Potentiometer, an electrical device that measures potential difference between two points in a circuit by comparison with a standard battery of known potential difference. The name is also applied to a variable resistor that provides varying amounts of potential difference.
Mathematics achieves the sublime. Sometimes, as with tessellations, it rises to art. In their simplest form, tessellations consist of a single shape that repeats over a two-dimensional plane without any gaps. Why was M.C. Escher so fixated on them?
Nuclear radiation can be extremely beneficial or extremely harmful -- it all depends on how it's used. Learn what nuclear radiation is all about.