# Length Contraction oes the object or travel distance shrink?

1. Dec 1, 2013

### Superposed_Cat

Length Contraction:Does the object or travel distance shrink?

I had always thought that length contraction meant that the object itself shrunk but I stumbled across an article where they said "Because of length contraction the photon doesn't travel any distance at all. Which is it? Any help appreciated.

2. Dec 1, 2013

### WannabeNewton

You should always link an article if you're going to draw phrases from it. If that is what the article said verbatim then it is a nonsensical statement.

3. Dec 1, 2013

4. Dec 1, 2013

### Mentz114

Some of the answers are wrong too

This is nonsense. No material object can be measured to be travelling at the speed of light.

5. Dec 1, 2013

### WannabeNewton

The article is completely nonsensical.

6. Dec 1, 2013

### cepheid

Staff Emeritus
In answer to the question in the thread title: it depends on the frame of reference. Whatever is doing the moving is length contracted. If you're sitting on a train, from your point view as the world whizzes past you, it is contracted. The distance you perceive between two points that pass by you in succession is less than the rest frame distance of those two points. On the other hand, from the point of view of a person standing next to the track, it's the train that is contracted.

I agree that using a photon as the example moving object was a bad idea, since a photon rest frame cannot be defined. EDIT: I also agree that this article is bunk. What supposed "physicist" is doing the answering here?

Last edited: Dec 1, 2013
7. Dec 1, 2013

### Superposed_Cat

I have no idea. I just followed a link after reading another article. So the entire universe is contracted?

Last edited: Dec 1, 2013
8. Dec 1, 2013

### cepheid

Staff Emeritus
Sure. This seems surprising until you realize that what's going on is that spacetime is the fundamental construct. The direction through spacetime that is experienced as "time" and the directions that are experienced as "space" are different for different observers in relative motion.

9. Dec 1, 2013

### Superposed_Cat

Nah physics in general seems surprising.

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