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Can light travel through a vacuum?

  1. May 12, 2003 #1
    Can light travel through a vacuum? If so, can you provide an example.

    thx.
     
    Last edited by a moderator: Feb 4, 2013
  2. jcsd
  3. May 12, 2003 #2
    Have you ever seen the moon? :wink:
     
  4. May 12, 2003 #3
    Space is essentially a vaccuum. Furthermore, C is the speed of light in a vacuum, so how do you think we got that?!?
     
  5. May 12, 2003 #4

    dav2008

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    Yeah, unlike most other waves, light doesnt need a medium to travel through..It was proposed that there was some medium called the ether, but I think experiments could not find conclusive evidence supporting it.
     
  6. May 12, 2003 #5

    FZ+

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    And current theories of light as a group of mutually supporting electric and magnetic fields have made the ether rather pointless, as well as explained several other phenomenons....
     
  7. May 13, 2003 #6
    light is a electromagnetic waves....
    sure can through a vacuum
     
  8. May 13, 2003 #7
    No ethir means no difference for any experiment in moving vs non-moving with any velocity lab. So, h, c, G, e and all laws of nature shall not depend on lab's velocity. This in turn requires that h, c, G, e shall be invariant values (shall not depend on velocity of moving by them pobserver). This in turn requires space and time to be transformed very certain way (called Lorents transformations). Special relativity then precepitates from those transformations mathematically.
     
  9. May 13, 2003 #8
    No ether means no difference for any experiment in moving vs non-moving with any velocity lab. So, h, c, G, e and all laws of nature shall not depend on lab's velocity.

    This in turn requires that h, c, G, e shall be invariant values (=shall have the SAME numerical values measured by DIFFERENT observers regardless their mutual motion). Say, observer moving with some velocity past electric charge shall measure same charge as non-moving observer. Or observer moving by flashlight shall measure same c as non-moving one.

    This in turn requires space and time to be transformed very certain way between moving systems (called Lorents transformations).

    Special relativity then precepitates from those transformations mathematically.
     
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