Why Does Science Have Two Sets of Laws? Since the original experiment, it has been re-created several times, and each time the results are identical and just as mind-boggling. The experiment is called a double-split experiment, and maybe you still remember it from school physics/science lessons. It involves projecting things such a quantum particles through a barrier that has two small holes in it and measuring the way that they are detected after they come through the openings. Common sense would suggest that when things start off on one side of the barrier as particles, that they would emerge at the other end also as particles. The evidence, however, shows that something extraordinary happens at some point between the place where the particles begin and where they finish. Scientists have found that when an electron passes through the barrier with only one opening available, it behaves in just the way it would be expected to: it begins and ends its journey as a particle. No surprises there. However.... when two slits are used, the same electron does something that sounds impossible. Although it begins its journey as a particle, something happens along the way – the electron passes through both slits at the same time. Only a WAVE of energy can do this, and the kind of pattern that was picked up was that which only a wave can make. This kind of strange behaviour is what physicists have come to call ‘quantum weirdness’. The only explanation (up to now) is that the presence of the second opening has somehow forced the electron to travel as a wave. In order to so, the electron has somehow to perceive that the second opening exists. Because it is assumed that an electron cannot really ‘know’ anything, the only other source of this knowledge is the person watching the experiment – the scientist. The conclusion that has been reached is that somehow the awareness that the electron has two possible paths to move through is in the mind of the scientist, and that it is this consciousness which then determines how the electron travels. It was as a result of these ‘weird results’ that the field of quantum physics came into being because some theory was needed to be able to explain this behaviour. So we now have two types of physics – classical physics which deals with large bodies (I’m not talking about overweight people here, but think more along the lines of planets and galaxies), and quantum physics which deals with subatomic particles. In 1998, almost 90 years after it first shook the foundations of classical physics, this double-slit experiment was repeated. This time, however, the scientists had better technology and more sensitive equipment. The original 1909 experiments were confirmed, and at the same time something else was also discovered – the more the particles were watched the more they were affected by the watcher. When a quantum "observer" is watching Quantum mechanics states that particles can also behave as waves. This can be true for electrons at the submicron level, i.e., at distances measuring less than one micron, or one thousandth of a millimeter. When behaving as waves, they can simultaneously pass through several openings in a barrier and then meet again at the other side of the barrier. This "meeting" is known as interference. Strange as it may sound, interference can only occur when no one is watching. Once an observer begins to watch the particles going through the openings, the picture changes dramatically: if a particle can be seen going through one opening, then it's clear it didn't go through another. In other words, when under observation, electrons are being "forced" to behave like particles and not like waves. Thus the mere act of observation affects the experimental findings. To demonstrate this, Weizmann Institute researchers built a tiny device measuring less than one micron in size, which had a barrier with two openings. They then sent a current of electrons towards the barrier. The "observer" in this experiment wasn't human. Institute scientists used for this purpose a tiny but sophisticated electronic detector that can spot passing electrons. The quantum "observer's" capacity to detect electrons could be altered by changing its electrical conductivity, or the strength of the current passing through it. Apart from "observing," or detecting, the electrons, the detector had no effect on the current. Yet the scientists found that the very presence of the detector-"observer" near one of the openings caused changes in the interference pattern of the electron waves passing through the openings of the barrier. In fact, this effect was dependent on the "amount" of the observation: when the "observer's" capacity to detect electrons increased, in other words, when the level of the observation went up, the interference weakened; in contrast, when its capacity to detect electrons was reduced, in other words, when the observation slackened, the interference increased. Thus, by controlling the properties of the quantum observer the scientists managed to control the extent of its influence on the electrons' behavior. Einstein spent the latter part of his life trying to find a ‘Unified Field Theory’ that could link the two together.....Now scientists belief that the ‘missing ingredient’ is…..our own consciousness. Fascinating isn’t it? References 1. ‘Quantum Theory Demonstrated: Observation Affects Reality’ Weizmann Institute of Science (February 26 issue of Nature 1998, Vol. 391, pp. 871-874) 2. Science Daily http://www.sciencedaily.com/releases/1998/02/980227055013.htm)