Science and Magic

Outrageous? Blasphemy? Hillarious?

Well, whatever you may think, I have believed for several years that science and magic are connected. You may want to call me a madman, but I am a student of science discipline myself; so I know what I am talking about, which makes me sane! There are many examples, many of them self-realised that can justify my claim. But I am a little too tired right now to go into a duel with you over our philosophies. And yet, I can not resist it. I can not resist telling you this story.

I have read many stories about stones. You might have, too. There is this one story that I remember with all the details: The Moonstone; its the first detective story in english written by Wilkie Collins, in which the moonstone is associated with ill-fate in the hands of a mortal. There are many more stories in which precious stones are associated with sorcery. This is one such story. However the stone involved is not a well known precious stone such as a moonstone or a diamond or an emerald.

It began almost eight years back, on the day of my thirteenth birthday. I remember it so well, partly because of the following story and partly because the birthday fell on a 13th with a particularly bright yellow full moon. I have this rather immature fascination for trinkets and ornaments. The odd ones especially. I am allergic to gold, but all other metals suit me well. That day, I had been to a jewellery store and the moment I entered, my eyes were set on a beautiful iridescent Opal. Nobody else seems to be interested in it at all. But then again not many share such a liking for odd trinkets! So I decided to buy it; it was costly, but not as much as the stone is worth which I came to know only later. Had any one known its true value, it would not have been on sale in the first place. How it ended up in the jewellery store and later around my neck is a mystery I am yet to solve till date. So far so good.
That night (oh, I am definitely not divulging the details of the party; thats for private listening) my life took such a dramatic change, I am still recovering from the effects, even as I am writing this article. (You must be thinking, I am writing this out of delirium, a side effect of that dramatic change. I know what you are thinking and your sarcasm hurts me!) I was taking a stroll in my garden, watching the bats flit by, listening to the cicadas' haywired chello orchestra, when all of a sudden the illusion broke down. Oh, I forgot to mention, this optical physicality that you see and force your brains to experience is an illusion and I dont want to argue trying to describe reality to someone who is so used to this illusion. So when the illusion broke down, I was in a secluded place. Everything was so different. Dynamic! The shape of the stones and boulders changed all the time. The ground under my feet itself was moving; grumbling rather. For a long time I stood trying to understand when an old woman appeared. She said, "Stop moulding your thoughts so much. You are wasting your energy!". That shocked me so much, I was thoughtless for a brief moment and during that time, everything around was still and I realised that the reality took the shape of my thoughts. Far fetched, eh? Does not matter. That is not the point of the story anyway. We, myself and the old woman, started talking and she explained to me what happened and that explanation is the point of the story.

If you have been reading carefully, I mentioned earlier that this story is not about diamonds and emeralds. I also mentioned that stones are associated with magic. I also mentioned about opal. I take it that you all have drawn your obvious conclusions. Yes, not all stones are associated with sorcery. Diamonds and emeralds are kept in the King's treasury. Wizards and witches carry opals and other stones. Whats so special about opals and those other stones? They are naturally occuring "photonic crystals".
Photonic crystals are optical equivalents of semiconductor electronic devices like diodes and transistors. Just like transistors are used to route a stream of electrons to desired locations in desired amounts, photonic crystals can be used to control stream of photons. While the speed of electrons depend on the voltage under which they accelerate, the speed of photons is .. well, you know. Needless to say, replacing the billions of transistors with an equivalent circuit made of photonic crystals (and using a photon source) will increase the speed of processing of a computer, for that matter, any electronic device. Since light is the fastest travelling entity known to muggle (non-magical) folk, this transformation is like achieving the pinnacle of a technology. But ofcourse, there are difficulties in implementing this. To understand them, it is essential to understand what photonic crystals really are.
The easiest way to understand the behaviour of light in a photonic crystal is to compare it to the movement of electrons and holes in a semiconductor. In a silicon crystal, for example, the atoms are arranged in a diamond-lattice structure, and electrons moving through this lattice experience a periodic potential as they interact with the silicon nuclei via the Coulomb force. This interaction results in the formation of allowed and forbidden energy states. Consider photons moving through a block of transparent dielectric material that contains a number of tiny air holes arranged in a lattice pattern. The photons will pass through regions of high refractive index - the dielectric - interspersed with regions of low refractive index - the air holes. To a photon, this contrast in refractive index looks just like the periodic potential that an electron experiences travelling through a silicon crystal. Indeed, if there is large contrast in refractive index between the two regions then most of the light will be confined either within the dielectric material or the air holes. This confinement results in the formation of allowed energy regions separated by a forbidden region - the so-called photonic band gap. Since the wavelength of the photons is inversely proportional to their energy, the patterned dielectric material will block light with wavelengths in the photonic band gap, while allowing other wavelengths to pass freely. We can also have a different dielectric material in place of air holes. By tweaking the parameters of the dielectric materials, such as the refractive index, the size and periodicity of the material, we can control the device. And just like doping introduces new energy levels in band gap in semiconductors, breaking the periodicty by changing size of the interspersed air holes introduces new levels in photonic band gap.

So why don't we have photo-chip fabs and opto-electro computers? (Don't mind those fancy names) The problem is the lattice spacing. A rough estimate of the lattice spacing is the wavelength. In case of the semiconductor devices, the electron wavelength and for photonic crystals its the electromagnetic wavelength (divided by the refractive index of the material, ofcourse). Now, you realise difference. The problem in making small structures is compounded because it is more favourable for a photonic band gap to form in dielectrics with a high refractive index, which reduces the size of the lattice spacing even further. For example, suppose we wanted to create a photonic crystal that could trap near-infrared light with a wavelength of 1 µm in a material with a refractive index of 3.0. We would have to create a structure in which the air holes were separated by about 0.3 µm - an extremely difficult task. If the scale was 1000 times smaller, we could build the structure atom-by-atom using a chemical reaction; and if it was 1000 times larger we could build the structure mechanically.

In 1991, Eli Yablonovitch and co-workers at Bell Communications Research in New Jersey produced the first photonic crystal by mechanically drilling holes a millimetre in diameter into a block of material with a refractive index of 3.6. The material, which became known as "Yablonovite", prevented microwaves from propagating in any direction - in other words, it exhibited a 3-D photonic band gap. Other structures that have band gaps at microwave and radio frequencies are currently being used to make antennae that direct radiation away from the heads of mobile-phone users.

So much for an introduction to photonic crystals. Opal is a naturally occuring photonic crystal. The very reason behind the iridescence of Opal is because its a photonic crystal, unlike diamonds which sparkle because of cut edges that reflect light totally internally. Apparently the opal around my neck had the optical signal that is the key to the real world out there. Thats how I ended up talking to the old woman. She told me how they exploited the applicability of these crystals to store energy. That is how iridescent stones became essential to using magic. They use the stored electromagnetic energy to do that spooky action at a distance. Thats a simple way of explaining things. Oh for those who of you who did not know, the word magic is derived from the root mage (I have an unsual interest in etymology, too; very essential for mages). Rings a bell?? Image! Imagination. Magic is science raised to its zenith with the help of imagination. Afterall, did not Albert say, "Imagination is more powerful than knowledge"!

Jade.