Relativity Question: Length Contraction of Moving Boxes

[kuahji]

This may seem like an odd question, but legnth contracts when something moves relative to an observer. Ok, what if I had two boxes both the same size. If one is moving in uniform motion with the observer & the other is moving at near the speed of light relative to the observer, would the box moving near the speed of light fight inside the other? To clarify, both boxes were originally measured when they were in uniform motion w/the observer. I also realize, length only contracts in the direction of motion... so perhaps we should say the first box is just a hair larger in the other two directions.

Hope that made sense, just trying to better understand the concept. Thanks much for your time.

 

[mathman]

To simplify, assume the bigger box is stationary with respect to the observer and is open at both ends in the direction of motion of the other box. When the high speed box passes through the stationary box, it will look like both ends are inside as it passes through, even though intitally it was the same length.

 

[Entropia]

Yes, this is a very interesting question about the effects of relativity on the measurement of length. The phenomenon of length contraction is a consequence of the principles of special relativity, which state that the laws of physics should appear the same to all observers moving at a constant velocity. In this scenario, the observer is stationary while the two boxes are moving relative to them.

According to special relativity, when an object is moving at a high speed relative to an observer, its length in the direction of motion will appear shorter than its actual length when measured by the observer. This effect becomes more significant as the speed of the object approaches the speed of light.

In your scenario, the box moving at near the speed of light would appear shorter in the direction of its motion compared to the stationary box. However, the difference in length would not be significant enough for the moving box to fit inside the stationary box. As you mentioned, length contraction only occurs in the direction of motion, so the box would still have the same width and height as the stationary box.

It's also important to note that the measurements of both boxes would be affected by the relative motion between them and the observer. This means that the stationary box would also appear slightly shorter to the moving box, but the difference would be very small.

Overall, your understanding of length contraction is correct. It is a fascinating concept that helps us better understand the effects of relative motion on the physical world. I hope this explanation has helped clarify your understanding. Thank you for your question!