Destructive interference and energy

In summary, when a pair of photons annihilate each other, their energy is transformed into the mass of the resulting particles. This is a rare occurrence and is not related to interference of visible light. The energy is conserved in this process.
  • #1
24forChromium
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Where do the energy go in a pair of photons that are annihilating each other exactly? What happens when they collide with something that absorbs photons like an electron? (I think electron can absorb the e. in a photon to jump into a higher level) Would this light wave become undetectable like destructively interfering sound?

I was thinking in the context of a laser beam, suppose light waves of various frequencies are sent, the beam may be less "powerful" because of interference, or so I heard.
 
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  • #2
Destructive interference creates areas of zero light intensity (the dark regions in a classical interference patterns), but there are also areas of constructive interference (the bright regions in the pattern) where the intensity is greater than it would otherwise be. The two effects balance so the total energy is conserved.

None of this has anything to do with photons, which don't annihilate each other when the interfere.
 
  • #3
24forChromium said:
where do the energy go in a pair of photons that are annihilating each other exactly?
The only way for that to happen is for them to produce a pair of particles (one is the anti-particle of the other). The photon energy goes into the mass of the pair.

This is extremely unlikely and requires very high energy photons. It is not related to interference of visible light.
 
  • #4
DaleSpam said:
The photon energy goes into the mass of the pair.
Said in this way could seem that "the photons energy disappear and is transformed in something else", which is false. The energy stay the same. Better to say that 2 particles transform in other 2 particles.

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FAQ: Destructive interference and energy

What is destructive interference?

Destructive interference is a phenomenon that occurs when two waves of equal frequency and amplitude meet and combine, resulting in a decrease in the overall amplitude of the resulting wave.

How does destructive interference affect energy?

Destructive interference can cancel out the energy of the two waves, resulting in a decrease in the overall energy of the resulting wave. This means that the energy of the wave is not conserved.

What are some examples of destructive interference?

Examples of destructive interference can be seen in everyday life, such as when two speakers playing the same frequency cancel each other out, or when two ocean waves meet and cancel each other's energy.

Can destructive interference be beneficial?

Yes, destructive interference can be beneficial in certain situations. For example, in noise-cancelling headphones, destructive interference is used to cancel out unwanted background noise, resulting in a quieter environment.

How is destructive interference different from constructive interference?

Destructive interference results in a decrease in amplitude and energy, while constructive interference results in an increase in amplitude and energy. Additionally, destructive interference occurs when two waves are out of phase, while constructive interference occurs when two waves are in phase.

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