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Light out of phase?

  1. May 18, 2010 #1
    if i have a laser beam getting bent by gravity , then i shoot another laser right on top of the other laser , like a fork in the road , and the lasers are perfectly out of phase , will their waves cancel each other out and i will see no light , And could this same thing happen with electron waves .
  2. jcsd
  3. May 18, 2010 #2


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    Using two lasers would not ensure perfect phase synchronism of the two beams. If you split an existing laser beam and send one part down a different path (near a black hole or just through a thin piece of glass) from the other then you can get cancellation in some regions (interferometry works this way)
    But you can't take your scenario to the limit that you want. At some point and in some region you can get a null but the beams will have slightly different geometries (even if it's just the fact that they spread out eventually) and there will be regions where the cancellation doesn't take place. That's where your energy will show up. It can't 'go nowhere'.

    And electron beams can exhibit refraction and interference effects, too, when fired, for instance, through a very thin sheet of Carbon. 'A level' School demo apparatus available from all good equipment suppliers!
  4. May 18, 2010 #3
    thanks for your response , i have done some electron diffraction in my physics lab.
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