Length Contraction & Time Dilation: Relative Velocity Impact?

In summary, When an object moves close to the speed of light, it will be length contracted and the distance it covers will also contract from the traveling object's point of view. This also applies to velocities, which are related by the relativistic velocity addition formula. Observers in different frames of reference may disagree about the velocity, but will agree on the velocity of the other object. This is illustrated by the example of a rocket traveling at near speed, which sees itself as normal while observers on Earth see it as length contracted. This concept can be further understood through the use of a light clock, where the duration of a complete cycle will be the same regardless of the orientation of the clock.
  • #1
sqljunkey
181
8
So an object moving close to the speed of light will be length contracted. Does that mean the distance it covers also contracts in length? From the traveling object's point of view it's surrounding's would contract as he sees them moving along.

In these scenarios wouldn't velocity be a relative component too? will the two frames of reference disagree about the velocity? given that time and space has been different.
 
Physics news on Phys.org
  • #2
Generally: yes, yes and yes. You want to formulate a bit more precisely (in particular who is the observer drawing such a conclusion), but you will learn that quickly enough when you do exercises.

Check out the MIT game -- it's fun
 
  • #3
Apart from the sign, the two frames agree on the velocity of the other. In general, velocities are related by the relativistic velocity addition formula.
 
  • #4
Okay. To be sure I understand this right, the distance the rocket traveling at near speed doesn't contract for an observer at rest right, only the rocket contracts
 
  • #5
Yes. The rocket sees itself as normal and the distance to its destination contracted. Observers on Earth see themselves as normal and the rocket length contracted
 
  • #6
I doodled a sketch here. Let's say there is a light clock 299792458 meters tall (or one light second) and instead of moving horizontally it moves vertically, with speed .999999c . Along this y-axis that it's moving it contracts to 24,486.42 meters. Wouldn't it be close to 1 second when the light traveled from the bottom of the light clock to the top of the light clock, since now the ceiling of the clock contracted. Instead of taking 570 something seconds if it was traveling horizontally ?
 
  • Like
Likes nitsuj
  • #7
You need to work out the duration of a complete cycle of the clock - from bottom to top and back down. Then you should get the same answer in both cases.

Edit: if you don't, post your maths and we'll see where you went wrong. I recommend working in units of seconds and light seconds. Then the speed of light is 1.
 

1. What is length contraction and time dilation?

Length contraction and time dilation are both concepts in Einstein's theory of relativity that describe how an object's length and time are perceived differently by observers in different states of motion.

2. How does relative velocity impact length contraction and time dilation?

Relative velocity refers to the speed of an object in relation to another object or observer. The higher the relative velocity between two objects, the greater the impact on length contraction and time dilation. This is because as relative velocity increases, the effects of relativity become more pronounced.

3. What are some real-world examples of length contraction and time dilation?

One example of length contraction is the measurement of a moving object's length by an observer at rest, which will appear shorter than its actual length due to the effects of relative velocity. Time dilation can be observed in the slowing down of time for objects moving at high speeds, such as in particle accelerators.

4. Can length contraction and time dilation be observed in everyday life?

Yes, the effects of length contraction and time dilation are present in everyday life, but they are only noticeable at extremely high speeds or in large-scale situations such as the movement of celestial bodies. For most everyday activities, the effects are too small to be observed.

5. What impact do length contraction and time dilation have on our understanding of the universe?

Length contraction and time dilation are crucial concepts in the theory of relativity, which has greatly expanded our understanding of the universe and the nature of space and time. These concepts have also been confirmed through various experiments and observations, further solidifying their importance in our understanding of the universe.

Similar threads

  • Special and General Relativity
Replies
10
Views
520
Replies
63
Views
3K
  • Special and General Relativity
2
Replies
45
Views
2K
  • Special and General Relativity
2
Replies
54
Views
708
  • Special and General Relativity
Replies
14
Views
353
  • Special and General Relativity
Replies
7
Views
1K
  • Special and General Relativity
Replies
11
Views
987
  • Special and General Relativity
Replies
5
Views
1K
Replies
38
Views
3K
  • Special and General Relativity
2
Replies
36
Views
2K
Back
Top