Coherence

[dastgir]

Dears,

What is the difference between " Coherence of Policy " and " coherence of Light "

Regards,

Gulam Dastgir

[Barb_D]

Could you let us know the context in which you read these things?

[dastgir]

Dear Barb,

These are as follows-

1. A coherent policy is needed to eradicate poverty.
2. Coherent light is emitted by LASER.

Regards,

Gulam Dastgir

[Barb_D]

Hi,

That makes a lot more sense - you're asking about the different meanings for "coherent," and not those two phrases.

Did you look in a dictionary? My favorite online one is www.m-w.com

coherent - Definition from the Merriam-Webster Online Dictionary

For the first one, either of the first two would seem to apply:
1 a: logically or aesthetically ordered or integrated : consistent <coherent style> <a coherent argument> b: having clarity or intelligibility : understandable <a coherent person> <a coherent passage>2: having the quality of cohering ; especially : cohesive, coordinated <a coherent plan for action> (If you click on "cohering" you'll see this: 3 a: to become united in principles, relationships, or interests b: to be logically or aesthetically consistent.)

So, a logically consistent plan.

For your second one, it's this: 3 a: relating to or composed of waves having a constant difference in phase <coherent light> b: producing coherent light <a coherent source> -- It's a physics definition, so if you need more information than this, you need to ask a scientist, not a writer.

[konungursvia]

To cohere is to stick together, and coherent policy makes sense, with no parts contradicting the other principles.

Coherent light is light which -- like soldiers marching -- moves along in phase, all the crests matching in time and distance, and all the troughs as well. Normal light sources are like a bunch of kids running along, not in lock-step at all. Some waves are moving up while others are moving down, etc.