Wave interference and energy conservation

[Bill Minerick]

If the crest of one light wave meets the trough of another light wave of the same frequency and intensity they supposedly cancel each other resulting in no light (e.g., the dark areas that result on the screen when both slits are open on a dual slit experiment). In particle physics, why then does the collision of an electron and a positron result in the release of a photon vs. just no energy at all?

 

[Jakell]

When light interferes ,the energy does not just disappear. You will get spots where there is destructive interference, and spots with constructive interference; the energy is isolated into the bright bands. As for the collision of an electron and a positron, both have positive energy (ie it takes energy to make them, me*c^2 for both), and so when they meet, they annialate each other releasing energy in the form of two photons (for momentum conservation).
The closest you can get to the release of no energy is with virtual particles; they spring into existence and then annialate each other, consuming or releasing no energy in the process.

 

[astrokreng]

I can explain that the phenomenon of wave interference and energy conservation is a complex and fundamental concept in physics. In the example mentioned, when the crest of one light wave meets the trough of another light wave, they do not completely cancel each other out. Instead, they interfere with each other, resulting in a decrease in the intensity of the light. This is because light is a form of electromagnetic radiation that exhibits wave-like properties, and when two waves meet, they can either reinforce or cancel each other out depending on the phase of the waves.

In the case of a dual slit experiment, the dark areas on the screen are a result of destructive interference, where the waves cancel each other out and result in no light. However, this does not mean that no energy is present in those areas. The energy of the light waves is still present, but it is distributed differently due to the interference.

In particle physics, the collision of an electron and a positron does not result in the release of a photon because of wave interference, but rather because of the conversion of mass into energy. According to Einstein's famous equation, E=mc², energy and mass are equivalent and can be converted into each other. When an electron and a positron collide, they annihilate each other, converting their mass into energy in the form of a photon. This process follows the principle of energy conservation, where the total energy before and after the collision remains the same.

In summary, the concept of wave interference and energy conservation applies to both light waves and particles in different ways. In the case of light waves, interference can result in a decrease in intensity, while in particle collisions, energy is conserved through the conversion of mass into energy. It is essential to understand the underlying principles and mechanisms behind these phenomena to gain a deeper understanding of the behavior of energy in the universe.