Monday, July 19, 2010

The age of measurement

In the beginning of the 20th century, physicists discovered that measurement was not only a means to quantify things, but something intrinsic to the definition of reality itself. In Newtonian mechanics, objects were defined by their precise location in space and time and had a precise velocity attached to them. But this description of reality is no longer true from the point of view of quantum mechanics. In this new view of the world, all objects merely have a wave-function associated with them. And unless an act of measurement is made, things like precise location and velocity no longer have any meaning for objects. So, an act of measurement is now not only to know the position and velocity of an object, but also to impart these things to the object itself. Unless this measurement is made, the object itself has no precise location or velocity. It could be anywhere and have any velocity (with certain probabilities, of course)!