by SamGurney » Oct 25th, '10, 18:16
Easy. The electromagnetic spectrum; of which visible light is only one wavelength. For example, the only way we know black holes exist is because they give off 'hawking radiation' which we can detect but the gravity is so strong that visible light cannot escape. Lots of physics is a triumph of rationalism from a phew empirical facts to the extent that we can make predictions before we have observed any phenomena; as an examples, Einstein's general relativity predicts certain things about the propagation of light and how it will bend and so on, which were confirmed with observational tests afterwards (although the first 1919 test in west africa was at the time said to have proved his theory, afterwards we realised it was just confirmation bias) . The same thing happened with effects of his like 'time dilation' and so on- the theory came first, the empirical evidence after.
So there are plenty of things which we can learn about before even seeing.
As a little bit of a digression, all this reminds me of Hume when he is discussing in dialogue form the theological question of whether God exists. One of the arguments that was given was the design argument and the analogy was given about hearing a voice in the dark and from that, you can infer there is a speaker.
''To go wrong in one's own way is better than to go right in another's.'' Dostoevsky's Razumihin.