Couldn't you accelerate past light by means of gravitational acceleration?

In summary: I see. So as you approach the speed of light, time slows down for you, but it still moves at the same speed for everyone else?Yes, time moves at the same speed for everyone else, but for you it slows down to an almost frozen state.
  • #1
questionpost
194
0
If I type in any equation for acceleration due to gravity, I can look and see that it will eventually become bigger than 186,000 miles per second. So, what's stopping the acceleration from being faster than light if the principal of the curvature of the fabric for space allows matter to follow a path that would do so? Your not adding kinetic energy to the system, your just converting the potential energy into kinetic energy via changes in gravitational potentials, the energy to travel faster than light is already there, and gravitational fields themselves don't lose energy through interaction, so there's your technical infinite energy supply.
Also, what about black holes? We have no idea what goes on inside a black hole itself, for all we know they might not even be part of the universe and therefore are not subject to all the rules of the universe. Couldn't one of those super-massive black holes be so big that there's a big enough gravitational well to accelerate past light? I mean I read in long chapter book just called "Black Holes" that it would take days for in-falling matter to reach the singularity, surely that would be enough time for very high gravity to accelerate something that much...
 
Physics news on Phys.org
  • #2
questionpost said:
If I type in any equation for acceleration due to gravity, I can look and see that it will eventually become bigger than 186,000 miles per second.

You're using the wrong equation.

You're using the equation for Newtonian acceleration; you need to use the relativistic equation for acceleration.

Read up on Lorentzian Transform.
 
  • #3
DaveC426913 said:
You're using the wrong equation.

You're using the equation for Newtonian acceleration; you need to use the relativistic equation for acceleration.

So something about the fabric of space being stretched in a way relative to the observer so that the space between you and the observer would increase or decrease as you approached light or something like that? What about black holes where its already really stretched out?
 
  • #4
questionpost said:
What equation is that?
Lorentzian Transform.

questionpost said:
And who are we to stop such a massive object from warping the fabric of space so severely?

Well, the universe is stopping it.
 
  • #5
DaveC426913 said:
Lorentzian Transform.
Well, the universe is stopping it.

How does traveling near the speed of light actually add more fabric of space into existence between you and an observer at rest? Or why would it stretch it out in such a way as to somehow...do whatever its doing.

By the way I think we keep responding to posts too soon...
 
  • #6
questionpost said:
How does traveling near the speed of light actually add more fabric of space into existence between you and an observer at rest?
It doesn't.

What gets distorted is time.
 
  • #7
DaveC426913 said:
It doesn't.

What gets distorted is time.

So as you accelerate near the speed of light, time (which I thought was part of the fabric of space?) or the rate at which you perceive photons coming from an object...and then something about dots following what looks like two inverse equations with slant asymtotes at y=x and -x.
I'm assuming that those asymtotes represent the acceleration at speed of light in some way, but I don't get exactly what is happening in reality.
So as you accelerate near the speed of light, what is happening to time exactly?
 
  • #8
It might do you to read up a bit on the subject. There are about a thousand threads here alone.

Can't really sum the whole thing up in one post.
 
  • #9
DaveC426913 said:
It might do you to read up a bit on the subject. There are about a thousand threads here alone.

Can't really sum the whole thing up in one post.

I kind of get what's going on.
Does it have something to do with that as you get closer to the speed of light, the speed of time relative to you slows down? And maybe it can't slow down all the way because they you wouldn't be able to travel distance over time? Something like that?
 
  • #10
questionpost said:
I kind of get what's going on.
Does it have something to do with that as you get closer to the speed of light, the speed of time relative to you slows down? And maybe it can't slow down all the way because they you wouldn't be able to travel distance over time? Something like that?
Well, yes. No matter how much you accelerate, your velocity only asymptotically approaches c. It will never each it.

At .999999999999999999c, you are time-dilated almost the the point of being frozen (from the point of view of the rest of the universe). Stars will grow old and die while you reach for the throttle.
 
  • #11
DaveC426913 said:
Well, yes. No matter how much you accelerate, your velocity only asymptotically approaches c. It will never each it.

At .999999999999999999c, you are time-dilated almost the the point of being frozen (from the point of view of the rest of the universe). Stars will grow old and die while you reach for the throttle.

Ok, it makes more sense, thanks.
 
  • #12
Actually now that I thought about it more, there's a little piece missing. I understand that it "does" happen asymptotically, but there's some little middle piece missing about why time's speed slowing down relative to you makes it so that you can't ever accelerate to light speed that I can't quite figure out.
 
  • #13
If you are going .99999999999999c passed one observer, it remains true for you that when you shine your flashlight in front of you, it is still going c. You have made no progress at all towards catching light as you see it. Further, note that for the observer you passed, light from your flashlight pointing forward goes at exactly the same speed as the observer's own flashlight (and both you and the 'stationary' observer see both beams going the same speed). There really is no distinguishable 'almost c' except from some chosen observer's point of view.
 

1. How does gravitational acceleration affect the speed of light?

Gravitational acceleration does not directly affect the speed of light. The speed of light is a fundamental constant and is always the same, regardless of the presence of gravity.

2. If gravity can bend light, why can't it accelerate light beyond its speed?

Gravity does not accelerate light because light has no mass. It is the mass of an object that determines how much it is affected by gravity. Since light has no mass, it cannot be accelerated by gravity.

3. Is there any way to accelerate past the speed of light?

No, according to the theory of relativity, the speed of light is the maximum speed at which anything can travel. It is a fundamental limit of the universe and cannot be surpassed.

4. What is the relationship between gravity and the speed of light?

Gravity and the speed of light are not directly related. However, gravity can affect the curvature of space-time, which in turn can affect the path that light takes, making it appear to "bend" around massive objects.

5. What happens if an object with mass reaches the speed of light through gravitational acceleration?

It is impossible for an object with mass to reach the speed of light, regardless of the means of acceleration. As an object approaches the speed of light, its mass increases infinitely and would require an infinite amount of energy to continue accelerating. This is known as the "mass-energy equivalence" principle.

Similar threads

  • Special and General Relativity
Replies
11
Views
559
  • Special and General Relativity
2
Replies
45
Views
3K
  • Special and General Relativity
Replies
12
Views
1K
  • Special and General Relativity
Replies
4
Views
1K
Replies
13
Views
534
  • Special and General Relativity
Replies
11
Views
172
  • Special and General Relativity
Replies
24
Views
1K
  • Special and General Relativity
Replies
5
Views
1K
  • Special and General Relativity
2
Replies
69
Views
4K
Replies
1
Views
124
Back
Top