I’ve decided to start what will hopefully be a long running series highlighting both basic and applicative scientific breakthroughs that have the possibility of drastically changing our lives in the next 20-50 years. If you see anything you want to add, send it over.
For my first entry, I want to talk about two breakthroughs that might be used to make next generation computing. Computational power has doubled roughly every two years since the invention of the integrated circuit in 1958. The majority of the increase in power is due to the increased number of transistors that can be cheaply integrated into a chip. The observation that the number of transistors approximately doubles every two years is known as Moore’s Law, named after one of the co-founders of Intel. This “law” is the reason why computers get so much faster every year. The problem is that we are now placing so many transistors on a single chip that each one has to be very tiny, and we are close to reaching the limits of miniaturization. The most advanced chips from Intel now have features that are a mere 45 nanometers, which is smaller than many viruses. In fact, if they were much smaller, they would be unable to reliably hold current. Due to quantum motion, many electrons would literally “warp” through the barrier and information would be lost.
It is well agreed that the limits of Moore’s Law are near, perhaps within the next one to two decades, and that a new foundation for computing should be devised. In fact, around the turn of the century, there was concern that the limits would be reached around 2012, but subsequent advances in material science has delayed that by a few years. Regardless, chip companies are currently focusing on improving their products by highlighting changes in layout and usage of multiple processors, rather than any stunningly new physical technology. This is a complete reversal from the 90s, where processors had dramatic technological changes, while display and storage technology was little changed.
One of the possibilities is to continue to use electrons as the means of transport, but change the material that comprises the “wires.” Graphene is a possible solution and what is really cool about this is that it is literally just a single atomic layer of carbon and can be produced from graphite. In order to study it, scientists devised a way to produce it using only two items: a #2 lead pencil and scotch tape…well and lots of labor by grad students trying to reduce the graphite to a single atomic layer. Graphene conducts electrons extremely efficiently and its structure if very unique. Not only will electrons travel much faster than they do in metallic transistors, but the electrons will be much more well behaved and so they can be much smaller. This will allow both a speed and density increase, and perhaps enable computers to be millions of times faster. The problem is figuring out how to produce it cheaply and also how to actually integrate it. The desirable properties are lost once the graphene is actually bonded to any substrate, so that’s a bit of a problem. Another unusual replacement for metallic transistors that has been suggested is spinach. Apparently it too far outperforms current materials when it comes to electron transport.
Another possibility is to replace electrons and use photons instead. In fact, we already have this technology to power the internet and cable, this is how fibre optic technology works. The problem is that the current materials for transmitting the photons are very fragile and cannot be bent; thus preventing them from being used on circuits. However, a group has devised an interesting replacement: DNA. The DNA strands are used to provide the framework for the “wires” and chromophores capable of transmitting light naturally attach to them. As the article mentions, the amazing thing about this technology is that it is perfect for self assembly and repair. Unfortunately, they haven’t figured out how to get the chromophores to distribute evenly and thus there is too much variation for practical use. Still, this concept is very similar to how plants perform photosynthesis, so hopefully further research will provide guidance.
Well that’s it for the first installment. I find it fascinating that the future might have supercomputers powered by pencils or DNA. I’m a computer programmer but all this seems really magical to me; I just try to think about how to put a million fold increase in processing power to good use. Surely Word and Windows will leave a little power for me.