- #1
pd3000
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Hi all, firstly, I must apologise for my level of physics knowledge and how this might be reflected in my question and the terminology used. I am trying to understand particle physics at an advanced age my neurons are not as elastic as they once were!
I have been listening to an excellent audio book by Brian Cox and Jeff Forshaw (Why does E=MC2), and for those relatively new (no pun intended!) to the subject, it uses some excellent examples to make this topic quite accessible.
The latest chapter explains time dilation using the light clock experiment as an example. I found this a really good example, having previously having had this explained, very confusingly, with the use of aeroplanes and atomic clocks! So, now I think I get it, and the implications this has for interstellar travel at light speed, but it raises a bunch of aditional questions for me that I'm hoping someone can explain.
In my mind I can envisage a subtle change to the experiment which causes me great consternation. Imagine for example, that instead of being stationary the 'observer' of the train carrying the light clock is also aboard another train moving paralllel to the clock carrying train and both trains are moving in diametrically opposite directions at close to the speed of light. In this example, the pythagorian mathematics which are the root of the calculations here suggest that the fleeting glimpse the observer sees of the clock is now so small that the light particle takes a path along the hypotenuse which is now so long that the mathematics must change immeasurably?
In the above example, if both trains are traveling at close to light speed, their separational speed must be nearly twice the speed of light? Is this a possible, or even logical conclusion?
Firstly, I know that special relativity tells me that "The speed of light is the same for all observers, no matter what their relative speeds". This is all well and good, but surely this means that each train in my example is now limited to half light speed in order to obey Newtonian physics? Does this also mean that any particle traveling across interstellar distances is also limited to half light speed just in case there is another particle taking a diametrically opposite path an 'observer' might be onboard one of these particles?
This also, to me, seems to restrict particle movement in a theoretically folded space time fabric (maybe this is a bit off topic). Let me use an example of my own. A photon is emitted from a distant star which I have measured to be one light year away, I can expect it to reach me at a predictable time because I know the distance, and the speed of light. What if the particle traverses previously unseen folded space and manages to reach me more quickly? Has it traveled more quickly than the speed of light, because I observe it to reach me more quickly, or must I factor in some distance differential? I know that there are arguments which suggest the folding of space time is possible, but would my previous example prove this one way or another as we would see light reaching us from previously known objects at different speeds depending on where they are in a warped space time fabric?
Apologies for the tangential last question, it just jumped into my head as I was writing.
As I said at the start, please be gentle with me, the more I learn here the more questions seem to raise themselves, try to answer me in a simple 'example' based way if possible, and please redirect me to a more basic forum if my questions are not worthy. As Marvin the Paranoid Android would have put it, "It gives me a headache just trying to think down to your level !". Please don't give yoursleves an aneurism trying to answer in a way I might comprehend :-)
Thanks.
I have been listening to an excellent audio book by Brian Cox and Jeff Forshaw (Why does E=MC2), and for those relatively new (no pun intended!) to the subject, it uses some excellent examples to make this topic quite accessible.
The latest chapter explains time dilation using the light clock experiment as an example. I found this a really good example, having previously having had this explained, very confusingly, with the use of aeroplanes and atomic clocks! So, now I think I get it, and the implications this has for interstellar travel at light speed, but it raises a bunch of aditional questions for me that I'm hoping someone can explain.
In my mind I can envisage a subtle change to the experiment which causes me great consternation. Imagine for example, that instead of being stationary the 'observer' of the train carrying the light clock is also aboard another train moving paralllel to the clock carrying train and both trains are moving in diametrically opposite directions at close to the speed of light. In this example, the pythagorian mathematics which are the root of the calculations here suggest that the fleeting glimpse the observer sees of the clock is now so small that the light particle takes a path along the hypotenuse which is now so long that the mathematics must change immeasurably?
In the above example, if both trains are traveling at close to light speed, their separational speed must be nearly twice the speed of light? Is this a possible, or even logical conclusion?
Firstly, I know that special relativity tells me that "The speed of light is the same for all observers, no matter what their relative speeds". This is all well and good, but surely this means that each train in my example is now limited to half light speed in order to obey Newtonian physics? Does this also mean that any particle traveling across interstellar distances is also limited to half light speed just in case there is another particle taking a diametrically opposite path an 'observer' might be onboard one of these particles?
This also, to me, seems to restrict particle movement in a theoretically folded space time fabric (maybe this is a bit off topic). Let me use an example of my own. A photon is emitted from a distant star which I have measured to be one light year away, I can expect it to reach me at a predictable time because I know the distance, and the speed of light. What if the particle traverses previously unseen folded space and manages to reach me more quickly? Has it traveled more quickly than the speed of light, because I observe it to reach me more quickly, or must I factor in some distance differential? I know that there are arguments which suggest the folding of space time is possible, but would my previous example prove this one way or another as we would see light reaching us from previously known objects at different speeds depending on where they are in a warped space time fabric?
Apologies for the tangential last question, it just jumped into my head as I was writing.
As I said at the start, please be gentle with me, the more I learn here the more questions seem to raise themselves, try to answer me in a simple 'example' based way if possible, and please redirect me to a more basic forum if my questions are not worthy. As Marvin the Paranoid Android would have put it, "It gives me a headache just trying to think down to your level !". Please don't give yoursleves an aneurism trying to answer in a way I might comprehend :-)
Thanks.
