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| 2.7182818284590...... |
 Posted: Mon Nov 02, 2009 6:59 pm |
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Guest
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The equation is:
Fdet = Femit * [(Vs +/- Vdet) / (Vs -/+ Vemit)], where
Fdet = Frequency detected
Femit = Frequency emitted
Vs = Velocity of sound, about 343 m/s
Vdet = Velocity of detector
Vemit = Velocity of emitter
Q1: How is a person (the detector) moving towards a stationary sound
different from the sound moving towards a stationary person? Both
situations would increase the frequency of Fdet, but there is a slight
difference between the two.
Q2: Can the speed of sound EXCEED 343 m/s under atmospheric
conditions (unlike light, which can ONLY occur at velocity =c)? |
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| Sam Wormley... |
| Posted: Tue Nov 03, 2009 12:45 am |
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| Sam Wormley... |
| Posted: Tue Nov 03, 2009 12:53 am |
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| Androcles... |
| Posted: Tue Nov 03, 2009 3:57 am |
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"2.7182818284590..." <tangent1.57 at (no spam) gmail.com> wrote in message
news:85b55ce5-79da-4677-9b87-45590210c729 at (no spam) j19g2000vbi.googlegroups.com...
[quote]The equation is:
Fdet = Femit * [(Vs +/- Vdet) / (Vs -/+ Vemit)], where
Fdet = Frequency detected
Femit = Frequency emitted
Vs = Velocity of sound, about 343 m/s
Vdet = Velocity of detector
[/quote]
WITH RESPECT TO THE AIR! Wind will cause a doppler shift.
[quote]Vemit = Velocity of emitter
[/quote]
WITH RESPECT TO THE AIR!
[quote]
Q1: How is a person (the detector) moving towards a stationary sound
different from the sound moving towards a stationary person? Both
situations would increase the frequency of Fdet, but there is a slight
difference between the two.
[/quote]
It isn't slight if Vemit is a plane travelling at the speed of sound with
respect
to the air.
[quote]Q2: Can the speed of sound EXCEED 343 m/s under atmospheric
conditions (unlike light, which can ONLY occur at velocity =c)?
[/quote]
The speed of sound in water is 1500 m/s under aquaspheric conditions.
http://en.wikipedia.org/wiki/Speed_of_sound#Water
You are babbling about the speed of light, all speeds are relative.
A snail can travel the length of a plane in 6 hours, so it can cross
the Atlantic at the same time and the speed of snails is 500 mph.
ALL speeds are RELATIVE to something else. Get used to it. |
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| John Polasek... |
| Posted: Tue Nov 03, 2009 11:33 pm |
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Guest
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On Tue, 03 Nov 2009 05:53:21 GMT, Sam Wormley <swormley1 at (no spam) mchsi.com>
wrote:
[quote]Sam Wormley wrote:
2.7182818284590... wrote:
The equation is:
See: http://scienceworld.wolfram.com/physics/DopplerEffect.html
Actually, these may be better for you:
http://en.wikipedia.org/wiki/Doppler_effect
http://en.wikipedia.org/wiki/Relativistic_Doppler_effect
[/quote]
All this fuss about the Doppler equation! But don't take it for
granted-there's more here than meets the eye.
Two things are interesting about a Doppler equation. One is that the
cited examples as above are taken for granted and used as if true. As
a matter of fact, most of them are incorrect including Wolfram and
Wiki and one given by NASA.
Where there is a derivation, it is usually based on an awkward effort
to show how the wavelength stretches in transit. e.g. Wolfram when in
fact the wavelength does not stretch in transit. All the effects occur
at the point of transmission and at the point of reception. Most
derivations are mired down by the complications of whether the source
is moving toward the sink or in the fixed medium and vice versa. I
have a derivation that skirts around all this stuff-I'm preparing a
paper on it.
John Polasek |
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| Sam Wormley... |
| Posted: Tue Nov 03, 2009 11:51 pm |
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Guest
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John Polasek wrote:
[quote]On Tue, 03 Nov 2009 05:53:21 GMT, Sam Wormley <swormley1 at (no spam) mchsi.com
wrote:
Sam Wormley wrote:
2.7182818284590... wrote:
The equation is:
See: http://scienceworld.wolfram.com/physics/DopplerEffect.html
Actually, these may be better for you:
http://en.wikipedia.org/wiki/Doppler_effect
http://en.wikipedia.org/wiki/Relativistic_Doppler_effect
All this fuss about the Doppler equation! But don't take it for
granted-there's more here than meets the eye.
Two things are interesting about a Doppler equation. One is that the
cited examples as above are taken for granted and used as if true. As
a matter of fact, most of them are incorrect including Wolfram and
Wiki and one given by NASA.
Where there is a derivation, it is usually based on an awkward effort
to show how the wavelength stretches in transit. e.g. Wolfram when in
fact the wavelength does not stretch in transit. All the effects occur
at the point of transmission and at the point of reception. Most
derivations are mired down by the complications of whether the source
is moving toward the sink or in the fixed medium and vice versa. I
have a derivation that skirts around all this stuff-I'm preparing a
paper on it.
John Polasek
[/quote]
Why not post what you've already got? Who knows, one of us might
find a useful correction for you.  |
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| Uncle Al... |
| Posted: Wed Nov 04, 2009 12:01 am |
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"2.7182818284590..." wrote:
[quote]
The equation is:
Fdet = Femit * [(Vs +/- Vdet) / (Vs -/+ Vemit)], where
Fdet = Frequency detected
Femit = Frequency emitted
Vs = Velocity of sound, about 343 m/s
Vdet = Velocity of detector
Vemit = Velocity of emitter
Q1: How is a person (the detector) moving towards a stationary sound
different from the sound moving towards a stationary person? Both
situations would increase the frequency of Fdet, but there is a slight
difference between the two.
[/quote]
<http://hyperphysics.phy-astr.gsu.edu/Hbase/Sound/dopp.html>
<http://hyperphysics.phy-astr.gsu.edu/HBASE/Relativ/reldop2.html>
[quote]Q2: Can the speed of sound EXCEED 343 m/s under atmospheric
conditions (unlike light, which can ONLY occur at velocity =c)?
[/quote]
Speed of sound is temperature-, composition-, and altitude-dependent.
If you exceed local speed of sound you get shocks. The optical
analogue is Cerenkov radiation when a charged particle exceeds local
speed of light (re refractive index) in a medium.
Count the shock diamonds in a jet engine's exhaust. Now you know
stuff. Measure the half angle between the nose and the engine
mounts. Now you know the top Mach speed.
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz4.htm |
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| John Polasek... |
| Posted: Wed Nov 04, 2009 12:41 pm |
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Guest
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On Wed, 04 Nov 2009 04:51:38 GMT, Sam Wormley <swormley1 at (no spam) mchsi.com>
wrote:
[quote]John Polasek wrote:
On Tue, 03 Nov 2009 05:53:21 GMT, Sam Wormley <swormley1 at (no spam) mchsi.com
wrote:
Sam Wormley wrote:
2.7182818284590... wrote:
The equation is:
See: http://scienceworld.wolfram.com/physics/DopplerEffect.html
Actually, these may be better for you:
http://en.wikipedia.org/wiki/Doppler_effect
http://en.wikipedia.org/wiki/Relativistic_Doppler_effect
All this fuss about the Doppler equation! But don't take it for
granted-there's more here than meets the eye.
Two things are interesting about a Doppler equation. One is that the
cited examples as above are taken for granted and used as if true. As
a matter of fact, most of them are incorrect including Wolfram and
Wiki and one given by NASA.
Where there is a derivation, it ic usually based on an awkward effort
to show how the wavelength stretches in transit. e.g. Wolfram when in
fact the wavelength does not stretch in transit. All the effects occur
at the point of transmission and at the point of reception. Most
derivations are mired down by the complications of whether the source
is moving toward the sink or in the fixed medium and vice versa. I
have a derivation that skirts around all this stuff-I'm preparing a
paper on it.
John Polasek
Why not post what you've already got? Who knows, one of us might
find a useful correction for you.
(Sure, come ahead)[/quote]
Take Wiki's equation f/f0 = c+vr/c+vs (c instead of s) and let the
receiver be stationary, vr = 0, to simplify the discussion. Then
Wiki has
f/f0 = c/c+vs = 1/1+vs/c (0) ****
So for vs/c = .5, Wiki gets
f/f0 = 1/1.5 = .666 (receding source)
Let me introduce my unique equation for Doppler. For any function of t
there is a time delayed function of t at the location D:
f(t,D) = f(t - D/c)
To add credibility, I propose a gedanken experiment with a clock and a
timer operated from a single switch that can measure frequency.
With even arbitrary switch on switch off times, I can repeatedly get
readings of Delta N and Delta t, with the frequency clearly deducible
from the quotient DN/Dt.
So unewssing monochromatic light f0, we can write
N(t,D) = f0(t - D/c) (1)
Take the derivative as above
f = dN/dt = f0(1 - Ddot/c) (2)
f/f0 = 1 - V/c (3) ****
where Ddot is the rate of separation, calling it V
Compare (3) with the defective Eq. (0) which apparently you would
prefer because 'it is written'.
Now for V/c = .5, my equation yields
f/f0 = .5 differing from Wiki's 0.666.
Notice that with this purely kinematic approach, all the fog is
cleared away and all the awkward efforts to show how the wavelength
stretches on the way are for nought.
We get the equation for wavelength by inverting Eq (3):
L/L0 = 1/1-V/c =defined as 1+z (4)
Solving for the only quantity of interest as a function of z, which is
V/c, the marker for actual recession velocity, gives
V/c = z/1+z (which I call beta) (5)
Very commonly, z is taken as equal to V/c in complete error. this is
even suggested in Wiki (relativity) for small V/c.
All those equations in Weinberg and Peebles that employ terms like cz
and cz/H0 are wrong!
The identity Eq. (5) was pointed out in
"C. Cattoen and M. Visser, "The Hubble series: Convergence properties
and redshift variables" [arxiv:0710.1887v1 [gr-gc] 10 Oct 2007",
but they offered no connection with physics, arguing only that Taylor
expansions using z would not converge in the complex plane.
I think I just showed you the physics of it.
John Polasek |
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| John Polasek... |
| Posted: Thu Nov 05, 2009 3:25 pm |
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Guest
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On Wed, 04 Nov 2009 12:41:29 -0500, John Polasek <jpolasek at (no spam) cfl.rr.com>
wrote:
[quote]On Wed, 04 Nov 2009 04:51:38 GMT, Sam Wormley <swormley1 at (no spam) mchsi.com
wrote:
John Polasek wrote:
On Tue, 03 Nov 2009 05:53:21 GMT, Sam Wormley <swormley1 at (no spam) mchsi.com
wrote:
Sam Wormley wrote:
2.7182818284590... wrote:
The equation is:
See: http://scienceworld.wolfram.com/physics/DopplerEffect.html
Actually, these may be better for you:
http://en.wikipedia.org/wiki/Doppler_effect
http://en.wikipedia.org/wiki/Relativistic_Doppler_effect
All this fuss about the Doppler equation! But don't take it for
granted-there's more here than meets the eye.
Two things are interesting about a Doppler equation. One is that the
cited examples as above are taken for granted and used as if true. As
a matter of fact, most of them are incorrect including Wolfram and
Wiki and one given by NASA.
Where there is a derivation, it ic usually based on an awkward effort
to show how the wavelength stretches in transit. e.g. Wolfram when in
fact the wavelength does not stretch in transit. All the effects occur
at the point of transmission and at the point of reception. Most
derivations are mired down by the complications of whether the source
is moving toward the sink or in the fixed medium and vice versa. I
have a derivation that skirts around all this stuff-I'm preparing a
paper on it.
John Polasek
Why not post what you've already got? Who knows, one of us might
find a useful correction for you.
(Sure, come ahead)
[/quote]
Sam, I thought if you had found some corrections you would help me
out but I haven't heard anything from you so I guess there aren't any.
I gave you enough equations to shoot at.
All that seems to be left of your sarcastic remark is your
condescending smiley and that has lost all of its original luster.
Why not be a man and admit that I showed you a really fine new way of
analyzing red shift?
Since everybody's been using the wrong equations, they got into some
trouble and came up with this spurious notion of cosmological red
shift where space supposedly stretches the wave. It's all Doppler if
it's done right.
I told you wrong about that reference that I cited. He never made any
connection with physics, nor discovered v/c = z/1+z. He just thought
it would be better if you used y = z/1+z since it gave mathematical
convergence.
Do you think the folks who think that the universe is accelerating
might change their mind if they used better mathematics? I don't care
for it myself. And I'm very sure God would not do any such thing.
John Polasek |
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| Sam Wormley... |
| Posted: Thu Nov 05, 2009 6:50 pm |
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Guest
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John Polasek wrote:
[quote]On Wed, 04 Nov 2009 12:41:29 -0500, John Polasek <jpolasek at (no spam) cfl.rr.com
wrote:
On Wed, 04 Nov 2009 04:51:38 GMT, Sam Wormley <swormley1 at (no spam) mchsi.com
wrote:
John Polasek wrote:
On Tue, 03 Nov 2009 05:53:21 GMT, Sam Wormley <swormley1 at (no spam) mchsi.com
wrote:
Sam Wormley wrote:
2.7182818284590... wrote:
The equation is:
See: http://scienceworld.wolfram.com/physics/DopplerEffect.html
Actually, these may be better for you:
http://en.wikipedia.org/wiki/Doppler_effect
http://en.wikipedia.org/wiki/Relativistic_Doppler_effect
All this fuss about the Doppler equation! But don't take it for
granted-there's more here than meets the eye.
Two things are interesting about a Doppler equation. One is that the
cited examples as above are taken for granted and used as if true. As
a matter of fact, most of them are incorrect including Wolfram and
Wiki and one given by NASA.
Where there is a derivation, it ic usually based on an awkward effort
to show how the wavelength stretches in transit. e.g. Wolfram when in
fact the wavelength does not stretch in transit. All the effects occur
at the point of transmission and at the point of reception. Most
derivations are mired down by the complications of whether the source
is moving toward the sink or in the fixed medium and vice versa. I
have a derivation that skirts around all this stuff-I'm preparing a
paper on it.
John Polasek
Why not post what you've already got? Who knows, one of us might
find a useful correction for you.
(Sure, come ahead)
Sam, I thought if you had found some corrections you would help me
out but I haven't heard anything from you so I guess there aren't any.
I gave you enough equations to shoot at.
All that seems to be left of your sarcastic remark is your
condescending smiley and that has lost all of its original luster.
Why not be a man and admit that I showed you a really fine new way of
analyzing red shift?
Since everybody's been using the wrong equations, they got into some
trouble and came up with this spurious notion of cosmological red
shift where space supposedly stretches the wave. It's all Doppler if
it's done right.
I told you wrong about that reference that I cited. He never made any
connection with physics, nor discovered v/c = z/1+z. He just thought
it would be better if you used y = z/1+z since it gave mathematical
convergence.
Do you think the folks who think that the universe is accelerating
might change their mind if they used better mathematics? I don't care
for it myself. And I'm very sure God would not do any such thing.
John Polasek
[/quote]
I'll get there John... Just haven't had time yet. Later tonight
or tomorrow.
-Sam |
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