Space-Time Lab - Tutor Page 9
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Answer: C) This experiment gives us the same results as if we were in the object's rest frame, which means it is not a very good experiment because obviously something is going on! It turns out that the fact that no interference is found is an event that is frame independent. Just as if I sneeze someone moving fast relative to me cannot 'not see me sneeze' because my sneezing is an event. We'll see later on things that are frame dependent. Here is another experiment for you: Lets say we send up a rocket into space, at a speedy .7c, and in this rocket we send an astronaut to set up an experiment with two perpendicular rods, in which one rod is parallel to the rocket's motion, and one is perpendicular. Notice in your browser window two rods of equal length(as measured in their rest frame) that are perpendicular to one another. Right now we are in the observer's frame (set at the bottom left of the applet). Press start to send the astronaut and the rods into space, so we can watch it from earth. What is going on here exactly? A) Everything is REALLY the same as it was when the rods weren't moving, except the high speed makes the rods parallel to the motion LOOK smaller. (An optical illusion) B) Everything at rest in the rod's rest frame is contracted in the direction of the rod's motion, according to the observer. C) The earthlings have noticed that everything in their rest frame has been contracted in the direction of the rod's motion, explaining why the measurement was shorter. |
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