Perception of faster than light travel?

In summary, the problem asks for the relative speed of two spaceships as they approach each other. The correct answer is 1.3c.
  • #1
metal_maniac
4
0
I'm currently taking a modern physics course, I came across this problem which really threw me off guard:

Three spaceships A, B, and C are in motion as shown in the figure. The commander on ship B observes ship C approaching with a relative velocity of 0.83c. The commander also observes ship A, advancing in the rear, with a relative velocity of 0.48c. As measured by commander on ship B, at what speed is ship A approaching ship C?

Attempt at a solution: I used the transformations equations which resulted in a value of 0.94c.
observed velocity = [(-0.83c) - 0.48c]/[1-(0.83c*0.48c/c^2)] = 0.937c
0.94c was one of the possible answers so I picked it... it was wrong.
The correct answer was 1.3c.

Is this even possible?
I do suppose that someone with no knowledge in physics would just add the two velocities like it was Galilean transformations, but we're taking about the commander of a ship, pretty sure he wouldn't just add them together.
Is this just a badly written question or am I missing some things in my understanding? Any help is appreciated!
Thank you
 
Physics news on Phys.org
  • #2
The relativistic formula for addition of velocities is used when you want to change frames.
Here things are different. You're actually calculating the closing speed of spaceships A and C in the B's frame. He sees A to travel at 0.48c and C to travel at 0.83c, so if he attempts to find the time derivative of the distance between the two, he has no way other than simply adding their velocities.
I should say that this doesn't violate SR since there is no mass or energy going faster than light!
Take a look at here for more information!
 
Last edited:
  • #3
You're a life saver!
I was stuck on this question for so long, and my textbook had no explanation for it.
Thank you so much!
 

1. How is it possible for anything to travel faster than the speed of light?

The current understanding of physics states that nothing can travel faster than the speed of light. However, some theoretical concepts, such as wormholes and the Alcubierre drive, suggest potential ways to bypass this limitation. These ideas are still just theories and have not been proven to be scientifically valid.

2. What would be the implications of faster than light travel?

If faster than light travel were possible, it would have significant implications for our understanding of the universe and could potentially open up new possibilities for space exploration and travel. It could also have consequences for our concept of causality and the laws of physics.

3. How does perception play a role in faster than light travel?

Perception is an important factor to consider when discussing faster than light travel because it is based on our human understanding and interpretation of the world around us. Our perception of the laws of physics, time, and space could be challenged if faster than light travel were possible.

4. Has faster than light travel ever been observed or proven to exist?

No, faster than light travel has never been observed or proven to exist. All current evidence and scientific theories suggest that the speed of light is the maximum achievable speed for any object in the universe.

5. What are some potential limitations or challenges of faster than light travel?

One major challenge of faster than light travel is the enormous amount of energy that would be required to achieve such speeds. Another limitation is the potential for time dilation and other effects on the human body, which could make it dangerous for humans to travel at such high speeds. Additionally, the concept of causality and the possibility of paradoxes could also pose as limitations to faster than light travel.

Similar threads

  • Special and General Relativity
2
Replies
40
Views
2K
  • Special and General Relativity
Replies
30
Views
3K
  • Special and General Relativity
Replies
6
Views
741
  • Special and General Relativity
Replies
5
Views
800
  • Special and General Relativity
Replies
8
Views
1K
  • Special and General Relativity
Replies
6
Views
1K
  • Special and General Relativity
Replies
28
Views
1K
  • Special and General Relativity
Replies
15
Views
2K
  • Special and General Relativity
Replies
4
Views
893
  • Special and General Relativity
Replies
6
Views
1K
Back
Top