Perpetual Ocean

The opening exhibit of a new show at the British Library about displays of scientific data, Beautiful Science, is an animated film depicting the world's oceans and the thousands of currents that drift and swirl across them. Perpetual Ocean, made by Nasa, is less beautiful than it is mesmerising: in three minutes the film shows the surface currents of the oceans over a two-and-a-half year period, from June 2005 to December 2007. There's a no less mesmerising 20-minute version too.

You can forget any notions you might have about currents moving simply from west to east or from A to B. The films shows how an ocean current is made up of countless others, one slipping into another, and as Nasa depicts them you could liken their overall effect to a molten Van Gogh. Having watched the film, you can't fail to recognise how hard it will be to come across the floating debris from the Malaysia Airlines plane that crashed on 7 March.

In The Fatal Shore, Robert Hughes wrote about the scale of the Indian Ocean, and imagined what the first convicts on their way to Australia would have made of it all:

The modern traveller, gazing down on the wrinkles of the earth's waters from an armchair six miles up, has no conception of the forbidding grandeur of the sea into which the First Fleet now moved. Its waves are the largest of any of the world's oceans, and from the deck of a boat they are overwhelming.

Last year, Fred Johnstone was a crew member aboard CV27 Team Garmin, one of boats taking part in the Clipper Round the World Race. The third leg is from Cape Town across the Indian Ocean to Albany, on the south coast of Western Australia. Johnstone wrote about it in his log:

One thing I really did notice about the Indian Ocean was the water. It was warm and actually quite pleasant. Let me give you an idea: I would wake up from a dreamless sleep by someone shaking me and saying, 'Fred, it's your shift.' I would pull on my boots, I would then pull on my water proofs, and then make my way outside. Once there, the wind would hit me on the face making me shiver and my hands would slip over cold, wet surfaces – if I wasn't already awake, now I was. I should also say that all this took place at a 40-degree angle. I would then climb up to the high side of the deck, and wait while the rest of my watch scrambled to join me. Then someone would pass a biscuit tin around, or someone would have some left over supper from last night and share it out. Inevitably, a wave would crash over us. On the Atlantic, the water was icy: On the Indian ocean, the water was warm, and let me tell you, there were fewer things more pleasant in this god-forsaken place than having your cold-numbed hands warmed by the ocean water. Everyone would let out a loud sigh of relief and relish the fact that we could feel our fingers again.

The 5400-mile journey took just over three weeks. Two hundred years earlier, convicts heading to the penal colony at Botany Bay took more than eight weeks to cross the Indian Ocean. 'To grasp what exile to such a place meant,' Hughes writes, 'one must think of the size of the world in the late 18th century, so much vaster than it is today.' Technology may make the world appear much smaller than it was in 1780, but the disappearance of MH370 into the Indian Ocean reminds you that the idea is an illusion. The Indian Ocean was – and is – vast.