Questions tagged [harmonics]
The harmonics tag has no usage guidance.
198
questions
0
votes
1
answer
95
views
Is this image on harmonics and overtones wrong?
I saw this image and believed this to be the definition of what the relationship between harmonics and overtones to be in strings, closed pipes and open pipes.
That the $n^{th}$ harmonic = $n-1^{th}$ ...
0
votes
0
answers
19
views
How was the $\Gamma _\mu$ be used as a gauge condition in the Generalized Harmonic formulation $R_{\mu\nu}$
I'm watching a video(ICTP-SAIFR Numerical Relativity by Sascha Husa) where he mentioned that
$$R_{\mu\nu}
=-\frac{1}{2}
g^{\lambda \rho} g_{\mu\nu,\lambda \rho}
+\nabla_{ (\mu }\Gamma_{\nu)}
+\...
0
votes
1
answer
44
views
How is a resonant bandpass filter similar/different from a damped mass-spring oscillator? They seem to behave both similar and different in testing
Background
I am using resonant bandpass filters as musical oscillators. One can excite an array of them at harmonic frequencies and given Q values for a note by, for example, running a burst of noise ...
1
vote
1
answer
47
views
String vibration dimensions
We're all familiar with the typical diagrams of standing waves of a string, as in this image from Wikipedia:
The thing that bothers me is that they ignore the reality that the string is vibrating in ...
0
votes
1
answer
35
views
Observations of harmonics in gravitational wave experiments
In gravitational wave astronomy, we usually observe $f_{GW}=2f_K$ (gravitational wave frequency twice the orbital frequency from keplerian motion). However, we also know there should be harmonics with ...
1
vote
1
answer
73
views
Change in Frequency while Tearing Paper
Let us assume you have a 30cm strip of paper, and you tear it lengthwise. Let us abbreviate the frequency produced when you reach the end of the paper as $f_2$ and the frequency of sound heard when ...
0
votes
2
answers
44
views
Air Columns non-resonant frequencies
I understand that both open and closed-end air columns have many resonant frequencies, called harmonics and a fundamental frequency. At these frequencies, we expect to observe standing waves of ...
0
votes
0
answers
27
views
Loss of energy during harmonic resonance
I have been trying to determine the function describing how energy is lost during harmonic resonance:
Say an input of energy at the resonant frequency of a closed resonator. I know the following ...
0
votes
2
answers
64
views
How does a string thickness affect the frequency of its harmonics?
The harmonics of a theoretically infinitely small diameter string are pure integer multiples of the fundamental frequency. However, a real string has a thickness, and when vibrating in a harmonic, the ...
1
vote
0
answers
30
views
Natural Harmonics on a String
Consider the Dirichlet boundary value problem of a guitar string stretched between two fixed points which is made to oscillate by pinching and releasing the string.
It can be shown in quite ...
1
vote
1
answer
47
views
Viewing String Oscillations with a Camera
In this video, a demonstrator shows normal modes on a string. If one is doing this with a high speed camera, how many frames per second does one need to view the oscillations?
My intuition was that ...
0
votes
0
answers
63
views
What is heard when a tuning fork is struck?
When a tuning fork is struck I hear two tones. From a distance I can hear a high octave frequency of the pitch of the tuning fork. Though, if I listen to it closely (closer to my ears), I also hear a ...
9
votes
3
answers
1k
views
Why is the energy of the harmonics in a vibrating string not infinitesimal?
When you pluck a guitar string, initially the vibration is chaotic and complex, but the components of the vibration that aren't eigenmodes die out over time due destructive interference. This ...
0
votes
0
answers
79
views
Phase difference of standing waves
The phase difference of a standing wave is zero.
The above statement is found online when searching about standing waves. However, it doesn't make much sense to me.
Consider the above diagram of a ...
1
vote
1
answer
89
views
Harmonics in closed and open pipes
What exactly would happen if we sent a frequency that was not one of
the harmonics into a closed and open pipe? What would happen if we
gradually increased this frequency?
From my understanding, I ...
0
votes
2
answers
42
views
Phase difference problem
What's the phase difference between A and B on the following diagram. Where it is a standing wave. This question doesn't even make sense to me as from watching animations of standing waves, points A ...
2
votes
2
answers
164
views
Clarifications on standing waves within a pipe?
Standing waves are causing great confusion for me. I have read many answers on stackexchange. However, I still don't understand standing waves within closed and open tubes.
Problem 1. I struggle to ...
1
vote
1
answer
57
views
How is wavelength defined for standing waves?
How is wavelength defined for standing waves? I cannot understand why the first harmonic is half a wavelength rather than a full wavelength. I see how wavelength is defined for progressive waves but I ...
3
votes
2
answers
206
views
Why do water sounds different at different levels?
I observed that when we fill a water bottle it sounds different at different levels of height.
means it sounds different while filling at $\frac{1}4$ level and different at $\frac{1}2$.
I just want to ...
5
votes
2
answers
462
views
How to create a standing wave that doesn't oscillate with the fundamental frequency?
Is there a way to make the string on my violin vibrate in an overtone frequency instead of the fundamental frequency?
0
votes
1
answer
24
views
First Harmonic/Closed Tube/Net Transfer of Energy
Standing waves have no net transfer of energy. But, when watching simulations of the first harmonic for a closed tube, I see what looks like a transfer of energy - the particles clearly appear to ...
1
vote
2
answers
95
views
Can a pendulum have detectable harmonic frequencies
Can a pendulum produce harmonic frequencies? Like could I detect harmonic frequencies if I had a sensor on the pendulum?
1
vote
2
answers
138
views
Why is time harmonic follow the form of $e^{-i\omega t}$, not $e^{i\omega t}$? [closed]
In physics, when we solve an PDE or ODE, the solution usually has the form of
\begin{equation}
f=C_+e^{i\lambda x}+C_-e^{-i\lambda x}
\end{equation}
and the "causility" will eliminate one ...
7
votes
2
answers
514
views
What do I hear when listening to a computer-generated sine wave?
When I use a sine-wave generator (such as this one), I give credit to the software and my hardware that a pure sine wave is produced (as close as is technologically possible) — that is, no harmonics. ...
3
votes
2
answers
70
views
In what respect does the wave pattern of a noise and music differ?
Does the wave pattern of musical sounds contain only harmonics (other than the fundamental frequency) while noise contains random overtones (that are not harmonics)?
3
votes
1
answer
206
views
The definition of "total curvature" for a scalar field
In Modern Electrodynamics, Zangwill remarks that the total curvature vanishes at every point where $\nabla^2 \varphi = 0$.
Now my question(s): how is "total curvature" defined for a scalar ...
3
votes
1
answer
83
views
What is the simplest PDE/ODE/model I can use to understand how nonlinearities can lead to leakage of energy to higher harmonics in an oscillator?
I came across this problem in the study of surface waves in an oscillating cylindrical vessel of liquid.
There are various eigenmodes described using Bessel functions, and energy transfer can happen ...
1
vote
0
answers
82
views
Is there a 'better' tuning frequency than 440 Hz? [closed]
My apologize if this question is a bit broad or open ended but I'm asking here rather than a music forum for two reasons:
I'm trying to gain a better understanding of the physics of sound
and ...
2
votes
2
answers
1k
views
What are harmonic waves?
I am studying waves for my examination. Harmonic waves is also in my syllabus and I don't know what it is. I searched for it on google and got two possibly different answers. One answer is from en....
0
votes
0
answers
78
views
HOW are harmonics generated in longitudinal waves on the particle level?
I have been looking through the physics.se and all over the internet for weeks now honestly, and I still don't understand how harmonics are formatted on the particle level. Yes, I know that only ...
2
votes
0
answers
43
views
The cause of higher harmonics amplitude drop in an air column?
In the case of the real life string, I believe I understand the cause of the amplitude drop as we go into higher harmonics: the bendability of the string is not infinite and as we get lower ...
1
vote
1
answer
36
views
Length of a water column executing SHM in a U-shaped Tube
I was watching the lecture 30 of Walter Lewin ( 8.01 ). Here is a link:
https://youtu.be/hAYeA3Wwb4U
At 29:30, when he was describing the SHM of water in a U shaped tube. Lewin says that for the ...
4
votes
1
answer
69
views
Does rope in a standing wave expand and contract as it moves between being straight vs sine?
Images of standing waves often show two people using a jump rope. The shape of the rope goes from straight to waves to straight, then a sine wave the other way and then straight again as it repeats. ...
2
votes
1
answer
82
views
Why only harmonics allowed in the Casimir effect?
My question is really a request for an intuitive explanation as to why only harmonic frequencies of photons allowed between two conduction plates.
Why do the plates have to be conductive?
And can real ...
2
votes
2
answers
186
views
Is timbre a physical noumenon or a perceptual phenomenon? [closed]
I have a question relating the "timbre" of a sound, namely what is exactly and exhaustively defined by this word? Most definitions that I come across seem somewhat loose as "the color ...
1
vote
3
answers
450
views
How can I calculate the number of nodes on a plucked string?
Given the length of the guitar string, can you predict the number of nodes that would exist on that string?
My textbook says that there are an infinite number of harmonics that can be created when a ...
1
vote
2
answers
158
views
How does one apply the phase change of $π$ on reflection at the rigid end of a string?
Consider a string, with a free end $P$ and another end $Q$ which is rigidly fixed.
Now, we start oscillating the point $P$ (with $0$ initial phase difference) and a wave starts traveling(in the ...
2
votes
4
answers
138
views
Does the standing wave equation proof require $\ell=Nλ$? [closed]
Consider two identical sources $S_1$ and $S_2$ of waves, separated by a distance $\ell$ (as shown in the figure).
The sources produce waves in opposite directions(and towards each other). Now, ...
2
votes
2
answers
985
views
Why does an antinode form at the open end of an organ pipe?
I recently learnt about reflection of waves in various media and the resultant standing waves formed. In a string which is tied at an end, the wave formed reflects with a phase difference of 180 (at ...
0
votes
1
answer
60
views
How to calculate the overall harmonics of a system of tubes?
Let's say there is a tube closed at one and and open from the other. The open end is connected to another tube (of smaller diameter) which is open from both ends. How can I calculate the overall ...
2
votes
2
answers
200
views
What exactly happens, step by step, in string harmonics?
I know that a string when plucked shows harmonics but I do not really understand how. Like, I understand resonating air column and how standing waves are formed there, but I can't seem to get the step ...
6
votes
2
answers
449
views
Why does plucking a string produce harmonics instead of a pulse?
If I jerk a wire from the free end fixed at an end and then fix the free end, it will produce a pulse travelling back and forth between the two ends. So in a string fixed at both ends, if we pluck it ...
0
votes
1
answer
64
views
Why is the Ocean Blue? [closed]
I'm writing an article on the physical property that binds Music and Water -- Harmonics. I understand that the blueness of ocean water is due to the three vibrational modes of water (i.e, symmetric, ...
1
vote
1
answer
253
views
Standing wave in a string clamped at one end
*In the case of a standing wave formed with one end clamped (fixed), there is an anti-node at the free end irrespective of the overtone.
My question is why is there has to be an antinode. Is there any ...
0
votes
1
answer
88
views
Steven Weinberg says $L$ is the fundamental EM wavelength in a cubical cavity $L^3;$ not the typically asserted $2L.$
This is from Steven Weinberg's Lectures on Quantum Mechanics, 2nd Ed., page 2:
For instance, for a cubical box of width $L,$ whatever boundary condition is satisfied on one face of the box must be ...
0
votes
1
answer
79
views
Standing waves confusion
Its just so confusing as to why the antinodes are formed from the constructive interference by superposition of the wave formed by the incident wave and the reflected wave... The phase difference is ...
2
votes
1
answer
69
views
Which harmonic we hear from organic pipe from all possible outcome?
I have gone through about each case of standing wave in open and closed organ pipe and understand antinode and node concepts. But i am confused that if all harmonics are possible in organ pipe, then ...
1
vote
3
answers
214
views
Plucked string eigenvalues/harmonic frequencies: integer multiples (or not)
I'm trying to derive a model of a plucked string from Newton's second law. My derivation results in $$ω_n = C\cdot\sqrt{n},\, n=1,2,3\dots\text{integer}$$ I think it should be $$ω_n = C\cdot n,\, n=1,...
1
vote
2
answers
727
views
Why are there both antinodes at both ends of the tube? [duplicate]
I learned stationary/standing waves the other day. For stationary waves in open tubes, the textbook says both ends must have an antinode. Can anyone tell me why? (shown as figure)
And also, when ...
2
votes
0
answers
335
views
Upper limit of Schumann resonance harmonics?
This is a re-post from the Earth Science Stack Exchange which was posted two month ago. Due to the nature of the question and the SE site, it might be better to post this question here.
As the Earth'...