Is it possible to make a light source that shifts waves of light to cause destructive interference to cancel the other light source out to make it fully dark?

  • $\begingroup$ Polarizer sheets work using the mechanism you've described. $\endgroup$
    – Yashas
    Commented Feb 22, 2017 at 12:21
  • $\begingroup$ @YashasSamaga So if I shine light through a polarizer sheet onto where another light (which is not being polarized) shines, would the polarized light cancel out the other light? $\endgroup$
    – kirill2485
    Commented Feb 22, 2017 at 12:24
  • $\begingroup$ And where the energy of the light from the sources will go? For light destructive interference without constructive interference isn't possible. $\endgroup$ Commented Feb 22, 2017 at 20:04
  • $\begingroup$ This refers to a part of the question physics.stackexchange.com/questions/88422/… and physics.stackexchange.com/questions/9628/… . Although - I have seen only a vague claim, that 'because of energy conservation' there will be always some part the will be interfering constructively $\endgroup$
    – jaromrax
    Commented Apr 18, 2017 at 11:39

1 Answer 1


in theory yes you can do it. But real word is harsh, the light you see every day is mix of almost all wave lenght so to interfire whit that you would need emiter that send all waves but moved by pi/2 (to make it simple i asume every wave is sinusoidal). It might work at still viev but at dinamic you wolud have to know the future to destroy incomig light. Beside that it will work as long as you stay behind you foton destroyer (sorry for broken eng)


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