Maximum Gravitational Force

[Harry Costas]

Hello Little Bang

 

What do you mean by where did I get the proof from, that the universe is infinite.

 

What else could it be?

 

Do you think there is a wall at the end or another dimension.

[Racoon]

Been waitin' for ya Harry..

 

Ya' helped lil' ol' Racoon out about Blackholes earlier.. :circle:

Much Obliged..

 

My Brain has a hard time imagining an endless Space continuum :confused: :ebomb:

 

Sounds all so fascinating! :hyper:

 

:shade: :singer: :hyper:

[Little Bang]

Since the field strength of gravity is determined by the amount of matter(and/or radiation) packed into a volume of space or zero volume of space then the max field strength would be when all matter and/or radiation in the universe is collapsed into a single point.

 

As far as an infinite universe, since I can only see, at this time to about 15 billion years and we still see galaxies I can not saw the universe is infinite or not. There is no proof one way or the other.

[Tormod]

As far as an infinite universe, since I can only see, at this time to about 15 billion years and we still see galaxies I can not saw the universe is infinite or not. There is no proof one way or the other.

 

Correct. We have no evidence to prove or disprove an infinite universe.

 

We should not confuse the observable universe, which is finite, with all of the universe. The observable universe is defined by the limit of how far light has travelled since the big bang, seen from our point of view (ie from the Earth).

 

We know that the observable universe is not infinite, and that it is expanding, and as such it cannot have existed forever.

 

It is however impossible to infer much about the universe as a whole from this.

[coldcreation]

...... I can not saw ....

 

I have yet to hear what might the boundary look like (or what might it be) in a finite universe.

 

The boundary condition problem is old.

 

We pro-infinite universers have no problem with a boundary, simply because there is none.

 

cc

[HIENVN]

Is there a maximum gravitational force that an object can exert, similar to how the speed of light is the maximum velocity?

 

I have been thinking about this in regard to black holes. If a black hole exists in the center of a galaxy, it would be slowly but surely absorbing all of the matter of that galaxy. As it absorbs more matter it would gain mass and increase its gravitational force. This would keep increasing constantly as more matter was absorbed by the hole. The event horizon would grow outward until it had absorbed the entire galaxy. And then it would be a massive void in space absorbing additional galaxies that strayed into its area of influence. If that were the case it would be rare to see any old galaxies. Or their would be evidence of them shrinking.

 

Instead I think we are seeing a steady state, if you will, where the mass orbiting the black hole is in actually at an equilibrium. This would not happen if the black holes were constantly packing in more and more gravitational force. Everything in the galaxy would be in a decaying orbit as the gravity of the whole was constantly increasing.

 

This could could also play into the notion of "Hawking Radiation". If such radiation does exist, it would indicate not only the particle halves escaping the close proximity of the event horizon, but the particle halves trapped by it. That alone would mean that a black hole was a constantly growing entity.

 

Because I don't think we are witnessing such behaviors, I am left to conclude that there is a maximum gravity for a body. If this is so, what would it mean to the mathematics of General Relativity?

 

Bill

 

Scientists may maximum Gravitational Force, or even minimum this Force if they know about gravitational waves. This will happen so far in the future because recent scientists went to a wrong way for a discovery of gravitational waves.

Scientists are hunting for gravitational waves in the prediction of Einstein's general relativity theory in 1916. in my opinion, these scientists should hunt gravitational waves in a prediction of Einstein's unified field theory that he proposed in 1920.

[Qfwfq]

As far as an infinite universe, since I can only see, at this time to about 15 billion years and we still see galaxies I can not saw the universe is infinite or not. There is no proof one way or the other.

Actually, if we could make enough measurements of intergalactic distances, and angles subtended, to measure curvature and we found a fairly homogeneous value consistent with the Hubble constant, it would be rather strong evidence in favour of the standard model of cosmology, according to which space, at a given cosmic time, is a hyperspherical surface and thus not infinite but with no boundary. It'll take a long time, so start soon, fillin' up the universe with automata that'll make the measurements and radio back the data...

[Janus]

 

Instead I think we are seeing a steady state, if you will, where the mass orbiting the black hole is in actually at an equilibrium. This would not happen if the black holes were constantly packing in more and more gravitational force. Everything in the galaxy would be in a decaying orbit as the gravity of the whole was constantly increasing.

Bill

 

What gravitational effect would you expect on the Magellanic Clouds( Small satellite galaxies of our own) if the The Milky Way galaxy were to collapse into a black hole?.

Answer: None.

They would go on orbiting the newly created Black hole just as they did the Galaxy. The Black Hole has no more gravity than the stars that formed it, it is just that the mass of those stars are now squeezed into a smaller package.

 

Having a growing Black hole at the center of a galaxy won't put everything in in any more of a decaying orbit than they would be in if the core was just packed with stars.

[TheFaithfulStone]

a hyperspherical surface and thus not infinite but with no boundary.

 

Heed the words of Qfwfq! Heed them! For he is wise!

 

TFS

[coldcreation]

Heed the words of Qfwfq! Heed them! For he is wise!

 

TFS

 

True. Very Wise. Though, finite without bounds, or infinite with a boundary are purely geometric arguments. Observations are what is needed to determine the geometry of the natural world.

 

The latest evidence (post-1998) on observational fronts shows an infinite hyperbolic universe.

 

That aside, I find this thread interesting, not because of the hypothetical maximum of G, but it makes me think of the minimum gravitational force: zero. And thus the probability that there is no negative gravity, or anti-gravity: no negative curvature.

 

Don't fight the chill.

 

Yo.

[InfiniteNow]

Nice to see you around again cc. Cheers. :shrug:

[TheBigDog]

What gravitational effect would you expect on the Magellanic Clouds( Small satellite galaxies of our own) if the The Milky Way galaxy were to collapse into a black hole?.

Answer: None.

They would go on orbiting the newly created Black hole just as they did the Galaxy. The Black Hole has no more gravity than the stars that formed it, it is just that the mass of those stars are now squeezed into a smaller package.

 

Having a growing Black hole at the center of a galaxy won't put everything in in any more of a decaying orbit than they would be in if the core was just packed with stars.

What you say is true. But there would be a huge change in how objects would interact with each other. For instance the Milky Way and Andromeda are going to pass through each other in few billion years. It is said that because there is so much empty space in a galaxy that they will on a large part just pass through each other. If one of them were condensed into a single large black hole it would distort and absorb much of the other galaxy as it passed through - a huge difference.

 

Bill

[WillieB]

In my view the gravitational force is generated by the velocity of certaain particles which, for lack of a more applicable term, we will call a constituent of the graviton. In a field completely devoid of matter their velocity will be zero with respect to a stationary point. If a gathering of matter approaches an infinite value, their maximum velocity will approach c, the speed of light, multiplied by the square root of two. How to calculate the resultant accelerative force is beyond my ken.

[Janus]

What you say is true. But there would be a huge change in how objects would interact with each other. For instance the Milky Way and Andromeda are going to pass through each other in few billion years. It is said that because there is so much empty space in a galaxy that they will on a large part just pass through each other.

Here's a link to an image that shows two galaxies colliding, they are not just passing through each other, there is a lot of distortion involved.

 

http://www.universetoday.com/am/publish/ngc_520_merging_galaxies.html?2682005

 

If one of them were condensed into a single large black hole it would distort and absorb much of the other galaxy as it passed through - a huge difference.

 

Bill

 

Distortion, yes, but there will be distortion with a regular collision also. Absorbtion, not very much.

 

Consider: and Galaxy-massed black hole will have about 100 billion times the mass of the Sun. A sun massed black hole would be about 3km in radius. The radius of a black hole is directly porportional to its mass, so its radius will be about 300,000,000,000 km or 3/100 of a light year.

 

The acceleration due to gravity at the event horizon will be 15g.

 

Andromeda is heading towards the Milky Way at a rate of 100 km/sec. This speed will increase as it gets nearer due to acceleration caused by the gravitational attraction between the two masses. by the time the Black hole touches the outer edge of the Galaxy, their relative speed will be about 193 km/sec

 

At that relative speed, any star that is more than 50 ly from the path of the black hole will not be pulled into a trajectory that will intersect the event horizon of the Black hole. (the star will be pulled into a new trajectory, but the periapis of that trajectory will be outside the event horizon of the black hole.)

 

So the black hole will only absorb those stars that are in that 50 ly radius corridor. How many stars that is depends on exactly where and how the black hole passes through the galaxy. It will, of course, disturb stars outside that corridor, it just won't absorb them.

 

But the point I wished to make was that it was not necessary to posit a limit to gravity to explain why the black holes at the center of galaxies don't contiune to eat up their galaxies. It makes no difference to the Sun's path around the center of the galaxy if the stars at the center have been absorbed into a black hole or not. Those stars already contributed to the gravity controlling the Sun's orbit and their absorbtion into a black hole does not change this contribution.

 

Once the black hole finishes gobbling that material with orbits that take it close enough to the black hole, it simply runs out of fuel. The rest of the galaxy just continues along as if nothing happened.

[WillieB]

Harry Costas,

 

I was impressed by the thorough analysis of gravity in the link you posted (metaresearch.org)as a reply to Big Dog in answer to the thread "maxmum gravitatonal force." I would like to offer a potential answer as to why the gravitatonal force exerted on earth by the sun appears to be directed toward the instantaneous position of the sun rather than that position the sun was in when the gravitational force originated. In order to appreciate the explanation you must read "The Incremental Universe" which is also posted on this forum. Of particular relevance is discussion item 7 (Gravity and Momentum) and item 24 (The Casimir Attraction).

 

When increments depart a surface such as that of the earth or the sun they tend to be polarized so that their flows are perpendicular to that surface. Hence their graviational impetus will be directed to ward the surface from w hich they departed. As they travel toward the second surface (the earth)they will encounter the increments that have been polarized by departing from that second surface. Thus their polarization will become influenced to become more perpendicular to that surface (the Earth's) and when they strike the Earth they will direct their gravitional pull to a line which is perpendicular to the Earth's surface.

 

Whether or not this will result in a pull directly toward the instantaneous position of the Sun I will let you mathmaticians determine, but it certainly would pull this line in that direction.