| Topic: |
Science > Physics |
| User: |
"The Lord of the Rain\ Suresh __NoJunkMail kumar" |
| Date: |
28 Jan 2004 09:29:43 AM |
| Object: |
Interesting Concept to Read |
http://www.wikiworld.com/KooMar/Papers/gravity.pdf
comments welcome, esp. from Al
-suresh
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| User: "Sam Wormley" |
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| Title: Re: Interesting Concept to Read |
28 Jan 2004 04:24:19 PM |
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"The Lord of the Rain( Suresh __NoJunkMail kumar)" wrote:
http://www.wikiworld.com/KooMar/Papers/gravity.pdf
It's Crap! Suggest you read:
o "Newton's Principia for the Common Reader" by S. Chandrasekhar (1995)
Clarendon Press . Oxford
ISBN 0 19 851744 0
o Newton, Isaac "The Principia: Mathematical Principles of Natural
Philosophy" Trans. I. Bernard Cohen and Anne Whitman, with the
assistance of Julia Budenz (University of California Press: Berkeley,
1999)
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| User: "The Lord of the Rain\ Suresh __NoJunkMail kumar" |
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| Title: Re: Interesting Concept to Read |
28 Jan 2004 05:41:07 PM |
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Gravity could use any medium to propagate, like sound. Sound is vibration
that spreads, with any medium underneath and Sound decays by inverse square
law.
-suresh
"Sam Wormley" <swormley1@mchsi.com> wrote in message
news:40183691.5AA57B2E@mchsi.com...
"The Lord of the Rain( Suresh __NoJunkMail kumar)" wrote:
http://www.wikiworld.com/KooMar/Papers/gravity.pdf
It's Crap! Suggest you read:
o "Newton's Principia for the Common Reader" by S. Chandrasekhar (1995)
Clarendon Press . Oxford
ISBN 0 19 851744 0
o Newton, Isaac "The Principia: Mathematical Principles of Natural
Philosophy" Trans. I. Bernard Cohen and Anne Whitman, with the
assistance of Julia Budenz (University of California Press: Berkeley,
1999)
.
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| User: "Franz Heymann" |
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| Title: Re: Interesting Concept to Read |
29 Jan 2004 03:45:49 PM |
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"The Lord of the Rain( Suresh __NoJunkMail kumar)"
<sur_remove_kumdev_theunderscore_1@yahoo.com> wrote in message
news:bv9hai$pq2bt$1@ID-182852.news.uni-berlin.de...
Gravity could use any medium to propagate, like sound. Sound is vibration
that spreads, with any medium underneath and Sound decays by inverse
square
law.
It depends on what physical quantity describing the sound you are
considering.
Neither the particle velocity nor the pressure varies as an inverse square
law.
Franz
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| User: "The Lord of the Rain\ Suresh __NoJunkMail kumar" |
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| Title: Re: Interesting Concept to Read |
29 Jan 2004 04:17:12 PM |
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"Franz Heymann" <notfranz.heymann@btopenworld.com> wrote in message
news:bvbuud$15f$10@hercules.btinternet.com...
"The Lord of the Rain( Suresh __NoJunkMail kumar)"
<sur_remove_kumdev_theunderscore_1@yahoo.com> wrote in message
news:bv9hai$pq2bt$1@ID-182852.news.uni-berlin.de...
Gravity could use any medium to propagate, like sound. Sound is
vibration
that spreads, with any medium underneath and Sound decays by inverse
square
law.
It depends on what physical quantity describing the sound you are
considering.
Neither the particle velocity nor the pressure varies as an inverse square
law.
Notice my exact words. Sound decays by inverse square law. I never said
anything about velocity or pressure.
Franz
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| User: "Franz Heymann" |
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| Title: Re: Interesting Concept to Read |
30 Jan 2004 03:24:13 PM |
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"The Lord of the Rain( Suresh __NoJunkMail kumar)"
<sur_remove_kumdev_theunderscore_1@yahoo.com> wrote in message
news:bvc0p6$qmbdj$1@ID-182852.news.uni-berlin.de...
"Franz Heymann" <notfranz.heymann@btopenworld.com> wrote in message
news:bvbuud$15f$10@hercules.btinternet.com...
"The Lord of the Rain( Suresh __NoJunkMail kumar)"
<sur_remove_kumdev_theunderscore_1@yahoo.com> wrote in message
news:bv9hai$pq2bt$1@ID-182852.news.uni-berlin.de...
Gravity could use any medium to propagate, like sound. Sound is
vibration
that spreads, with any medium underneath and Sound decays by inverse
square
law.
It depends on what physical quantity describing the sound you are
considering.
Neither the particle velocity nor the pressure varies as an inverse
square
law.
Notice my exact words. Sound decays by inverse square law. I never said
anything about velocity or pressure.
"Sound decays......." Is a meaningless ststement. Sound has no units and
is not a physical observable. The pressure, amplitude, intensity, energy
density, energy flux, etc of sound have and are. Some of these dedecrease
as an inverse square law and some do not.
Franz
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| User: "The Lord of the Rain\ Suresh __NoJunkMail kumar" |
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| Title: Re: Interesting Concept to Read |
30 Jan 2004 04:00:34 PM |
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----- Original Message -----
From: "Franz Heymann" <notfranz.heymann@btopenworld.com>
Newsgroups: sci.physics
Sent: Friday, January 30, 2004 4:24 PM
Subject: Re: Interesting Concept to Read
"The Lord of the Rain( Suresh __NoJunkMail kumar)"
<sur_remove_kumdev_theunderscore_1@yahoo.com> wrote in message
news:bvc0p6$qmbdj$1@ID-182852.news.uni-berlin.de...
"Franz Heymann" <notfranz.heymann@btopenworld.com> wrote in message
news:bvbuud$15f$10@hercules.btinternet.com...
"The Lord of the Rain( Suresh __NoJunkMail kumar)"
<sur_remove_kumdev_theunderscore_1@yahoo.com> wrote in message
news:bv9hai$pq2bt$1@ID-182852.news.uni-berlin.de...
Gravity could use any medium to propagate, like sound. Sound is
vibration
that spreads, with any medium underneath and Sound decays by inverse
square
law.
It depends on what physical quantity describing the sound you are
considering.
Neither the particle velocity nor the pressure varies as an inverse
square
law.
Notice my exact words. Sound decays by inverse square law. I never said
anything about velocity or pressure.
"Sound decays......." Is a meaningless ststement. Sound has no units and
is not a physical observable. The pressure, amplitude, intensity, energy
density, energy flux, etc of sound have and are. Some of these dedecrease
as an inverse square law and some do not.
This is your failure to understand both the word "Sound" and the physical
conotations associated with sound.
When someone tell to decreare the sound level of your setero? what would you
do?
Remember that your level of intellect at playing scrabble has nothing to do
with physics.
-suresh
Franz
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| User: "Franz Heymann" |
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| Title: Re: Interesting Concept to Read |
31 Jan 2004 03:33:44 PM |
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"The Lord of the Rain( Suresh __NoJunkMail kumar)"
<sur_remove_kumdev_theunderscore_1@yahoo.com> wrote in message
news:bvek65$racil$1@ID-182852.news.uni-berlin.de...
----- Original Message -----
From: "Franz Heymann" <notfranz.heymann@btopenworld.com>
Newsgroups: sci.physics
Sent: Friday, January 30, 2004 4:24 PM
Subject: Re: Interesting Concept to Read
"The Lord of the Rain( Suresh __NoJunkMail kumar)"
<sur_remove_kumdev_theunderscore_1@yahoo.com> wrote in message
news:bvc0p6$qmbdj$1@ID-182852.news.uni-berlin.de...
"Franz Heymann" <notfranz.heymann@btopenworld.com> wrote in message
news:bvbuud$15f$10@hercules.btinternet.com...
"The Lord of the Rain( Suresh __NoJunkMail kumar)"
<sur_remove_kumdev_theunderscore_1@yahoo.com> wrote in message
news:bv9hai$pq2bt$1@ID-182852.news.uni-berlin.de...
Gravity could use any medium to propagate, like sound. Sound is
vibration
that spreads, with any medium underneath and Sound decays by
inverse
square
law.
It depends on what physical quantity describing the sound you are
considering.
Neither the particle velocity nor the pressure varies as an inverse
square
law.
Notice my exact words. Sound decays by inverse square law. I never
said
anything about velocity or pressure.
"Sound decays......." Is a meaningless ststement. Sound has no units
and
is not a physical observable. The pressure, amplitude, intensity,
energy
density, energy flux, etc of sound have and are. Some of these
dedecrease
as an inverse square law and some do not.
This is your failure to understand both the word "Sound" and the physical
conotations associated with sound.
When someone tell to decreare the sound level of your setero? what would
you
do?
Notice that subtle little word "level" you used there. That is common
parlance for the logarithm of the radiated sound power.
Now find a valid criticism of what I averred, or bow out.
Have you still not realised that the pressure decreases as the inverse
*first* power of the distance in a spherical sound wave
Have you still not realised that in a speaking tube the pressure, the
particle velocity, the intensity, the power flux are all independent of
distance, except for some small exponential attenuation with distance?
Remember that your level of intellect at playing scrabble has nothing to
do
with physics.
Save the praise for later.
Franz
.
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| User: "The Lord of the Rain\ Suresh __NoJunkMail kumar" |
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| Title: Re: Interesting Concept to Read |
31 Jan 2004 05:57:11 PM |
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i put the word "level" in there, because otherwise your mind miss the
meaning of an extremely valid colloqiual sentence. That my way of showing
what your real "level" is.
-suresh
"Franz Heymann" <notfranz.heymann@btopenworld.com> wrote in message
news:bvh6vo$2f3$8@sparta.btinternet.com...
"The Lord of the Rain( Suresh __NoJunkMail kumar)"
<sur_remove_kumdev_theunderscore_1@yahoo.com> wrote in message
news:bvek65$racil$1@ID-182852.news.uni-berlin.de...
----- Original Message -----
From: "Franz Heymann" <notfranz.heymann@btopenworld.com>
Newsgroups: sci.physics
Sent: Friday, January 30, 2004 4:24 PM
Subject: Re: Interesting Concept to Read
"The Lord of the Rain( Suresh __NoJunkMail kumar)"
<sur_remove_kumdev_theunderscore_1@yahoo.com> wrote in message
news:bvc0p6$qmbdj$1@ID-182852.news.uni-berlin.de...
"Franz Heymann" <notfranz.heymann@btopenworld.com> wrote in message
news:bvbuud$15f$10@hercules.btinternet.com...
"The Lord of the Rain( Suresh __NoJunkMail kumar)"
<sur_remove_kumdev_theunderscore_1@yahoo.com> wrote in message
news:bv9hai$pq2bt$1@ID-182852.news.uni-berlin.de...
Gravity could use any medium to propagate, like sound. Sound is
vibration
that spreads, with any medium underneath and Sound decays by
inverse
square
law.
It depends on what physical quantity describing the sound you are
considering.
Neither the particle velocity nor the pressure varies as an
inverse
square
law.
Notice my exact words. Sound decays by inverse square law. I never
said
anything about velocity or pressure.
"Sound decays......." Is a meaningless ststement. Sound has no units
and
is not a physical observable. The pressure, amplitude, intensity,
energy
density, energy flux, etc of sound have and are. Some of these
dedecrease
as an inverse square law and some do not.
This is your failure to understand both the word "Sound" and the
physical
conotations associated with sound.
When someone tell to decreare the sound level of your setero? what would
you
do?
Notice that subtle little word "level" you used there. That is common
parlance for the logarithm of the radiated sound power.
Now find a valid criticism of what I averred, or bow out.
Have you still not realised that the pressure decreases as the inverse
*first* power of the distance in a spherical sound wave
Have you still not realised that in a speaking tube the pressure, the
particle velocity, the intensity, the power flux are all independent of
distance, except for some small exponential attenuation with distance?
Remember that your level of intellect at playing scrabble has nothing to
do
with physics.
Save the praise for later.
Franz
.
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| User: "Sam Wormley" |
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| Title: Re: Interesting Concept to Read |
29 Jan 2004 06:54:36 PM |
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"The Lord of the Rain( Suresh __NoJunkMail kumar)" wrote:
Gravity could use any medium to propagate, like sound. Sound is vibration
that spreads, with any medium underneath and Sound decays by inverse square
law.
The inverse square law is a starting approximation (for a spherical emitter),
but sound propagation is much more complicated and is primarily dissipated by
scattering.
"Acoustic Fields and Waves in Solids, Vol I & II" by B.A. Auld, 2nd edition
(February 1990), Krieger Publishing Company; ISBN: 089874783X
"Ultrasonic Testing of Materials" by Josef Krautkramer, Herbert Krautkramer,
4th/revised edition (November 1990), Springer Verlag; ISBN: 0387512314
.
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| User: "Tom Potter" |
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| Title: Re: Interesting Concept to Read |
30 Jan 2004 05:06:58 AM |
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"Sam Wormley" <swormley1@mchsi.com> wrote in message
news:4019AB45.29BD656@mchsi.com...
"The Lord of the Rain( Suresh __NoJunkMail kumar)" wrote:
Gravity could use any medium to propagate, like sound. Sound is
vibration
that spreads, with any medium underneath and Sound decays by inverse
square
law.
The inverse square law is a starting approximation (for a spherical
emitter),
The inverse square law is a starting approximation
for a constant, isotropic, propagation velocity,
in a homogenous three-dimensional medium.
The shape of the emitter is not a factor.
However, if the medium is not homogenous,
or if the velocity of propagation is not constant in all directions,
there will be variations from a pure inverse square law.
--
Tom Potter http://tompotter.us
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| User: "Franz Heymann" |
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| Title: Re: Interesting Concept to Read |
31 Jan 2004 04:03:57 AM |
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"Tom Potter" <tdp@hotsheet.com> wrote in message
news:bvddqr$ragjh$1@ID-188019.news.uni-berlin.de...
"Sam Wormley" <swormley1@mchsi.com> wrote in message
news:4019AB45.29BD656@mchsi.com...
"The Lord of the Rain( Suresh __NoJunkMail kumar)" wrote:
Gravity could use any medium to propagate, like sound. Sound is
vibration
that spreads, with any medium underneath and Sound decays by inverse
square
law.
The inverse square law is a starting approximation (for a spherical
emitter),
Are you talking about pressure, particle velocity or intensity?
The inverse square law is a starting approximation
for a constant, isotropic, propagation velocity,
in a homogenous three-dimensional medium.
Only for a spherical wave, if you happen to be talking about the intensity.
The shape of the emitter is not a factor.
Utter rubbish.
However, if the medium is not homogenous,
or if the velocity of propagation is not constant in all directions,
there will be variations from a pure inverse square law.
And indeed, in a speaking tube, the pressure is almost independent of
distance, except for a slight exponential rate of decrease.
Franz
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| User: "Tom Potter" |
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| Title: Re: Interesting Concept to Read |
31 Jan 2004 08:28:32 AM |
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"Franz Heymann" <notfranz.heymann@btopenworld.com> wrote in message
news:bvfuid$g8h$10@sparta.btinternet.com...
"Tom Potter" <tdp@hotsheet.com> wrote in message
news:bvddqr$ragjh$1@ID-188019.news.uni-berlin.de...
"Sam Wormley" <swormley1@mchsi.com> wrote in message
news:4019AB45.29BD656@mchsi.com...
"The Lord of the Rain( Suresh __NoJunkMail kumar)" wrote:
Gravity could use any medium to propagate, like sound. Sound is
vibration
that spreads, with any medium underneath and Sound decays by inverse
square
law.
The inverse square law is a starting approximation (for a spherical
emitter),
Are you talking about pressure, particle velocity or intensity?
The inverse square law is a starting approximation
for a constant, isotropic, propagation velocity,
in a homogenous three-dimensional medium.
Only for a spherical wave, if you happen to be talking about the
intensity.
The shape of the emitter is not a factor.
Utter rubbish.
However, if the medium is not homogenous,
or if the velocity of propagation is not constant in all directions,
there will be variations from a pure inverse square law.
And indeed, in a speaking tube, the pressure is almost independent of
distance, except for a slight exponential rate of decrease.
Hopefully "Franz Heymann" will back up his childish statement:
"Utter rubbish" with an explanation of why he thinks that
"The shape of the emitter is a factor" in the "inverse square law".
--
Tom Potter http://tompotter.us
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| User: "Sam Wormley" |
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| Title: Re: Interesting Concept to Read |
30 Jan 2004 08:27:52 AM |
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Tom Potter wrote:
The shape of the emitter is not a factor.
Thunder is an excellent example where shape is a factor!
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| User: "Tom Potter" |
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| Title: Re: Interesting Concept to Read |
30 Jan 2004 09:50:14 AM |
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"Sam Wormley" <swormley1@mchsi.com> wrote in message
news:401A69DE.41A0AFD6@mchsi.com...
The inverse square law is a starting approximation (for a spherical
emitter),
Thunder is an excellent example where shape is a factor!
The inverse square law is a starting approximation
for a constant, isotropic, propagation velocity,
in a homogenous three-dimensional medium.
The shape of the emitter is not a factor.
However, if the medium is not homogenous,
or if the velocity of propagation is not constant in all directions,
there will be variations from a pure inverse square law.
--
Tom Potter http://tompotter.us
.
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| User: "Franz Heymann" |
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| Title: Re: Interesting Concept to Read |
31 Jan 2004 04:03:47 AM |
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"Tom Potter" <tdp@hotsheet.com> wrote in message
news:bvdue6$rjmcc$1@ID-188019.news.uni-berlin.de...
[snip]
The shape of the emitter is not a factor.
That is incorrect.
Solve the wave equation in spherical, cylindrical and cartesian coordinates.
Think of the source shapes needed to maintain sound waves corresponding to
those solutions.
[snip]
Franz
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| User: "Tom Potter" |
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| Title: Re: Interesting Concept to Read |
31 Jan 2004 08:33:23 AM |
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"Franz Heymann" <notfranz.heymann@btopenworld.com> wrote in message
news:bvfui2$g8h$1@sparta.btinternet.com...
"Tom Potter" <tdp@hotsheet.com> wrote in message
news:bvdue6$rjmcc$1@ID-188019.news.uni-berlin.de...
[snip]
The shape of the emitter is not a factor.
That is incorrect.
Solve the wave equation in spherical, cylindrical and cartesian
coordinates.
Think of the source shapes needed to maintain sound waves corresponding to
those solutions.
It is interesting to see that "Franz Heymann"
thinks that the shape of an emitter is a factor
in the inverse square law.
--
Tom Potter http://tompotter.us
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| User: "Franz Heymann" |
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| Title: Re: Interesting Concept to Read |
31 Jan 2004 03:33:47 PM |
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"Tom Potter" <tdp@hotsheet.com> wrote in message
news:bvgea5$rr6fk$1@ID-188019.news.uni-berlin.de...
"Franz Heymann" <notfranz.heymann@btopenworld.com> wrote in message
news:bvfui2$g8h$1@sparta.btinternet.com...
"Tom Potter" <tdp@hotsheet.com> wrote in message
news:bvdue6$rjmcc$1@ID-188019.news.uni-berlin.de...
[snip]
The shape of the emitter is not a factor.
That is incorrect.
Solve the wave equation in spherical, cylindrical and cartesian
coordinates.
Think of the source shapes needed to maintain sound waves corresponding
to
those solutions.
It is interesting to see that "Franz Heymann"
thinks that the shape of an emitter is a factor
in the inverse square law.
I do. The inverse square law for the radiated intensity is true only in the
case of a spherical wave.
In the case of a plane wave, the intensity is independent of the distance.
The source shapes for these two waves are different.
Franz
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| User: "Robert J. Kolker" |
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| Title: Re: Interesting Concept to Read |
31 Jan 2004 09:08:08 AM |
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Tom Potter wrote:
It is interesting to see that "Franz Heymann"
thinks that the shape of an emitter is a factor
in the inverse square law.
The shape of the emitter is a factor in the shape of the orbit, when one
is in close to a non-spherical object. Far away from the object, the
force on a test mass behaves like the force exerted by a spherically
symmetric field. Close in, not so.
Bob Kolker
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| User: "Gregory L. Hansen" |
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| Title: Re: Interesting Concept to Read |
31 Jan 2004 07:53:37 AM |
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In article <bvdue6$rjmcc$1@ID-188019.news.uni-berlin.de>,
Tom Potter <tdp@hotsheet.com> wrote:
"Sam Wormley" <swormley1@mchsi.com> wrote in message
news:401A69DE.41A0AFD6@mchsi.com...
The inverse square law is a starting approximation (for a spherical
emitter),
Thunder is an excellent example where shape is a factor!
The inverse square law is a starting approximation
for a constant, isotropic, propagation velocity,
in a homogenous three-dimensional medium.
The shape of the emitter is not a factor.
The shape of the emitter is not a factor if your distance from the emitter
is much greater than its size.
That the shape of the emitter matters can be seen easily enough by
thinking of two separate masses. If you have one mass above you and one
below you, obviously the field will be different than a point mass in the
middle. If you're far enough away, the quadrupole and higher moments die
off and the separated masses will look like a single point mass.
Newton's law applies to point masses and spherically symmetric masses.
Spacecraft follow a wobbly orbit around lumpy masses, and that's used to
explore mass distributions of moons and planets.
--
"We don't grow up hearing stories around the camp fire anymore about
cultural figures. Instead we get them from books, TV or movies, so the
characters that today provide us a common language are corporate
creatures" -- Rebecca Tushnet
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| User: "Franz Heymann" |
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| Title: Re: Interesting Concept to Read |
31 Jan 2004 03:33:46 PM |
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"Gregory L. Hansen" <glhansen@steel.ucs.indiana.edu> wrote in message
news:bvgc11$uao$2@hood.uits.indiana.edu...
In article <bvdue6$rjmcc$1@ID-188019.news.uni-berlin.de>,
Tom Potter <tdp@hotsheet.com> wrote:
"Sam Wormley" <swormley1@mchsi.com> wrote in message
news:401A69DE.41A0AFD6@mchsi.com...
The inverse square law is a starting approximation (for a spherical
emitter),
Thunder is an excellent example where shape is a factor!
The inverse square law is a starting approximation
for a constant, isotropic, propagation velocity,
in a homogenous three-dimensional medium.
The shape of the emitter is not a factor.
The shape of the emitter is not a factor if your distance from the emitter
is much greater than its size.
You have forgotten that the wavelength matters too. A 10 MHz sound wave
emitted from a plane oscillating crystal with a surface scale dimension of
1 metre will take very, very many metres of propagation before the inverse
square law for the intensity becomes nearly true. . The characteristic
distance is in fact surface area/lambda.
That the shape of the emitter matters can be seen easily enough by
thinking of two separate masses. If you have one mass above you and one
below you, obviously the field will be different than a point mass in the
middle. If you're far enough away, the quadrupole and higher moments die
off and the separated masses will look like a single point mass.
Newton's law applies to point masses and spherically symmetric masses.
Spacecraft follow a wobbly orbit around lumpy masses, and that's used to
explore mass distributions of moons and planets.
Gregory, I think you came into the thread a little late. It has drifted to
a discussion on how sound waves are propagated. (Ayt least, the part I am
playing in has done so)
Franz
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| User: "Gregory L. Hansen" |
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| Title: Re: Interesting Concept to Read |
31 Jan 2004 04:15:50 PM |
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In article <bvh6vp$2f3$10@sparta.btinternet.com>,
Franz Heymann <franz.heymann@btopenworld.com> wrote:
"Gregory L. Hansen" <glhansen@steel.ucs.indiana.edu> wrote in message
news:bvgc11$uao$2@hood.uits.indiana.edu...
In article <bvdue6$rjmcc$1@ID-188019.news.uni-berlin.de>,
Tom Potter <tdp@hotsheet.com> wrote:
"Sam Wormley" <swormley1@mchsi.com> wrote in message
news:401A69DE.41A0AFD6@mchsi.com...
The inverse square law is a starting approximation (for a spherical
emitter),
Thunder is an excellent example where shape is a factor!
The inverse square law is a starting approximation
for a constant, isotropic, propagation velocity,
in a homogenous three-dimensional medium.
The shape of the emitter is not a factor.
The shape of the emitter is not a factor if your distance from the emitter
is much greater than its size.
You have forgotten that the wavelength matters too. A 10 MHz sound wave
emitted from a plane oscillating crystal with a surface scale dimension of
1 metre will take very, very many metres of propagation before the inverse
square law for the intensity becomes nearly true. . The characteristic
distance is in fact surface area/lambda.
Yeah, I was thinking of a pretty long wavelength, there.
That the shape of the emitter matters can be seen easily enough by
thinking of two separate masses. If you have one mass above you and one
below you, obviously the field will be different than a point mass in the
middle. If you're far enough away, the quadrupole and higher moments die
off and the separated masses will look like a single point mass.
Newton's law applies to point masses and spherically symmetric masses.
Spacecraft follow a wobbly orbit around lumpy masses, and that's used to
explore mass distributions of moons and planets.
Gregory, I think you came into the thread a little late. It has drifted to
a discussion on how sound waves are propagated. (Ayt least, the part I am
playing in has done so)
What do you mean, "slow of mind"?
--
"Experiments are the only means of knowledge at our disposal. The rest is
poetry, imagination." -- Max Planck
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| User: "Franz Heymann" |
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| Title: Re: Interesting Concept to Read |
01 Feb 2004 11:32:20 AM |
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"Gregory L. Hansen" <glhansen@steel.ucs.indiana.edu> wrote in message
news:bvh9em$7vq$2@hood.uits.indiana.edu...
In article <bvh6vp$2f3$10@sparta.btinternet.com>,
Franz Heymann <franz.heymann@btopenworld.com> wrote:
"Gregory L. Hansen" <glhansen@steel.ucs.indiana.edu> wrote in message
news:bvgc11$uao$2@hood.uits.indiana.edu...
In article <bvdue6$rjmcc$1@ID-188019.news.uni-berlin.de>,
Tom Potter <tdp@hotsheet.com> wrote:
"Sam Wormley" <swormley1@mchsi.com> wrote in message
news:401A69DE.41A0AFD6@mchsi.com...
The inverse square law is a starting approximation (for a spherical
emitter),
Thunder is an excellent example where shape is a factor!
The inverse square law is a starting approximation
for a constant, isotropic, propagation velocity,
in a homogenous three-dimensional medium.
The shape of the emitter is not a factor.
The shape of the emitter is not a factor if your distance from the
emitter
is much greater than its size.
You have forgotten that the wavelength matters too. A 10 MHz sound wave
emitted from a plane oscillating crystal with a surface scale dimension
of
1 metre will take very, very many metres of propagation before the
inverse
square law for the intensity becomes nearly true. . The characteristic
distance is in fact surface area/lambda.
Yeah, I was thinking of a pretty long wavelength, there.
That the shape of the emitter matters can be seen easily enough by
thinking of two separate masses. If you have one mass above you and
one
below you, obviously the field will be different than a point mass in
the
middle. If you're far enough away, the quadrupole and higher moments
die
off and the separated masses will look like a single point mass.
Newton's law applies to point masses and spherically symmetric masses.
Spacecraft follow a wobbly orbit around lumpy masses, and that's used
to
explore mass distributions of moons and planets.
Gregory, I think you came into the thread a little late. It has drifted
to
a discussion on how sound waves are propagated. (Ayt least, the part I
am
playing in has done so)
What do you mean, "slow of mind"?
You beat me there. {:-((
Franz
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| User: "Sam Wormley" |
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| Title: Re: Interesting Concept to Read |
30 Jan 2004 08:00:17 AM |
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Tom Potter wrote:
"Sam Wormley" <swormley1@mchsi.com> wrote in message
news:4019AB45.29BD656@mchsi.com...
"The Lord of the Rain( Suresh __NoJunkMail kumar)" wrote:
Gravity could use any medium to propagate, like sound. Sound is
vibration
that spreads, with any medium underneath and Sound decays by inverse
square
law.
The inverse square law is a starting approximation (for a spherical
emitter),
The inverse square law is a starting approximation
for a constant, isotropic, propagation velocity,
in a homogenous three-dimensional medium.
The shape of the emitter is not a factor.
Of course the shape of the emitter is a factor.
http://www.ndt-ed.org/EducationResources/CommunityCollege/Ultrasonics/CalibrationMeth/thompsongray.htm
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| User: "Tom Potter" |
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| Title: Re: Interesting Concept to Read |
30 Jan 2004 09:46:39 AM |
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"Sam Wormley" <swormley1@mchsi.com> wrote in message
news:401A6367.76B32857@mchsi.com...
Tom Potter wrote:
"Sam Wormley" <swormley1@mchsi.com> wrote in message
news:4019AB45.29BD656@mchsi.com...
"The Lord of the Rain( Suresh __NoJunkMail kumar)" wrote:
Gravity could use any medium to propagate, like sound. Sound is
vibration
that spreads, with any medium underneath and Sound decays by inverse
square
law.
The inverse square law is a starting approximation (for a spherical
emitter),
The inverse square law is a starting approximation
for a constant, isotropic, propagation velocity,
in a homogenous three-dimensional medium.
The shape of the emitter is not a factor.
Of course the shape of the emitter is a factor.
http://www.ndt-ed.org/EducationResources/CommunityCollege/Ultrasonics/Calibr
ationMeth/thompsongray.htm
This Community College Industrial Arts URL
does not mention shapes nor emitters.
--
Tom Potter http://tompotter.us
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| User: "Franz Heymann" |
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| Title: Re: Interesting Concept to Read |
31 Jan 2004 04:03:59 AM |
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"Tom Potter" <tdp@hotsheet.com> wrote in message
news:bvdu6d$r288p$1@ID-188019.news.uni-berlin.de...
"Sam Wormley" <swormley1@mchsi.com> wrote in message
news:401A6367.76B32857@mchsi.com...
Tom Potter wrote:
"Sam Wormley" <swormley1@mchsi.com> wrote in message
news:4019AB45.29BD656@mchsi.com...
"The Lord of the Rain( Suresh __NoJunkMail kumar)" wrote:
Gravity could use any medium to propagate, like sound. Sound is
vibration
that spreads, with any medium underneath and Sound decays by
inverse
square
law.
The inverse square law is a starting approximation (for a spherical
emitter),
The inverse square law is a starting approximation
for a constant, isotropic, propagation velocity,
in a homogenous three-dimensional medium.
The shape of the emitter is not a factor.
Of course the shape of the emitter is a factor.
http://www.ndt-ed.org/EducationResources/CommunityCollege/Ultrasonics/Calibr
ationMeth/thompsongray.htm
This Community College Industrial Arts URL
does not mention shapes nor emitters.
That is very remiss of it.
Franz
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| User: "Tom Potter" |
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| Title: Re: Interesting Concept to Read |
31 Jan 2004 08:24:08 AM |
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"Franz Heymann" <notfranz.heymann@btopenworld.com> wrote in message
news:bvfuif$g8h$12@sparta.btinternet.com...
"Tom Potter" <tdp@hotsheet.com> wrote in message
news:bvdu6d$r288p$1@ID-188019.news.uni-berlin.de...
"Sam Wormley" <swormley1@mchsi.com> wrote in message
news:401A6367.76B32857@mchsi.com...
Tom Potter wrote:
"Sam Wormley" <swormley1@mchsi.com> wrote in message
news:4019AB45.29BD656@mchsi.com...
"The Lord of the Rain( Suresh __NoJunkMail kumar)" wrote:
Gravity could use any medium to propagate, like sound. Sound is
vibration
that spreads, with any medium underneath and Sound decays by
inverse
square
law.
The inverse square law is a starting approximation (for a
spherical
emitter),
The inverse square law is a starting approximation
for a constant, isotropic, propagation velocity,
in a homogenous three-dimensional medium.
The shape of the emitter is not a factor.
Of course the shape of the emitter is a factor.
http://www.ndt-ed.org/EducationResources/CommunityCollege/Ultrasonics/Calibr
ationMeth/thompsongray.htm
This Community College Industrial Arts URL
does not mention shapes nor emitters.
That is very remiss of it.
Hopefully "Franz Heymann" will explain why
a web site should have information about a bject
just because somene used that URL as a phony reference.
It seems to me,
that the onus shuld be on the person
who used the url as a reference.
--
Tom Potter http://tompotter.us
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| User: "Franz Heymann" |
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| Title: Re: Interesting Concept to Read |
31 Jan 2004 03:33:45 PM |
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"Tom Potter" <tdp@hotsheet.com> wrote in message
news:bvgdon$s9omt$1@ID-188019.news.uni-berlin.de...
"Franz Heymann" <notfranz.heymann@btopenworld.com> wrote in message
news:bvfuif$g8h$12@sparta.btinternet.com...
"Tom Potter" <tdp@hotsheet.com> wrote in message
news:bvdu6d$r288p$1@ID-188019.news.uni-berlin.de...
"Sam Wormley" <swormley1@mchsi.com> wrote in message
news:401A6367.76B32857@mchsi.com...
Tom Potter wrote:
"Sam Wormley" <swormley1@mchsi.com> wrote in message
news:4019AB45.29BD656@mchsi.com...
"The Lord of the Rain( Suresh __NoJunkMail kumar)" wrote:
Gravity could use any medium to propagate, like sound. Sound
is
vibration
that spreads, with any medium underneath and Sound decays by
inverse
square
law.
The inverse square law is a starting approximation (for a
spherical
emitter),
The inverse square law is a starting approximation
for a constant, isotropic, propagation velocity,
in a homogenous three-dimensional medium.
The shape of the emitter is not a factor.
Of course the shape of the emitter is a factor.
http://www.ndt-ed.org/EducationResources/CommunityCollege/Ultrasonics/Calibr
ationMeth/thompsongray.htm
This Community College Industrial Arts URL
does not mention shapes nor emitters.
That is very remiss of it.
Hopefully "Franz Heymann" will explain why
a web site should have information about a bject
just because somene used that URL as a phony reference.
It seems to me,
that the onus shuld be on the person
who used the url as a reference.
If that URL does not realise that the details of the propagated sound wave
depend quite drastically on whether the source is an oscillating sphere, an
oscillating cylinder or a vibrating plane, then I will not waste my time
reading it.
Franz
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| User: "Bjoern Feuerbacher" |
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| Title: Re: Interesting Concept to Read |
28 Jan 2004 10:44:47 AM |
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"The Lord of the Rain( Suresh __NoJunkMail kumar)" wrote:
http://www.wikiworld.com/KooMar/Papers/gravity.pdf
comments welcome, esp. from Al
The text accompanying eq. (1) to (3) is mostly nonsense; particularly
the conclusion that H = 0 is totally wrong.
Eq. (4) is right, but seems to be only written down for the
one-dimensional case. If one wants to derive Newton's law of gravity,
one should do the calculations in three dimensions!
The text after eq. (4) is again strange.
Then comes the crucial part: WHERE ON EARTH does eq. (5) come from???
The only way to get this formula I can imagine is if one *starts* with
Newton's law of gravity - exactly the one which is tried to derive here!
So, apparently, the argument is totally circular. If there is another
source for eq. (5), please tell us where it came from.
Eq. (6) to (11) follow then straightforwardly - my only quibble is that
one should write "r" instead of "x".
Conclusion: not a derivation (and certainly not one based on Hamilton's
mechanics! Formula (4) is a well-known formula, one doesn't need any
Hamiltonian to derive it!), but simply a circular argument.
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| User: "The Lord of the Rain\ Suresh __NoJunkMail kumar" |
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| Title: Re: Interesting Concept to Read |
28 Jan 2004 11:36:41 AM |
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"Bjoern Feuerbacher" <bfeuerba@ix.urz.uni-heidelberg.de> wrote in message
news:4017E6FF.FAF45A82@ix.urz.uni-heidelberg.de...
"The Lord of the Rain( Suresh __NoJunkMail kumar)" wrote:
http://www.wikiworld.com/KooMar/Papers/gravity.pdf
comments welcome, esp. from Al
Then comes the crucial part: WHERE ON EARTH does eq. (5) come from???
The only way to get this formula I can imagine is if one *starts* with
Newton's law of gravity - exactly the one which is tried to derive here!
So, apparently, the argument is totally circular. If there is another
source for eq. (5), please tell us where it came from.
The idea is 'influence'. There is mass M inside the sphere of radius x^2.
However, you have to notice, every quantum mechanically, particle that
compose M are not stationary. You also know that virtual particles enter and
exit the system. Definitely there is a sea of virtual particles, that enter
and exit the system from time to time.
In a way, what i m indirectly claiming that velocity v of particle m, gets
altered very slightly.
Eq. (6) to (11) follow then straightforwardly - my only quibble is that
one should write "r" instead of "x".
Conclusion: not a derivation (and certainly not one based on Hamilton's
mechanics! Formula (4) is a well-known formula, one doesn't need any
Hamiltonian to derive it!), but simply a circular argument.
Formula (4) can be derived from Hamiltonian mechanics or Langrangian
Mechanics. There are two concepts you are missing.
H = 0 is one equation. This is no more than requiring the total energy of
the system to 0, at all time. You are right in a way, the Formula (4) doesnt
require Hamiltionian mechanics. However, what you are failing to understand
is the following
m dv/dt = - d/dx V is a path of least action
1/2 mv^2 + V(x) = 0 total energy of the system is zero.
2 different systems with entirely 2 different meanings. This is not a
circular arguement.
-suresh
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| User: "The Lord of the Rain\ Suresh __NoJunkMail kumar" |
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| Title: Re: Interesting Concept to Read |
28 Jan 2004 11:16:32 AM |
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"Bjoern Feuerbacher" <bfeuerba@ix.urz.uni-heidelberg.de> wrote in message
news:4017E6FF.FAF45A82@ix.urz.uni-heidelberg.de...
"The Lord of the Rain( Suresh __NoJunkMail kumar)" wrote:
http://www.wikiworld.com/KooMar/Papers/gravity.pdf
comments welcome, esp. from Al
The text accompanying eq. (1) to (3) is mostly nonsense; particularly
the conclusion that H = 0 is totally wrong.
I claimed that the particle's velocity is 0 and thus 1/2 mv^2 = 0.
I introduced a potential
H = 1/2 mv^2 + V(x)
such that H = 0 since energy is conserved. I dont see any nonsense. You
need to justify urself better,instead of hand waving arguements.
Eq. (4) is right, but seems to be only written down for the
one-dimensional case. If one wants to derive Newton's law of gravity,
one should do the calculations in three dimensions!
The text after eq. (4) is again strange.
Then comes the crucial part: WHERE ON EARTH does eq. (5) come from???
The only way to get this formula I can imagine is if one *starts* with
Newton's law of gravity - exactly the one which is tried to derive here!
So, apparently, the argument is totally circular. If there is another
source for eq. (5), please tell us where it came from.
Eq. (6) to (11) follow then straightforwardly - my only quibble is that
one should write "r" instead of "x".
Conclusion: not a derivation (and certainly not one based on Hamilton's
mechanics! Formula (4) is a well-known formula, one doesn't need any
Hamiltonian to derive it!), but simply a circular argument.
.
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