The discussion centers on the misconceptions surrounding the formation of black holes due to objects traveling at relativistic speeds. Participants clarify that an object's increase in relativistic mass does not lead to black hole formation, as the source of gravity in General Relativity is the stress-energy tensor, which includes momentum and pressure. The consensus is that speed is relative, and no object can become a black hole solely due to its velocity. The conversation references the Schwarzschild radius and emphasizes the importance of understanding reference frames in relativity.
PREREQUISITESPhysics students, astrophysicists, and anyone interested in the theoretical aspects of black holes and relativistic physics.
Mentz114 said:How would you know ? It is clear you can't do physics.
The case of a body undergoing constant acceleration is well described by the Rindler space-time. No black hole is formed in any frame of reference.
That would be an horizon, not a black hole.
Physics is an experimental science.NewDescartes said:LOL. Physics is philosophy.
Getting back to the core of the subject, you said that an object traveling @ C will not become a black hole. Why? This is an apparently obvious truth to me, and I would like to know why mainstream physics doesn't believe this to be true.
I completely agree with everything you say here. You guys are more familiar with the subject, so perhaps I should listen more, but there is a huge hole in physics and this subject is at the core of it. I only wish to debate a little to see why present day physics comes to irrational decisions.Mentz114 said:Physics is an experimental science.
When I was very small it was 'apparent and obvious' to me that the whole world was a cot and I was the centre of the universe. Sadly, I was wrong.
We've done our best to explain to you why a body won't become a black hole, however fast you accelerate it. This is based on theories which explain those things we can see very well. It is not dogma but the considered view of a lot of people smarter than you or I.
[edit]I think your problem is 'a body moving at c'. There's no such thing for us. It looks as if nature won't let this happen without erecting a 'horizon' that stops us perceiving it.
In relativity it's impossible for an object with mass to move exactly at c, only massless particles like photons can move at c. If an object is moving slower than light in one inertial frame, then it's moving slower than light in all inertial frames, and in every one of these inertial frames the energy needed to increase an object's speed approaches infinity as its speed approaches c, so you can never accelerate it to c with any finite energy.NewDescartes said:It is highly red shifted @ .999999% C. It flat lines @ C. We never catch an object moving @ C, nor can our probing light rays.
Whoops, I got things backwards here--the light would actually be highly blueshifted as the object approached you, contrary to what NewDescartes was saying. Only when it was moving away from you would it be highly redshifted.JesseM said:And what if an object passes right next to you at a high fraction of c? You could probably observe it as it passed an millimeter from your face, right? (especially since the moment after it passed you, it would be moving away from you rather than towards you and thus highly blueshifted rather than redshifted)
JesseM said:Whoops, I got things backwards here--the light would actually be highly blueshifted as the object approached you, contrary to what NewDescartes was saying. Only when it was moving away from you would it be highly redshifted.
Well, that's exactly why it's impossible to have a massive object moving at c in SR.NewDescartes said:All I am arguing is that if matter travels at velocity C, it is a black hole. Sure the original mass of the object is invariant, but the energy needed to accelerate the object to C is infinite.
How can a black hole accelerate mass to light speed? This certainly isn't true in general relativity, and in pure special relativity there is no spacetime curvature and thus no gravity to alter the motion of nearby objects.NewDescartes said:A black hole is needed to accelerate mass to light speed.
JesseM said:Well, that's exactly why it's impossible to have a massive object moving at c in SR.
How can a black hole accelerate mass to light speed? This certainly isn't true in general relativity, and in pure special relativity there is no spacetime curvature and thus no gravity to alter the motion of nearby objects.
This also seems like weird circular reasoning--you say a black hole is a massive object moving at light speed, but you also say a black hole is needed to accelerate massive objects to light speed in the first place?
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