• Bob replied to the topic Time Travel in the forum Pseudoscience and the Paranormal 1 day, 20 hours ago

    Widdershins:  “It has also been proved that gravity warps space/time, which are believed to be the same thing just like matter and energy are different forms of the same thing.”

    Last item first: I suggest matter is probably as close to being a thing as we can get, particularly in macro scales.  Energy is not a thing; it is a measure of matter’s potential to displace other matter (to do what we call work).  Note that the “push” which may cause displacement is the only force we think we really understand well.  Not two forms of the same thing.

    First item: No way for me to buy into the idea that space (which is probably a thing) being the same as time (which I believe is not a thing at all).

    The notion that gravity appears to warp space seems to be correct.  If so, how do we determine a “straight” (un-warped) line?  Moreover, would’t we need to use gravity-corrected units to describe distance accurately?  What a crazy yardstick we would have, stretched out on one or both ends, or even in the middle, and bent this way and that, depending on where we put it and which way we point it.

    On the other hand, in order for us to realize warped vs not warped wouldn’t we need an absolute frame of reference?  And then of course, there’s the question of how a wave could propagate through a variable density medium while maintaining a constant speed.