Are Black Holes Truly Fiction? Examining the Evidence

[Red-Arrow]

I was talking to a very interesting person that made the case for Black Holes being the work of Fiction.

Can anybody else support this position?

 

[Dale]

Hi Red-Arrow, welcome to PF!

Can you outline the argument here? It is rather difficult to either support or contradict an undisclosed argument.

 

[HallsofIvy]

It is believed that black holes have been identified at the center of at least several galaxies.

 

[bcrowell]

The evidence for the existence of black holes is indirect, but extremely strong. See http://www.lightandmatter.com/html_books/genrel/ch06/ch06.html#Section6.3 (subsection 6.3.4)

 

[Nabeshin]

It's true that a lot of what is said about black holes is extremely speculative, plain wrong, or just science fiction. That said, the scientific community is quite resonant in their opinion of such objects -- there is a wealth of evidence supporting their existence.

 

[bcrowell]

Another way to put it is that at this point it would really be the *non*-existence of black holes that would be more like science fiction. That is, if you look for a theory that says that Cygnus X-1 and Sagittarius A* are not black holes, you can find such theories -- but they are extremely speculative and poorly supported by empirical evidence. For info about such theories, you can google on terms like black star, gravastar, fuzzball, quark star, boson star, and q-ball.

 

[Red-Arrow]

Well as I understand it all the evidence for Black Holes is all indirect? which means no proof exist directly, Is this scientific?

The case was made that Block Hole are a Psychological or Pathological invention. Then the Information Paradox was explained. Here is an exert from Wiki unfortunately.


"In 1975, Stephen Hawking and Jacob Bekenstein showed that black holes should slowly radiate away energy, which poses a problem. From the no hair theorem, one would expect the Hawking radiation to be completely independent of the material entering the black hole. Nevertheless, if the material entering the black hole were a pure quantum state, the transformation of that state into the mixed state of Hawking radiation would destroy information about the original quantum state. This violates Liouville's theorem and presents a physical paradox."

 

[russ_watters]

Well as I understand it all the evidence for Black Holes is all indirect? which means no proof exist directly, Is this scientific?

Any physical phenomena can only be described and defined by its properties. A "black hole" is a name given to a set of observed properties. Those observations exist. That's a fact.

 

[bcrowell]

Well as I understand it all the evidence for Black Holes is all indirect? which means no proof exist directly, Is this scientific?

Yes, science often deals with indirect evidence. For instance, the existence of atoms only became established over a long period (roughly the 19th century) based on indirect evidence.

The case was made that Block Hole are a Psychological or Pathological invention.

The case was made by whom? Please tell us your source.

Then the Information Paradox was explained.

What makes you think that the black hole information paradox is relevant here? The black hole information paradox has to do with quantum gravity. We don't have a theory of quantum gravity. The existence of black holes has to do with classical gravity. We do have a theory of classical gravity.

 

[Red-Arrow]

Any physical phenomena can only be described and defined by its properties. A "black hole" is a name given to a set of observed properties. Those observations exist. That's a fact.

Of course I understand this but the Black Hole was Theorized before it was even searched for, is that right?

Yes, science often deals with indirect evidence. For instance, the existence of atoms only became established over a long period (roughly the 19th century) based on indirect evidence.

Does the scanning tunneling microscopy not give us direct evidence of Atoms? do we have anything that can show us direct evidence of a Black Hole?

The case was made by whom? Please tell us your source.

It was Professor at a SoCal University.

What makes you think that the black hole information paradox is relevant here? The black hole information paradox has to do with quantum gravity. We don't have a theory of quantum gravity. The existence of black holes has to do with classical gravity. We do have a theory of classical gravity.

You are correct but it was mentioned in passing as another person join in.

I hope this thread stays on course. Can anybody make a case that Black Holes do not exist?

Any doubts at all from anyone? or does everybody sing from the same hymn sheet? I do not know the dynamics of this website but are unconventional ideas welcome or banned? I have no wish to be banned for a genuine question?

 

[George Jones]

Any doubts at all from anyone? or does everybody sing from the same hymn sheet? I do not know the dynamics of this website but are unconventional ideas welcome or banned? I have no wish to be banned for a genuine question?

Everyone agrees to Physics Forums rules when they join. These rules,

https://www.physicsforums.com/showthread.php?t=414380,

in part, state

Overly Speculative Posts: One of the main goals of PF is to help students learn the current status of physics as practiced by the scientific community; accordingly, Physicsforums.com strives to maintain high standards of academic integrity. There are many open questions in physics, and we welcome discussion on those subjects provided the discussion remains intellectually sound. It is against our Posting Guidelines to discuss, in most of the PF forums or in blogs, new or non-mainstream theories or ideas that have not been published in professional peer-reviewed journals or are not part of current professional mainstream scientific discussion.

 

[Dale]

It was Professor at a SoCal University.

Can you provide any details? There is more than one professor at SoCal and each professor has written more than one thing. Is the professor even a physics professor? You are being very evasive about your source, which probably means that even you do not find the source to be credible or that you are deliberately taking the quote out of context.

I do not know the dynamics of this website but are unconventional ideas welcome or banned? I have no wish to be banned for a genuine question?

Read the link at the top of the page labeled "Rules", particularly the section on overly speculative posts. That should give you guidance on what is permitted. This site is not for discussing unconventional ideas, it is for learning mainstream science.

Black holes are a prediction of the current best classical theory of gravity, GR. GR is considered the best because it fits the observed data better than any alternative theory with the fewest free parameters. There is a lot of observational evidence for GR.

While we do not currently have a quantum theory of gravity there are indeed some discrepancies between QM and GR. This is one of the reasons that so much effort is being put into developing a quantum theory of gravity. However, in the classical limit that theory must reduce to GR, so it is unlikely that black holes will not be a feature of a quantum gravity theory.

 

[russ_watters]

Of course I understand this but the Black Hole was Theorized before it was even searched for, is that right?

Yep. That's one of the neat things about science and compelling things about black hole theory (GR)!

But whether the properties were defined and given a snappy name before or after black holes were found doesn't really have anything to do with the conclusion that they exist.

I'm still uncomfortable with this "indirect evidence" thing. What does that even mean? Does a person who says that believe that the only thing that qualifies as "direct evidence" is a visible light photograph of the object itself? If that's the case, then there is an awful lot of hard science that is based on this so-called "indirect evidence".

As I said in my previous post, an object is defined and identified by its properties. One of the more critical properties that defines what our sun is is its mass. So too for black holes.