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Ways to send signals

  1. Oct 10, 2009 #1
    Is there any other way to send signals a significant distance other than with EM radiation or (doubtfully) gravity?

    By signal I mean the complex information that we are able to send via radio or other EM transmission.

    I don't think there is any other way other than EM radiation but I cannot think of an air tight explaination why this is the case. There are no other forces available for such a signaling method. The Strong and Weak forces are too short range and gravity is a monopole force and extremely weak which makes it difficult to use for a signaling method.

    Can anybody either shoot down my claim or find a better explaination why EM radiation is the only possible way to send signals.
     
  2. jcsd
  3. Oct 11, 2009 #2
    Consider that the forces have mediating particles (gravity is undetected).

    Is having a mediating particle a requirement for being able to send a signal?
     
  4. Oct 11, 2009 #3

    Cleonis

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    Gold Member

    I think the considerations you have provided yourself are spot on.

    The nuclear interactions are by nature short range. Electromagnetism and gravitation are both long range, but gravitation is way too hard to modulate.


    You also raised the question how the answer to your inquiry looks like in terms of quantum physics. I can only sketch a vague answer, you might want to resubmit the question in the quantum physics forum.

    What if you have an omnidirectional source of light, surrounded with scintillation counters? Detection of light by a scintillation counter behaves like a particle-particle interaction, the energy of a quantum of electromagnetic radiation is transferred locally to a spot on the scintillation counter. (For instance, some stars are so far away that reception of light from them can be resolved into individual scintillation events.)
    In terms of classical wave mechanics the wavefront should be thought of as spread out over an ever increasing surface, as it expands from the source. But in the interaction with a scintillation counter it is as if the lightsource has emitted a particle, headed for that scintillation counter all along.
    You may be tempted to think that particles can travel further than waves.

    However, as I understand it this has no bearing on the range of the interaction.
    Quantum physics describes that the probability of any scintillation counter detecting a photon from the source falls off quadratically with distance.

    It's not a good idea to try and sneak around particle/wave duality. Any visualization in which you give in to temptation to think like "It may look like waves, but its really particles." (or vice versa) is likely to lead you astray.

    Cleonis
     
  5. Oct 11, 2009 #4
    Cleonis

    My question about mediating particles and forces related in a round-about-way to the question original question: Is there any other way to send a signal other than EM?

    If there was such a force other then EM (or gravity) that could be used to send signals, wouldn't we be able to see its mediating particle either experimentally or at least predicted in the standard model?

    If a force is not required to send signals, then I am at a loss how such a thing would work.

    Either way, I am having difficulty explain why, EM is the only possible way to send complex signals over significant distances.
     
  6. Oct 12, 2009 #5
    Hi adamwho
    At one time, there was discussion about communicating with submerged U.S. submarimes at sea via modulated neutrino beams. This would be via weakly interacting particles.
    Bob S
     
  7. Oct 12, 2009 #6
    I am not seeing that thread.

    This type of communication at best seems like binary unless you are using some sort of pulse-width modulation (distance between pulses and width of pulses encode the data). There are obviously some very significant engineering obstacles to creating, modulating, sending or receiving such a signal.

    An interesting idea, though.
     
  8. Oct 13, 2009 #7
    It is an interesting idea that some scientifically illiterate people instantly accept as a of marvel of modern science. See
    http://physicsworld.com/cws/article/news/40619
    This is about as possible as anti-particle propulsion for inter galactic space travel.
    Bob S
     
    Last edited by a moderator: Apr 24, 2017
  9. Oct 13, 2009 #8
    I don't think the neutrino communication is viable or really speaks to the OP.


    Rephrasing the original question: What about EM radiation makes it the only viable candidate for sending signals significant distances? Is that that EM is a dipole force? Is it because of its range (obviously)? Is it because the mediating particle has "zero" mass?
     
    Last edited by a moderator: Apr 24, 2017
  10. Oct 13, 2009 #9
    Adamwho-
    You (The OP) asked for ways of communicating that are neither EM nor gravity. Neutrinos are neither. See this article in Physics World:
    http://physicsworld.com/cws/article/news/40619
    So some people are still talking and writing about military uses of neutrinos.
    Bob S
     
    Last edited by a moderator: Apr 24, 2017
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