3 ms·

I can tell you right now, they don't hold water. They do not fit observations, even a little.

ars 10y ago
Can you elaborate? People are downmodding me for having an idea and putting it out there for comment (is that really so bad?) But I really do just want to know if my ideas hold water or not, and if not why not. For example the time dilation on black holes fits every description of black holes I've ever seen. Gravitational potential energy of stars being significant makes sense to me - after all the farther from the center, the higher the "apparent" mass of the star (as seen in its orbit), which matches well with the potential energy also being higher when it's farther. Is it not enough maybe?
- InclinedPlane 10y ago
  OK, so, go read the wikipedia article on dark matter in its entirety (it's not that long) then come back. One of the reasons you're being downvoted is because it's fairly obvious you haven't done much due diligence. And just throwing out half-baked ideas may seem fun, but it's not particularly helpful. The biggest problem with your ideas is that we already have numerous lines of evidence that dark matter and regular matter can become separated, and that would seem to be something that directly challenges your hypothesis.
- kirrent 10y ago
  An alternative criticism to the other comment. I actually don't really know what your sentences are trying to say. When you say, 'Black holes don't exist (time dilation prevents them from forming in a finite time)'. Do you mean that you think a singularity would form asymptotically slowly from an outside frame of reference as gravitational time dilation increased? That's the most generous construction I can give your statement and it's still ridiculous because the event horizon would exist anyway so the effect will be the same. I think the majority of people try to be generous and give the benefit of the doubt, but I'm a physics grad and even after a lot of thought I'm not sure what you're saying. It's hard to give informed criticism in that case but easy to downvote and move on.
  - ars 10y ago
    > Do you mean that you think a singularity would form asymptotically slowly from an outside frame of reference as gravitational time dilation increased? Yes. > it's still ridiculous because the event horizon would exist anyway so the effect will be the same. How would exist? It would only form after infinite time - time dilates as a function of how close it is to a black hole (i.e. you don't have to already be a black hole to dilate time), reaching infinity as it forms the event horizon. > I think the majority of people try to be generous and give the benefit of the doubt, but I'm a physics grad and even after a lot of thought I'm not sure what you're saying. It's hard to give informed criticism in that case but easy to downvote and move on. Thanks for the reply. If I gain nothing else except an understanding of how a black hole can ever form the downvotes would be well worth it. As best as I can understand it can't form, yet everyone just seems to implicitly believe it can. The rest I just kind of threw out there to see what criticism I would get (none as of this writing, just some insults), but the black hole one really bothers me because that one is grounded in ordinary, orthodox, descriptions of black holes. Every description describes them as matter caught falling in infinitely slowly, yet simultaneously say matter actually falls in and somehow forms a black hole. It's a contradiction - I can't be the only person in the entire world to see that.
    - guard-of-terra 10y ago
      You're not alone: http://physics.stackexchange.com/questions/21319/how-can-anything-ever-fall-into-a-black-hole-as-seen-from-an-outside-observer/21357#21357 http://physics.stackexchange.com/questions/21319/how-can-any...
    - kirrent 10y ago
      Oh, I see now. Yeah, you're right. From our outside frames of references we'll never see anything cross the event horizon, instead matter approaches the event horizon asymptotically slowly. In our exterior frame of reference/coordinate system you'll not see one form and because they'll never form from the outside we'll never see a black hole because there aren't any. So as far as that goes you're right. What this doesn't mean is that black holes don't exist in any reference frame. The simple test is to jump into the black hole. Time dilation won't affect you, you're in a free fall after all, following your geodesic. You'll pass a well defined event horizon and pass into what is undeniably a black hole.

ars 10y ago

Can you elaborate? People are downmodding me for having an idea and putting it out there for comment (is that really so bad?) But I really do just want to know if my ideas hold water or not, and if not why not. For example the time dilation on black holes fits every description of black holes I've ever seen. Gravitational potential energy of stars being significant makes sense to me - after all the farther from the center, the higher the "apparent" mass of the star (as seen in its orbit), which matches well with the potential energy also being higher when it's farther. Is it not enough maybe?

InclinedPlane 10y ago
OK, so, go read the wikipedia article on dark matter in its entirety (it's not that long) then come back. One of the reasons you're being downvoted is because it's fairly obvious you haven't done much due diligence. And just throwing out half-baked ideas may seem fun, but it's not particularly helpful. The biggest problem with your ideas is that we already have numerous lines of evidence that dark matter and regular matter can become separated, and that would seem to be something that directly challenges your hypothesis.
kirrent 10y ago
An alternative criticism to the other comment. I actually don't really know what your sentences are trying to say. When you say, 'Black holes don't exist (time dilation prevents them from forming in a finite time)'. Do you mean that you think a singularity would form asymptotically slowly from an outside frame of reference as gravitational time dilation increased? That's the most generous construction I can give your statement and it's still ridiculous because the event horizon would exist anyway so the effect will be the same. I think the majority of people try to be generous and give the benefit of the doubt, but I'm a physics grad and even after a lot of thought I'm not sure what you're saying. It's hard to give informed criticism in that case but easy to downvote and move on.
- ars 10y ago
  > Do you mean that you think a singularity would form asymptotically slowly from an outside frame of reference as gravitational time dilation increased? Yes. > it's still ridiculous because the event horizon would exist anyway so the effect will be the same. How would exist? It would only form after infinite time - time dilates as a function of how close it is to a black hole (i.e. you don't have to already be a black hole to dilate time), reaching infinity as it forms the event horizon. > I think the majority of people try to be generous and give the benefit of the doubt, but I'm a physics grad and even after a lot of thought I'm not sure what you're saying. It's hard to give informed criticism in that case but easy to downvote and move on. Thanks for the reply. If I gain nothing else except an understanding of how a black hole can ever form the downvotes would be well worth it. As best as I can understand it can't form, yet everyone just seems to implicitly believe it can. The rest I just kind of threw out there to see what criticism I would get (none as of this writing, just some insults), but the black hole one really bothers me because that one is grounded in ordinary, orthodox, descriptions of black holes. Every description describes them as matter caught falling in infinitely slowly, yet simultaneously say matter actually falls in and somehow forms a black hole. It's a contradiction - I can't be the only person in the entire world to see that.
  - guard-of-terra 10y ago
    You're not alone: http://physics.stackexchange.com/questions/21319/how-can-anything-ever-fall-into-a-black-hole-as-seen-from-an-outside-observer/21357#21357 http://physics.stackexchange.com/questions/21319/how-can-any...
  - kirrent 10y ago
    Oh, I see now. Yeah, you're right. From our outside frames of references we'll never see anything cross the event horizon, instead matter approaches the event horizon asymptotically slowly. In our exterior frame of reference/coordinate system you'll not see one form and because they'll never form from the outside we'll never see a black hole because there aren't any. So as far as that goes you're right. What this doesn't mean is that black holes don't exist in any reference frame. The simple test is to jump into the black hole. Time dilation won't affect you, you're in a free fall after all, following your geodesic. You'll pass a well defined event horizon and pass into what is undeniably a black hole.