-6

What does it mean, "gravity is so strong that not even light can escape from a BH..."?

This can physically interpreted IMHO that beyond the event horizon of the BH, light is phase transitioned (accelerated) to a FTL superluminal energy that breaks known physics. The inner of the BH therefore appears in our spacetime as "Nothing"!

Exactly as the rest of vacuum space appears to us, basically as nothing. Someone could therefore infer that vacuum space we generally describe us nothing is actually something and considering the physics of BHs it points to the possibility that vacuum space could be a superluminal FTL (i.e. faster than light speed c) unknown type of energy.

There is light, matter and vacuum in our universe. Seems to me that vacuum could be a different energy than matter and light, defying our known physics which we mastered over millennia and concern more about matter and light and their interactions.

The vacuum is still a mystery today. Much to learn in the future. Maybe sci-fi Star Wars creators imagination was right after all when saying "...prepare for a jump to hyperspace!".

Markoul11
  • 3,853
  • 1
    The speed of light is a local phenomenon. There is no hint in any known data that this local phenomenon changes near black holes. – FlatterMann May 19 '23 at 18:02
  • 2
    -1 Personal theories are off-topic. Non-mainstream physics is off-topic. After five years of being a member you know the rules for this site. – Ghoster May 19 '23 at 18:06
  • Still, the question is there beginning from the first paragraph. Why light cannot escape the BH and in the same time the inner BH appears having no light and as nothing? Note: Please don't give the answer, because gravity is so big or the curvature of space-time is so big (same answer as gravity one). Personally, I cannot find any other explanation than a phase transition of normal light occurring beyond the event horizon which necessarily involves c which is most probably going up and not down. After all it is known that BHs break our known physics. – Markoul11 May 19 '23 at 18:41
  • @Ghoster I am here on PSE for asking for the current most updated consensus which I believe is one step ahead in PSE from WP, Not so sure anymore... – Markoul11 May 19 '23 at 18:51
  • I think either an answer — or, more likely, closure — will make the consensus clear, in case the downvotes have not done so. – Ghoster May 19 '23 at 20:30
  • 1
    Please try to write more clearly. If you don't want people to dismiss your posts as non-mainstream speculation I suggest that you don't invent your own jargon like "light is phase transitioned (accelerated) to a FTL superluminal energy". – PM 2Ring May 20 '23 at 01:08
  • We have numerous answers on this site stating that there isn't some kind of phase transition affecting light or the vacuum at the event horizon. Eg, https://physics.stackexchange.com/q/689129/123208 – PM 2Ring May 20 '23 at 01:32
  • 1
    it is known that BHs break our known physics This is false. There is no experimental evidence from observing black holes that cannot be understood on the basis of General Relativity and other standard physics. – Ghoster May 20 '23 at 01:59
  • @Markoul11 "I am [...] asking for the current most updated consensus" - Don't make a mistake of thinking that "the consensus" is always correct. No scientific breakthrough ever in the history of the humankind has been made by "the consensus", but always against it. – safesphere May 20 '23 at 04:34

1 Answers1

3

Are cosmological Black Holes superluminal FTL phenomena?

No. Nothing moves faster than the local speed of light.

What does it mean, "gravity is so strong that not even light can escape from a BH..."?

It's a phrase for introducing the idea to non-physicists starting from Newtonian gravity, and intuitions about the increase of the escape velocity with mass. It's technically true, but not a very good way of describing it.

A more accurate way to describe a black hole is to say that spacetime is twisted round so that the entire future light cone (i.e. 'the future') points into the hole. Locally, spacetime appears perfectly normal, both outside and inside the event horizon.

We can say that getting back from the future into the past means passing backwards through the future light cone, which means travelling faster than light. Hence, it's true to say that a black hole is a region from which even light cannot escape. But it's more useful to say that time points inwards, and the real barrier is not being able to go backwards in time, rather than not being able to go faster than light. They're the same thing, but the former phrasing give the more fundamental reason. Light can't escape from the future into the past, either.

Coordinate systems that try to keep treating the radial inwards direction as spacelike end up in a confused state inside the hole, with the wrong signature, and a divide-by-zero coordinate singularity at the horizon where they switch over, that sometimes deceived people into thinking there was something unphysical about the horizon and interior. During the early days of general relativity this belief was mainstream, with even Einstein denying the possibility of black holes existing. So I don't think it's an unreasonable misunderstanding. But it's not true. Spacetime inside the hole is normal, the local speed of light measured by freefalling observers is the same, and physical laws like the lightspeed limit all obeyed. General relativity only breaks down when you get to the very centre, where the futures all flow in towards the worldline of the central point.

Any future-directed lightcone in empty space acts as a one-way barrier exactly like a black hole's event horizon - this is just the obvious observation that once you pass into the future, you cannot ever get back. Rindler coordinates for a uniformly accelerating observer represents flat, empty spacetime in just this way. Spacetime is filled with 'event horizons', which we cross over all the time. The region on the other side is perfectly normal. It's called 'the future'. And the laws of physics still apply there.

Nullius in Verba
  • 31
  • 1
    In the unlikely case you read comments while deleting your account after each answer for over 7 years, your correctly point out that the inside is the future, but fail to clarify, the future relative to what. It's the future relative to any external event in the past light cone for the eternity of the cosmological time. This clearly is nonsense, because "after the eternity" is not a valid concept either physically or mathematically. In other words, the Schwarzschild spacetime being globally hyperbolic (preserving causality) implies that there is no inner spacetime in astrophysical black holes. – safesphere May 20 '23 at 04:21
  • @safesphere I agree with you. You cannot describe something using known physics that is breaking known physics in the first place. And I believe we all agree that beyond the event horizon of a BH our established physics are broken. Therefore, it is only logical and wise to assume new physics that violate the old have to be used. Well, the first thing that comes in mind is violating the speed of light c meaning superluminal. IMO BHs are phase transitioning normal matter and light to superluminal energy and integrating them back into the vacuum, The undisturbed vacuum is superluminal energy. – Markoul11 May 20 '23 at 18:51
  • "we all agree that beyond the event horizon of a BH our established physics are broken." No, we don't agree. GR works perfectly well inside the EH (event horizon), except at the very centre of the BH. As I said here, we need a theory of Quantum Gravity to talk about the core of a BH, but that core is likely to be smaller than an atom. And of course we won't ever be able to directly test a BH core theory, since nothing inside the EH can affect events outside the EH. – PM 2Ring May 24 '23 at 03:19
  • @PM2Ring ""since nothing inside the EH can affect events outside the EH."" Not so sure about that one... https://doi.org/10.3847/2041-8213/acb704. https://doi.org/10.3847/1538-4357/acac2e. – Markoul11 May 24 '23 at 09:59