Notices
Results 1 to 11 of 11

Thread: Relativity question

  1. #1 Relativity question 
    Forum Junior
    Join Date
    Feb 2008
    Posts
    213
    If your in a plane going at the speed of sound, you can hear noises inside the plane, but no sounds can catch up to you outside of the plane.

    So if your in a plane going the speed of light, the electronics in the plane will all work properly because that light is also traveling on the plane. So if you looked out the window of the plane traveling at the speed of light, what would you see? Darkness? Or would their still be light even though the plane is traveling at the same speed of light?


    Reply With Quote  
     

  2.  
     

  3. #2 Re: Relativity question 
    Forum Junior DivideByZero's Avatar
    Join Date
    Dec 2007
    Posts
    260
    Quote Originally Posted by Raymond K
    If your in a plane going at the speed of sound, you can hear noises inside the plane, but no sounds can catch up to you outside of the plane.

    So if your in a plane going the speed of light, the electronics in the plane will all work properly because that light is also traveling on the plane. So if you looked out the window of the plane traveling at the speed of light, what would you see? Darkness? Or would their still be light even though the plane is traveling at the same speed of light?

    I don't think you'd see darkness. You'd probably see the past if speed of light travel is even possible.


    Reply With Quote  
     

  4. #3  
    Forum Junior
    Join Date
    Feb 2008
    Posts
    213
    Well, I mean, if sound travels in waves and your moving at the same speed of the waves, they will never reach you.

    Electromagnetic radiation also moves in waves, visible light being one of them, now if light can't catch up to you then how would you see outside of the plane's window moving at the speed of light?
    Reply With Quote  
     

  5. #4  
    Moderator Moderator Janus's Avatar
    Join Date
    Jun 2007
    Posts
    2,070
    One of the postulates of Relativity is that the Speed of light is measured to be the same by all observers in inertial frames. (as measured relative to the observer.) In other words, one would measure the speed the light in the plane as being the same as the speed of light outside of the plane no matter what speed you are traveling relative to the source of the light.

    That being said, one conclusion that comes of this is that no material object can travel at the speed of light. As as result, it is meaningless to ask what would happen for a plane traveling at the speed of light, because assuming that the plane can travel at the speed of light breaks that rules that we would use to determine what would happen.
    Reply With Quote  
     

  6. #5  
    Forum Junior
    Join Date
    Feb 2008
    Posts
    213
    Quote Originally Posted by Janus
    One of the postulates of Relativity is that the Speed of light is measured to be the same by all observers in inertial frames. (as measured relative to the observer.) In other words, one would measure the speed the light in the plane as being the same as the speed of light outside of the plane no matter what speed you are traveling relative to the source of the light.

    That being said, one conclusion that comes of this is that no material object can travel at the speed of light. As as result, it is meaningless to ask what would happen for a plane traveling at the speed of light, because assuming that the plane can travel at the speed of light breaks that rules that we would use to determine what would happen.

    With a plane going at the speed of sound the sound outside of the plane is NOT traveling as fast as the sound inside of the plane? What makes light so special if it travels in the same ways of sound?
    Reply With Quote  
     

  7. #6  
    Moderator Moderator Janus's Avatar
    Join Date
    Jun 2007
    Posts
    2,070
    Quote Originally Posted by Raymond K
    Quote Originally Posted by Janus
    One of the postulates of Relativity is that the Speed of light is measured to be the same by all observers in inertial frames. (as measured relative to the observer.) In other words, one would measure the speed the light in the plane as being the same as the speed of light outside of the plane no matter what speed you are traveling relative to the source of the light.

    That being said, one conclusion that comes of this is that no material object can travel at the speed of light. As as result, it is meaningless to ask what would happen for a plane traveling at the speed of light, because assuming that the plane can travel at the speed of light breaks that rules that we would use to determine what would happen.

    With a plane going at the speed of sound the sound outside of the plane is NOT traveling as fast as the sound inside of the plane? What makes light so special if it travels in the same ways of sound?
    Light doesn't travel in the same way as sound. Sound requires a medium to travel, such as the air in the plane and the air outside the plane. Sound's speed is relative to the medium it is traveling through. Light, however, does not require a medium.
    Reply With Quote  
     

  8. #7  
    Forum Junior
    Join Date
    Feb 2008
    Posts
    213
    Quote Originally Posted by Janus
    Quote Originally Posted by Raymond K
    Quote Originally Posted by Janus
    One of the postulates of Relativity is that the Speed of light is measured to be the same by all observers in inertial frames. (as measured relative to the observer.) In other words, one would measure the speed the light in the plane as being the same as the speed of light outside of the plane no matter what speed you are traveling relative to the source of the light.

    That being said, one conclusion that comes of this is that no material object can travel at the speed of light. As as result, it is meaningless to ask what would happen for a plane traveling at the speed of light, because assuming that the plane can travel at the speed of light breaks that rules that we would use to determine what would happen.

    With a plane going at the speed of sound the sound outside of the plane is NOT traveling as fast as the sound inside of the plane? What makes light so special if it travels in the same ways of sound?
    Light doesn't travel in the same way as sound. Sound requires a medium to travel, such as the air in the plane and the air outside the plane. Sound's speed is relative to the medium it is traveling through. Light, however, does not require a medium.
    And it is because of their not being a medium that it always travels at a constant speed?
    Reply With Quote  
     

  9. #8  
    Forum Professor sunshinewarrior's Avatar
    Join Date
    Sep 2007
    Location
    London
    Posts
    1,526
    Raymond

    1. If you are in a plane travelling at the speed of sound, or just above, only sound from directly behind you will fail to reach you. Sound from the side will hit you, and sound from in front will hit you at high frequencies.

    2. Einstein formulated his theory of relativity (though some scientists claim it is better described as the theory of invariance) by imagining what it would be like to ride on a beam of light. It was exactly his knowledge that the speed of light does not change, regardless of the motion of the transmitter/receiver, that made him realise that the only way for there to be no paradoxes is to suggest that no matter can attain the speed of light.

    3. Therefore, whilst your speculation may be interesting, physically it is as meaningful as dividing by zero.

    Hope this helps.

    cheer

    shanks
    Reply With Quote  
     

  10. #9  
    Forum Bachelors Degree Shaderwolf's Avatar
    Join Date
    Dec 2005
    Location
    OPSEC, baby. Sorry.
    Posts
    425
    I thought that photons created their own medium in the form of an electromagnetic field... Where did I hear that, and why is it wrong?
    Reply With Quote  
     

  11. #10  
    Forum Junior
    Join Date
    Sep 2007
    Location
    Mumbai, India
    Posts
    203
    Light has absolute speed. At speed of light, the Newtonian model of relative speed cannot be applied. Einstein's model says that , if you r travellin' at the speed of light, light coming toward you will still seem to be going with the speed of light in vacuum. So, you will still be able to see light in the plane
    Beyond Equations,

    Pritish
    Reply With Quote  
     

  12. #11  
    Forum Bachelors Degree Shaderwolf's Avatar
    Join Date
    Dec 2005
    Location
    OPSEC, baby. Sorry.
    Posts
    425
    Yes... I know that. Someone said that light didn't need a medium earlier in this post. ZI thought that it created it's own medium in the form of anelectromagnetic field. was I wrong? If I was, what is the truth? I thought that electromagnetic waves (such as light) were surrounded by an electromagnetic field witch let them travel through a vacume.
    Reply With Quote  
     

Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •