I was reading a story (a.k.a. urban myth) this week about an eminent quantum physicist who was stopped for speeding in his car. When told by the traffic cop that he was doing 63 miles per hour, he responded by asking if this was an accurate measurement. Being told that it was he explained that, therefore, they could not definitely determine if he was inside the 35 miles per hour zone at the time. Alternatively, if they were sure that he was within the zone, it was physically impossible – due to the fundamental laws of quantum mechanics – for the speed measurement to be accurate.
OK, so the story was phrased a little more colloquially that this. When asked if he knew how fast he was travelling, the eminent physicist replied “No, but I know where I am”. Of course, our eminent physicist was simply explaining that, according to the Heisenberg uncertainty principle, it is impossible to simultaneously determine the precise values of certain pairs of physical properties, such as position and momentum, of an object.
It’s an interesting theory; and you may want to ponder if, when you measure the transfer rate of your high speed Internet connection or the performance of a new super fast hard disk, the results actually apply to your neighbor’s DSL line or your wife’s laptop instead. Although in reality this effect only reveals itself where you are dealing with very small or very fast things. Perhaps if I write this blog post using 6 point Arial, and type fast, there’s a danger that the text might end up in a different paragraph, or even a different document.
And as for really small and fast things, you don’t get much better than the electrons that make up the ones and zeros of your latest and greatest computer programs. So there’s definitely a danger that, if you make your new enterprise application run too quickly, you won’t be able to tell which server it’s running on when you come to do performance testing. Probably a good argument for installing a server farm.
And does this uncertainty extend to other pairs of physical properties? Can I argue that my spelling is so bad because it’s impossible to determine the actual alphabetic letter and its position within a word at the same time? Or insist that my BMI must be around 25 because it’s impossible to simultaneously measure my weight and height? Perhaps if I was also running very fast at the time it would work.
However, what’s really disappointing is that Heisenberg’s principle also puts paid to my idea for becoming a millionaire by patenting a device for removing the space junk that I keep reading is increasingly endangering satellites and space craft in Earth orbit. I’d just finished the design for a rocket fitted with a large magnet when I read that most of the junk is travelling at six miles per second – which probably means that I can’t determine how big the chunks are. So how would I know what size magnet I’d need?