Can special relativity result in alternative realities?

In summary, the traincar thought experiment involves a train rigged with sensors that will trigger an explosion if light is detected on both sides within a small fraction of time. From the perspective of an observer inside the train, the light hits both sides of the sensor simultaneously, causing the train to explode. However, from the perspective of an observer outside the train, the light hits one side of the sensor before the other, preventing the explosion. This raises questions about the role of the frame of reference in the experiment and whether the results should be the same for both observers. Ultimately, the principles of relativity state that the results should be the same in all inertial frames.
  • #1
junglebeast
515
2
Take the traincar thought experiment with light emitted towards front and back of the train. Assume that the train is rigged with mirrors at the wall that will direct the light around the edges of the train wall, ceiling, and then back to the center of the train at the rooftop, where a sensor is located. The sensor is rigged to blow up the train if it receives light from both sides within some small fraction of time.

To an observer from the perspective within the train, the light hits both sides of the sensor simultaneously and the train blows up (killing the observer). To an observer outside of the train, the light hits one sensor long before the other, so the train does not blow up, and the person inside the train survives.

Is this right?
 
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  • #2
Both observers must give the same result for an experiment such as "does the traincar explode or not"? The idea is that the sensors are inside the train, so they obey the rules that apply inside the train; the train explodes. To analyze it from outside, you have to boost yourself into the inside frame first to see what the sensors are seeing.
 
  • #3
Matterwave said:
Both observers must give the same result for an experiment such as "does the traincar explode or not"? The idea is that the sensors are inside the train, so they obey the rules that apply inside the train; the train explodes. To analyze it from outside, you have to boost yourself into the inside frame first to see what the sensors are seeing.

Suppose that the sensor device is see-through and the observer is watching with a telescope that allows him to see in great detail what is going on inside that sensor. The sensor is governed by simple mechanical principles. If he does not observe the light to enter both sides of the sensor at the same time, then he will not observe those visible principles to trigger the sensor. So, if what you are saying is true, he must observe some great "action at a distance" in order to explain the spontaneous explosion of the train.

Secondly, if what you are saying is true, then the frame of reference makes a difference for the experiment...and I thought that one of the principles of relativity is that it should not make a difference what frame of reference the calculations are done in...
 
  • #4
junglebeast said:
Is this right?
No, SR will never result in alternative realities.

Your description of the scenario was a little confusing, but there are really only two questions that need to be answered to show whether or not the bomb explodes:
1) where and when does each sensor trigger in some inertial frame
2) how does the bomb determine if the sensors were triggered simultaneously

No matter how you answer those two questions, the result will be the same in all inertial frames.
 

1. What is special relativity?

Special relativity is a theory developed by Albert Einstein that explains how time and space are affected by the motion of an object. It states that the laws of physics are the same for all observers in uniform motion and that the speed of light is constant in all frames of reference.

2. How does special relativity relate to alternative realities?

Special relativity does not directly address the concept of alternative realities. However, it suggests that time and space are relative and can be experienced differently by different observers. This has led to speculation about the possibility of alternative realities.

3. Can special relativity lead to time travel?

Special relativity does not allow for time travel in the traditional sense of going back in time. However, it does suggest that time can be experienced differently depending on an observer's motion. This has been explored in science fiction, but it is not currently possible according to our understanding of physics.

4. Are there any experiments that support the idea of alternative realities in special relativity?

There is currently no scientific evidence or experiments that support the existence of alternative realities in the context of special relativity. While the theory allows for the possibility, it is still a highly debated and speculative concept.

5. Can special relativity be used to explain the existence of parallel universes?

Special relativity is not capable of explaining the existence of parallel universes. While it allows for the possibility of alternative realities, it does not provide any evidence or explanation for the existence of multiple universes. The concept of parallel universes is still a topic of great debate and is not currently supported by scientific evidence.

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