Thought experiment:
Imagine you have an old pendulum clock. When the pendulum is swinging, at any speed, (frequency), then then you can use it to tell the time. No matter what speed it swings, you can use different gears to make it work. However if you stop the pendulum swinging, no mechanism that you can attach to the clock will make it tell the time. Therefore the concept of zero Hz is meaningless.
Imagine you have an old pendulum clock. When the pendulum is swinging, at any speed, (frequency), then then you can use it to tell the time. No matter what speed it swings, you can use different gears to make it work. However if you stop the pendulum swinging, no mechanism that you can attach to the clock will make it tell the time. Therefore the concept of zero Hz is meaningless.
pinkmouse said:
I understand what you're saying and I agree that zero Hz is mathematically meaningless until I get to daydreaming .................
A speaker/pendulum continually reduces it's frequency ..... 10Hz .... 1Hz ..... 0.1Hz .... 0.0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001Hz
What comes next? Yes, I do know, but it's interesting and you get what I mean! Surely this number is more than a reasonably accurate representaion of 0Hz.
To me, it's like trying to comprehend all the stars in the universe ..... or .... the universe.
I think I'll just try to counteract tonight's insomnia by accepting that 0 Hz = Stop.
Keruskerfuerst said:
is that the difference between a dynamo and an alternator?pinkmouse said:
How come I can make an electromagnet out of an old nail, a coil of wire, and a 9V battery then?
one produces DC and the other produces AC (that needs to be rectified).
Both machines depend on electromotive force and electromagnetic field.
BTW,
what is chopped DC?
Actually 0 Hz can be interpreted in many different ways.
One would be like the professor next door to me says: "frequency is the same as 'often-ness'". From that definition, 0 Hz would mean that the event that we study has never happened. Like: At what frequency has God created earths (ok, bad example for religous people ).
Another one would be Fourier analysis. A signal only containing 0 Hz would be a signal that has been and will be forever "on" at a fixed value. Even before big bang, it was on. This is of course not possible.
Yet another way would be to make Fourier analysis of a snippet of a signal (this is the way we usually do it). By doing so we limit the frequency resolution and each frequency bin will have a non-zero width. In this case, the DC of the signal comes out in the 0 Hz bin.
One would be like the professor next door to me says: "frequency is the same as 'often-ness'". From that definition, 0 Hz would mean that the event that we study has never happened. Like: At what frequency has God created earths (ok, bad example for religous people
).Another one would be Fourier analysis. A signal only containing 0 Hz would be a signal that has been and will be forever "on" at a fixed value. Even before big bang, it was on. This is of course not possible.
Yet another way would be to make Fourier analysis of a snippet of a signal (this is the way we usually do it). By doing so we limit the frequency resolution and each frequency bin will have a non-zero width. In this case, the DC of the signal comes out in the 0 Hz bin.
Sonusthree said:I don't remember mentioning amplitude? I referred to altering the frequency of a pendulum.
If I remember correctly, and I think it's what y8s is referring to, is that as a pendulum reduces it's amplitude, the frequency does not change. In order to change the frequency, you must change the length of the pendulum.
Did I get that right?
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