What I am going to do is use sound to measure the doppler shift of light.

This is the set up.

S is a monochromatic light source, emitting light of frequency 7.5E14 hz (FL).

For every 7E14 cycles of that light, the source emits a short beep of sound.
The Beep frequency is 1 second.

A detector at rest with the source and some distance away counts the beeps and
correctly calculates the frequency of the emitted light to be FL.

Next, the detector is set in motion towards the source at half the velocity of
sound. The received beep frequency increases to double its previous value, ie.,
to 2Fs.

This implies that the detector is now receiving twice the number of light
cycles per second as it did when at rest. In other words the light appears to
have been doppler shifted to double its frequency in the source frame.

Q) What is the colour of the light seen by an observer moving with the
detector?

On Apr 28, 2:43 pm, PD <TheDraperFam...@gmail.com> wrote:



On Apr 28, 12:32 am, rbwinn <rbwi...@juno.com> wrote:

On Apr 27, 6:16 pm, Bryan Olson <fakeaddr...@nowhere.org> wrote:

rbwinn wrote:
Tom Roberts wrote:
rbwinn wrote:
The speed of sound is only 1,087 feet per second. �Half of that would
only be 543.5 feet per second. �That is not fast enough to change the
frequency of the light enough to worry about.
Sure it is! This is how police radar and laser guns measure the speed of
traffic, and they do so for motions ~100 times smaller. A laboratory
instrument could measure speed thousands of times better than that.

Radar does not change frequency.  It is reflected from a target at the
same frequency it had before.

Dude, just look it up.

I used to work on radar.

One application, yes. You might want to look up Doppler radar, which
meteorologists use to look for differential velocity of moist air
masses, which would be a signal for rotation, a possible tornado. This
is a little different use of radar than ranging radar, which you might
have used in Vietnam.

So are you saying that Doppler radar is top secret, and you cannot
explain it, or what?

"Bryan Olson" <fakeaddress@nowhere.org> wrote in message
news:u2fRj.12268$GE1.8109@nlpi061.nbdc.sbc.com...
rbwinn wrote:
Bryan Olson wrote:
rbwinn wrote:
Tom Roberts wrote:
rbwinn wrote:
The speed of sound is only 1,087 feet per second. ?Half of that
would
only be 543.5 feet per second. ?That is not fast enough to change
the
frequency of the light enough to worry about.
Sure it is! This is how police radar and laser guns measure the speed
of
traffic, and they do so for motions ~100 times smaller. A laboratory
instrument could measure speed thousands of times better than that.

Radar does not change frequency. It is reflected from a target at the
same frequency it had before.
Dude, just look it up.

I used to work on radar. A transmitter sends out a signal, a receiver
picks up a signal reflected from a target. Unless the books about
radar the Navy gave us were incorrect, there is no appreciable
difference in frequency of the signals. There is a carrier wave of
constant frequency which is reflected from targets and received by a
radar receiver at the same frequency. The information concerning
targets is in the form of modulation of the carrier wave caused by the
reflection. Doppler radar works the same way. The carrier wave has
the same frequency whether being transmitted or received. What shows
the Doppler effect used to calculate speed are modulations of the
carrier wave.

Dude, look it up already.

That's a suggestion. I realize I've no authority to command you to do
anything.

I will point out that "look it up" does *not* mean ramble on about
what you think you know.

Given modern tools, how hard is it to check out whether Tom Roberts is
right in saying that Doppler shift "is how police radar" works, or
whether R. B. Winn is right that radar "is reflected from a target at
the same frequency it had before"? I'd say: not hard. I was pretty
confident I knew the answer, but I looked it up anyway; checked
multiple sources just to be sure. Took roughly three minutes.

You are both correct so shake hands and come out fighting!

For example the Hawk system uses a system called Hi-Par / Low-Par
acquisition and tracking radar. which is a dual freq system using low freq
for acquisition and a higher freq once target is acquired. Both are
non-doppler
but several other systems such as the ones used by police and several
mapping
systems uses a doppler shift system.

Paul Mays wrote:
....
You are both correct so shake hands and come
out fighting!

You lost me. I hold, I believe in agreement with
Tom, that radar reflected from a moving target
is Doppler shifted from the transmitted
frequency, and the working of police radar is
based on that phenomenon. Robert claimed:

Radar does not change frequency. It is
reflected from a target at the same frequency it
had before.

We cannot both be right.

Dr. Henri Wilson skrev:
What I am going to do is use sound to measure the doppler shift of light.

This is the set up.

S is a monochromatic light source, emitting light of frequency 7.5E14 hz (FL).

For every 7E14 cycles of that light, the source emits a short beep of sound.
The Beep frequency is 1 second.

A detector at rest with the source and some distance away counts the beeps and
correctly calculates the frequency of the emitted light to be FL.

Next, the detector is set in motion towards the source at half the velocity of
sound. The received beep frequency increases to double its previous value, ie.,
to 2Fs.

This implies that the detector is now receiving twice the number of light
cycles per second as it did when at rest. In other words the light appears to
have been doppler shifted to double its frequency in the source frame.

Q) What is the colour of the light seen by an observer moving with the
detector?

Too obvious.
You are more funny when you don't try.
Like when you say:
"A small hot star reflecting off a very large orbiting WCH could
easily result in two different spectra, B and K, shifted 180 out
of phase."

THAT's funny.

Paul Mays wrote:
"Bryan Olson" <fakeaddr...@nowhere.org> wrote in message
news:u2fRj.12268$GE1.8109@nlpi061.nbdc.sbc.com...
rbwinn wrote:
Bryan Olson wrote:
rbwinn wrote:
Tom Roberts wrote:
rbwinn wrote:
The speed of sound is only 1,087 feet per second. ?Half of that
would
only be 543.5 feet per second. ?That is not fast enough to change
the
frequency of the light enough to worry about.
Sure it is! This is how police radar and laser guns measure the speed
of
traffic, and they do so for motions ~100 times smaller. A laboratory
instrument could measure speed thousands of times better than that.
Radar does not change frequency. �It is reflected from a target at the
same frequency it had before.
Dude, just look it up.
I used to work on radar. �A transmitter sends out a signal, a receiver
picks up a signal reflected from a target. �Unless the books about
radar the Navy gave us were incorrect, there is no appreciable
difference in frequency of the signals. �There is a carrier wave of
constant frequency which is reflected from targets and received by a
radar receiver at the same frequency. �The information concerning
targets is in the form of modulation of the carrier wave caused by the
reflection. �Doppler radar works the same way. �The carrier wave has
the same frequency whether being transmitted or received. �What shows
the Doppler effect used to calculate speed are modulations of the
carrier wave.
Dude, look it up already.

That's a suggestion. I realize I've no authority to command you to do
anything.

I will point out that "look it up" does *not* mean ramble on about
what you think you know.

Given modern tools, how hard is it to check out whether Tom Roberts is
right in saying that Doppler shift "is how police radar" works, or
whether R. B. Winn is right that radar "is reflected from a target at
the same frequency it had before"? I'd say: not hard. I was pretty
confident I knew the answer, but I looked it up anyway; checked
multiple sources just to be sure. Took roughly three minutes.

You are both correct so shake hands and come out fighting!

You lost me. I hold, I believe in agreement with Tom, that radar
reflected from a moving target is Doppler shifted from the
transmitted frequency, and the working of police radar is based on
that phenomenon. Robert claimed:

� �Radar does not change frequency. �It is reflected from a target
� �at the same frequency it had before.

We cannot both be right.

For example the Hawk system uses a system called Hi-Par / Low-Par
acquisition and tracking radar. which is a dual freq system using low freq
for acquisition and a higher freq once target is acquired. Both are
non-doppler
but several other systems such as the ones used by police and several
mapping
systems uses a doppler shift system.

None of those are at issue except the police system.

On Apr 28, 6:17 pm, rbwinn <rbwi...@juno.com> wrote:





On Apr 28, 2:43 pm, PD <TheDraperFam...@gmail.com> wrote:

On Apr 28, 12:32 am, rbwinn <rbwi...@juno.com> wrote:

On Apr 27, 6:16 pm, Bryan Olson <fakeaddr...@nowhere.org> wrote:

rbwinn wrote:
Tom Roberts wrote:
rbwinn wrote:
The speed of sound is only 1,087 feet per second. �Half of that would
only be 543.5 feet per second. �That is not fast enough to change the
frequency of the light enough to worry about.
Sure it is! This is how police radar and laser guns measure the speed of
traffic, and they do so for motions ~100 times smaller. A laboratory
instrument could measure speed thousands of times better than that.

Radar does not change frequency.  It is reflected from a target at the
same frequency it had before.

Dude, just look it up.

I used to work on radar.

One application, yes. You might want to look up Doppler radar, which
meteorologists use to look for differential velocity of moist air
masses, which would be a signal for rotation, a possible tornado. This
is a little different use of radar than ranging radar, which you might
have used in Vietnam.

So are you saying that Doppler radar is top secret, and you cannot
explain it, or what?

It's not hard. Do you need a pointer for where to look it up to read
more? I can provide that. Or are you going to do more of your open-
mouthed "Feed me!" whining?

PD

Well, PD, all you are saying is that you are an important person, and

On Apr 28, 8:18�pm, Bryan Olson <fakeaddr...@nowhere.org> wrote:



Paul Mays wrote:
"Bryan Olson" <fakeaddr...@nowhere.org> wrote in message
news:u2fRj.12268$GE1.8109@nlpi061.nbdc.sbc.com...
rbwinn wrote:
Bryan Olson wrote:
rbwinn wrote:
Tom Roberts wrote:
rbwinn wrote:
The speed of sound is only 1,087 feet per second. ?Half of that
would
only be 543.5 feet per second. ?That is not fast enough to change
the
frequency of the light enough to worry about.
Sure it is! This is how police radar and laser guns measure the speed
of
traffic, and they do so for motions ~100 times smaller. A laboratory
instrument could measure speed thousands of times better than that.
Radar does not change frequency. �It is reflected from a target at the
same frequency it had before.
Dude, just look it up.
I used to work on radar. �A transmitter sends out a signal, a receiver
picks up a signal reflected from a target. �Unless the books about
radar the Navy gave us were incorrect, there is no appreciable
difference in frequency of the signals. �There is a carrier wave of
constant frequency which is reflected from targets and received by a
radar receiver at the same frequency. �The information concerning
targets is in the form of modulation of the carrier wave caused by the
reflection. �Doppler radar works the same way. �The carrier wave has
the same frequency whether being transmitted or received. �What shows
the Doppler effect used to calculate speed are modulations of the
carrier wave.
Dude, look it up already.

That's a suggestion. I realize I've no authority to command you to do
anything.

I will point out that "look it up" does *not* mean ramble on about
what you think you know.

Given modern tools, how hard is it to check out whether Tom Roberts is
right in saying that Doppler shift "is how police radar" works, or
whether R. B. Winn is right that radar "is reflected from a target at
the same frequency it had before"? I'd say: not hard. I was pretty
confident I knew the answer, but I looked it up anyway; checked
multiple sources just to be sure. Took roughly three minutes.

You are both correct so shake hands and come out fighting!

You lost me. I hold, I believe in agreement with Tom, that radar
reflected from a moving target is Doppler shifted from the
transmitted frequency, and the working of police radar is based on
that phenomenon. Robert claimed:

� �Radar does not change frequency. �It is reflected from a target
� �at the same frequency it had before.

We cannot both be right.

For example the Hawk system uses a system called Hi-Par / Low-Par
acquisition and tracking radar. which is a dual freq system using low freq
for acquisition and a higher freq once target is acquired. Both are
non-doppler
but several other systems such as the ones used by police and several
mapping
systems uses a doppler shift system.

None of those are at issue except the police system.

All of the radar I worked on had a carrier wave at constant
frequency.  The carrier wave was modulated by the wave being reflected
from targets.
Robert B. Winn

On Apr 28, 10:43 pm, PD <TheDraperFam...@gmail.com> wrote:

On Apr 28, 6:17 pm, rbwinn <rbwi...@juno.com> wrote:

On Apr 28, 2:43 pm, PD <TheDraperFam...@gmail.com> wrote:

On Apr 28, 12:32 am, rbwinn <rbwi...@juno.com> wrote:

On Apr 27, 6:16 pm, Bryan Olson <fakeaddr...@nowhere.org> wrote:

rbwinn wrote:
Tom Roberts wrote:
rbwinn wrote:
The speed of sound is only 1,087 feet per second. �Half of that would
only be 543.5 feet per second. �That is not fast enough to change the
frequency of the light enough to worry about.
Sure it is! This is how police radar and laser guns measure the speed of
traffic, and they do so for motions ~100 times smaller. A laboratory
instrument could measure speed thousands of times better than that.

Radar does not change frequency.  It is reflected from a target at the
same frequency it had before.

Dude, just look it up.

I used to work on radar.

One application, yes. You might want to look up Doppler radar, which
meteorologists use to look for differential velocity of moist air
masses, which would be a signal for rotation, a possible tornado. This
is a little different use of radar than ranging radar, which you might
have used in Vietnam.

So are you saying that Doppler radar is top secret, and you cannot
explain it, or what?

It's not hard. Do you need a pointer for where to look it up to read
more? I can provide that. Or are you going to do more of your open-
mouthed "Feed me!" whining?

PD

Well, PD, all you are saying is that you are an important person, and
are too good to converse with the common people.

 That is the basic
problem that scientists have and why they will become more and more
irrelevant as time continues to pass.  

What I see happening with you
is that you become increasingly gun shy with every conversation
because you make mistakes like calculating t' from the Lorentz
equations at a velocity of .9c wrong.  

After a while you have nothing
to say except that you are too good to carry on a conversation.  OK,
you are too good to carry on a conversation.  But trying to carry on a
conversation with you is like trying to carry on a conversation with a
parrot anyway.  You have some phrases you have learned that you repeat
over and over.  Other than that you do not say much.

On Apr 29, 6:46 am, rbwinn <rbwi...@juno.com> wrote:





On Apr 28, 10:43 pm, PD <TheDraperFam...@gmail.com> wrote:

On Apr 28, 6:17 pm, rbwinn <rbwi...@juno.com> wrote:

On Apr 28, 2:43 pm, PD <TheDraperFam...@gmail.com> wrote:

On Apr 28, 12:32 am, rbwinn <rbwi...@juno.com> wrote:

On Apr 27, 6:16 pm, Bryan Olson <fakeaddr...@nowhere.org> wrote:

rbwinn wrote:
Tom Roberts wrote:
rbwinn wrote:
The speed of sound is only 1,087 feet per second. �Half of that would
only be 543.5 feet per second. �That is not fast enough to change the
frequency of the light enough to worry about.
Sure it is! This is how police radar and laser guns measure the speed of
traffic, and they do so for motions ~100 times smaller. A laboratory
instrument could measure speed thousands of times better than that.

Radar does not change frequency.  It is reflected from a target at the
same frequency it had before.

Dude, just look it up.

I used to work on radar.

One application, yes. You might want to look up Doppler radar, which
meteorologists use to look for differential velocity of moist air
masses, which would be a signal for rotation, a possible tornado. This
is a little different use of radar than ranging radar, which you might
have used in Vietnam.

So are you saying that Doppler radar is top secret, and you cannot
explain it, or what?

It's not hard. Do you need a pointer for where to look it up to read
more? I can provide that. Or are you going to do more of your open-
mouthed "Feed me!" whining?

PD

Well, PD, all you are saying is that you are an important person, and
are too good to converse with the common people.

Sorry, not my intent at all. However, there are certainly
opportunities, especially on an internet-based medium, where it makes
more sense to link to other internet resources than it does to retype
them all into a newsgroup post. I realize that you probably would like
to have it all retyped into a newsgroup post, but I don't think you
should regard it as stuffy if people don't necessarily follow your
wishes.

 That is the basic
problem that scientists have and why they will become more and more
irrelevant as time continues to pass.  

Well, that's all the more reason for you to spend your time on a sci
newsgroup, isn't it? Are you spending any time on the Aztec newsgroup?
They're even more irrelevant than science newsgroups.

What I see happening with you
is that you become increasingly gun shy with every conversation
because you make mistakes like calculating t' from the Lorentz
equations at a velocity of .9c wrong.  

What mistake. I recall you've made two so far.

After a while you have nothing
to say except that you are too good to carry on a conversation.  OK,
you are too good to carry on a conversation.  But trying to carry on a
conversation with you is like trying to carry on a conversation with a
parrot anyway.  You have some phrases you have learned that you repeat
over and over.  Other than that you do not say much.

Well, it's true that I don't put what you want on a spoon and drop it
into your open mouth.

On Apr 29, 5:54 am, PD <TheDraperFam...@gmail.com> wrote:



On Apr 29, 6:46 am, rbwinn <rbwi...@juno.com> wrote:

On Apr 28, 10:43 pm, PD <TheDraperFam...@gmail.com> wrote:

On Apr 28, 6:17 pm, rbwinn <rbwi...@juno.com> wrote:

On Apr 28, 2:43 pm, PD <TheDraperFam...@gmail.com> wrote:

On Apr 28, 12:32 am, rbwinn <rbwi...@juno.com> wrote:

On Apr 27, 6:16 pm, Bryan Olson <fakeaddr...@nowhere.org> wrote:

rbwinn wrote:
Tom Roberts wrote:
rbwinn wrote:
The speed of sound is only 1,087 feet per second. �Half of that would
only be 543.5 feet per second. �That is not fast enough to change the
frequency of the light enough to worry about.
Sure it is! This is how police radar and laser guns measure the speed of
traffic, and they do so for motions ~100 times smaller. A laboratory
instrument could measure speed thousands of times better than that.

Radar does not change frequency.  It is reflected from a target at the
same frequency it had before.

Dude, just look it up.

I used to work on radar.

One application, yes. You might want to look up Doppler radar, which
meteorologists use to look for differential velocity of moist air
masses, which would be a signal for rotation, a possible tornado.. This
is a little different use of radar than ranging radar, which you might
have used in Vietnam.

So are you saying that Doppler radar is top secret, and you cannot
explain it, or what?

It's not hard. Do you need a pointer for where to look it up to read
more? I can provide that. Or are you going to do more of your open-
mouthed "Feed me!" whining?

PD

Well, PD, all you are saying is that you are an important person, and
are too good to converse with the common people.

Sorry, not my intent at all. However, there are certainly
opportunities, especially on an internet-based medium, where it makes
more sense to link to other internet resources than it does to retype
them all into a newsgroup post. I realize that you probably would like
to have it all retyped into a newsgroup post, but I don't think you
should regard it as stuffy if people don't necessarily follow your
wishes.

 That is the basic
problem that scientists have and why they will become more and more
irrelevant as time continues to pass.  

Well, that's all the more reason for you to spend your time on a sci
newsgroup, isn't it? Are you spending any time on the Aztec newsgroup?
They're even more irrelevant than science newsgroups.

What I see happening with you
is that you become increasingly gun shy with every conversation
because you make mistakes like calculating t' from the Lorentz
equations at a velocity of .9c wrong.  

What mistake. I recall you've made two so far.

After a while you have nothing
to say except that you are too good to carry on a conversation.  OK,
you are too good to carry on a conversation.  But trying to carry on a
conversation with you is like trying to carry on a conversation with a
parrot anyway.  You have some phrases you have learned that you repeat
over and over.  Other than that you do not say much.

Well, it's true that I don't put what you want on a spoon and drop it
into your open mouth.

You scientists do not say much of anything to me because I am good at
catching your mistakes.

 What I usually do after all scientists are in
silent mode is just go into another topic and make a statement that
will get scientists riled up like saying that radar has a carrier wave
of constant frequency.  Totally irrelevant to anything being discussed
before,

but it gives scientists confidence once again to attack.
Robert B. Winn

On Tue, 29 Apr 2008 01:54:09 +0200, "Paul B. Andersen"
paul.b.andersen@guesswhatuia.no> wrote:

Dr. Henri Wilson skrev:
What I am going to do is use sound to measure the doppler shift of light.

This is the set up.

S is a monochromatic light source, emitting light of frequency 7.5E14 hz (FL).

For every 7E14 cycles of that light, the source emits a short beep of sound.
The Beep frequency is 1 second.

A detector at rest with the source and some distance away counts the beeps and
correctly calculates the frequency of the emitted light to be FL.

Next, the detector is set in motion towards the source at half the velocity of
sound. The received beep frequency increases to double its previous value, ie.,
to 2Fs.

This implies that the detector is now receiving twice the number of light
cycles per second as it did when at rest. In other words the light appears to
have been doppler shifted to double its frequency in the source frame.

Q) What is the colour of the light seen by an observer moving with the
detector?
Too obvious.
You are more funny when you don't try.
Like when you say:
"A small hot star reflecting off a very large orbiting WCH could
easily result in two different spectra, B and K, shifted 180 out
of phase."

THAT's funny.

Maybe you didn't understand that the small hot star is the B and the reflected
light might that from a K.

Do you still want to argue about the phase difference?

On Apr 29, 9:14 am, rbwinn <rbwi...@juno.com> wrote:





On Apr 29, 5:54 am, PD <TheDraperFam...@gmail.com> wrote:

On Apr 29, 6:46 am, rbwinn <rbwi...@juno.com> wrote:

On Apr 28, 10:43 pm, PD <TheDraperFam...@gmail.com> wrote:

On Apr 28, 6:17 pm, rbwinn <rbwi...@juno.com> wrote:

On Apr 28, 2:43 pm, PD <TheDraperFam...@gmail.com> wrote:

On Apr 28, 12:32 am, rbwinn <rbwi...@juno.com> wrote:

On Apr 27, 6:16 pm, Bryan Olson <fakeaddr...@nowhere.org> wrote:

rbwinn wrote:
Tom Roberts wrote:
rbwinn wrote:
The speed of sound is only 1,087 feet per second. �Half of that would
only be 543.5 feet per second. �That is not fast enough to change the
frequency of the light enough to worry about.
Sure it is! This is how police radar and laser guns measure the speed of
traffic, and they do so for motions ~100 times smaller. A laboratory
instrument could measure speed thousands of times better than that.

Radar does not change frequency.  It is reflected from a target at the
same frequency it had before.

Dude, just look it up.

I used to work on radar.

One application, yes. You might want to look up Doppler radar, which
meteorologists use to look for differential velocity of moist air
masses, which would be a signal for rotation, a possible tornado. This
is a little different use of radar than ranging radar, which you might
have used in Vietnam.

So are you saying that Doppler radar is top secret, and you cannot
explain it, or what?

It's not hard. Do you need a pointer for where to look it up to read
more? I can provide that. Or are you going to do more of your open-
mouthed "Feed me!" whining?

PD

Well, PD, all you are saying is that you are an important person, and
are too good to converse with the common people.

Sorry, not my intent at all. However, there are certainly
opportunities, especially on an internet-based medium, where it makes
more sense to link to other internet resources than it does to retype
them all into a newsgroup post. I realize that you probably would like
to have it all retyped into a newsgroup post, but I don't think you
should regard it as stuffy if people don't necessarily follow your
wishes.

 That is the basic
problem that scientists have and why they will become more and more
irrelevant as time continues to pass.  

Well, that's all the more reason for you to spend your time on a sci
newsgroup, isn't it? Are you spending any time on the Aztec newsgroup?
They're even more irrelevant than science newsgroups.

What I see happening with you
is that you become increasingly gun shy with every conversation
because you make mistakes like calculating t' from the Lorentz
equations at a velocity of .9c wrong.  

What mistake. I recall you've made two so far.

After a while you have nothing
to say except that you are too good to carry on a conversation.  OK,
you are too good to carry on a conversation.  But trying to carry on a
conversation with you is like trying to carry on a conversation with a
parrot anyway.  You have some phrases you have learned that you repeat
over and over.  Other than that you do not say much.

Well, it's true that I don't put what you want on a spoon and drop it
into your open mouth.

You scientists do not say much of anything to me because I am good at
catching your mistakes.

Uh-huh, keep telling yourself that.

I stop saying much when you tell me you refuse to look at links to
experimental data. This tells me that you aren't really interested in
the physics, and you're more interested in seeing how much you can get
scientists to type into a newsgroup post for you, whether you're
interested in it or not.

Now, you can make up whatever you want about that. You usually do.

 What I usually do after all scientists are in
silent mode is just go into another topic and make a statement that
will get scientists riled up like saying that radar has a carrier wave
of constant frequency.  Totally irrelevant to anything being discussed
before,

Well, you also said that radar doesn't use any frequency variation in
radar applications, which is wrong. So as well as being irrelevant,
it's wrong. And if you're doing it to get scientists riled up, that's
trolling.

So if you're telling me that what you do is post irrelevant, wrong,
trolling posts, then I guess I'd probably go along with that.

YOU are indeed hilarious....even moreso when you are trying to extricate
yourself from an embarrassing situation.

Henri Wilson. ASTC,BSc,DSc(T)www.users.bigpond.com/hewn/index.htm

....specialising in teaching physics to engineers and mathematicians....