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Theoretically speaking, does the frequency of em wave range from 0 to infinity?
Well it can't be zero. It can approach zero, though. It also can't be infinity (being that infinity is not a real number). It can approach infinity, though.Theoretically speaking, does the frequency of em wave range from 0 to infinity?
But Wikipedia on Plank length says that there is no proven physical significance of the Plank Length.I think its limited by the Planck length when you go toward 0 and limited by the size of the universe as you go toward infinity.
https://en.wikipedia.org/wiki/Electromagnetic_spectrum
In classical physics of the 19th century, it was believed to be continuous going from 0 to infinity.
Whole numbers? No. Ignoring possible quantum and cosmological effects, the range includes all positive real numbers, whole or not.Do you mean that it's range is infinite from a whole numbers perspective? Because something's frequency can't literally be 'infinity'
It is more of a question of semantics. Neither zero nor infinite wavelengths are practically possible. But there is no theoretically defined 0<limit or limit<infinity.Do you mean that it's range is infinite from a whole numbers perspective? Because something's frequency can't literally be 'infinity'
If we uniformly accelerate an electron and then allow it to continue at constant velocity, the radiated E-field would seem to be unidirectional, and hence it must possess a zero frequency component.It is more of a question of semantics. Neither zero nor infinite wavelengths are practically possible. But there is no theoretically defined 0<limit or limit<infinity.
So I think the best way to say it is that the limits are practical, not theoretical.
That's interesting. Can you tell me the difference between a zero-frequency zero-energy photon and no photon at all?If we uniformly accelerate an electron and then allow it to continue at constant velocity, the radiated E-field would seem to be unidirectional, and hence it must possess a zero frequency component.
No, a wave pulse consists of many frequencies that interfere with each other to form the pulse. A wave with zero frequency can't be called a wave at all because nothing is changing. There is no oscillation, no vibration, nothing.Does a wave exist with 0 frequency? If so, should it be just a wave pulse?
Based on a picture in book 'Fundamentals of physics', wave pulse does not look like as you said.No, a wave pulse consists of many frequencies that interfere with each other to form the pulse. A wave with zero frequency can't be called a wave at all because nothing is changing. There is no oscillation, no vibration, nothing.
Yea... the first one sounds like a wave can exist with 0 frequency (case of DC) I don't know the second.In electronics, a "zero frequency" signal would be considered DC. So for EM, would a stationary magnet be analogous?
Sure it does. The different frequencies interfere with each other such that they sum to zero or near zero everywhere outside of the pulse.Based on a picture in book 'Fundamentals of physics', wave pulse does not look like as you said.
You can probably think of it like that, but I would still say that a wave with zero frequency isn't a wave at all.In electronics, a "zero frequency" signal would be considered DC. So for EM, would a stationary magnet be analogous?
I agree, DC isn't a wave at all, at least not by any definition I can think of, or even just common sense. I was just pointing out a convention, or thinking that I think I've seen, that zero hertz would be thought of as DC (but no longer a 'wave'). I'm pretty sure there is a software front end for a 'wave generator' that would let you set the "frequency" to zero, and apply a DC offset.You can probably think of it like that, but I would still say that a wave with zero frequency isn't a wave at all.
To a DC current? I guess you could say they are analogous in the sense that there is no change in the "signal".Would a stationary magnet be analogous to that thought?
Thanks for clarification, so there is frequency even in wave pulse.Sure it does. The different frequencies interfere with each other such that they sum to zero or near zero everywhere outside of the pulse.
The details of the electric current is a bit complicated. A simple explanation is that electrons are always whizzing about in all directions and current flow is the net flow of electrons in a direction. The frequency of this net flow is the rate of the oscillation in it. The electrons themselves aren't vibrating back and forth at this frequency.Is the frequency in electric current is caused due its patterned flow in a conductor, like in AC current, energy flow half - cycle up and then half cycle down creating to and fro motion treating as wave but not the actual frequency at which electrons vibrate when the disturbance/energy flow through conductor... Am I right anywhere?
Well, I'd say that in the context of current flow, the signal is the measurement of the voltage or current flow at any particular moment in time, regardless of its properties. The behavior of the signal can be described as wave-like when it behaves a certain way, namely that there is a repeating pattern that a wave equation can be applied to.And what's the difference between a signal and a wave?
That's right. Mathematically, any pulse can be broken down into the waves composing it by using a Fourier Transform.Thanks for clarification, so there is frequency even in wave pulse.
Does that mean electrons literally displace and flow?electrons are always whizzing about in all directions and current flow is the net flow of electrons in a direction.
Since particles in EM wave are too small and a wave of size of universe means each particle should show enormous displacement stably without disturbance, I think it is impossible.limited by the size of the universe as you go toward infinity.
The electrons in the conduction band of a conductor are constantly moving about within the conductor in random directions and velocities. The electric field of an AC voltage source merely gives this random motion a small net velocity. In other words, more electrons move move one way past a point in a wire over time than in the other direction leading to a net flow of current in the circuit.Does that mean electrons literally displace and flow?
The net flow is the sum of all the different velocities and it is this net flow that oscillates in direction and magnitude. Any single electron is not oscillating back and forth.Rate of oscillation in what? The whole bunch of flowing electrons? That whole bunch move back and forth as they flow just like a ship sailing back and forth in harsh waters? Then some people say frequency as cycles/sec. Can it be anywhere linked to this?
I have always understood that they areThe electrons themselves aren't vibrating back and forth at this frequency.
Thanks for help, Understood what you have said and satisfied.The electrons in the conduction band of a conductor are constantly moving about within the conductor in random directions and velocities. The electric field of an AC voltage source merely gives this random motion a small net velocity. In other words, more electrons move move one way past a point in a wire over time than in the other direction leading to a net flow of current in the circuit.
The net flow is the sum of all the different velocities and it is this net flow that oscillates in direction and magnitude. Any single electron is not oscillating back and forth.