What does a Bose-Einstein condensate look like?
The simple answer is that it looks like a dense little lump in the bottom of the magnetic trap/bowl. This lump of condensate is like a drop of water condensing out of damp air when it is cooled. When it first forms, the condensate is still surrounded by the normal trapped gas atoms, so it looks a bit like a pit inside a cherry. Could I just look into the experiment and see it? In principle yes, but there are several reasons it is difficult. First, it is quite a small lump, so you would need a microscope. Second, you would have to illuminate it with the special deep red color to which the rubidium atom responds. (Click here to learn more about atoms and the colors to which they respond.) It is transparent to any other color. Third, you would have to either use very dim light, or you would have to look very quickly, because shining light on the condensate quickly heats it up so much that it evaporates back into being normal gas atoms. The way Wieman and Cornell first looked at it was to
