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Regarding the relationship of mass, velocity, and time

  1. Dec 17, 2015 #1
    Perhaps someone can clarify something for me that's been bugging me for a while. Assuming that singularities are not a singular event but occur naturally, we believe the objects for be of infinite density and infinite heat. On the other hand, in the case of black holes, it's logical to assume that once all energy has been released from material crossing the horizon, that these objects would be infinitely cold (little or no molecular motion). Enter time into this thought process and it seems to become clear, at least to some degree, that massive objects relatively increase the passage of time. The very idea of a singularity becomes perplexing then as the object is massively hot (infinitely hot and dense) and a black hole, while still very massive remains at or near absolute zero. If an object were to be placed near a black hole, time would speed up while time near a singularity would slow down? So I guess my question is that since we know mass affects time, velocity affects time, does lack of heat affect time? And does that go in both directions? It's not easy to contemplate because we try to think as an observer regarding something of quantum size where all normal physics breaks down. It remains something I try to calculate as near massive objects, time speeds up, so does the sparse nature of matter in the universe speed time up?
  2. jcsd
  3. Dec 17, 2015 #2


    Staff: Mentor

    Singularities in physical models are generally considered by physicists to be an indication that the model predicting them breaks down in that regime, not an indication that "infinite density and infinite heat" ever actually happen.

    No, this is not a good assumption. Objects falling into a black hole do not change temperature; locally, no observation of the object will indicate that it is falling into a black hole.

    I'm not sure what you mean by this.

    The rest of your post is basically reasoning from incorrect starting assumptions to incorrect conclusions. I suggest taking some time to become familiar with how GR actually models black holes. Chapter 7 of Carroll's online lecture notes gives a good discussion. (The notes in their entirety are a good introduction to GR in general.)
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