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

Ralph Rabbidge, you're not even able to go to bathroom alone...

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

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.

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.

(Henri's "riddle" is utterly ridiculous, and shows how deep are his
misunderstandings of very basic physics.)

Tom Roberts

On Apr 26, 6:06?pm, HW@....(Dr. Henri Wilson) wrote:
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? ?

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

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

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.

Robert B. Winn

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.

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.

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

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.

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.

On Apr 27, 9:32 pm, 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.

Not in any capacity relevant to the discussion since the phrase
"Doppler shift" means nothing to you and you admit not knowing about
Maxwell's equations.

You confuse "working on radar" with "I was handed a black box and told
how to use it when I was in the Navy".

No, I was not handed a black box. I was assigned to repair old World

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.

--
--Bryan- Hide quoted text -

- Show quoted text -

"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.

--
--Bryan

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.

--http://fast.filespace.org/PaulRMays/Postulate.pdf

--
Paul R. Mays
"I Believe in Nothing, I Know, I think I Know or I Do Not Know
�I Never Believe... For to Believe is a Religious Incantation"- Hide quoted text -

- Show quoted text -

"rbwinn" <rbwi...@juno.com> wrote in message

news:be25c1d1-9e02-4d9b-9b89-827941bb3606@a1g2000hsb.googlegroups.com...
On Apr 28, 9:05?am, "Paul Mays" <Pa...@Mays.com> 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.

--
--Bryan

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.

--http://fast.filespace.org/PaulRMays/Postulate.pdf

--
Paul R. Mays
"I Believe in Nothing, I Know, I think I Know or I Do Not Know
?I Never Believe... For to Believe is a Religious Incantation"- Hide
quoted text -

- Show quoted text -

Well, the ones I worked on transmitted and received on the same
frequency.
Robert B. Winn

I got that but you seemed to argue thats the way they all work.
thats just not the case. Theres even systems that do both at the
same time. Use a modulated carrier and detect the freq shift
of the subset freq and time measure the carrier. This is really good
way to target war heads with precicion.