# Tag Info

1

Speech sounds can be either periodic, like "aaah," or nonperiodic, like "sh." Periodic means that the pattern repeats over and over with a certain frequency. Here's a graph of sound pressure versus time for me singing the vowel "ah" at a fixed pitch: This kind of graph is referred to as a "time domain" representation of the sound, because it has time on ...

4

First of all, let me note that it is misleading to say that we're not even dealing with a particle We are still dealing with a particle, but the state of the particle at a given moment in time is no longer described by a pair $(x(t),p(t))$ of position and momentum in a classical phase space, it is instead a state $|\psi(t)\rangle$ in a Hilbert space. ...

0

The lowest frequency limit is provided by the size of the universe. If we could make an antenna that size, the frequency would be "very close" to zero. The highest EM frequency limit is provided by the smallest antenna we could make. I believe that would be the size of a hydrogen atom, giving us, $$F_u = \frac{2.997x10^8}{6.28x5.29x10^{-11}} = ... 14 I've found some sources. Mathematical To start with, as for the mathematical notion of "beats", it seems that one Ibn Yunus (c. 950-1009) was responsible for first demonstrating the trigonometric identity$$ \cos a \cos b = \frac 12 \left( \cos ( a + b) + \cos (a - b) \right )  quoting A History of Mathematics By Carl B. Boyer, Uta C. Merzbach At ...

2

It seems that Thomas Young (1773-1829) was one of the first who where interested in beats and interferences, and in fact, it seems that the concept of beats leads him to the concept of interferences (around $1801$), see page $92$ of this reference (in french only). For instance, it is said (page $92$), (traduced in English by google): This is the ...

0

I think you mean: for a given loudness, which frequencies involve greater physical movement, high frequencies or low? And that is simple - the lower the frequency the greater the amplitude of the movement. Here's a simple demonstration. Take the grille cloth off a speaker with a woofer. Play music through the speaker, something with sustained notes like ...

-1

This phenomenon is not special to light or Maxwell's equations: it's a simple consequence of detector nonlinearity and I should think that this would have been pretty clear to any bright experimentalist who thought carefully about how his or her kit makes its measurements. In the simplest case, the detector's response $y(t)$ as a function of time $t$ is ...

5

Theoretically, the shortest wavelengths of light would be limited by the Planck length, at some point the space 'closed' by the wavelength would be so small that gravitational effects would dominate, in the same way that black holes can bend light passing near their event horizon at very small scales the wavelength would be so small that it might be at the ...

13

Do keep in mind that the frequency of light is reference frame dependent. So, for example, the cosmic background microwave radiation would appear as a concentrated gamma radiation source 'in front' to an observer with ultra-relativistic speed relative to the CMB. In other words, light emitted from a body of a particular frequency in that body's frame of ...

1

Short answer - Frequency ($\nu$) stays constant since it is a characteristic property of the source. Using the relation $v = \lambda \nu$ in the definition of the refractive index, $n = c/v$, your required answer follows.

8

The electromagnetic spectrum does range between (almost) zero and (almost) infinity. It's just that your eyes are sensitive to a very small part of it (from about 380 nm to about 800 nm). At the lowest frequencies, it becomes difficult to recognize the signal from background fluctuations. From this site: "Gamma-rays are detected by observing the effects ...

0

Calling all finite-element model experts :-) . I can only offer one small tidbit: for wind instruments, aside from the octave hole, which exists primarily to facilitate exciting the higher frequency notes, the tone is primarily defined by the distance from the mouthpiece to the first open hole. As a long-time clarinetist, I'm fully aware that the pitch ...

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