Point Masses and the Speed of Light: An Exploration of Relativity

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In summary, the conversation discusses the hypothetical scenario of releasing two point masses 1 kg each, 1 meter apart and whether they would reach the speed of light. It is mentioned that according to relativity, the force of gravity would approach infinity and the acceleration would decrease as the velocity approaches the speed of light. The concept of increasing mass and the role of quantum effects are also brought up.
  • #1
mr200backstrok
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i was sitting here wondering about something, and I'm not sure, so ill ask.

suppose you take 2 point masses, say 1 kg each, 1 meter apart, and release them. Would they ever reach the speed of light? As they got very close, the [tex]F _{g}[/tex] would near infinity ( [tex] \lim _{distance \rightarrow 0} F_{g} = \infty [/tex] ), which means that it would accelerate at an infinite rate past the speed of light. but, relativity doesn't allow that, and would start reducing the acceleration as the velocity approached c. so, is [tex] \lim _{distance \rightarrow 0} v = c [/tex] (if v is velocity and c is the speed of light)?
 
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as particles increase in speed, they also increase in mass (and the mass can go to infinity). So the energy would, in fact, be infinite, but not the velocity
 
  • #3
Another issue that has to be considered is that as the two particles get close to each other, the point assumption breaks down. Also quantum effects would begin to play a role.
 

Related to Point Masses and the Speed of Light: An Exploration of Relativity

1. What is a point mass?

A point mass is an object with negligible size and shape, meaning it can be treated as a single point in space. It is often used in physics as a simplification of more complex objects.

2. How does a point mass affect the speed of light?

According to the theory of relativity, the speed of light is constant and does not change regardless of the observer's frame of reference. Therefore, the presence of a point mass does not affect the speed of light.

3. Can a point mass travel at the speed of light?

No, according to the theory of relativity, only massless particles, such as photons, can travel at the speed of light. A point mass, by definition, has mass and therefore cannot reach the speed of light.

4. How does relativity explain the behavior of point masses?

Relativity explains the behavior of point masses by taking into account the effects of gravity and the curvature of space-time. The theory states that the presence of a massive object, such as a point mass, can cause a distortion in space-time, which affects the motion of other objects in its vicinity.

5. Why is the concept of point masses important in relativity?

The concept of point masses is important in relativity because it allows for the simplification of complex systems and makes it easier to analyze and understand the behavior of objects in space. It also plays a crucial role in the understanding of gravity and the effects it has on the movement of objects.

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