I just think that around 'time' there is an extremely unscientific vague grey area about what actually exists and does not exist. And it is this that I am addressing. (If you look at many book titles on time they imply directly that they are apparently about a real thing, which may be 'warped', and -really- considered as a 4th dimension, etc).
E.g. when someone as distinguished in the field of cosmology as Hawking says "rapid space-travel, or travel back in time, can't be ruled out, according to our present understanding", ( http://www.hawking.org.uk/space-and-time-
Then I am 'confused'. Is the cosmological expert, Professor Hawking saying it is completely understood that time is nothing more than a useful mental concept... but it's 'fun' to 'pretend' it is real, and could be travelled through? Or is he saying that the current expert understanding is that time is a real thing?
It seems a problem to me that anyone else in such a scientific field is happy to say 'it doesn't matter if this fundamental 'time' thing is real or just an idea. But let's not bother to clarify it, let's just carry on talking about it ambiguously, and try to work out any confusion that follows, as if all before it has been checked'.
I'm obviously paraphrasing, but in the 'jigsaw puzzle of physics', I`m looking at the piece marked 'time' and saying I think I can show that's wrong. And just as in a real puzzle, if a single piece is wrong but assumed to be right, or not to matter, then there will always be problems around that piece which will hinder the puzzle as a whole being solved. (added)- And lead to endless, circular discussions. Inherently inconclusive because they build on poorly defined, and scientifically unchecked hypothesis (e.g. that terms like 'the past' relate to some real thing, and not just a useful 'idea').
RE *with an implicit understanding of before/after assumed*, try pushing a mug etc, from left to right with your finger. Is your finger really 'in the past', doing something before now, so that after-wards the mugs position is changed 'in the future'? Or is everything always just happening now.
My guess is that immediately on reading the above, you may want to say something about 'semantics'. If so, it is, imo, absolutely critical, -not- to just assume a semantic problem has been spotted, therefore the matter is closed. But instead to be absolutely clear whether the semantic confusions around 'time'...
A -Wrongly- use language to make it look like time does not exist. or,
B- Wrongly- use language to make it look like time does exist.
I'm just suggesting I can fully show B is the case, and that if it is the case that time does not really exist, it is quite amazing, and very useful to grasp as many answers and simplifications of various relativity issues etc follow.