Synchronous Sources and Interference

[bgq]

Hi,

What is the scientific definition of "synchronous sources" when we talk about the conditions of interference?

Thank you.

 

[Tom.G]

Same Frequency and a Constant Phase relationship between them. ("Usually" the phase difference is assumed to be zero.)

 

[jtbell]

In English, we usually say "coherent" instead of "synchronous" in this context.

 

[bgq]

Well, is this mean that "coherent" and "synchronous" are the same? Is it just a linguistic issue?

 

[jtbell]

Where have you seen the term "synchronous sources" in the context of interference? I've never seen it, before this thread. "Coherent" is the standard term, in English-language textbooks etc.

I said "usually" in my previous post because I wanted to leave myself a loophole in case someone actually gave an example.

 

[bgq]

Actually, I have completed two years general physics in university, I have learned that the sources should be coherent (talking about interference).

A student in the secondary school asked me about synchronous. In his textbook (translated from french), they say about the conditions of interference that the sources should be synchronous and coherent. I tried to understand the word "synchronous" literally, but I cannot find anything that makes a sense.

It seems from the examples in his textbook, that they mean by "synchronous" having same frequency. But I thing this doesn't make any sense because coherent sources have already same frequency; beside this, I cannot understand how the word "synchronous" could mean having same frequency.

 

[Ibix]

I've not heard the term either. But "coherent" could be describing each source as having a well defined frequency and a long coherence time individually, and "synchronous" adding that both coherent sources have the same frequency.

I guess, anyway. There certainly are linguistic oddities with translated physics.

The text ought to define its own terms somewhere. I take it there are no helpful index or glossary entries?

 

[bgq]

OK, thank you all very much