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Speed of light-anyone??? (1 Viewer)

Lingb

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hey...i have this question....
"Identify the significance of Einstein’s assumption of the constancy of the speed of light by stating what this means for space and time"

i understand Einstein's assumption of the speed of light, and i understand that this means that both time and space become relative.

and that it also means that time passes differently for different observers, depending upon their velocity.

-----is this true???

would anyone be able to expand upon this for me, just for clarrifcation or correct me if im wrong in my thinking!

thankyou
 

alcalder

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Is this true?? Very good question. Can they prove it?

Here is a site that lists some experiments designed to test various aspects of Einstein's relativity.

http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html

But again, is the speed of light constant? A good question.

Some argue it is, some argue it is not. I think we can assume in the perfect HSC Physics world that it is but in fact, it may not be. It is still an argument that is going on.

http://www.ldolphin.org/bowden/centj.html
 
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Lingb said:
hey...i have this question....
"Identify the significance of Einstein’s assumption of the constancy of the speed of light by stating what this means for space and time"

i understand Einstein's assumption of the speed of light, and i understand that this means that both time and space become relative.

and that it also means that time passes differently for different observers, depending upon their velocity.

-----is this true???

would anyone be able to expand upon this for me, just for clarrifcation or correct me if im wrong in my thinking!

thankyou
Basically time and space become relative

Time passes differently, depending on your frame of reference. If you are in a train travelling at the speed of light passing a platform. Say a person sneezes on the platform. The person will sneeze in normal time, but for the person in the train passing they will think the sneeze went a little longer than it really did. Who is right? They are both right, because they are observing from their frame of reference.

Space = distance and this means length contraction. Think about it if you are in a plane or train or something travelling past something at high speeds the thing outside its going to appear shorter than it really is.
 

milton

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originally most ppl thought space and time are absolute and the speed of light is relative

but most experiments seemed to suggest that the speed of light is in fact constant.
so einstein assumed that the speed of light is indeed constant and showed that the only logical conclusion is that space and time are relative
the assumption that the speed of light is constant is critical to the the theory of relativity, the whole freaking theory is based on it!
 

alcalder

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milton said:
the assumption that the speed of light is constant is critical to the the theory of relativity, the whole freaking theory is based on it!
And if they prove it is not constant then the whole "freaking theory" goes out the window. Hence the reason that most scientists will not cause that apostasy and continue on regardless. It happens all the time. There is one guy challenging Newton's Laws and is getting howled down because he is going against the establishment.

Just don't ever get too attached to established to scientific "facts" because everything is always up for negotiation.

eg. Look up Mordehai Milgrom and Modified Newtonian Dynamics (MOND).
 
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airie

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lol, weren't these people trying to rewrite the rules of Einstein's Special Relativity? Something called "Very Special Relativity", uhh...very original name...:p
 

Lingb

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thankyou soo much ladies and gents,
i was pretty happy with what i thought, but all your help has left me in doubt :)
appreciate it hugely!!!

hope everyone has a good friday, bring on the wkend :D

thanx once again!
 

alcalder

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I'm so sorry LingB. Just go with the basic theory that the HSC syllabus outlines and is in the textbooks. But always keep in mind it is just a theory and an early one at that. But then again, part of the Physics syllabus is to appreciate the development of theories over time.

The classic one that is studied is the theory of the atom. The Syllabus really only follows the mainstream development that led to the current theory. If you look into that more closely there are many tangents that were followed but abandoned as further evidence and interpretation came to light.

Einstein's relativity is another such theory that will be modified and changed or abandoned as time goes by. We are just in the middle of it all at the moment.
 

bboundy

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webby234 said:
http://home.houston.rr.com/bybayouu/SN1987A.html
Yes - if you look out the window of a spacecraft travelling at a high velocity, events outside the spacecraft will appear to be quicker.
Not sure about this^

My understanding is that events outside the spacecraft will appear slower to the person inside the spacecraft.
BUT...
A person outside the spacecraft will be moving relative to the spacecraft, therefore they see events inside the spacecraft slower.

I could be wrong. Any thoughts?
 

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