This display used to be in the Physics lab. It was set up to illustrate the Schrodinger's Cat story. About 100 years ago, it was thought that an electron was a particle. Experiments show this. This is what you are taught at GCSE. Then more experiments were done that showed that it behaved like a wave. So what is it really? In Physics, wave and particle are diametrically opposite ideas. Particle is about position and wave is about movement. Schrodinger wanted to explain clearly that a wave couldn't be both. He said that they are as opposite as alive and dead. You can't be both alive and dead. The story can be told in a more complicated way that specifies the random mechanism, but let's simplify it by saying that a hypothetical cat is put into an opaque box which has poison in it and that conditions are rigged so that there is exactly a 50% chance that the cat will eat the poison and die. You go to the box, as seen below. You can't see in so is the cat alive or is it dead? Schrodinger said that logically the cat must be 50% alive and 50% dead since chance comes into it. This is impossible so an electron must be either a wave or a particle. He favoured the wave idea. However, others have used the story to explain that we don't really know what an electron really is. we just have these two human-made ideas: wave and particle. The electron is in a state of uncertainty as far as we are concerned until we do an experiment to investigate. The design of the experiment will fix the probability of whether we find a wave or a particle. The state of uncertainty is called the wave-particle duality. Physicists have probed the nature of reality and discovered that there are limits to what we can know. In one sense, the truth is not out there!
