Which part of the light wave do we take? (quick question)

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sameeralord
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Hello,

Quick question. This is a light wave

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This is another light wave

http://www.chem.yale.edu/~chem125/125/xray/DiffractionMasks/sinpositiont1.JPG

Why doesn't this graph have another perpendicular graph. Are they talking about the particles in the magnetic field or electric field here or both.

Simply how do they make one wave out of a light wave that has two waves.
 

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sameeralord said:
Why doesn't this graph have another perpendicular graph. Are they talking about the particles in the magnetic field or electric field here or both.
While your first diagram seems like the usual depiction of an EM wave (which is what light is, classically), it's not clear what that second diagram is supposed to show. (It looks like it's meant to depict the force on some charged particle.)
Simply how do they make one wave out of a light wave that has two waves.
A light wave has both electric and magnetic fields, which are at right angles to each other. But that doesn't mean you always have to show both in a diagram.
 
Doc Al said:
While your first diagram seems like the usual depiction of an EM wave (which is what light is, classically), it's not clear what that second diagram is supposed to show.

A light wave has both electric and magnetic fields, which are at right angles to each other. But that doesn't mean you always have to show both in a diagram.

Thanks Doc Al! :smile: So most of the time I think they show the electric field. When light has a particular freuqency would both electric and magnetic waves travel at that frequency. I think they do because one is created from the other.
 
sameeralord said:
When light has a particular freuqency would both electric and magnetic waves travel at that frequency.
Yes.
 
Doc Al said:
Yes.

Thanks Doc Al :smile: Topic closed unless someone wants to start the topic if light is a wave or particle :smile:
 
sameeralord said:
Thanks Doc Al! :smile: So most of the time I think they show the electric field. When light has a particular freuqency would both electric and magnetic waves travel at that frequency. I think they do because one is created from the other.

Wrong. Electric and Magnetic fields in EM waves DO NOT "create each other". Sorry Wikipedia is wrong on that. (and they won't correct it, because they are determined to keep it wrong) Electric and Magnetic fields of waves are both created by the source of the waves (moving charges) not each other.