Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Speeding up Light

  1. Oct 16, 2003 #1
    Recently, I read that light has been made to go faster. What effects can this discovery have on our concepts of physics?
  2. jcsd
  3. Oct 16, 2003 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

  4. Oct 17, 2003 #3
    The speed of light is about 186,300 miles per second. The speed of light does not change, relative to any observer.
    Last edited: Oct 17, 2003
  5. Oct 17, 2003 #4
    I know what he means, I don't have sources though. Someone has did experiments where the light was recieved just a little before it was emitted, inicating that from the lab's reference frame, the light went faster than 299792458m/s and went like billionth of a second back in time. I thought this was all well known.
  6. Oct 17, 2003 #5


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    It is old news. It deals with a pulse's phase velocity, not its group velocity, and does not violate relativity in any way.

    - Warren
  7. Oct 17, 2003 #6


    User Avatar

    I would REALLY like to read more about this. :)
    Anyone got any links or anything?
  8. Oct 17, 2003 #7


    User Avatar
    Science Advisor
    Gold Member

    It's basically quantum mechanical tunelling, it's implications aren't as great as you might think as importantly it cannot lead to casuality violations and at no spefic time can you say that the light actually travelled faster than c.
  9. Oct 17, 2003 #8

    Guys....i would REALLY listen to Warren on this one. This is how it happened. The rest of you are just speculating.
  10. Oct 17, 2003 #9


    User Avatar

    Staff: Mentor

    Ie, it has nothing at all to do with the velocity of individual photons.
  11. Oct 17, 2003 #10

    Chi Meson

    User Avatar
    Science Advisor
    Homework Helper

    Ditto. I'm just annoyed that Chroot keeps beating me to the punch.

    When this news came out two years ago, the media kept saying "light breaks the speed limit." BUt every physicist they quoted said things like, "well, not really." But the headlines are all some people read.
  12. Oct 17, 2003 #11
    Hehe...because the media sucks at translating science into something the general public can understand without dumbing it down.
  13. Oct 17, 2003 #12
    One thing more

    Neutroncount stated :
    Ok, the physicists said that there was nothing special. But what the reason behind their statement?

    Jonathan :
    so, it proves that time can be made to slow down! I have posted a topic titled " Light carries time " (theory development),in which I have stated that time does travel with light! Is'nt the above quote a proof for my article?
  14. Oct 17, 2003 #13

    Chi Meson

    User Avatar
    Science Advisor
    Homework Helper

    As to a proof, I disagree. Reread Chroot's post. Scientists publish their findings because that's what they do when they've done a neat trick. The report was snagged by a publicist because media attention wouldn't hurt. Sort of like when Dirak's last theorem was cracked: millions were agog yet maybe a dozen people in the world could follow the proof.

    Yes they were manipulating quantum effects, but it was all according to their predictions, and none of the predicitons included manipulating time. Something about it does not allow faster than light information. It will not work with individual photons. I read through some of the material and I don't understand most of it, but in the end it was simply not that fantastic and certainly does not indicate that time slowed down.
  15. Oct 17, 2003 #14
    Re: One thing more

    Jonathan didn't know. He was just commenting on maybe he THOUGHT that that's what he heard.

    Here is the link you want to read. Read it carefully and don't assume you know what you're talking about.

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook