Gravitational acceleration

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18 years 9 months ago #14695 by Cindy
Replied by Cindy on topic Reply from
<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by tvanflandern</i>
This is just Hatch's way to limit the speed of the test particle to c, instead of speed going to infinity as Newtonian gravity would imply. -|Tom|-
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Thank you Uncle Tom,

1. Do you think Mr. Hatch's escape-velocity-equation is more correct compared to the classical escape velocity v = sqrt(2GM/r) ?
( Mr. Hatct also said that his equation imply no blackhole exist )

2. I wish to know how an escape velocity equation which is derived from GR look like. Would you inform me the GR-escape-velocity equation if you know it. Thanks

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18 years 9 months ago #14696 by tvanflandern
<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Cindy</i>
<br />Do you think Mr. Hatch's escape-velocity-equation is more correct compared to the classical escape velocity v = sqrt(2GM/r)?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">It probably is somewhat better. (BTW, in my previous, I should have said that 2GM/r is Newtonian escape velocity <i>squared</i>.)

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Mr. Hatch also said that his equation imply no blackhole exist<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Most deep reality physicists agree that singularities are impossible to exist in reality. That would violate the physical tprinciple "The finite cannot become infinite" because it requires a miracle. As I explained, Mitchell stars or some other entity (the Meta Model suggests quasars) are a more probable result of gravitational collapse beyond the neutron star stage.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">I wish to know how an escape velocity equation which is derived from GR look like. Would you inform me the GR-escape-velocity equation if you know it.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">GR has escape velocity reaching the speed of light at the event horizon instead of the center. Inside the event horizon, space and time change roles so the concept of "escape velocity" in undefined. Nothing can escape a "black hole" if such a thing could exist. -|Tom|-

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18 years 9 months ago #17173 by Cindy
Replied by Cindy on topic Reply from
<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">GR has escape velocity reaching the speed of light at the event horizon instead of the center. Inside the event horizon, space and time change roles so the concept of "escape velocity" in undefined. Nothing can escape a "black hole" if such a thing could exist. -|Tom|-
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Thank you, Uncle Tom,

I would like to have the GR-escape-velocity equation to compute and compare its result with result form Mr. Hatch's equation in case of a neutron star. Would you please inform me ? Thanks

(By the way, how do Meta theory's escape-velocity equation and gravitational acceleration equation look like ?)

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18 years 9 months ago #14698 by tvanflandern
<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Cindy</i>
<br />I would like to have the GR-escape-velocity equation to compute and compare its result with result form Mr. Hatch's equation in case of a neutron star. Would you please inform me?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">That's not easy to derive. But from Meta Research Bulletin 8:54-59 (1999), a comparable formula appears to be the following, where the -sqrt- term is the Newtonian escape velocity:
v = [(1-2GM/rc^2)/(1+2GM/rc^2)^3] sqrt(2GM/r)
This goes to zero at the event horizon (r = 2GM/c^2), so it is not really escape velocity, but rather the velocity actually attained by an infalling body. Naturally, that is merely the appearance when coordinate time is used. In proper time, things remain Newtonian. These complications about what time and space mean in GR are part of the reason why the question is hard to answer in any general way.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">By the way, how do Meta theory's escape-velocity equation and gravitational acceleration equation look like?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">The physics in MM is different from that in either of the others. Escape velocity near a source mass is purely Newtonian for a test mass at rest. But the velocity attained by an infalling body from infinity (for comparison with the above and Hatch's example), the formula (made to look as similar to the others as I can do) would look something like this:
v = (1-2GM/rc^2) sqrt(2GM/r)
This too goes to zero at the critical distance r = 2GM/c^2, reflecting the difficulty of propagating at all in super-dense elysium. -|Tom|-

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18 years 9 months ago #17309 by jrich
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<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by tvanflandern</i>
The physics in MM is different from that in either of the others. Escape velocity near a source mass is purely Newtonian for a test mass at rest. But the velocity attained by an infalling body from infinity (for comparison with the above and Hatch's example), the formula (made to look as similar to the others as I can do) would look something like this:
v = (1-2GM/rc^2) sqrt(2GM/r)
This too goes to zero at the critical distance r = 2GM/c^2, reflecting the difficulty of propagating at all in super-dense elysium. -|Tom|-
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Dr. Van Flandern,

I'm a little unclear on your position as to whether infalling matter can exceed lightspeed. Will the elysium medium always prevent it by essentially becoming infinitely dense to ordinary matter near lightspeed, or is elysium of sufficiently low density except perhaps near large masses to allow movement of ordinary matter at FTL speeds through it? If the latter, why do we not see such phenomena? Or do we?

Also, is Cindy really your niece?

JR

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18 years 9 months ago #14700 by tvanflandern
<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by jrich</i>
<br />I'm a little unclear on your position as to whether infalling matter can exceed lightspeed. Will the elysium medium always prevent it by essentially becoming infinitely dense to ordinary matter near lightspeed, or is elysium of sufficiently low density except perhaps near large masses to allow movement of ordinary matter at FTL speeds through it?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">The situation is somewhat analogous to attempting to exceed the speed of sound through propeller propulsion alone. We simply can't make air molecules move fast enough to do that. But other means of propulsion, such as jets, can easily help us break the sound barrier.

When matter moves through elysium, part of that movement is ballistic, and that part can be accelerated by very fast forces such as gravity to indefinitely high speeds. However, part of the movement consists of electrons circling nuclei by propagation through elysium, and the propagation speed of electrons is definitely limited by the speed of light (the wave speed of elysium). If a nucleus attempts to go faster, its electrons can't keep up and will all end up trailing the nucleus, with the attractive forces on the nucleus from the electrons then all acting in the same direction to slow the forward progress of the nucleus. That is the "drag" that keeps the nucleus from exceeding the speed of light.

In the future, we may learn how to collapse matter to super-dense states not presently achievable -- far denser than atomic nuclei or any quantum particle. If we built a shield of such super-dense material and enclosed ordinary matter inside it, the shield would be oblivious to the elysium outside (which could not penetrate the shield), and the elysium inside would be at rest with respect to the ordinary matter inside. A spacecraft built on this design could reach indefinitely high speeds.

It's just a matter of engineering details -- and another factor of a million or so in our ability to detect and manipulate "fundamental" entities.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">If the latter, why do we not see such phenomena? Or do we?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Spacecraft are very small masses compared to planets or stars. We have detected a few instances of Cerenkov raduation from stellar-sized objects. But we are still a long way from being able to detect it from spacecraft-sized objects. (Cerenkov radiation is what happens when something exceeds the speed of light, analogous to a sonic boom.)

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Also, is Cindy really your niece?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">I can't really tell because she has not listed a last name. But there has been no previous communication between me and a relative of that name interested in physics. -|Tom|-

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