But if we were working entirely from observed measurements, we&#x27;d never have discovered relativity. It wasn&#x27;t evident from the measurements you&#x27;d get from normal experimentation.<p>I mean, it <i>is</i> possible to measure the effect. But you need to first design the experiment in order to make the measurement. It was necessary for Einstein to sit and think for a long time, to come up with the idea, which others were able to design experiments around.<p>You can&#x27;t just say that somebody would have noticed the discrepancy sooner or later. Really, doing experimentation that way is a statistical error, of the sort that&#x27;s really plaguing the sciences these days.