Blackholes,distance and time

Junk science: Any science where the conclusion is assumed before the hypothesis is even made based on non-scientific reasoning, such as for political or religious reasons.

Originally posted by James the Lesser
Hey JJ thanks for backing the science community!

hehe Of that community I am a member, albeit in the medical field.

I like the explanation of the light not being effected byt the space it is in. But this leads to the question of if nothing is faster then light then uh, how to put it so it is understandable...

Ok, I think I know. Light photon moving east, gravity affects the space it is in and pulls it north. But how is the gravity able to affect the light? Imagine a car going mach 2, you are going to try and effect it by kicking it, only problem is you can't catch it for it is faster then you. So is gravity "faster" then light? But they say nothing can be faster then light....

Why I love science, so many questions, so few answers, and when you do get an answer it brings about dozens of questions.

Well, soon the hypothesis of gravity waves will be put to the test. If it turns out to be true, then gravity would travel at the speed of light, too.

I think you're looking at gravity incorrectly, though. It is a constant force exerted by a mass. As a result, it would be like a car going mach 2 as you try to kick it. More like that car going mach 2 as it hits a lake. Those models of space where it is a flat plane and objects of mass cause dimples in that plane make the concept a bit easier to understand. You have a mass, and around it is a constant attractive force that gradually loses strength the further from the object you get. A photon, or light particle, travels on that plane, hugging the surface. As it comes to a planet, or even a star, the dimple in space is relativly small and doesn't have much opportunity to change the course of that particle. If you have a shallow bowl and throw a marble into it off center as a sufficent enough speed, that marble will pop out on the other side just barely traveling in a different direction. However, if you were to do the same with a pool, by the time the marble exited the pool, it's path would be severly altered.

A black hole is suspected to create a massive dimple in space. As light comes to it, far, far away the gravity begins to effect it. It doesn't reach out to grab the light, the light meets the gravity. It was always there while that mass existed. There is a lot of time for the gravity to begin to alter that photon's path towards its center. If the light passes the event horizon, or point of no return, it will be sucked into the black hole. If it does not, it will come out on a very different trajectory than it had before. Were you to be looking from the other side of the black hole, and that photon came from a star, it would appear as though that star were in a totally different position in the sky than it really is.

So next time you're looking up at the night sky, spying a star, you may not even be looking remotely in the direction that star lies.

Now what I want to know is, how does that photon maintain its speed after these forces have effected it. If the speed of light is a constant in a vaccum, it may slow down passing through an atmosphere or gravity well, but immediately speeds back up as soon as it's out.

Originally posted by James the Lesser
Take said mattress with bowling ball at one end and marble at other. Drop the marble on the other side of the bed away from the bowling ball, what happenes? The marble isn't pulled towards it, and even when it lands it may not roll if it is far enough away.

The mass difference between a marble and a bowling ball is far smaller than that of a photon and a black hole. Also, the trouble with the example you're using is you're failing to account for the gravitational pull of the Earth. In your example, both of the masses are attracted far more to the Earth than they are to one another. Doing the same experiment in space away from gravitational influence would yield a different result, although still tiny.

You have to admit, that marble and bowling ball always, when dropped, thrown or whatever, get sucked in by the gravitational pull of the Earth.

How much mass does it take to start gravity?

Can we get enough dust, gather it together in space and create gravity?

OR

Does gravity exists at the first grain of dust (particle?).

Seems like we could create an asteroid as a science experiment to find out how much mass it takes to start the eventual gravity that will collect the rest of the dust into a sphere in space?

Might be hard exoeriment to do since there are so many near by "heavy" gravity sources that would distort the data.

Looking at Saturns rings..one would think they would have all become moons or asteroids by now unless they are relatively new to Saturn.

Lits of questions about gravity.

I am surprised modern man still cant really explain it at least no on terms for a layman to understand.

X

Modern man can't explain it because modern man isn't sure how it works yet, just that it's there. There is a device being built on the east coast that will hopefully detect gravimetric waves, but only will be able to if they're there. Even so, if they do exist, these waves behave differently than others, in that they pull rather than push.

As to your question about what size is needed to create gravity, from what I understand all mass has gravity. So even that spck of dust, or even a photon, exerts a gravitational force, albeit a very small one. The problem with your asteroid idea is that we don't have a way to detect gravity yet short of setting a particle towards the object and seeing if it changes course.

I thought we already have probes orbiting the earth measuring gravity? Gravity Probe A and B I believe they are called.

oK I have quite a strange question to ask.

A Gravitational well is a curve right ? So does this mean that Gravity does not reduce proportionately as the distance of one object from the piece of matter causing the gravity increases.

From the models I've seen, the well has a parabolic curve. That means that it starts out gradually, but as it gets closer to the source it increases. It's not a true parobla, because gravity isn't infinite at the center of every mass, but rather caps out based on the mass of the object.

Correct me if I am wrong, but I think that according to the parabola of a gravitational well, gravity is actually 0, at the centre of the mass. Gravity is actually the most for a piece of matter, when an object is just barely touching the surface of the matter exerting the Gravity. I say this because the parabola is flat at the bottom of the matter, it begins to flatten when it reaches its maximum gradient or maximum gravity, it does this on the point on the curve that is parrallel to the centre of the mass.

I also think that for a blackhole, with infinate density, the place on the parabola of the gravitational well with the most gravity, has a gradient of Infinity, or is just a vertical line. A vertical line or a line with infinate gradient, cannot be on a parabola, so this would mean that spacetime has been torn, and if this is true, there would be a very strange phenomenon, because the blackhole would no longer lie on spacetime ! It would be outside the bounds of the Universe !

All this is purely my thoughts, so please correct my mistakes.

From what I understand, and this so going back to highschool physics so it's been a while, but at the very center of a mass, gravity does not exist as such. So using the flat plane with parabolic dimples example, it would look a bit like a funnel cake mold, A sort of \|/ shape. The only reason for that, though, is because the universe likes spherical objects, and at the exact center the mass is equal on all sides of you and is pulling you in all directions at once. So instead of the absence of gravity, it is the presence of gravity surrounding you everywhere.