Question: What is the best thing you've learnt so far!

Lidunka Vocadlo answered on 15 Jun 2015:

@AimeeTGS there are some amazingly weird things in science – one of my favourites is something called Young’s Double Slit Experiment. Basically light behaves as a wave and a particle (so called wave-particle duality). Now in this experiment, you make a screen and put two very very thin slits some distance apart in it. You then shine light through the slits. The slits are so thin that this causes an “interference pattern” to be seen on the sheet the other side of the slits. This interference pattern is basically a series of light and dark lines. Now this interference patter is characteristic of a wave. What you then do is send light through the slits just one particle at a time (this is quite tricky to do, but can be done). Now you would think that the particle has to “choose” which slit to go through. But what actually happens is pretty amazing. As the single particles of light go through the slit (sent through individually, one after the other), they hit the paper (say photographic paper), and the interference pattern that we had before emerges. It’s as if each particle “knows” what has happened before it!!!! It really is quite an extraordinary experiment.