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Radio waves slower than light????

Discussion in 'Science' started by rachel_g41, Oct 26, 2011.

  1. rachel_g41

    rachel_g41 Established commenter

    Please tell me no!

    On another forum, in a discussion about the neutrino experiment, this question has arisen

    if radio waves are electromagnetic radiation why does it take longer to bounce a radio signal off the moon than it takes to bounce a light ??

    why does the frequency of the radio waves above make a difference in their speed.?

    Where does this misunderstanding (if that's what it is) come from? Does anyone know? Is this a common belief? I'd never heard of it before.

    When I asked for more info, I was simply asked to prove my assertion that they travel at the same speed, because apparently thats like saying a Tiger Moth travels at the same speed as Concorde because they both fly.


    The discussion came about because of a TV programme about the neutrino expt. I didn't see the programme so don't know whether it has contributed to general misunderstanding or not.

    Your thoughts please
  2. My advice? Stay away from such forums.
    I've just had a quick browse through several on this topic and managed to discover that some believe that radio can travel faster than visible light whilst others believe that radio travels slower than visible light.
    All electromagnetic waves travel at the same speed in a vacuum. This has been shown so often.
    Of their speeds in other media do depend upon their frequencies but the difference in air is minimal - this is shown constantly by our use of RADAR.
    You were asked to 'prove' your assertion? Were they able to prove theirs?
    Rest easy.
  3. rachel_g41

    rachel_g41 Established commenter

    Thanks Robbie. I will sleep better for that :)

    You're overseas as well I think, aren't you? I wondered if anyone here had seen the programme which I assume was on british tv. I wondered if it was something in the programme itself that led to such misconceptions or if it's just that these programmes provoke discussion which reveals misunderstandings.

    I was drawn into the discussion by a comment along the lines of "neutrinos could be technically massless and therefore not limited by the speed of light".......
  4. Yes this comment is wrong on two counts;
    The Standard Model (original) asssumed that neutrinos had no mass - however neutrino oscillation experiments have shown tha neutrinos have a 'non-zero' mass but despite this non-zero mass they are still able to fit into the Standard Model.
    Everything is limited by the speed of light (in vacuo), including light.
    It would be interesting if others are able to repeat the results from CERN's neutrino speed experiment but unless they do we should still adhere to the current opinion of the speed of light (in vacuo) limit. It is grossly unscientific to do otherwise.
  5. rachel_g41

    rachel_g41 Established commenter

    Yes, I did ask whether it was the programme which had given the impression that anything with no mass was not limited in terms of velocity. I'm still not clear whether it did or not.

    I was genuinely surprised to find such misconceptions in people who are interested enough in this stuff to be watching these programmes and posting on the internet about them.

    I blame the teachers.
  6. phlogiston

    phlogiston Star commenter

    I thought radio waves were slower because they only need to travel at the speed of sound, while TV signals are faster because they carry light too![​IMG]
  7. blazer

    blazer Star commenter

    What about the Light programme?
  8. phlogiston

    phlogiston Star commenter

    Nice one - they had to replace it with radio 2 because it was getting to receivers too fast.
  9. phlogiston

    phlogiston Star commenter

    A sign that both you and I are older than some of the other posters!

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