Surfing the Waves: Hyper-Fast Computers

Who hasn’t heard of a computer? In a society entirely dominated by these transistor infested boxes there are probably only a few remaining isolated tribes in the Amazon or around the Kalahari that have not been affected. From organizing our finances, flying a plane, warming up food, controlling our heartbeat (for some), these devices are prevalent in each and every aspect of our society. Whether we are talking about personal computers, mainframe computers, or the embedded computers that we find in our mobile phones or microwave ovens, it is very hard to even imagine a world without them. The term computer, however, means more than just your average Apple Mac or PC. A computer, at its most basic level, is any object that can take instructions, and perform computations based on those instructions. In this sense computation is not limited to a machine or mechanical apparatus; atomic physical phenomena or living organisms are also perfectly valid forms of computers (and in many cases far more powerful than what we can achieve through current models). We’ll discuss alternative models of computation later in this chapter. Computers come in a variety of shapes and sizes and some are not always identifiable as computers at all (would you consider your fridge a computer?). Some are capable of doing millions of calculations in a single second, while others may take long periods of time to do even the most simple calculations. But theoretically, anything one computer is capable of doing, another computer is also capable of doing. Given the right instructions, and sufficient memory, the computer found in your fridge could, for example, simulate Microsoft Windows. The fact that it might be ridiculous to waste time using the embedded computer in your fridge to do anything other than what it was designed for is irrelevant – the point is that it obeys the same model of computation as every other computer and can therefore – by hook or by crook – eventually achieve the same result. This notion is based on what is now called the Church–Turing thesis (dating back to 1936), a hypothesis about the nature of mechanical calculation devices, such as electronic computers.