Imagine a tsunami wave. Out at sea, it slowly raises the water level not more than a few inches or feet, and passes by standing boats with barely any resultant turbulence. It moves very fast, but it's also very thin and wide. As it comes close to land, it suddenly compresses and reduces speed, but also there forms into the tall, destructive wave that's known for.

What if electromagnetic waves worked in a similar way? With even the concept of observing these waves, the proverbial 'land' is brought near, and the nature of the wave changes. Therefore, photon particles are less definable as discrete objects of their own, but more rather the 'shape' of the electromagnetic waves themselves, which have changed from the long and thin 'sea-tsunami' wave form into a condensed and discrete-looking 'crashing-tsunami', which behave like discrete particles.

This of course directly suggests that the act of just observing passing electromagnetic waves does indeed have a physical effect on them. This is the part I do not yet understand fully, however.

Does this explanation corroborate with how the theory is understood mathematically?


1 Answer 1


You can observe a water wave using light, but there is no analogous way to observe an electromagnetic wave. To observe an EM wave you must take energy out of it, so observing it does indeed affect it.

The wavelength of EM waves is made shorter when they move from a vacuum into some other medium, in which their speed is slower. This is wave behaviour, and is not related to wave-particle duality. Water waves are slowed by the depth of water decreasing, which is why their wavelengths reduce near the coast.

Within water waves the water (being incompressible) must move backwards or forwards as the wave passes. Breakers are caused when this movement becomes too great. However there is no analogous physical movement in the EM field as an EM wave moves, so there is no EM equivalent to breakers or tsunamis.

Wave particle duality is about the ambiguity of phenomena which sometimes behave like waves and sometimes like particles. Usually we describe particles as "packets of waves" or describe waves as statistical representations of how particles behave en masse. Your suggestion, while interesting, is not really a good way to explain wave-particle duality.

  • $\begingroup$ If observing an EM wave takes energy out of it, that does sound similar to a large wave losing energy as it encounters a coastline... $\endgroup$
    – hamstar
    Nov 27, 2023 at 3:27
  • $\begingroup$ @hamstar the wave encountering a coastline continues to behave like a wave. This is the fundamental difference between quantum physics and classical physics. The quantum waves totally stop behaving like waves when we perform observations of their particle character. $\endgroup$ Nov 27, 2023 at 3:59
  • $\begingroup$ @hamstar, superficially yes, but not really. If you do an experiment detecting very low intensity light you find light arriving at random times, with nothing at all in between. Brighter light means the waits are shorter, but each time light of the same colour arrives it carries the same energy. Water waves (and other classical waves) don't behave this way; low intensity just means less height in the waves. $\endgroup$
    – Peter
    Nov 27, 2023 at 4:39
  • $\begingroup$ @naturallyInconsistent sure, but even water in much smaller amounts behaves differently, due to surface tension. It might be possible that whatever makes photon particles appear from waves could happen due to forces that could at least superficially compare to the concept of surface tension, and therefore photon particles are still akin to 'wave shapes'. $\endgroup$
    – hamstar
    Nov 27, 2023 at 6:32
  • $\begingroup$ @hamstar we are trying to tell you that small alterations will NOT work. It is NOT AT ALL like surface tension. The behaviour is completely different. It is not "wave shapes". It is stop behaving like waves at all. $\endgroup$ Nov 27, 2023 at 6:58

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