Quote Originally Posted by danzibr View Post
*By "outside the universe" I mean... naively suppose you can pinpoint where in 4-space the big bang occurred. Time passes, universe expands, etc.

Void inside the (observable) universe has properties, like permittivity and permeability of free space. Question is, would the same hold for outside? Would there be a way to know?
Actually you can pinpoint the location in 4-space where the big bang occurred (assuming that the 4th dimension is time). The time co-ordinate is <insert current best calculated age of universe>.

The space co-ordinates are "everywhere".

This is what is meant by the expansion of the universe - there is no "outside" to measure it against (or if there is, none of the spacial co-ordinate systems we can use inside have any meaning there). Every point in the universe came from the big bang.

This means that your question isn't meaningful - there isn't an outside (as we currently understand it) to observe. You also cannot go back before the beginning because although you can calculate a theoretical time postion, there's no reference to observe it passing - time itself is also meaningless before the big bang.

If we suppose that there was something before the big bang, and than time and spacial coordinates have meaning, they still don't relate to those we use inside the universe (or at least we cannot relate them) so the best answer becomes "possibly". An equivalent question is "if we postulate the ability to see gravity in the same way we see light, would the gravity of the earth look blue?" It's a meaningless because we don't have the referents to answer it.