Can light produce darkness and can noise procude quiteness 4

TheOne123

This is do with wave I think but i'm intrigued with this. As with waves sometimes they can cancel each other out but what about this:

• Can light produce darkness?
• Can noise produce quietness?

the pro

due a to redistribution of energy as a result of interference , the light seems to produce darkness, when it is passed through slits

Gerenuk

You can create just the right type of "anti-noise" to cancel some noise
http://en.wikipedia.org/wiki/Noise-c...ing_headphones
So in a way that is noise creating silence?

Similarly for light in solids. Sometimes the process of absorbing or reflecting light can be seen as the electrons creating just the right "anti-light" to cancel any further propagation of the light waves.

The trick is always to examine the signal that you want to cancel and produce a suitable anti-signal. Otherwise light or noise are not going to interfere destructively.

Blenton

Just as a side note, should light be cancelled out by interference, what happens to the energy?

kinetic guy

darkness is always there; light just covers it. also darkness is instantaineous

Gerenuk

The energy is redistributed. You cannot cancel light without creating more light somewhere else.

kinetic guy

oh by the way i'm new to this forum so how do you post questions?
thanks

the pro

also there in chemistry ther is a method to creat exp: metal to gold due to bombing the atoms and creat new atoms

Redbelly98

Very good question -- see Gerenuk's response. You cannot have destructive interference everywhere in the wave, at some locations there will be constructive interference. That is where the energy is.

Go to a subforum page, like
http://www.physicsforums.com/forumdisplay.php?f=111
and click the "New Topic" button, to the above left of the Threads In Forum list.
For homework and any course-related questions, post in one of the Homework forums:
http://www.physicsforums.com/forumdisplay.php?f=152

Not sure I see the relevance to this discussion

TheOne123

Thanks for all the answers guys. Would love some links would love to read more on this

DrGreg

For a start, try the Wikipedia article Interference (wave propagation) The animation shows areas that are permanently coloured cyan (pale blue) where there is no energy, and areas in between where there is more energy.