved over millions of years. As everyone knows from school biology, all plants use a molecule called chlorophyll to convert energy from sunlight into sugars and important carbohydrates. This one molecule forms the pillar on which all complex life feeds upon; be it tiny insects or docile jellyfish, deadly snakes or intelligent apes.

Chlorophyll is a fussy molecule. Of the whole spectrum of colours (which extends far beyond the tiny part we can see), chlorophyll only uses two specific blocks of light: red and blue. In between these two broad regions of light is a tiny segment of the rainbow that photosynthesis cannot use. All plant leaves and algal cells reflect this narrow band of light, each in a slightly different way. This is what we see as green, and over millions of years our eyesight has become incredibly accurate at viewing it. And when the difference between a good meal and being poisoned is the tiniest change in the shade of green, it is easy to see why.

But physics could not care less about how human eyes are built. All stars glow across a broad range of light – the white that we see in most stars is due to the light of the whole rainbow being squashed together. However, the green colour our eyes are focused on is far too narrow to be seen in stars. So, while the earth may be teeming with turquoise, emerald and olive greens, the universe itself is, astonishingly, purple.