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Still More Evidence of Life of Mars

Posted by michael on from the wishful-thinking dept.

dirtyhank writes: "According to this article a group of Hungarian scientists have found another potential evidence of life on Mars. Apparently some groups of dark spots spread every martian spring. They say this could be caused by photosynthetic organisms."

3 of 249 comments (clear)

  1. Re:Life by Legion303 · · Score: 1, Offtopic
    Excuse me, sir, I think your tinfoil hat is loose.

    -Legion

  2. Your "nasty little truth" sig. by Christopher+Thomas · · Score: 1, Offtopic

    Your sig:

    "Nasty Little Truth About Spacetime Physics" (http://home1.gte.net/res02khr/crackpots/notorious .htm)

    As far as I can tell, this is much hot air to the effect that "time travel is motion through spacetime, which is impossible because it already contains time, so all the physicists talking about time travel are crackpots".

    This seems rather silly, because what physicists actually talk about when they say "time travel" is simply a configuration of an object's world-line (graphed in spacetime) such that the world-line can intersect itself (or that the "future" light-cone from the world-line crosses some "past" part of the world-line, allowing communication, or any of a number of similar scenarios). This does not involve "motion" of the hypothetical fabric of spacetime; it's just a class of paths that objects can take within it.

    Possibly I have misinterpreted the document, but this seems unlikely, as it makes it abundantly clear that time travel involves "motion" of spacetime, which "is impossible".

    Can you clear up this apparent discrepancy?

    1. Re:Your "nasty little truth" sig. by Louis+Savain · · Score: 1, Offtopic

      Possibly I have misinterpreted the document, but this seems unlikely, as it makes it abundantly clear that time travel involves "motion" of spacetime, which "is impossible".

      Certainly but you misinterpreted my argument. Why is there no motion in spacetime? Because for something to move in spacetime (or in time) it would need to have a variable temporal coordinate. This is impossible because a changing time coordinate is self-referential: it takes time to change, by definition.

      And it is not simply a matter of not being able to move backward in time. There is no motion at all in time, forward or backward. Therefore there is no time dimension. And if there is no time dimension, there is no time travel either, closed time-like loop notwithstanding.