Do we have any negative frequency?
Yes - that`s true.yes,but whenever i ask this question most of the replies are:''its just a theoritical concept"
As a property of a sinusoidal signal or any other periodical mechanical phenomenon (mechanical pedulum, for instance) the thing called "frequency" is NOT a theoretical definition but a parameter that can be measured in reality.It's like asking: "Can you have negative time?"
Sure you can!
If frequency = n/time
and time can be negative, then frequency can be negative.
Well said.As a property of a sinusoidal signal or any other periodical mechanical phenomenon (mechanical pedulum, for instance) the thing called "frequency" is NOT a theoretical definition but a parameter that can be measured in reality.
And as such - it is based on positive times only.
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I think you are really asking if anything can have a less than zero magnitude which, I suppose, is impossible. Obviously many things are defined as negative and positive. For example, how about an electron charge and a positron (or proton) charge. What other words could you use besides positive and negative for the charge of those?....................
I often wonder if anything negative exists in the real world, that is properly negative, ie; goes less than zero.
Most of the examples people will cite are just positive things occurring in a different direction (like - voltage or - current etc).
I like to restrict myself on time - and in this context, something comes into my mind which may serve as a counter example: Group delay.Well said.
I often wonder if anything negative exists in the real world, that is properly negative, ie; goes less than zero.
Hmmm - good question.But what does a positive time mean? It is merely a measure of some quantity relative to some reference. We assign it a positive value if the moment in question occurs after the reference. How is that any more or less "real" then assigning it a negative time if the moment in question occurs before the reference.
Not necessarily. Have you ever wondered by the NASA guy says, "T minus 1 hour"? It's because the reference for the measurement, T, is at a point in the future, namely main engine ignition.Hmmm - good question.
Here is my opinion:
At first - what is the "reference point"? I think it is the start time for the measurements (t=0). Thus, all measurements are performed for positive times. However, if the "moment in question" occurs before the reference point (t=0) we have absolutely no information (no measurements). Thus, it makes no sense to assign negative time values to this "moment in question".
Of course, we can say at time tx=-30 minutes I had breakfast and 30 minutes later I started measurements.
Why?But coming back to the original problem (frequeny) it is necessary to combine the time with measurement results (occurences per second) - and this, I think, is possible for positive times only.
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