On 9/27/2011 8:36 PM, Painius wrote:
> On Tue, 27 Sep 2011 07:10:59 -0400, HVAC<***@gmail.com> wrote:
>
>> On 9/26/2011 11:15 PM, Painius wrote:
>>>
>>>>>
>>>>> Also, take the case of a black hole. If whatever causes gravity is
>>>>> generated by the mass of the black hole, then how is it that light
>>>>> cannot escape the event horizon, but gravity can?
>>>>
>>>> Because the mass is still there. This mass distorts the
>>>> space following the same laws as does any other star.
>>>>
>>>> The fact that this is yet another nail in your 'theory'
>>>> of gravitation, I'm sure has no effect on you. You will
>>>> still go along your merry pop-sci/religious way.
>>>
>>> I don't have a "theory of gravitation", per se, TwitVAC, because I'm
>>> not a physicist (thank Gaud). I merely have my own "idea" as to what
>>> CAUSES gravitation.
>>>
>>> So... you say that the mass is still there (duh). And the mass
>>> somehow manages to distort the space in its vicinity. And yet this
>>> distorted space somehow manages to escape the event horizon. It gets
>>> outside the event horizon even though light and other energy cannot
>>> get outside. How can this spatial distortion manage to get outside
>>> the event horizon even when light cannot?
>>>
>>> In other words, your feeble attempt to answer the question (thank you
>>> for finally making an attempt, feeble as it was) requires that the
>>> question be asked again with a bit more clarity.
>>>
>>> How can the distortion of space that is generated by the mass (that is
>>> still there) manage to escape the event horizon when even light, as
>>> fast as it is, cannot escape?
>>
>> Please listen very carefully. Gravity is NOT a force.
>
Whether gravity is a force or not depends on the physics used to
describe it. It is certainly considered to be a force under Newtonian
physics and Special Relativity.
>
>> It is not
>> like em radiation which is carried by photons at various frequencies.
>> Mass curves space. In the vicinity of a black hole, it is curved
>> to the extent that the escape velocity is greater than light's
>> speed, creating a black hole. I know that kooks hate this idea because
>> that means they can't have anti-gravity, but that's just the way it is.
>
> Now YOU listen carefully. I disagree with you for two reasons: (1)
> you don't know stick about science, and (2) you don't know stick
> about science. You're a poseur who isn't even smart enough to know to
> quit when you're just a little behind.
>
> So the escape velocity of a black hole is greater than lightspeed, eh?
> Escape velocities do not apply to vehicles with propulsion, did you
> know that, Harlow? What escape velocity means is actually like this:
>
> You pilot a rocket into the sky, and at a certain altitude you decide
> to cut your engines. If, when you cut your engines, your velocity was
> below the escape velocity, then you and your vehicle will either go
> into orbit, or your altitude will decay until you plunge back down
> into the planet. On the other hand, if you cut your engines at an
> achieved velocity at or above the escape velocity, then your rocket
> will have enough energy to continue to move away from the planet, EVEN
> THOUGH YOU HAVE TURNED OFF YOUR ENGINES.
>
Hold it! You said escape velocities do not apply to vehicles with
propulsion. A vehicle without propulsion would not have an engine.
> > If you never turn your engines off, then you can keep cruising away
> from the planet at any angle even if you don't achieve escape
> velocity.
>
> This must beg the question, does a photon have energy? or does it just
> float through space as if it has no propulsion? In other words, an
> energy particle like a photon should be able to leave a black hole
> that has an escape velocity of light speed.
>
> To illustrate, we'll say that your rocket ship moves upward at 5 miles
> per second under power. Even though the escape velocity of Earth is 7
> miles per second, your rocket that is under power will continue to
> move away from Earth with no problem. So we turn Earth into a black
> hole and your rocket into a photon. The escape velocity is, say, 1.1
> times the speed of light. The photon moving at the speed of light
> should be able to continue past the event horizon the same way your
> ship could escape Earth even though it had not achieved escape
> velocity.
>
> Now there's a gnarly little enigma for you. Can you furnish evidence
> that this is incorrect?
>
First, some basics.
Gravitational attraction is a function of the masses of the objects
involved and the distances between them.
Gravitational force diminishes with distance. In Newtonian equations
describing gravity, only the distance factor is squared. Therefore
distance has a greater effect on the force than does mass, which is not
squared. As distance doubles, the force of gravity diminishes four
times. As mass doubles, the force of gravity doubles.
Let's consider the case of a rocket being launched from Earth.
There is a distance from Earth where the gravitational attraction of the
Earth on the rocket is balanced by the gravitational attraction the
other objects in space have on it. If a balance between those forces is
maintained, we say that the rocket is in orbit. If the external forces
are greater than Earth's gravitational force, we say the object has
escaped the Earth's gravity.
To reach such a distance, a rocket must be propelled by a force stronger
than the force of Earth's gravity at each of the distances it passes
through. If the propelling force caused the rocket to continuously
travel at 5 MPH, for example, to a place beyond the distance where the
gravitational forces balance, the rocket would have escaped the Earth's
gravity. As a practical matter, propelling the rocket at a greater speed
allows kinetic energy to work together with the propelling energy.
The speed at which the rocket's energy is sufficient to overcome the
force of Earth's gravity at the balance point is called the escape
velocity. (It would be more accurate to call it the escape speed but
that's a discussion for another time.)
If the rocket's kinetic energy is powerful enough to maintain a speed
exceeding escape velocity at the balance point, propulsion is not necessary.
NOTE: It must be understood that the above relationships are based on
Newtonian physics.
Painus fails when he turns the Earth into a black hole. Black holes seem
to be enigmatic because Newtonian physics does not apply within the
event horizon of a black hole.
The physics of black holes is based on Einstein's General Theory of
Relativity rather than Newtonian physics.
The photon cannot escape the black hole's event horizon because its path
is bent back toward the black hole's mass by the distortion of
space-time caused by that very compact mass. The photon cannot travel in
what a hypothetical observer would call a straight line and, therefore,
cannot continue past the event horizon.