Is There a Giant Black Hole at the Centre of the Universe?

[Brad_Ad23]

No problem. I suggest some helpful things to search for are potential energy, escape velocity, and dark energy.

 

[russ_watters]

Originally posted by M. Gaspar
Purely curious: Have there EVER been mathematical "PROOFS" that have eventually been "proven" to be false?

What if something vital is omitted from an equation?

If you're wondering if we'll find the math behind black holes to be flawed, I find it unlikely that there is much wrong with the equations. Years after the equations were worked out (which was before any were found), black holes have been found and the equations have been verified by observation to be accurate.

 

[Sting]

One thing that is important concerning the fact that there is no "center" of the Universe since something like the Big Bang happened to space, not in space.

 

[Brad_Ad23]

Very true. It is not an explosion like many people picture in space. But rather it is an explosion of space...in other words every point is the center.

 

[Mr. Robin Parsons]

Lets see, escape velocity is the speed required to overcome the gravitational force, as to escape it.

The event horizon of a Black Hole is the point at which the escape velocity goes SUB-LIGHTSPEED, or SUB C, drops below C for the very first time, which is not to say that there is no longer any gravity there, just that the escape velocity has decreased to a point at which light could/can escape the gravitational atraction currently working there.

On the inside of the event horizon of a black Hole the escape velocity would be greater then C.

Gravitational atractiveness drops off relative to distance, the divided by D², hence it has the abitlity to delineate space as per it's relative strength, the reason why there is an event horizon in the first place.

But the gravitational attractions do not stop at any point outside of the gravitational body, at no known distance does gravity stop working, hence all matter will,eventually, be gravitationaly recondenced.

 

[M. Gaspar]

Mr. Robert Parsons

PLEASE TELL ME YOUR ARE A SCIENTIST OR MATHEMATICIAN...

not a crackpot like myself.

I will FRAME your last posting if you are.

 

[Mr. Robin Parsons]

Sorry, neither of those professionally. (nothing right now 'Professionally')

It has been a bane in my recent life that I have NOT been able to obtain the accreditation that I am due, so, till that happens, I am just Mr. Robin Parsons...47 years old, and lots of that time spent thinking, in study, learning, on, and on, and on, but Thanks for the compliment, just the same.

 

[Brad_Ad23]

Unfortunatly there is one thing that seems to be neglected here. As I suggested looking up, dark energy. It is another force of sorts that is driving the expansion of the universe. So it is not just material moving away itself, it is the actual fabric of spacetime expanding between any two points.

 

[M. Gaspar]

Mr. Robert Parsons...

Please factor in the "dark energy" per Brad and see if the Universe still collapses. Might there be a countervaling force to dark energy that has not, as yet, been theorized or "discovered".

Indeed, is dark energy the results of a mathetical theory based on observations...or is is something measurable (and I don't mean by its EFFECT).

Remember, I'm currently ill-informed, so please be kind (Brad).

 

[Mr. Robin Parsons]

And another one being neglected is "Dark Matter" which is needed to 'square up' the observed motion of the galaxies, the idea that the entire galactic disk turns as if it were 'one thing', unlike the water going down a drain analogy which swirls faster at the center and slower at the outer edge.

Dark energy, well, proven to be?, or speculated? as to fill in certain 'missing elements' of the current theories of the universe?

Brad_Ad23, your turn!

 

[Mr. Robin Parsons]

Brad_Ad23, an assist, (perhaps) look https://www.physicsforums.com/showthread.php?threadid=704", perhaps you will understand it better.

 

[M. Gaspar]

Mr. Robert Parsons...

You're becoming VERY VALUABLE to me. Thanks for the lead.

(How'd you DO that?!) (Also, how to capture quotes?)

 

[M. Gaspar]

Oh my God...

Your name is ROBIN. I got it now.

 

[Mr. Robin Parsons]

It's done like this <url=" insert adress here"> Type words here </url> and the capturing of quotes is two manners, one is to use the "quote" button on eveyones posting, or simply type <quote> the text goes in here that you want cited </quote> (you can simply copy/paste the quotable sections)

The only catch is that I have used the < > 'greater then' and 'less then' signs to demonstrate the usage, the right ones to use is the bottom set of brackets [ ].

The reason is that if I did it the other/right way, you wouldn't be able to see it. There are explanation on the forum itself, in the FAQ's section, Greg's put up several notices on the math symbols, your window for typing has several features that allow you to play with text Fonts, Colors, SIZES, and lots of other little toys of the trade, so explore!

 

[Brad_Ad23]

Yes actually that did help. It shows several things: One dark energy is acounted for, and does much more than dark matter (since that only interacts gravitationally as well). And it also shows how silly the notion of the universe folding on itself is. It will keep expanding. Scaling down a dimension, imagine a sphere that just keeps getting larger and larger. It won't ever fold on itself.

 

[Eh]

Andrei Linde posted a paper a while back on the subject of dark energy. Under some models of super gravity, the dark energy (assumed to be vacuum energy from QM) driving the acceleration would not continue to increase as time goes by. Instead, the value would eventually stop increasing, and then drop towards zero. But it wouldn't stop there - as the value would begin to take on a negative value. An omnipresent dark energy with positive preasure would then cause the universe to contract.

There was a topic about this on the old PF, but I'll see if the article is still lying around somewhere. Does anyone here know anything about super gravity?

 

[M. Gaspar]

Eh...

From Oxford Dictionary of Science (1996) ...

Supergravity: A unified-field theory for all the known fundametal interactions that involves supersymmetry. Supergravity is most naturally formulated as a Kaluz-Klein theory in evleven dimensions. The theory contains particles of spin 2, spin 3/2, spin 1, spin 1/2 and spin 0. Although supersymmetry means that the infinities in the calculations are less severe than in other attempts to construct a quantum theory of gravity, it is probable that supergravity still contains infinities that cannot be removed by the process of renormalization. Is is thought by many physicicts that to obtain a consistent quantum theory of gravity one has to abandon quantum field theories, since they deal with point objects, and move to theories based on extended objects, such as superstrings and supermembranes, and therefore that supergravity is not a complete theory of the fundamental interactions.

Eh: I hope that was helpful. And if you can come through with recent data that supports the eventual collapse of the Universe, I will be grateful.

 

[Brad_Ad23]

Yes, supergravity theories are nice and all, however they have shown to be inadequate, which is why most of the research is now turned to the current big 3: M-Theory, Loop quantum gravity, and Twistor Theory (to a lesser extent than the other two)

 

[Mr. Robin Parsons]

Try this one...

https://www.physicsforums.com/showthread.php?postid=11626#post11626"

 

[Eh]

For reference, here is the article I was talking about: http://news.bbc.co.uk/2/hi/sci/tech/2346907.stm

 

[M. Gaspar]

Eh...

I can't tell you how thrilled I am with the article you referenced.

I agree with it somewhat, except I would not use the phrase that the "Dark Energy" will turn "negative"...but believe that perhaps there will be a "trigger" (overall temperature drop, perhaps) that will cause the "Dark Energy" to convert to "Dark Matter" to start the implosion process of the Universe.

And while I agree with Prof. Linde's conjecture that the Universe will collapse, I do NOT agree that it is "doomed to disappear."

In fact, might it not be possible that it would contract to a singularity that, in turn, would burst forth into the NEXT "Big Bang".

This is a "Life Cycle" that I can live with...and that the Universe can LIVE WITH TOO!. Expanding out into a frigid eternity doesn't even appeal to the cosmologists who are proposing it. It is much more satisfying (to ME, at least) to believe the Universe is an "eternal entity of energy" that enjoys infinite incarnations via the expansion/contraction model.

In fact, as I have said before, I believe the Universe is a living, conscious Entity that evolves -- as we do -- via infinite incarnations. [?] [?] [?] [?]

But that's off topic.

 

[Eh]

The reference to negative energy seems to actually be about preasure. Normal matter has positive preasure, while the dark energy of the vacuum is said to have negative preasure and so does not gravitationally attract. The transformation would be that negative preasure becoming positive.

 

[Messiah]

Originally posted by KL Kam
the universe doesn't have a centre

Using any given point in space as an X,Y,Z axis, one may theoretically extend equidistant lines to infinity through the limitless spectrum of polar coordinates. The procedure inscribes a sphere which theoretically encompasses the Universe. By definition, the selected point is the center of that sphere - and the center of the Universe. Since the same can be done for all points, it seems every position in the cosmos is its center.

 

[Mr. Robin Parsons]

The center of the universe is everywhere, just that our limited perception of it allows us only to see it somewhere.

It is because the light is invisible to our eyes, all we ever see is light when it is interacting with matter, NOT when it is traveling from source, to surface, rebound, back towards surface or source, ad infinitum, sorta, it wears out in time due to interactive energy loses, hence, dark, if not replaced by more light!

It is a constant activity