A thought occurred to me In precalculus class. At the moment we are learning about sin/cos/tan/cot/sec/csc and their amplitude, periods and phases shifts. I've studied electronics on and off for about a year. I would like to know if we actually know what radio waves look like? do they actually look like the sine and cosines like in mathematics textbooks. Or are those wave functions just representations of something we can't see be can only analyze their effects. And therefore something we don't know what they look like.