"Only A Theory..."

“Ah, but it’s only a theory” they say. Or maybe “Science can never truly prove anything”. I must have heard this countless times, and every time I hear it I feel my fists begin to clench and my blood begin to boil. How can people that live life so dependent on scientific ideas be so obtuse about their validity?

"Turtles all the way down". 

Let’s start with an easy example. The Earth is not flat. You notice I used the word is, rather than saying ‘our best theory is that…’ and that would be because THE EARTH IS NOT FLAT.  Neither is it, as the old lady said to Richard Feynmann "Turtles all the way down". The first recorded measurements of our earths shape were performed by Eratosthenes in around 250BC by using the shadows in wells on the summer solstice. Since then we have built greatly upon this measurement. If that measurement was a cornerstone of science, we now tower so high over the landscape below we are lost in the clouds. We know the Earths radius to within a few centimetres. Satellites orbit the planet every hour, feeding back data from every square inch of this orb we live on. We know the orbits of the other planets well enough to predict exactly where any one of them will be millions of years into the future. We have built communication systems that encircle the globe and explored every last patch of land or puddle of ocean.

Not one observation in 2300 years suggests that we live on a flat earth. It would take an incredibly self-centred view of the universe not to believe the volumes of evidence we have as fact.

But what about a great paradigm shift? Does it not topple the ivory tower in which we scientists inhabit? The best example is the shift from Newton’s laws of gravity to Einstein’s in 1918. For many years, the laws of gravity Newton developed matched the observations of the moon, the planets and objects on Earth perfectly.  However, not until science had developed much further did Newton’s laws begin to become a bit frayed at the edges. Mercury’s orbit, for example, was slightly wrong. But this anomaly did not destroy gravity. Apples still fell from trees, moons still orbited planets. And in 1918 Einstein came along and described gravity in perfect detail once again. As astronomy progressed, our view of the universe sharpened and we were able to view more detail. If Eratosthenes started off with a vague, unfocused image of what the universe is like, we now have a wonderfully clear picture, with infinitely more detail and infinitely more beauty.

What is clear is that there is such a thing as a science fact. We have proved beyond all doubt that the earth is round. We know that gravity pulls two masses together. So much evidence exists from the natural world that we can say with all certainty that organisms do evolve by natural selection. Science itself evolves by natural selection; those ideas that are proven to be right by a great wealth of evidence are added to our combined knowledge of the universe. Those ideas that are proved to be wrong are discarded.

Not all science is as clear cut: fringe hypotheses may be put forward, developed upon and then found to be wrong. But science is always rooted in observations of the real world. No paradigm shift can ever occur that will wipe hundreds of years of science away. If a few blocks fall from the pinnacle here and there, so be it. As long as science is still valued, our knowledge will continue to grow like a tree reaching for the sun.

The Sagan Series

I am unfortunate to have not been born when Carl Sagan put his voice to the Cosmos series in 1980. I watched the first series for the first time only recently and, despite it being over thirty years old, it is still a breathtaking voyage through human history, exploration and ingenuity. And even today, scientists can be heard still singing with praise for what was one of the most-watched science shows on the globe. When the great american astronomer passed away in 1996, the world lost one of its most important thinkers. 

So I was astounded to watch a newly made video with Sagan's characteristically calm voice over the top. NASA [EDIT: actually its this guy], using snippets of previously-recorded audio material and hundreds of high-definition videos, have put together a series of short films based on Carl Sagan's wonderful thoughts. They are simply awe-inspiring. Throughout all eight parts, the hairs on my skin were lifted in sheer joy. Just as Cosmos did before, this series has the power to inspire another generation of school-children into science.

But don't take my word for it. Just watch...

Quantum Immortality

Could we all live forever thanks to the twisted world of quantum mechanics? As crack-pot theories go, this one is an eye-opener. Let me explain how it works...

Everybody has heard of the famous Schrodinger's Cat thought experiment. Put a cat inside a sealed box with a vial of poisonous gas that will only be released if a radioactive atom spontaneously decays. While our feline friend is in the box, it exists in a superposition of states - both alive and dead at the same time. Despite its strangeness, this experiment underlies much of the theory of quantum mechanics. And, while it would be wonderful to say that quantum mechanics is just another crack-pot theory, it has been experimentally proven dozens of times. Hugh Everett III took the Schrodinger's Cat experiment one step further and suggested that, instead of being both dead and alive in the same universe, the universe splits into two allowing one reality in which the cat survives, and one in which it doesn't.

So, how does a cat in a box make you immortal? Well, to answer that, we must look at the point of view of the cat. We don't have to get down on hands and knees and purr to do this; lets just replace Schrodinger's poor pet with you. Now, when the box is closed and the experiment set up, quantum mechanics says you will go into a superposition of states, in one of which you are dead. However, we humans are observers - we cannot exist as both dead and alive at the same time. This means we have to always take the path (or, according to Hugh Everett, the universe) in which we survive. Unfortunately human aging does not involve statistical choices like the lives of atoms. But maybe it's possible that this strange quirk of quantum mechanics explains why you or I have not yet stumbled into the path of an oncoming bus. I would certainly not bet my life on it.

In defense of Astronomy

In modern society we take the night sky for granted. Astronomy is thought of as a fool’s errand (or worse, a nerd's errand) with no commercial benefit. But since the dawn of human curiosity, the three thousand stars visible to the naked eye have inspired great literature, art and science. The phases of Venus and the moons of Jupiter helped show that we live in a universe not centred on the Earth. The pirouetting motion of the moon around the Earth and the Earth around the Sun led inexorably to the idea of gravity. The observation of light from distant galaxies tore down the eternal notion of the universe and gave it a start date. All this from sitting on the ground, observing the sky above.

The thick clouds of Venus (nasa data centre)

 
But imagine, if it is possible, a world enshrouded by impenetrable clouds; with nights remarkable only for their lack of daylight. These planets do exist. Far above Venus’s highest peaks exists a thick sulphuric acid cloud layer that scatters all light away. Titan, Saturn’s largest moon, is also covered by haze, this time created by hydrocarbon molecules such as ethane. Even the Earth has its own layer – if human eyes were adjusted to a wavelength around 1mm we would see a star-consuming haze above caused by atmospheric water.

So, how would humanity have developed if the night sky was devoid of the features we take for granted now? It seems certain that humanity’s perception of our place in the universe would change - lives will be played out in two dimensions, as if sandwiched between two sheets of paper. In this parallel reality, the world would probably be thought of as flat until the time of global exploration.

Even if the study of mathematics, thermodynamics, electricity and magnetism continued, without observations of the other planets, the system of an Earth-centred universe may well have persisted. The idea of gravity would also be a relative late-comer, developed only after the force theories of electricity and magnetism. Not only would the theories of physics be different, but so would any notion of how our world formed. Only through observing our own solar system (and others) have we theorised how our planet and the seven other planets around our sun were formed. Without the night sky to prove this, ancient creation myths will have endured.

However, suppose this hypothetical civilisation reached a technological age. Having lived under cloudy starless skies for an eternity, picture the moment when the first ever rocket to carry humans above the thick hazy atmosphere arrived. Until pictures could be taken and developed, the stories of those first few astronauts would almost certainly be met with disbelief. After this eureka moment, the perceptual shift would be incomprehensible. Where before there was nothing but grey haze above, there was suddenly a universe teeming with stars. Planets circle in eccentric orbits around a great shining ball of fire at the centre of the solar system. Galaxies spin millions of light-years away containing a hundred billion suns. And this is what we get to see. Every night. The most amazing thing is that no one seems to realise how lucky we are.

Another Earth?

A few years ago, during the course of a pre-university preparation week, I took part in an Arts vs Sciences debate. (I say 'took part', I was one of the 90% that, never having debated before, stood at the back trying to avoid participation of any sort). But during the course of this petty intellectual squabble one argument stands out in my mind:.
"Art simply poses questions. It is up to science to answer them."
     I think the reason this stuck in my memory like gum to a shoe was because I was so opposed to it. When, I thought, has art ever given science a helpful push in the right direction? Was it only with John Milton's Paradise Lost that Newton could invent his law of gravitation? Did Picasso's 'Blue period' inspire Einstein to create the special theory of relativity. Could Stanley Kubrick's 2001: A Space Odyssey have led to our knowledge of black holes. The answer, to me, seemed to be a resounding No. Art kept to its corner of society, science kept to ours.

But today a piece of art set my mind rolling along avenues usually reserved for scientific thinking. The inceptive art piece was a trailer for an independent movie released in October called 'Another Earth'. The plot is set around the fantastical premise that a second planet Earth has appeared in the solar system, and on it is contained a carbon copy of all human life, including ourselves. Ok, so at first the idea of a planet cloning itself seems a little wacky, and I would completely agree. But it led me to think -how impossible would it be for two habitable planets, orbiting each other to circle a star such as our sun? Could there be a planetary system, somewhere, with two Earths?

Many bodies in the universe orbit each other in binary partnerships. Most stars are thought to have stellar companions formed when gas collapsed under their own gravity. Some of these binary systems such as Mizar and Acrux can be seen on clear nights. A handful of asteroids have been found that orbit each other as they slowly move about the sun. The dwarf planet Pluto and its large moon Charon are also often called a double planet system. This is because Charon, weighing in at one ninth of the mass of Pluto, orbits a combined centre of mass that lies between it and Pluto. But how about Earth-sized bodies?

Just like in art, original ideas are hard to come by in science - often it seems like everything interesting has been done. However, despite many discovered binary systems, a quick journal search for binary planet formation shows almost no results! Exploring whether these equal-mass double-planet systems are possible would not only be incredibly interesting, but also could become testable as more and more exoplanets are discovered. In fact, the detection of a binary exoplanet might even put to rest one of the longest standing arguments in planetary science - whether large, Jupiter-like planets formed by gravitational instabilities (which, being similar to star formation, might create binary systems) or by accretion (which wouldn't). They might also help explain why planets have been found wandering freely through the galaxy, as it might be easier for binary planets to destabilise and be thrown from the solar systems.  'Three-body problems' are extremely complex, however, and the interaction of the sun and with other large planets may make such systems impossible.

Despite my previous opposition, bouncing scientific ideas off art can generate interesting and unproven results. So maybe, just maybe, art has a use after all...

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.

Paradox

Curiosity is an instinctive thirst for knowledge that we all have, whether we know it or not. Some people say we lose our desire for knowledge after childhood, but only by asking questions can we learn more about the world around us.


Often the questions our curiosity leads us to have no logical reason for being answered - such as about distant stars or the tiniest particles. But that does not make them insignificant. By attempting to understand the world around us, no matter how trivial, we add beauty to the world. The great physicist (and even better quote mine) Albert Einstein once said that the important thing is not to stop questioning. Curiosity has its own reason for existing. One cannot help but be in awe when he contemplates the mysteries of eternity, of life, of the marvelous structure of reality. It is enough if one tries merely to comprehend a little of this mystery every day.


The truth is that curiosity can never be cured. It is a beautiful parasite on the human species; only by feeding our curiosity with scraps of information can our minds grow.