Time dilation, mirror question

In summary, the concept of time dilation was explained using mirrors in a spacecraft, where the light would take longer to travel vertically if viewed from a stationary frame. However, when the mirrors are placed horizontally and the light travels horizontally, it results in length contraction and the light takes less time to travel between the mirrors. This is known as the Relativity of Simultaneity, where events that are simultaneous for one frame may not be simultaneous for another frame. Both frames will agree that the light pulse will return at the same time, but the time taken for the pulse to reach the mirrors will be perceived differently.
  • #1
ucsdhopeful
3
0
I only know time dilation in it's basic form and it was explained to me beautifully using mirrors in a spacecraft . The light would go vertically, taking longer if you were at a stationary frame looking into the spacecraft . This all made sense to me; however, what would happen if the mirrors were horizontally placed, and light traveled horizontally? I know this is the basis of length contraction, but wouldn't light take less time to go from one mirror to another?
 
Physics news on Phys.org
  • #2
Maybe this will help: consider a spacecraft traveling very close to the speed of light. For the vertical orientation of the mirrors, the path of the light will be very close to a straight line as viewed from the stationary frame. Now if you consider the horizontal orientation of the mirrors, they have to be very close together in order for the light path to be the same distance and therefore to take the same amount of time as the vertical orientation.

Just think if they were no closer together, it would take a very long time for the light to catch up to one of the mirrors in the horizontal orientation.
 
  • #3
ucsdhopeful said:
I only know time dilation in it's basic form and it was explained to me beautifully using mirrors in a spacecraft . The light would go vertically, taking longer if you were at a stationary frame looking into the spacecraft . This all made sense to me; however, what would happen if the mirrors were horizontally placed, and light traveled horizontally? I know this is the basis of length contraction, but wouldn't light take less time to go from one mirror to another?

If you mean that according to the stationary frame, the light will take less time to between the mirrors going one way than when going the other, then yes. This is an effect known as the Relativity of Simultaneity. For instance, let's say that you are halfway between two mirrors and you sent a pulse of light to both. According to you, the pulses will reach the mirrors at the same time. However, from a frame which considers you as moving, the pulse will arrive at the mirrors at different times. Event that are simultaneous for you are not simultaneous for them.

You will both agree that the light pulse will return to you at the same time . For you, each pulse took the same time going out and coming back, and for the other frame one pulse took less time going out and more coming back while the other pulse took more time going out and less time coming back.
 

Related to Time dilation, mirror question

1. What is time dilation?

Time dilation is a phenomenon in which the passage of time is affected by the relative motion between two objects. It is a consequence of Einstein's theory of relativity and has been observed in various experiments.

2. How does time dilation work?

According to Einstein's theory, time dilation occurs because the speed of light is constant for all observers. As an object moves closer to the speed of light, time slows down for that object relative to a stationary observer.

3. What is the mirror question in relation to time dilation?

The mirror question is a thought experiment used to illustrate the concept of time dilation. It involves a person standing in front of a mirror and observing their own reflection as they move at a high speed. The reflection would appear to age slower due to time dilation.

4. Can time dilation be observed in everyday life?

Yes, time dilation can be observed in everyday life, but the effects are extremely small unless you are moving at very high speeds close to the speed of light. GPS satellites, for example, have to take time dilation into account in order to provide accurate positioning information.

5. What are the implications of time dilation?

Time dilation has significant implications for our understanding of the universe. It helps explain phenomena such as the twin paradox, where one twin who travels at high speeds ages slower than the other twin who stays on Earth. It also has implications for space travel and the possibility of time travel.

Similar threads

  • Special and General Relativity
2
Replies
45
Views
3K
  • Special and General Relativity
Replies
10
Views
593
  • Special and General Relativity
Replies
16
Views
739
  • Special and General Relativity
Replies
15
Views
2K
  • Special and General Relativity
Replies
12
Views
547
  • Special and General Relativity
3
Replies
88
Views
3K
  • Special and General Relativity
Replies
6
Views
2K
  • Special and General Relativity
Replies
11
Views
1K
  • Special and General Relativity
Replies
11
Views
1K
  • Special and General Relativity
Replies
34
Views
681
Back
Top