Black holes may not exist!

[Undefined]

Funny thing just occurred to me undefined.....Here you are suggesting, I'm throwing the baby out with the bath water [or in other words, not considering that which maybe worthwhile considering], and in the other thread, you are telling me I'm dreaming and not being realistic suggesting that theoretically FTL is possible and should be researched.
Is it just me, or do you smell some hypocritical irony in comparing the two?

I only presented GR/spacetime facts about what different types of GR warping entail and their inherent propagatory/non-propagatory nature/limitations. What you 'read into' the scientific information I and Declan have presented for your benefit is entirely up to you IF you wish to read it subjectively instead of understanding objectively. That was all that is suggested: Objective reading/assessment. No more; no less.

It's your agenda that needs questioning undefined, as I have just shown.

My agenda is well demonstrated to be positive about this site, its discussions on scientific issues/merits and NOT the person/source. If you imagine any other 'agenda', it will be demonstrably falsified by the record. How about your agenda, mate; is that as honourable and scientific and objective as mine? Look to your own ego, paddo; then tone down all the 'personal' and 'source' stuff a little bit, hey?

 

[Undefined]

Just to clear up that twisted point you have tried to make...
I'm at this site to answer questions when I can, and to learn from other reputable contributors.
I enjoy speculative ideas, I encourage Innovation, I encourage Imagination...why I even partake in them myself.
I do not though encourage or support any one with delusions of grandeur, coming here, saying they have rewritten a 100 years of physics and cosmology.


In other words just as I have said a dozen times.


And undefined, despite your accusations and claims about me, and what you think of me, both our conduct will be judged by our peers and moderators here.
I'll stand by that,

I'm here for the objective science based discussion of new ideas/perspectives. What you're here for is your affair. The two types of interactions occur here; that is, new ideas discussion and old text exchanges. Just carry on with what you want to get out of the site; don't confuse the two activities; and you won't be disturbed by what 'the other half' is doing. Chill.

 

[paddoboy]

I'm here for the objective science based discussion of new ideas/perspectives. What you're here for is your affair. The two types of interactions occur here; that is, new ideas discussion and old text exchanges. Just carry on with what you want to get out of the site; don't confuse the two activities; and you won't be disturbed by what 'the other half' is doing. Chill.

That's quite admirable....Let's hope we have no more claims of people supplanting GR or the BB or any other delusional theory without peer review.
Because they will be challenged by many here.

 

[paddoboy]

I only presented GR/spacetime facts about what different types of GR warping entail and their inherent propagatory/non-propagatory nature/limitations. What you 'read into' the scientific information I and Declan have presented for your benefit is entirely up to you IF you wish to read it subjectively instead of understanding objectively. That was all that is suggested: Objective reading/assessment. No more; no less.

I read very carefully the three reputable links I gave re GR BH's and EH's.
They all made perfect sense to me and supported what I have previously read and heard.
I also read your relevant post but was not really impressed with it at all.
So there I am in a quandary.....the three links of mine aligning with what I already knew, or the 4 or 5 different other Interpretations as outlined by you and others, each not only contradicting the mainstream version and my links, but all contradicting each other, and none having been peer reviewed.

I really don't think any more need be said.

 

[Beer w/Straw]

I'm here cause I heard this is where they were handing out the Word Salad Awards.

Also to meet some distinguished and would-be authors. One of whom should be due his five Nobel Prizes soon!

 

[origin]

You can't imagine extrapolating przyk's SUPERSIZED BH scenario where the EH was so 'gentle' that the infalling observer would feel nothing untoward? Try extraolating that to a UNIVERSAL SIZED BH scenario where that 'gentleness' can almost be described as 'flat space'; and further extrapolate that any 'visible universe' content/process like that which we observe may exist at such a 'flat' space region EH of an unimaginable huge BH. That was all it involves. Your own extrapolation and imagination based on what przyk pointed out obtained in his example. Ok now?

It was OK before. You can 'extrapolate your imagination' all you want. The point remains that what you're imagining is absurd.

 

[Farsight]

If that is your point, then you really need to get to know me better. Because I think that in total Einstein and myself are in perfect agreement of about what GR is. It's become fuller and more robust since Einstein first published his 1915 papers. He and others have fine tuned it over the years. But there is no conflict in what Einstein thought GR is and what I think it is.

You do realize that Einstein wrote many papers on GR, presented several ideas and interpretations that he later discarded, right? You can not pick any one paper and say "Einstein says,,,, " and be sure of being correct. Each individual paper or interpretation has to considered in the context of the entire canon, because ALL scientists are like ALL other people, they form, present, retract and tweak their ideas all the time.

Noted Declan. Let's see how it goes.

 

[Farsight]

It's not a spatial curvature. You can think of the electromagnetic field as a "curvature", but it's associated with an abstract phase coordinate space (related to an arbitrary phase convention you can use for the charged matter field in QED). Roughly, the Faraday tensor tests for the presence of a nontrivial electromagnetic vector potential (i.e. one that can't be eliminated by changing the field phase convention) in the same way that the Riemann curvature tensor tests for the presence of a nontrivial gravitational field (i.e. one that you can't completely eliminate by changing the coordinate system).

There's something very real underlying that "abstract phase coordinate space", przyk. But let's talk about it some other time.

But switching coordinates isn't "putting a stopped observer in front of a stopped clock", so you haven't at all criticised what these derivations actually did. Also, you're presuming your own conclusion. It's true that if everything were really stopped at a black hole event horizon, then it would be meaningless to try to identify locally inertial reference frames there, and any attempt to do it would fail. But you've never shown that, and when we try it, it doesn't fail.

I've criticized them till the cows come home. The clock stops. You can't eliminate that by changing the coordinate system.

No. Formally, at the level of how the theory is mathematically defined, the metric defines a scalar product between vectors. It also provides a distance measure (specifically the spacetime interval in GR) simply because, in geometry, a vector's length is the same thing as the square root of its scalar product with itself. When you express the spacetime line element $$\mathrm{d}s$$ in terms of infinitesimal coordinate changes $$\mathrm{d}x^{\mu}$$, the metric components $$g_{\mu\nu}$$ give you a measure of how locally stretched or twisted etc. the coordinate system you are using is.

And again, when your light clock stops, you aren't going to be measuring any distance or time. We've spoken previously about the SR invariant spacetime interval being related to lightpath lengths. The lightpath length is zero.

I've only ever seen that picture in popular science-level expositions of general relativity. I've never seen it actually derived from GR, and as far as I know there isn't any sense in which it is an accurate depiction of the Schwarzschild geometry.

I'm saying there is a sense in which it's a fair depiction of a black hole. The black region is a hole in your metric.

But generally not at the event horizon. That's the point. Calculate invariant curvature measures from the Schwarzschild metric and you'll find they're generally finite and can be arbitrarily small for a large enough black hole. If you had an inertial astronaut as close as you like to the event horizon of a large enough black hole, they wouldn't experience anything special or uncomfortable there. They generally wouldn't be torn apart by tidal forces, for instance.

No problem. I was saying as such to James.

 

[Farsight]

Actually, they'd instantly die. They'd be 'sucked in' by the huge gravitational well, and then be beyond the EH (or 'frozen' at the EH if you accept Farsight's interpretation). If you are 'arbitrarily close' to an EH, without any kinetic energy moving you away from the BH's EH, you are then going to be falling into the BH. Whether you 'cross' the EH or are 'frozen' at the EH is irrelevant. You are dead. This is true even if it is a pre-blackhole such as a neutron star that is still sucking in matter, just before it collapses into a BH. If you fall to the 'surface' of a neutron star you are squashed flatter than a pancake, and your atoms are all turned into neutrons (one huge nucleus of neutrons). It's even worse for you if the neutron star takes in more matter and collapses into a BH.

Actually Walter, I think they'd die way before that. Check out Friedwardt Winterberg's firewall. If I were to drop an astronaut into a black hole, he would fall faster and faster and faster. But the coordinate speed of light gets lower and lower and lower as he approaches the black hole. Something's got to give. Pooof. At some point, I see a little gamma-ray burst. Well, quite a big one actually.

 

[Farsight]

My own reaction long ago (and still current) to the initial hypothetical of pair-separation near event horizon etc, was: How the heck can a background ZERO energy that DOES separate into TWO opposite energy states WHICH STILL EQUAL ZERO energy taken together, and which cannot, as far as the GRAVITY will drag them BOTH downwards into the EH, be imagined to affect the BH energy content EITHER WAY?

They fall in, they equal ZERO energy, and the quantum states of the BH are unaffected one way or the other, surely? Else if the energy-pair can increase the BH mass/effect/extent, then every black hole that was ever created by implosion of spent star cores would eat up surrounding 'virtual quanta pairs' and grow in no time to universal size!

There is definitely something left to be sorted out in HAWKING RADIATION and like hypotheses before anyone can take them seriously, in my opinion based on the above observation. Still, it IS fun conjectures, and fodder for 'all those betting types', hey?

All points noted, Undefined. I concur. Doubtless paddoboy will defend Hawking radiation to the death.

If both fall in together, the net gain by the BH is zero.

The idea is that the pair have been created from vacuum energy. Spatial energy. Dark energy if you like. Outside the black hole. So if they both fall in the black hole grows.

If they both fly off together, the universal net is still zero. If the negative of the pair falls in the total in the BH goes down a net 1, but the stuff outside goes up a net 1. The universal total is the same. But the black hole has gone down, the outside stuff has gone up.

There are no negative-energy particles.

But the real problem I have with Hawking radiation, is statistical mechanics dictates that just as many of the in-falling of the pair will be positive as there will be negative, so in the end the Hawking radiation puts in just as much as it takes out and makes me want to just forget Hawking's tunneling virtual pairs to keep things simple.

It makes me want to forget Hawking radiation altogether.

 

[James R]

Farsight:

There's not much point in arguing with you on this any further, as far as I can see.

General relativity tells us that nothing special happens to the proper time of an observer falling into a black hole. The event horizon is a coordinate singularity, not a real singularity. Many alternative coordinate choices (other than Schwarzschild coordinates) remove the apparent singularity that occurs at the horizon. I can think of three commonly-used coordinate systems that have no singularity at the horizon, just off the top of my head. And I'm no expert.

So, you can talk about people with heartbeats all you like. The fact remains that somebody falling into a black hole will have just as much of a regular heartbeat as those sitting outside at a safe distance. For the infalling observer, nothing obviously special happens at the horizon. In particular, that observer's clocks and heart go right on ticking as usual.

If you have something that refutes any of this, then we might have something to discuss further. But if all you have is your assertions, I can't see that further discussion will be useful. I'll leave you to it.

 

[Farsight]

I have something that refutes it. But to convince you that it is refuted, I have to take it one step at a time. The first step is Time travel is science fiction. Read the OP, and indicate your agreement with it. It's very easy to agree with, it's all plain-vanilla mundane stuff. Then I give you the next step, which is more of the same.

 

[James R]

Farsight,

I don't agree with the whole post you linked.

For a start, I have a problem when you say something like "You can jump 1 metre, but you can't jump 1 second". The problem is that space and time aren't really separate. As you know, they are different aspects of spacetime, and are observer dependent. One observer's space is part of a relatively-moving observer's time, for example.

I don't see how the linked post is relevant, though, unless you're trying to propose some "preferred" standard of motion.

 

[Farsight]

James: you should find yourself in agreement with the sense of the post. You really shouldn't have a problem with "You can hop forward a metre, but you can’t hop forward a second. And you can’t hop backward a second either." You and I might move relative to one another as per the twins. Then when we meet up our clock readings are different. But we meet up at the same time, regardless of our clock readings. You don't jump into the past. Time dilation is not time travel. And time travel is science fiction.

The post is very relevant. You have to understand time, then the speed of light, then gravity, then black holes. And every step of the way you say, yes, I agree with that. You're left with the frozen-star black hole, and nowhere else to go. Any other position is untenable.

 

[James R]

James: you should find yourself in agreement with the sense of the post. You really shouldn't have a problem with "You can hop forward a metre, but you can’t hop forward a second. And you can’t hop backward a second either." You and I might move relative to one another as per the twins. Then when we meet up our clock readings are different. But we meet up at the same time, regardless of our clock readings. You don't jump into the past. Time dilation is not time travel.

The age difference when the twins meet up in the twin paradox is real. Do you agree?

 

[OnlyMe]

James: you should find yourself in agreement with the sense of the post. You really shouldn't have a problem with "You can hop forward a metre, but you can’t hop forward a second. And you can’t hop backward a second either." You and I might move relative to one another as per the twins. Then when we meet up our clock readings are different. But we meet up at the same time, regardless of our clock readings. You don't jump into the past. Time dilation is not time travel. And time travel is science fiction.

The post is very relevant. You have to understand time, then the speed of light, then gravity, then black holes. And every step of the way you say, yes, I agree with that. You're left with the frozen-star black hole, and nowhere else to go. Any other position is untenable.

Farsight, your example of hopping a meter or a second is flawed. In "reality" there is no difference. When one hops one meter, one must move across the spacial distance between the beginning and ending of that hop. The same is true for time. The change of location in space, during the hop of one meter, is associated with an equivalent change in time, as the hopper's location changes. The velocity of the change in location being the connecting variable.

The only real difference is that, one can turn around and hop back in space, while being unable to change direction in time.

Part of the difficulty is that "time" itself is an abstraction. It is a conceptual observation of change. Change does occur and it always occurs from the present to the future. Time is our way of conceptually providing meaning to the rate of change we observe.

To answer, Paddoboy's question earlier, while space exists and is real and change exists and is real, spacetime is an abstract geometry which is real only to the extent that it describes, reality . . , meaning that which has either been experimentally proven or observed as occurring in the world, apart from the theoretical model.

 

[nimbus]

Then we work to complete it and understand that "odd" implication.

For that try... Kruskal–Szekeres and Gullstrand–Painlevé.

This threads going nowhere and Farsight is offering nothing new in respect of challenging the coordinates systems of Kruskal–Szekeres and Gullstrand–Painlevé.
Those systems having no coordinate singularity anywhere except the central real singularity.
Farsight has not shown anything new of which Kruskal, Szekeres and Gullstrand and Painlevé were not already aware of when they formed their systems.
He is demonstrating his inability to understand an evolving GR.

 

[przyk]

I've criticized them till the cows come home. The clock stops. You can't eliminate that by changing the coordinate system.

This is repetition, Farsight. Not criticism. You're not actually criticising alternative coordinate systems because you never refer to how they are actually derived. You're instead dismissing them out of hand because you think the conclusion they show (that the clock isn't really stopped) contradicts what you believe (that the clock is stopped). Why should anyone believe the clock is stopped in the first place? You never explain that, and nor do any of the sources you link to.

And again, when your light clock stops, you aren't going to be measuring any distance or time.

What does this have to do with what I said? My point was that you have an inaccurate appreciation of what a metric is. Certain aspects of the metric are measurable. Others, such as the metric components $$g_{\mu\nu}$$ in a particular coordinate system, generally are not measurable.

Saying the metric is "what you measure" is useless. That's so vague it could mean anything.

We've spoken previously about the SR invariant spacetime interval being related to lightpath lengths. The lightpath length is zero.

What's the relevance of this? Also, the spacetime interval isn't just "related to lightpath lengths". In fact it's mainly defined for spacelike separated events, where it is generally nonzero.

I'm saying there is a sense in which it's a fair depiction of a black hole.

So how and where is this derived?

 

[paddoboy]

Actually Walter, I think they'd die way before that. Check out Friedwardt Winterberg's firewall. If I were to drop an astronaut into a black hole, he would fall faster and faster and faster. But the coordinate speed of light gets lower and lower and lower as he approaches the black hole. Something's got to give. Pooof. At some point, I see a little gamma-ray burst. Well, quite a big one actually.

On this point Walter is wrong...Tidal gravitational effects would be virtually nil for a SMBH, due to a more gradual gradient of critical space/time curvature. One could theoretically approach, and cross the EH, with no slowing or stopping of time and nothing extraordinary happening...At least until a lot closer to the real Singularity.

All points noted, Undefined. I concur. Doubtless paddoboy will defend Hawking radiation to the death.

Hmmmm, Interesting.....I don't believe I have spoken of Hawking Radiation in this thread, I've been too busy refuting the nonsense you are posting about GR and BH's in general.
But actually, quantum mechanical reasoning, does support Hawking Radiation, and I also see it as quite viable and a logical outcome.

I have something that refutes it. But to convince you that it is refuted, I have to take it one step at a time. The first step is Time travel is science fiction. Read the OP, and indicate your agreement with it. It's very easy to agree with, it's all plain-vanilla mundane stuff. Then I give you the next step, which is more of the same.

You have nothing but more delusions of grandeur and unsupported claims.
If you did have anything of any substance, that invalidates SR/GR, you would not be here.
Time travel also [as with the twin paradox] is theoretically possible, and in limited ways, we see it in particle accelerators and such.

The post is very relevant. You have to understand time, then the speed of light, then gravity, then black holes. And every step of the way you say, yes, I agree with that. You're left with the frozen-star black hole, and nowhere else to go. Any other position is untenable.

Realy? Are you serious? And the reason why you don't get all these aspects of reality peer reviewed is???? Oh yes, I know...the immovable stubborn nature of mainstream science.
So, you are a conspiracy theorist also?



You realize that if what you say you have was true [which it isn't] you would be a shoe in for next year's Nobel prize for physics?

 

[Farsight]

The age difference when the twins meet up in the twin paradox is real. Do you agree?

Of course. But you could achieve the same result a different way. Like this: twins born years apart.