> Ligth and sound waves seem to be practically IDENTICAL, DESPITE the
> > longitudinal versus transversal wave and here's why:
>
> An apple is like an orange except one is an apple and another is an
> orange. The fact that light waves are transverse and material waves
> are longitudinal is a symptom of the deeper fact that they are
> DIFFERENT THINGS.
>
> Until you can derive the wave equations for both
> light and sound, and then solve them, you are
> incapable of meaningfully participating in
> any such discussion.
Are longitudinal and transverse the total variety of waves? What is the definition of a wave, anyhow?
They have identical frequency and wavelength, different speed and amplitude.
At the exact centre of this model of a ripple,
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the wave is not travelling. At any point away from the centre it has a constant speed. Therefore it instantly accelerates with infinite acceleration.
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"a disturbance or variation that transfers energy progressively from point to point in a medium and that may take the form of an elastic deformation or of a variation of pressure, electric or magnetic intensity."
"John Larkin" wrote news: snipped-for-privacy@4ax.com...
" Some liquid media at usual temperatures and pressures are good shear wave conductors at high frequencies (0.5-1.0 MHz and above) [16]. " This is from:
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Is it possible that all liquids support shear wave at very high frequencies?
"While a mechanical wave exists in a medium (which on deformation is capable of producing elastic restoring forces), waves of electromagnetic radiation (and probably gravitational radiation) can travel through vacuum, that is, without a medium"
It is in agreement with this:
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But all big scientists try to make a model of ether. Up to now without success. F. Gorbatshevich assumed that planets moves in ether without resistance. Planets travel with ether. Only satellites "plough" eter. Is there any resistance? S*
That's not my area of expertise. I suppose that viscous losses are low in regimes where the liquid is relatively stiff, so transverse waves may travel useful distances. I suppose "liquid" is, umm, a fluid definition.
"Szczepan Bia³ek" wrote news:gaq81n$9m0$ snipped-for-privacy@node1.news.atman.pl...
"But although it meets the definition of outer space, the atmospheric density within the first few hundred kilometers above the Kármán line is still sufficient to produce significant drag on satellites. Most artificial satellites operate in this region called low earth orbit and must fire their engines every few days to maintain orbit" (From:
"George Herold" wrote in message news: snipped-for-privacy@a18g2000pra.googlegroups.com... On Sep 17, 10:09 am, John Larkin wrote:
I'm way over my head here also, but what is it that separates a gas from a liquid? At some "point" a liquid has some stickiness.
George =====================================
This will surprise you, but consider an analogy. What separates a freeway from a city? On the freeway, cars travel at 70 mph +/- 20 mph... that's a gas. In the city, cars travel at 25 mph +/- 5 mph... that's a liquid. In the city centre during rush hour, cars travel at 1 mph, gridlocked. That's a solid. Ok, it's not a very good analogy, cars cling together because they are driven by human beings and humans cling together for social, not physical reasons. What we need is a physical reason for molecules to hold together in a solid or a liquid. The answer to that is right under your nose, although few will recognise it. F = GMm/r^2. Whilst the values of M and m are very small, so is the value of r, and even smaller is r^2. The closer M and M are, the greater the force between them. And that is called gravity. What separates a space shuttle from the Earth? A hell of a lot of energy. All the satellites we've ever launched are analogous to a gas around the Earth. Energy separates gas from liquid, and when you boil water you reach 100 degrees C and no higher - until all the water has gone. It's as though you were sending satellite after satellite into space until all the Earth is used up. Now I can't tell you what gravity is anymore than I can tell you what magnetism is, all anyone can describe is how it behaves; the force resulting from the inverse square law is very powerful indeed. Of course the naysayers will call me an idiot... but think it through. We look on gravity as a weak force, but it gets mighty strong when molecules are close together.
Continuum mechanics isn't my area of expertise, but here's this from long ago:
A liquid has surface tension, and a gas doesn't. The meniscus on a water surface abruptly disappears at the critical point, which is 374C and 22.6 MPa (about 223 atmospheres). Viscosity isn't the issue.
Above the critical point, you can't distinguish liquid from gas, so it's just called a 'fluid' phase.
If you put a sufficiently large load on a piece of material, it will creep, and the creep rate goes up as the load goes up. On a plot of the rate of creep vs load, fluids are materials where the curve goes through the origin, i.e. they creep under an arbitrarily small load. Solids have a creep vs stress curve that goes to zero at some nonzero stress. The difference may not be obvious initially. For instance, if you turn a jar of peanut butter and a jar of blackstrap molasses upside down, the molasses eventually all winds up sitting on the lid--it's a liquid--but the peanut butter doesn't--it's a soft solid. (Good quality latex wall paint is also a soft solid.)
Stress in a solid is a tensor quantity, so besides compression (scalar) and transverse (vector) waves, you can transmit torsional waves in solids as well.
Transverse waves don't propagate in fluids because there's no elastic restoring force in that direction, just friction. Thus a transverse disturbance propagates like heat rather than like a wave, and dissipates exponentially with distance.
So then, Love is by FAR the weakest of the four fundamental forces?
Best regards, Spehro Pefhany
--
"it\'s the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
I think the Xtians and Mohammedans will be sorely surprised when they show up at the pearly gates and discover that Satan has been in charge since the Garden of Eden.
Currently, he's manifest as Government. >:->
Cheers! Rich
--
For more information, please feel free to visit http://www.godchannel.com
"Phil Hobbs" wrote news: snipped-for-privacy@electrooptical.net...
Real waves are always the combination of transverse and longitudinal. The same is probably in space. It is very important to know if vacuum brakes comets and spacecrafts. Are such data available? S*
"RichD" wrote news: snipped-for-privacy@w39g2000prb.googlegroups.com...
The longitudinal and transverse separately are only in math. In real media are oscillations around almost fixed locations in ALL DIRECTIONS. Like in water: " Ripples on the surface of a pond are actually a combination of transverse and longitudinal waves; therefore, the points on the surface follow orbital paths." In math media are ideal (eg. incompressible). In reality no such. S*
Thanks Phil, I've been doing some with autocorrelation functions lately (in relation to noise). I was thinking you could define a spacial correlation function. Solids are highly spacially correlated, gasses not at all and perhaps liquids have a short range correlation.
Crystals have high spatial correlations over long distances, but amorphous solids don't. Even 2-D crystals e.g. graphene don't have long range order, interestingly enough---you need 3 dimensions before the sums of the random fluctuations remain bounded as x->infinity.
Yeah and people are always telling me that glass can be thought of as a liquid... but with a long relaxation time. Is the same true of all amorphous solids?
"Even 2-D crystals e.g. graphene don't have long
Hmm, why is that? Is it because they tend to "roll up" or at least are free to move in the third dimension. Or is this the result of the random fluctuations of which you speak?
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