JEROME - Black holes do not exist

[KingMerv00]

And both are incredibly dense.

Both stretch things out beyond all recogition?

Both are surrounded by clouds of hot gas?

Both bend reality?

Both make simple acts go on forever?

Both demand to be fed at all times?

 

[JEROME DA GNOME]

I wasn't looking at your avatar, I was looking at your posts. However, if you claim not to believe in Sky Daddy, I will be suprised, but I will take you at your word.

Avatar: an incarnation in human form

an embodiment (as of a concept or philosophy) often in a person

 

[Upchurch]

Avatar: an incarnation in human form

an embodiment (as of a concept or philosophy) often in a person

*sigh*

Given the context, the appropriate definition is this one:

4: an electronic image that represents and is manipulated by a computer user (as in a computer game)

 

[The Man]

In a sense, the term "Black Hole" is a made up item. Before "black holes" they were called other names. But they were all theoretical objects. Made up due to theory.

As opposed to something that was discovered, then given a name.

But that is how the scientific method works, theory to generate hypothesis, hypothesis to generate testable predictions which are either supported or refuted by observations. Naming things once then have been discovered is a matter of happenstance. Finding hypothesis to be confirmed or denied is science.

The invisible objects that stars rotate around might be what we think of when we say "black holes", but so far it isn't like we have photographic evidence that there are black holes.

No more then we have photographic evidence of photons, electrons neutrons and protons or atoms for that matter. Photographs just represent the interactions of these things that we have defined and named, some of those interactions being specifically what we define as and have named a photograph.

They could be neutron stars, or something we don't know about yet. Same for the massive objects causing all those huge jets of matter and energy to go shooting across the Universe, at almost the speed of light.

They could also be a giant toilet flushing everything in their vicinity jetting out the drain, but the observations fit what we define as and have named a black hole.

We call them "black holes", but from a super skeptical point of view, they are what they are. Black Holes is what we made up to call them.

There is noting skeptical about that point of view, it is a simple matter of fact, things are what they are regardless of what we choose to call them but it is the defining features that we ascribe to those names that tell us what things are.

Just like we make up names for all kinds of invisible objects. Sometimes we make up names before we even have evidence that something exist, then later find that there is something, just like was predicted.

It is not just making up names but ascribing the defining characteristics to those names. Finding an object with those defining characteristics is finding that named object.

But it is true, that Jerome did not say "Black Holes do not exist", which makes the topic title misleading. Of course some people will say this is all semantics, or nitpicking, or something. People say all kinds of things.

So what? What I don't get is why a few people get so emotional and insulting over the matter. It isn't like Jerome ran over your cat.

As the thread just keeps getting longer and longer, it is educational. If you want to really get some skeptics riled up, and have a really long thread, just say something like, "Neutrinos don't exist", or "There are electric currents in outer space".

For some reason that gets way more attention than trying to discuss sound science in a logical and rational way.

Discussing sound science in a logical rational way would require Jerome to clearly define what he considers sound science or at least just evidence, something that he has specifically stated that he will not do. Lacking in that, we are left with discussing the topic based on what Jerome is willing to assert which so far is that he did not say “Black Holes do not exist” but that they are made up and (or so) not evidenced. So although Jerome is not saying that he ran over someone’s cat, he is saying that the cat was made up and (or so) there is no evidence that it was run over. So, until Jerome defines what he would consider at least evidence, we are left with Jerome’s flat cat.


One of my previous signatures

“The more times you run over a dead cat, the flatter it gets”

 

[Dan O.]

A wedge world at the galactic center?

The orbital period p = 2πr/sqrt(GM/r). If the mass forms a circular wedge that tapers to a point at the center, M = πr^3dw (where d is the density, w is the width proportional to r). For any distance from the center, p = 2πr/sqrt(Gπr^3dw/r)*and the r's cancel leaving p = 2π/sqrt(Gπdw) so the wedge will rotate as a solid. Given the parameters of R=4.5AU, M=3.7e6 solM and d=5.5e3 kg/m^3 (the average density of the earth), we can find the wedge factor w = 1.4e-6 (a very shallow slope), the maximum width is 9.4e6 m, the orbital period is about 57 days and the maximum velocity is under 0.03 c. The gravity normal to the surface is just over 2g near the outer edge and tapers to 0 at the center.

My slide rule is a little rusty and it's possible that I slipped a factor here or there so these numbers should be verified.

 

[zosima]

A wedge world at the galactic center?

The orbital period p = 2πr/sqrt(GM/r). If the mass forms a circular wedge that tapers to a point at the center, M = πr^3dw (where d is the density, w is the width proportional to r). For any distance from the center, p = 2πr/sqrt(Gπr^3dw/r)*and the r's cancel leaving p = 2π/sqrt(Gπdw) so the wedge will rotate as a solid. Given the parameters of R=4.5AU, M=3.7e6 solM and d=5.5e3 kg/m^3 (the average density of the earth), we can find the wedge factor w = 1.4e-6 (a very shallow slope), the maximum width is 9.4e6 m, the orbital period is about 57 days and the maximum velocity is under 0.03 c. The gravity normal to the surface is just over 2g near the outer edge and tapers to 0 at the center.

My slide rule is a little rusty and it's possible that I slipped a factor here or there so these numbers should be verified.

Ah, well that makes more sense than 45 AU. I was thinking about trying to find some time to do the integral, if I get a chance, I'll do a double check.

Thanks for all the info. (-:

 

[Paulhoff]

My slide rule is a little rusty and it's possible that I slipped a factor here or there so these numbers should be verified.

Well it doesn't really matter, if there where something like that, it wouldn't last long as it collapses into a black hole.

Paul

 

[zosima]

Well it doesn't really matter, if there where something like that, it wouldn't last long as it collapses into a black hole.

Paul

Well, I think the point is, that if it had the correct, improbable, density distribution, that the acceleration due to gravity would be balanced by centripetal acceleration.

Whether it lasts doesn't really depend on the balance of forces but whether it is stable with perturbations. If it were it wouldn't collapse, although my intuition is that it would be unstable.

 

[Paulhoff]

Well, I think the point is, that if it had the correct, improbable, density distribution, that the acceleration due to gravity would be balanced by centripetal acceleration.

Whether it lasts doesn't really depend on the balance of forces but whether it is stable with perturbations. If it were it wouldn't collapse, although my intuition is that it would be unstable.

For the same reason that the rings of Saturn are not solid, the same is true for a solid disk of that size, it would be extremely unstable.

Paul

 

[zosima]

For the same reason that the rings of Saturn are not solid, the same is true for a solid disk of that size, it would be extremely unstable.

Paul

You may be right. Though, there is a little subtly in the argument that your example doesn't capture. I apologize if you are already aware of it.

In the rings of Saturn, gravity from Saturn(and Saturn's moons to be technical) is significant, but gravity from the rings is not significant. This means that the angular velocity at each different stable radius will be slightly different. The solution proposed varies the density of the disc so that the gravity from the disc is significant. In fact it is designed so that gravity from the disc is defined to scale acceleration linearly with distance from the center of mass at all points, in the same way that centripetal acceleration scales linearly with distance.

So the question is if we perturb the distribution of mass in this disc, does it change the solution in such a way that it becomes unstable? Another question is what material we could use that would allow us to vary the mass density(although maybe a circular wedge would solve this problem). Since, in theory, there is 0 net force at any point, we might imagine that the resistance to perturbation in the disc would be at least greater than the strength of the bonds in the material.

 

[Dan O.]

Ah, well that makes more sense than 45 AU. I was thinking about trying to find some time to do the integral, if I get a chance, I'll do a double check.

Thanks for all the info. (-:

45 AU is correct. My spreadsheet says 4.50e1

Does a world need a sun? This would be the ultimate solution to global warming where the climate is balanced between the power generation needs and the black body radiation. We of course would see very little radiation from the wedge since it would be edge on from our perspective.

 

[zosima]

45 AU is correct. My spreadsheet says 4.50e1

Well that is pretty much that. Guess it isn't happening.

Does a world need a sun? This would be the ultimate solution to global warming where the climate is balanced between the power generation needs and the black body radiation. We of course would see very little radiation from the wedge since it would be edge on from our perspective.

I guess it depends on whether you want it to be habitable. I guess in the situation that we're talking about where we have improbable and unnatural configurations matter we could easily just have some suns orbiting up above or below the disk. I think in the stuff I've read about Alderson disks there would actually be a hole in the middle and the sun would oscillate up and down through the hole, first illuminating one side then illuminating the other.

If the sun popped up through the center, depending on the angle of the wedge, I could imagine it making a pretty steep angle with the surface. In fact a wedge shaped disc make a better angle with an oscillating sun. The cool thing about the configuration is that you could get a back and forth sun oscillation through the hole without applying an excess energy, although I think a wedge would decrease the efficacy of this property.

In an ideal disc, when you are on the surface the planar components of the gravity cancel, as you move above the surface gravity actually increases as the disk is better approximated as a massive point source; as planar components tend not to cancel. Thus the sun is sucked back down through the hole, potentially bobbing up and down for a very long time.

I'm not sure what you mean about black body radiation. We'd still need a power source that would heat the disc to maintain a constant black body.

 

[rsaavedra]

Does a world need a sun?

This made me think of life forms not needing at all visible light from a star, but radiation with shorter wave-lengths. Life forms that would depend on ultraviolet, X-rays, or even gamma rays! Now that would be weird. Of course, that wouldn't be a life-form based on the DNA structures we know; would need to be based on some other molecules / structures entirely.

 

[Dan O.]

I don't think a wedge world would be a natural formation. There is nothing to stop a central mass from accumulating and the rest of the mass would probably tend to break up into individual planets. But unlike Ring Worlds, Dyson Spheres, and other advanced habitats, material strength is not an issue with a wedge world. Construction is simply a matter of accumulating debris, transporting it to the rim and dumping it there.

All the energy the inhabitants of the wedge world need could be generated internally by controlled fusion (which is much more efficient than energy produced in a star that mostly escapes as radiation and probably easier on the nerves than waiting for the day your sun decides to go nova). Most energy produced will eventually be released as heat and all the heat will eventually radiate into space. The balance between the energy produced and the thermal radiation into space will determine the average temperature of the world. The world would also not be dark as all of the suns in the galactic core would be shining on this world.

 

[zosima]

I don't think a wedge world would be a natural formation. There is nothing to stop a central mass from accumulating and the rest of the mass would probably tend to break up into individual planets. But unlike Ring Worlds, Dyson Spheres, and other advanced habitats, material strength is not an issue with a wedge world. Construction is simply a matter of accumulating debris, transporting it to the rim and dumping it there.

All the energy the inhabitants of the wedge world need could be generated internally by controlled fusion (which is much more efficient than energy produced in a star that mostly escapes as radiation and probably easier on the nerves than waiting for the day your sun decides to go nova). Most energy produced will eventually be released as heat and all the heat will eventually radiate into space. The balance between the energy produced and the thermal radiation into space will determine the average temperature of the world. The world would also not be dark as all of the suns in the galactic core would be shining on this world.

Actually I was just thinking about it and I think there may be a problem with a wedge world. I think you may only be able to get a force free situation with a completely flat disk that has linearly varying mass-density with radial distance from the center.(Assuming the solution is correct, I have not yet verified)

The problem would be that the top of the wedge while orbiting at the same speed, the orbital angle would tend to be downward and the orbital angle from the bottom of the rim would tend upward. The only 0 angle would be the angle of the ecliptic. All the mass would tend to move around the center of mass, giving different orbital inclinations to different parts of the wedge. This would create a force within the material of any solid structure and would probably cause collisions in a non-solid structure.

That said, I could be wrong, it can be difficult to reason about this stuff, even a geometric plan like this gets pretty complicated.

I'll try to draw a picture.

|\ <----this rim tends to an orbit pointed toward center of mass(down)
|
|
|
|------------------* <----ecliptic orbit
|
|
|
|/ <-----this rim tends toward orbit pointed toward center of mass(up)

* = center of mass

 

[Dan O.]

More fundamentally, the wedge would have a column of mass up to 9e6 meters high with a gravity of 2.2g at the surface. This would create a vertical pressure many times that at the earths center. But because the centripetal force is balancing the radial gravity there is no radial pressure. The structure will collapse into an oblate spheroid like all good planets.

 

[JEROME DA GNOME]

*sigh*

Given the context, the appropriate definition is this one:

I introduced the word!!!


This is insane and all to common here.

The reader defines the words that are written and when corrected by the writer the reader tells the writer he is wrong.

This is insane.




ETA: Maybe I should try this. I could go about and redefine anything that I disagree with and ... THIS IS INSANE!!!

 

[sol invictus]

This is insane and all to common here.

The reader defines the words that are written and when corrected by the writer the reader tells the writer he is wrong.

This is insane.

How strange that people would understand what you say based on the definitions of the words you use!

 

[The Man]

ETA: Maybe I should try this. I could go about and redefine anything that I disagree with and ... THIS IS INSANE!!!

But that is what you’re doing in defining black holes as made up and not a consequence of the well tested and confirmed principles of General Relativity. Conversely you take the opposite approach as to the term “evidence”, which you refuse to present your definition of while claiming black holes are not evidenced. For one proclaiming the significance of the definitions intended by the writer you certainly take a different tact when asked to define what you mean by “evidence” in your writing. If you choose to call that “insane” then that is your prerogative as the writer of such inane assertions.

 

[Paul]

I introduced the word!!!

Well done, would you like a biscuit?

This is insane and all to common here.

It certainly is in this thread.

The reader defines the words that are written and when corrected by the writer the reader tells the writer he is wrong.

That depends on whether the writer is deliberately using, or pretending to use, words in an unexpected way or with an entirely new definition.

This is insane.

I think you've established that already.

ETA: Maybe I should try this. I could go about and redefine anything that I disagree with and ... THIS IS INSANE!!!

Maybe you should try this: when you use a word with a meaning which should be obvious given the context, but which you have decided has an entirely different definition, you could link to the definition you wish to use. This would remove any misunderstandings and save you from having to not tell use anything more than once.