Speed of Light Past Event Horizon

If gravity is a wave,following the rules of the universe as we know them at present, Max Speed=C, then it could not attain sufficient velocity to escape a black hole.A black hole would be sealed off from the rest of the universe, it would be self-healing, so to speak.If however, it is a geometeric funtion of spacetime, the characteristics of a black hole would be as observed today. If we ever observe a ripple in the gravitational field that originates inside of a black hole, then it will probably be an instrumentation error.

In accordance with the conservation of momentum principle, a photon entering a black hole will orbit the center at a faster and faster rate, as it's orbit decreases to sweep out an equal area in the same amount of time, so a photon will orbit almost forever once near the singularity until it makes it's final rotation, and then the momentum will be converted into energy, which cannot escape.(Hawking radiation aside),Therefor the singularity must be a reservoir of energy, trapped by gravity, the unforgiving attractor of everything except spacetime itself, which is a "skin" that serves to keep our universe contained separate and apart from other universes.Can a singularity ever become "sharp" enough to penetrate that skin and emerge into another universe as a "white hole"?

Only Time will tell, and right now, Time is silent on the subject.

HTRN

Hi HTRN,

Yes, gravity is not a 'wave', hence things outside can observe the gravity of a black hole. It is a field or curved spacetime, being static for a non-rotating BH. Also true, we can only observe 'ripples' in the spacetime that originates outside the event horizon. Anything that falls in adds to the energy of the BH (or of the singularity, if you want).

According to our best theories, a photon will only 'orbit forever' if it is in a perfectly circular orbit at r=3GM/c² around a non-rotating BH. If it strays inward from there, it will fall more and more radially, until at the horizon (r=2GM/c²), it will travel precisely radially. Inside the horizon, it has only one possible path - radially towards the central singularity, scientists think, but are not sure; all their theories break down at the BH singularity.

It may also be quite different for a spinning BH - a photon may perhaps not fall all the way to the central singularity, but may 'tunnel' to another dimension and be spewed out. This may be the white hole that you referred to, but nobody knows...

-J

Hi HTRN,

"If gravity is a wave,following the rules of the universe as we know them at present, Max Speed=C, then it could not attain sufficient velocity to escape a black hole.A black hole would be sealed off from the rest of the universe"

I think you have hit upon the reason for the article that Jorrie and I were discussing. Everyone agrees that gravity is instantaneous (or nearly so) except for hypothetical gravity waves. See paragraph 3 in post 91. So one would have to conclude that gravity is not a wave (except possibly when it is disturbed).

"Can a singularity ever become "sharp" enough to penetrate that skin and emerge into another universe as a "white hole"?"

A singularity has no size by definition (but they are hypothetical). I think that white holes have been shown to be impossible. From Wikipedia:

"...such a solution of the Einstein equations has a white hole region in its past.^[1] This region does however not exist for black holes that have formed through gravitational collapse, nor are there any known physical processes through which a white hole could be formed.

-S

Ok, so we said that using fluctuations in gravity may be a way to transmit information faster than light, what about a magnet. I know magnetic forces are not the same as gravity, but as I understand it neither are exactly defined yet.

I read somewhere that they tested the speed of light by bouncing a laser off a mirror and something???

Well, if you used a magnet to switch on the laser and sensor, you could show that the magnet activated the sensor before the light from the laser made it back.

Drew

My problem with the concept of a gravity wave is that I cannot grasp the idea how to modulate gravity and remain consistent with the field equations. Matter cannot appear and disappear from the space distorting object. The spatial inertial location of the mass will not change without imposition by an outside force, however since equal and opposite forces will happen on both inertial references the net gravitational field will not have changed. (That's not well phrased, I need more caffeine.|_P ) I realize that I have only a classical view of gravity here. But to my knowledge, any new theory must comply with the earlier theory in the regions that the earlier theory demonstrated true. (More coffee, please.)

Hi RF, you wrote: "My problem with the concept of a gravity wave is that I cannot grasp the idea how to modulate gravity and remain consistent with the field equations. Matter cannot appear and disappear from the space distorting object."

In Einstein's field equations (EFEs), any two masses in orbit around each other generate gravitational waves (or 'modulate' the gravitational field, so to speak). The energy going into those ripples in the field (energy which can be transferred to distant objects by alternately squeezing and stretching them) is lost from the total orbital energy of the two objects. The energy transferred is long-wave and extremely small at large distances, hence the difficulty in detecting those waves. If gravitational waves do not exist, the EFEs must be wrong at a fundamental level, which is possible, but unlikely. They are in all likelihood incomplete, but not 'wrong'.

BTW, even Newton's theory of gravity predicts some form of 'gravity wave', called 'tidal gravity' (causing the Earth-Moon-Sun coastal tides), but it is different from the gravitational waves of the EFE. It is a relatively short range effect which, in a way, acts as the 'antenna' for the gravitational waves of EFE, but that's a long story...

-J

Hi J,

I think I have found a worse article than the Meta-science one. This one is on gravity waves. How would you categorize this one?

-S

Hi S,

No, nothing wrong with that article. The problem lies with unfortunate 'overlapping' of terminology between the two disciplines. The relativistic ones are actually called gravitational waves and the atmospheric (or fluid dynamics) ones gravity waves, but they are quite different beasts. The only connection they have is that gravity is a mechanism in both. The ripples on a pond are, in a way, gravity waves. Only the ripples in spacetime qualify as gravitational waves.

-J

Hi Drew.

"what about a magnet"

Lots of things are unknown, but magnetic fields are part of electromagnetic waves which travel at c. I am sceptical that any information can travel faster, but would encourage any experiments to find out.

"I read somewhere that they tested the speed of light by bouncing a laser off a mirror and something???"

Mirrors have been used many times in measuring c. Here is some history if c measurements.

-S

Wikipedia is not an authoritative source, as it's content is constantly updated by viewers.

Even if it were, the key phrase here is "known physical processes".We know nothing about what happens in the "core" of a black hole.We can only speculate.One idea is as good as another.

What if there is another state of matter/energy that exists that is spewing out "strings" of this "unknownium" into our universe and forms the basic building blocks of all matter?This would be a complete loop.Everything recycled.No matter or energy lost or destroyed, simply converted.This tends to follow all of nature's laws of conservation.

Perhaps the emmission point is as diffuse as the black hole is concentrated:Everywhere!

Or perhaps not.

HTRN

It is hard to imagine a black hole with no spin,since they originated from a spinning mass.As the matter compressed, the rpm should have increased to the point that it (the singularity) should have a disc shape similar to our galaxy.The singularity must be a very cold energy pool, with no heat, as defined by current science, because not only do molecules not move, they do not exist.Wierd things happen at extremes of pressure and temperature.Normally, one would equate temperature with pressure:more temperature, more pressure, etc.

An Eistein- Boseman substance, can actually crawl up the side of the container, ignoring gravity.And these conditions are reproducable in the laboratory.Hard to imagine what special properties matter and energy could aquire at the extremes of a black hole.

Perhaps matter does have a limit to it's compressability that we are not aware of at present, and the singularity is made of this.

I know there is much to argue about a black hole being very cold, but consider the coldest spot in the universe(outside of the lab).It is created by an expanding gas cloud expelled by an exploding star, absorbing heat as it expands.

If a black hole ever exploded, the resulting expansion would absorb any heat around it in order to keep expanding. Same with the Big Bang, I would suppose.It may have started intitally with energy causing the explosion, but immediately would begin absorbing all avaiable energy in the surroundings as it expanded.It is still expanding, so it must be absorbing energy from somewhere.

The fluctuations in the expansion rate may be caused by a variation in the energy available from "outside" our visible universe.

There is some evidence that certain galaxies clusters are being influenced by matter (dark or otherwise) or gravity outside of our visible universe.

The deeper I dig into the well of knowledge, the bigger the hole of ignorance grows.Still I am not growing weary of the effort, and am energized by every nugget of enlightenment I find along the way.Sometimes it was "fool's gold" that I thought was the real thing, but actually had no real value.

You have provided many nuggets along my endeavor, and helped me to correct my course many times.I don't always agree with your opinion, but I do consider it when forming my own. After all, have you ever learned much from someone that always agrees with you?

HTRN

Would you like to take a trip through a wormhole? No guarantee you will return to your starting place/time:

Try this link.

http://www.spacetimetravel.org/wurmlochflug/wurmlochflug.html

HTRN