Special relativity implies very odd results

[harrylin]

I think I need to explain my original thinking here which most of you probably can't fathom. When I spoke of a ship suddenly making a right angle turn I was thinking of what has often been reported as observations of UFOs. One pilot described them as looking like they hit a solid plane in space and bounced at another angle. Since you say conventional physics says there is a problem with inertia here you would probably say this behavior is impossible. You don't seem to grasp that their technology could be way in advance of ours and they know how to do this while you don't. I was also thinking of electrons traveling in a wire which had a sharp right angle bend in it. How is it that an electron with very little mass, but at the speed of c now has a huge mass and is able to decelerate to zero in one direction and almost instantly accelerate to c in another direction? Am I over complicating because I'm struggling? Or it could be protons which cause the current.

Only if UFO's exist and are made of massive objects. Some people speculate that they are a kind of projections. Anyway, I guess that you'll agree, now that you've concluded that there is no inconsistency here at all, this is more a matter of "UFO's imply very odd results".

 

[michelcolman]

By the way, when I said that the results are the same no matter which coordinate system you use and it doesn't matter what the numbers are, you might get the impression that relativistic effects are somehow "not real" and that things like length contraction are only caused by the funny reference systems we like to use to measure things. However, this is not the case, the effects are very real indeed. Take, for example, the passing trains paradox.

Two trains, each 100 meters long (at rest) have to pass each other on an 80 meter long section of double track. Of course this should be impossible unless... both are traveling at 0.6c. Someone standing on the platform will see that the trains are now only 80 meters long and can pass each other just fine. He can measure this any way he likes (for example using a photo detector next to the rails, timing the passage of the front and back end of the train) and it will really be 80 meters. However, if you are sitting on one of the trains, that train is still 100 meters (it is not moving relative to you), but the platform is only 64 meters (contracted by 80%). Fortunately though, the other train is coming towards you at 0.88c so it's only 47 meters long. It has just enough time to pass between the two ends of the double section in the time it takes for your long train to get through.

This is a perfect example of how different points of view can describe a situation differently while coming to the same result: both observers will disagree on the length of the trains and the platform, and the timing of the passage of the front and back ends, but they will agree that the trains just missed each other on each end. And that's all that matters.

Now, if you would jump from the platform onto the train, would you suddenly see that train expand and the platform shrink? Yes, no matter how strange that may seem. Of course the word "see" is not the right word for it, "infer from your observations" would be more appropriate. If you time how long it takes for you to pass the two ends of the double section and multiply that with your speed, you will find it's really 64 meters. But of course you would be using a clock to measure that, and someone on the platform will say your clock suddenly started to run more slowly the moment you jumped onto the train.

I would encourage you to read more of this kind of paradoxes on wikipedia or other sources on the internet, they are what finally got me to understand relativity. It will take a while for it to really sink in, though.

Maybe start with http://en.wikipedia.org/wiki/Relativity_of_simultaneity

 

[discountbrain]

I think you are trying to explain things that are well understood by everyone. I don't need to look at your references. I answered my question myself with no help from you. Read what I said about considering points in space which need not be associated with physical objects. The one who said I was wrong in say there would no longer be a distance contraction if one ship crashed is right, but I agree for the above mentioned reason.

I had originally thought I came across a paradox.

Everyone knows nothing happens instantaneously (but maybe some things do) and this doesn't need to be explained even to non science people.