Since it's summer and i'm only taking a chem class I picked up my physics text and started browsing. I found the following problem and I was able to get an answer close to what the book has in the back..I can't really explain why that is so. it's my opinion on the matter that even though I found an answer pretty close it doesnt matter because I don't really know why. anyway, the problem goes something like: Suppose the sun is about to explode. In an effort to escape, we depart traveling in a space craft at the velocity .800c and head towards the star Tau Ceti, 12.0 lightyears away. At the midpoint of our journey from earth we see our sun explode, and at the same time see Tau Ceti explode. In the spacecrafts frame of ref, should we conclude that the two explosions occurred simultaneously. If not which occurred first?(adsbygoogle = window.adsbygoogle || []).push({});

since i've only read the Papers on SR and GR, and labored over the conceptualizations without an adequate mathematical foundation I proceeded as follows:

at first I figured that the sun exploded first. I don't know why but I did. Looked up the answer and it was wrong. This made sense since light travels the same speed regardless of the reference frame. I figured then that the light from the sun must have traveled a shorter distance, since the space craft was only traveling at a fraction of the speed of light and the inverse is true for Tau Ceti.

This is where I stop really understanding what's going on and start guessing and checking. I proceeded to multiply the 'distance' traveled, 6 ly the midpoint, by .8 . I figured this was the distance the light from the sun exposion had to travel to reach the space craft. It turned out to be 4.8. For the other side I divided by .8 and got 7.5. When I took the difference (2.7) and multiplied it by 6, I obtain 16.2. The answer in the back is that the explosion of Tau Ceti occurred 16.0 years before the sun. The fact that the answer is to 3 significant figures gives me an indication that i'm incorrect so I really don't care how wrong I am, I'm more concerned about how to obtain the answer.

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# Homework Help: Relativity problem in a text not homework though

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