Reality: Is matter real?
来源：未知 作者：从踩惜 时间：2019-03-14 02:03:00
By Jan Westerhoff Read more: “Special issue: What is reality?“ NOTHING seems more real than the world of everyday objects, but things are not as they seem. A set of relatively simple experiments reveals enormous holes is our intuitive understanding of physical reality. Trying to explain what goes on leads to some very peculiar and often highly surprising theories of the world around us. Here is a simple example. Take an ordinary desk lamp, a few pieces of cardboard with holes of decreasing sizes, and some sort of projection screen such as a white wall. If you put a piece of cardboard between the lamp and the wall, you will see a bright patch where the light passes through the hole in the cardboard. If you now replace the cardboard with pieces containing smaller and smaller holes, the patch too will diminish in size. Once we get below a certain size, however, the pattern on the wall changes from a small dot to a series of concentric dark and light rings, rather like an archery target. This is the “Airy pattern” – a characteristic sign of a wave being forced through a hole (see image). In itself, this is not very surprising. After all, we know that light is a wave, so it should display wave-like behaviour. But now consider what happens if we change the set-up of the experiment a bit. Instead of a lamp, we use a device that shoots out electrons, like that found in old-fashioned TV sets; instead of the wall,