Speed of Light & Space: Exceeding the "Universal Speed Limit

In summary: However, from an external perspective, the distance between us and the object is increasing faster than the speed of light. This is due to the expansion of space itself.
  • #1
Sullivan Stockwell
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It's generally understood that nothing can be accelerated up to the speed of light, and that nothing can surpass it. That being said, the expansion of space itself can exceed this "universal speed limit," as the Universe is expanding so fast that light can't catch up to it. Regarding the properties of light and Einstein's works on relativity, what mathematical aspects permit space to exceed the speed of light? What makes it seemingly exempt from the restriction of not being able to travel past the speed of light?
 
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  • #2
Sullivan Stockwell said:
That being said, the expansion of space itself can exceed this "universal speed limit,"
The distance to objects far away can increase faster than the speed of light. This is not an actual velocity, as it does not involve the motion of objects.

The speed of light is a limit for the motion of objects.
 
  • #3
Sullivan Stockwell said:
what mathematical aspects permit space to exceed the speed of light?
Space isn't a material. It doesn't have a velocity. Velocity has units of length/time, but the expansion of the universe is in units of 1/time, so it is not a quantity that can be sensibly compared to the speed of light.
 
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  • #4
mfb said:
The distance to objects far away can increase faster than the speed of light. This is not an actual velocity, as it does not involve the motion of objects.

The speed of light is a limit for the motion of objects.
Indeed. I wasn't sure what was meant by
mfb said:
The distance to objects far away can increase faster than the speed of light. This is not an actual velocity, as it does not involve the motion of objects.

The speed of light is a limit for the motion of objects.
mfb said:
The distance to objects far away can increase faster than the speed of light. This is not an actual velocity, as it does not involve the motion of objects.

The speed of light is a limit for the motion of objects.
This makes sense. I wasn't sure what was meant by space expanding faster than light. From our perspective, at a set velocity i.e.
 

1. What is the speed of light and why is it considered the universal speed limit?

The speed of light is approximately 299,792,458 meters per second in a vacuum. It is considered the universal speed limit because according to Einstein's theory of relativity, nothing can travel faster than the speed of light. This is due to the fact that as an object approaches the speed of light, its mass increases infinitely and it would require infinite energy to reach the speed of light.

2. Can anything exceed the speed of light in space?

No, according to our current understanding of physics, nothing can exceed the speed of light in space. As mentioned before, the closer an object gets to the speed of light, the more its mass increases and the more energy it would require to accelerate further. It is also worth noting that the laws of physics, such as the conservation of energy and momentum, would break down if the speed of light was exceeded.

3. Is there a limit to the speed at which the universe is expanding?

Yes, the speed at which the universe is expanding is limited by the speed of light. This is because the expansion of the universe is governed by the laws of physics, including the speed of light. As the universe expands, it is not creating new space, but rather stretching existing space, and this stretching cannot occur faster than the speed of light.

4. How does the speed of light affect time and space?

According to Einstein's theory of relativity, the speed of light is constant and the same for all observers. This means that as an object approaches the speed of light, time slows down for that object relative to an observer who is not moving at that speed. This phenomenon is known as time dilation. Additionally, the speed of light also affects the geometry of space, as it is a fundamental part of the equations that describe the curvature of space.

5. Could there be other forms of faster-than-light travel in the future?

While it is currently not possible to exceed the speed of light, there are theories and hypotheses that suggest the existence of loopholes in the laws of physics that could potentially allow for faster-than-light travel. However, these are still highly speculative and would require a significant advancement in technology and understanding of the universe. Until then, the speed of light remains the universal speed limit.

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