The frequency tag has no wiki summary.
10
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6answers
4k views
What determines color — wavelength or frequency?
What determines the color of light -- is it the wavelength of the light or the frequency?
(i.e. If you put light through a medium other than air, in order to keep its color the same, which one would ...
9
votes
2answers
6k views
How does load affect frequency on the power grid?
This story about the use of battery/freewheel based Frequency Regulators confused me about how the 60hz frequency of the North American power grid was set--saying that it was kept at that frequency by ...
7
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3answers
628 views
Can we transport energy over infinite distances through vacuum using light?
I know that light (or electromagnetic radiation in general) attenuates in intensity as the square of the distance it travels.
Why does it attenuate?
Are the photons being scattered by the medium ...
7
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3answers
73 views
Why do prisms work (why is refraction frequency dependent)?
It is well known that a prism can "split light" by separating different frequencies of light:
Many sources state that the reason this happens is that the index of refraction is different for ...
5
votes
3answers
278 views
Why does inverting a song has no influence?
I inverted the waveform of a given song and was wondering what will happen.
The result is that it sounds the exact same way as before.
I used Audacity and doublechecked if the wave-form really is ...
5
votes
2answers
615 views
How can a Human voice or animal voice have unique frequency
Well this is pretty noobish question and I am not sure how to ask.
When We talk we don't talk in an uniform frequency. Then how can one measure frequency of ones sound/voice ?
I am asking this cause ...
5
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5answers
975 views
How to Make RF Waves Visible
I understand RF (Radio Frequency) Waves are electromagnetic waves and a mode of communication for wireless technologies, such as cordless phones, radar, ham radio, GPS, and television broadcasts. Most ...
4
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5answers
936 views
How many colors exist?
How many "colors" do exist?
Our perception:
As far as I know, colors are just different frequencies of light. According to wikipedia, we can see wavelengths from about 380 nm und 740 nm. This means ...
4
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4answers
578 views
How to calculate the quantum expectation of frequency of a particle?
I know how to calculate the expectation of < $\Psi$|A|$\Psi$ >
where the operator A is the eigenfunction of energy, momentum or position, but I'm not sure how to perform this for a pure frequency.
...
4
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2answers
12k views
Why does wavelength change as light enters a different medium?
When light waves enter a medium of higher refractive index than the previous, why is it that:
Its wavelength decreases?
The frequency of it has to stay the same?
4
votes
3answers
544 views
What is the highest possible frequency for an EM wave?
What is the highest possible frequency, shortest wavelength, for an electromagnetic wave in free space, and what limits it? Is the answer different for EM waves in other materials or circumstances? ...
4
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2answers
942 views
Strategies against 50 Hz mains hum on detector signals?
I'm having problems with a strong 50 Hz mains hum on signals created by photodetectors. I assume that they are due to ground loops and I realize that the best option would be to remove those. What are ...
4
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2answers
433 views
The definition of “frequency” in different contexts
I have been doing some research on all kinds of sound-related topics lately and have been a bit confused by the different uses of the term "frequency". Of course, the most general meaning of frequency ...
4
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0answers
26 views
What is energy in $z \neq 1 $ theories?
In a critical theory with dynamical critical exponent $z \neq 1 $, which amongst frequency, $\omega$, and dispersion, $E(\vec{k})$, may be referred to as ''energy''? I'm confused about this since in ...
4
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5answers
508 views
Sound frequency of dropping bomb
Everyone has seen cartoons of bombs being dropped, accompanied by a whistling sound as they drop. This sound gets lower in frequency as the bomb nears the ground.
I've been lucky enough to not be ...
3
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3answers
231 views
Why frequency doesn't change during refraction?
When light goes through one medium to another it's velocity and wavelength changes. Why frequency doesn't change in this phenomenon?
3
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2answers
953 views
The energy of an electromagnetic wave
The intensity of an electromagnetic wave is only related to its amplitude $E^2$ and not its frequency. A photon has the same wavelength as the wave that's carrying it, and its energy is $h f$.
So ...
3
votes
1answer
266 views
Doppler cooling limit vs recoil limit
I was discussing laser cooling in class today and I understood that the main principle of the process is to tune a laser to a frequency lower than the absorbtion frequency of the atom and so only the ...
3
votes
2answers
688 views
Can 2 beams of ultraviolet light intersect and be visible where they intersect?
Is it possible that if you have 2 ultraviolet lasers, that are invisible to the human eye, and if you aim their beams to intersect at some point, that the place of intersection will show a lower ...
3
votes
1answer
40 views
How to determine frequency components present in distorted signal, with the set of possible components already known?
I am trying to choose the best approach to digitally analyse a signal, which is a mix of an unknown number (but less than 16) fundamental signals at specific frequencies (e.g., sines).
The goal is ...
3
votes
2answers
482 views
What is the specific meaning of “Fourier frequency” (as opposed to simply “frequency”)?
I've noticed that many journal articles (in optics) use the phrase "Fourier frequency" to describe, well, the frequency of something.
Google scholar search for "Fourier frequency".
Example:
...
2
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2answers
409 views
Is all kind of light same speed?
Is there any speed different between blue or red color? Is there speed different? or there are same speed?
2
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4answers
1k views
How does power consumption vary with the processor frequency in a typical computer?
I am looking for an estimate on the relationship between the rate of increase of power usage as the frequency of the processor is increased.
Any references to findings on this would be helpful.
2
votes
2answers
552 views
Phase difference of driving frequency and oscillating frequency
If a mass is attached to a spring and is oscillating (SHM). If a driving force is applied it must be at the same frequency as the mass's oscillation frequency. However I'm told that the phase ...
2
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1answer
54 views
Manufacturing Fresnel Lenses with Sound
I understand fresnel lenses are manufactured using CNC machines. I was wondering, if it would be possible to use sound to vibrate liquid silicon and then fast cool it into the standard form of a ...
2
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2answers
67 views
Frequency Modulation
If FM radios work by modulating the frequency, how is it that we can tune into a specific channel, and hear a song or station? Wouldn't the channel need to be modulated along with the varying ...
2
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2answers
106 views
What is the history behind the factors of 3 in the classification of electromagnetic radiation?
What is the history behind the factors of 3 in the classification of electromagnetic radiation?
See e.g. http://en.wikipedia.org/wiki/Radio_spectrum#By_frequency
Is this (just) inherited from the ...
2
votes
3answers
310 views
How does energy depend on frequency in an alternating current circuit?
In what relation is the energy input in an alternating current circuit to its frequency?
I'd guess I have to compute something like
$$E=\int P(\omega,t) dt=\int U(\omega,t) I(\omega,t) dt, $$
but ...
2
votes
4answers
139 views
Light refraction and causality
One way how to look at refraction by a dielectric medium like water or glass is that (phase) velocity of light decreases because it is the wavelength rather than the frequency of the light which ...
2
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1answer
167 views
How much power can be drawn from stray electromagnetism in the atmosphere?
I know this probably varies quite a bit from place to place on earth. But just some rough estimates: if I were to pull power via multiple antennae tuned to a variety of different frequencies, how much ...
2
votes
1answer
324 views
How can a Photon have a “frequency”?
I picture a light ray as composed of photons with an energy equal to the frequency of the light ray according to E=hf. Is this the good way to picture this? Although I can solve elementary problems ...
2
votes
6answers
2k views
Limit of human eye flicker perception?
I am designing a LED dimmer using software-controlled Pulse Width Modulation, and want to know the minimum PWM frequency that I must reach to make that LED dimming method indistinguishable from ...
2
votes
3answers
141 views
Frequency of a Tuning Fork
Question: Which of the following affect the frequency of a tuning fork?
Tine stiffness
Tine length
The force with which it's struck
Density of the surrounding air
Temperature of the surrounding air
...
2
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1answer
184 views
Radio waves and frequency of photon
Is 89MHZ station emitting photons of 89MHZ frequency? (I mean $\nu$ in $E=h\nu$).
2
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1answer
30 views
Relation of color and frequency for the visible spectrum
In this question the OP is looking for a way to see light that is outside of the visible spectrum without using electronic sensors. This got me wondering about the visible spectrum itself. Typically ...
2
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1answer
74 views
Is energy always proportional to frequency?
Google has no results found for "energy not proportional to frequency" and many results for E=hf. Is there an example of an energy that is not proportional to frequency?
2
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2answers
384 views
Do we see color with higher frequency first?
Out of the 7 colours of the rainbow, violet has the highest frequency and the smallest wavelength. Does this mean that our eye sees it first? If yes, then why? Does it travel at the same or higher ...
2
votes
1answer
558 views
static flow of water
The title, I don't know whether it's correct or not, but I came across a video in youtube, http://youtu.be/_PkgQQqpH2M.
The author of video used the title and hence I used the same..
The video ...
2
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1answer
506 views
Effects of high frequency lighting on human vision?
I have a couple of different LED flashlights. One of them has three different "modes" of brightness, and the way it controls it is via pulse width modulation (PWM). Here is a picture that illustrates ...
2
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3answers
182 views
5MHz RF pulse frequency analysed in software
Is there software available that can analyse a 5MHz RF pulse to give a plot of frequency spectrum.
The signal data is visible on a LCD screen or a print out could be obtained.
2
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3answers
539 views
How could this person have discovered the resonant frequency from this string of magnets?
I stumbled onto this page
http://mylifeisaverage.com/story/1364811/
and the post states that they were
all making strings and shapes with
these sets of 216 really small
spherical earth ...
2
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1answer
162 views
Frequency Response RLC circuit - Current against Frequency graph - Symmetry?
I understand that in a Frequency Response experiment dealing with an RLC circuit, the graph of Current against Frequency is supposed to be symmetrical about the resonant frequency theoretically.
...
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3answers
310 views
Does the Fundamental Frequency in a Vibrating String NOT Necessarily Have the Strongest Amplitude?
I am doing some experiments on musical strings (guitar, piano, etc.). After performing a Fourier Transform on the sound recorded from those string vibrations, I find that the fundamental frequency is ...
1
vote
2answers
328 views
How to capture electomagnetic radiation/waves?
If I wanted to find out what kind of electomagnetic waves "travel" through my room at which frequency, what kind of equipment would I need? Suppose I want to view frequencies from 0 Hz to 6 GHz.
1
vote
2answers
213 views
Can electrons change the frequency of light as they bounce off/around?
I know that light does not interact with other light, but can interfere it, at least its amplitude. With that said, lights frequency can be changed via bouncing off matter, where matter might absorb ...
1
vote
2answers
275 views
Why are different frequency bands used in different countries?
Why are different frequency bands used in different countries despite ITU's effort for a common frequency band use? There's got to be a reason behind this.
For instance, U.S.-based Verizon Wireless ...
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vote
2answers
923 views
Frequency of the sound when blowing in a bottle
I'm sure you have tried sometime to make a sound by blowing in an empty bottle. Of course, the tone/frequency of the sound modifies if the bottle changes its shape, volume, etc.
I am interested in ...
1
vote
1answer
274 views
Resonance and Natural Vibrations in Vacuum
In my Physics textbook, it says that if two pendulums of the same natural frequency are placed next to each other and if one is set into vibration, the other starts resonating and when the first one ...
1
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1answer
58 views
Will changing amplitude change the frequency?
Will changing the amplitude change the frequency of a wave, or is it possible for a specific frequency (50 Hz. for example) to generate from shifting amplitude patterns?
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1answer
116 views
How do the energy eigenvalues of rotational degrees of freedom in statistical mechanics come about?
I want to understand the hierarchy different degrees of freedom of a mechanical system. Specifically, I want to understand which subsystems equibrilate faster and why. This question comes up:
Why ...
