Radio waves faster than light
 

Radio waves faster than light
 

Jim Lux wrote:
wrote:
Szczepan Bialek wrote:
"Cecil Moore" napisal w wiadomosci
...
On Mar 14, 3:02 am, "Szczepan Bialek" wrote:
In todays textbooks is wrote that speed of light is frequency dependent
(glass prism).
The same is in air (atmosphere). Why the heliosphere is different?
The difference of which you speak is very small. The atmosphere is
about 0.27 % of the total distance between the earth and the moon.
0.27% of "very small" would be very, very small.

But heliosphere reach the last planet (at least).
S*

Yeah, and what is the density, refractive index, permeability, and
permittivity of the helioshpere, you babbling moron?



Hmm, without getting into the ad hominem attacks here..

This kind of thing is well documented. I'd start by downloading the
"Plasma Physics Handbook" from the Naval Research Lab. It has a nice
summary of all the relevant equations and typical values.

A quick google for "interplanetary EM propagation dispersion" turns up
plenty of references.

Again, though, it's very, very small (parts in 1E12 kind of small).. but
big enough to be of interest to scientists who measure such things. It
would be the ambitious amateur who could make a measurement of the
required precision, but it is doable. Several spacecraft transmit
simultaneous tones generated from a common high quality reference.
Working out and removing the effects of the Earth's ionosphere and
atmosphere are probably the biggest challenge.

Yeah, you know that and I know that, but the babbling moron that continues
to post his mindless gibberish refererenced to something written 150 years
ago doesn't know that.


--
Jim Pennino

Remove .spam.sux to reply.

Radio waves faster than light
 

On 3/14/2011 3:04 PM, Jim Lux wrote:

Not precisely true. Interplanetary space slightly dispersive. Emphasis
on *slightly*.

Kenelm Philip predicted a difference back in 1957

Modern estimates for electron density in interplanetary space of 1E6 to
1E10 per cubic meter.

dTau = e^2*Ne*L/(2*pi*m*c) * (1/f1^2 - 1/f2^2)

e= charge on an electron 1E-18 Coulomb
m = mass of an electron at rest (9.11E-31 kg)
c = velocity of light (3E8 m/s)
L = propagation distance
Ne = electron density (pick a number between 1E6 and 1E10)

f1 and f2 are the frequencies (in Hz) (assumed relatively closely spaced)

To bound the magnitudes.. for 1000 light year and 1 and 2 GHz, the
dispersion is about 1 nanosecond.


-- if you're interested in optical as opposed to RF
http://ipnpr.jpl.nasa.gov/progress_report/42-65/65I.PDF

For his idea of how things work I was plenty close enough. He's
thinking in digits of percent.

tom
K0TAR

Radio waves faster than light
 

On 3/14/2011 3:04 PM, Jim Lux wrote:

Not precisely true. Interplanetary space slightly dispersive. Emphasis
on *slightly*.

Kenelm Philip predicted a difference back in 1957

Modern estimates for electron density in interplanetary space of 1E6 to
1E10 per cubic meter.

dTau = e^2*Ne*L/(2*pi*m*c) * (1/f1^2 - 1/f2^2)

e= charge on an electron 1E-18 Coulomb
m = mass of an electron at rest (9.11E-31 kg)
c = velocity of light (3E8 m/s)
L = propagation distance
Ne = electron density (pick a number between 1E6 and 1E10)

f1 and f2 are the frequencies (in Hz) (assumed relatively closely spaced)

To bound the magnitudes.. for 1000 light year and 1 and 2 GHz, the
dispersion is about 1 nanosecond.


-- if you're interested in optical as opposed to RF
http://ipnpr.jpl.nasa.gov/progress_report/42-65/65I.PDF

Thanks for the link. Very nice, concise. Actually wasted some paper on it.

And I doubt sb has a hint of a clue concerning it. He'll probably think
it supports his twisted view of things.

I used to think he was a troll. I am now convinced that I was incorrect
and that the ad hominum attacks are probably deserved. Sometimes they
are the correct approach and produce results. See politics (both sides)
and national news (all) for examples.

tom
K0TAR

Radio waves faster than light
 

Uzytkownik "Jim Lux" napisal w wiadomosci
...
Speed of light in space is known thanks Roemer.s method. Now are radio
transmitters on the Mars and is possibility to use the Roemer's method
for radio waves. NASA know the results. Are thy pulished?


Of course, they're published. Widely. I would check Journal of
Geophysical Research or similar publications.

As a practical matter, precise measurements of the time of flight to/from
a spacecraft is used to figure out where the spacecraft is and its radial
velocity.

Typical range accuracy is on the order of a few meters, velocities good to
a few cm/s, for something at the orbit of Neptune or Uranus.

Precise doppler measurements are used for radio science experiments, e.g.
to determine the internal structure of a planet or moon by precisely
measuring the orbit of a satellite. A typical performance for such a
measurement is 1 part in 1E15 over 1000 seconds at 32 GHz or 8GHz.

Roemer's method is the one way measurement. See:
http://www.mathpages.com/home/kmath203/kmath203.htm

We know where Jovian is so the one way measurement is possible. With
spacecraft it is impossible.
Lately the one way is possible with the Mars. But independently for radio
waves and light. Mars has the satellite and radio transmitter.

In next your post is Table 1 and Fig 2. There are electrons density and
temperature. Speed of waves is temperature dependent.

Roemer's method is able to measure the speed of light in different region of
Solar system. Before me Maxwell was interested in this: "Incidentally,
Maxwell once suggested that Roemer's method could be used to test for the
isotropy of light speed, i.e., to test whether the speed of light is the
same in all directions. Roemer's method can be regarded as a means of
measuring the speed of light in the direction from Jupiter to the Earth.
Jupiter has an orbital period of about 12 years, so if we use Roemer's
method to evaluate the speed of light several times over a 12 year period,
we will be evaluating the speed in all possible directions (in the plane of
the ecliptic). "

It is interesting that Roemer has measured 220 000 km/s.
S*

Radio waves faster than light
 

On Tue, 15 Mar 2011 09:53:41 +0100, Szczepan Bialek rearranged some
electrons to say:


It is interesting that Roemer has measured 220 000 km/s. S*

Why is that interesting? He was wrong.

Radio waves faster than light
 

Velocity is delta-length divided by delta-time. The length of a meter
depends upon the velocity and orientation of the meter stick. The
length of a second depends upon the velocity of the clock. Are we sure
that the velocity of light is a *universal* constant or is it just a
conceptual stake in the ground to try to keep everything in the
universe from being relative to something else?
--
73, Cecil, w5dxp.com

Radio waves faster than light
 

" napisa³ w wiadomo¶ci
...
On Tue, 15 Mar 2011 09:53:41 +0100, Szczepan Bialek rearranged some
electrons to say:


It is interesting that Roemer has measured 220 000 km/s. S*

Why is that interesting? He was wrong.

From the same data Newton calculated 310 000 km/s. But it was for the Earth
the Sun (the hottest region).
Roemer's method measures speeds of light in different regions of the Solar
System.

Cecil wrote: "Are we sure that the velocity of light is a ".

"c" is the *universal* constant in EM (calculating factors between different
units).

"velocity of light" is the medium and temperature dependent.
S*

Radio waves faster than light
 

Szczepan Bialek wrote:
Uzytkownik "Jim Lux" napisal w wiadomosci
...
Speed of light in space is known thanks Roemer.s method. Now are radio
transmitters on the Mars and is possibility to use the Roemer's method
for radio waves. NASA know the results. Are thy pulished?

Of course, they're published. Widely. I would check Journal of
Geophysical Research or similar publications.

As a practical matter, precise measurements of the time of flight to/from
a spacecraft is used to figure out where the spacecraft is and its radial
velocity.

Typical range accuracy is on the order of a few meters, velocities good to
a few cm/s, for something at the orbit of Neptune or Uranus.

Precise doppler measurements are used for radio science experiments, e.g.
to determine the internal structure of a planet or moon by precisely
measuring the orbit of a satellite. A typical performance for such a
measurement is 1 part in 1E15 over 1000 seconds at 32 GHz or 8GHz.

Roemer's method is the one way measurement. See:
http://www.mathpages.com/home/kmath203/kmath203.htm

We know where Jovian is so the one way measurement is possible. With
spacecraft it is impossible.

not true. We do one way measurements from spacecraft all the time. A
high quality oscillator (aka USO)is used to generate a set of phase
coherent signals at different frequencies.

Look at PN ranging or Sequential Ranging.

Lately the one way is possible with the Mars. But independently for radio
waves and light. Mars has the satellite and radio transmitter.

As do Jupiter, Saturn, and outer planets

Radio waves faster than light
 

Szczepan Bialek wrote:

" napisa? w wiadomo?ci
...
On Tue, 15 Mar 2011 09:53:41 +0100, Szczepan Bialek rearranged some
electrons to say:


It is interesting that Roemer has measured 220 000 km/s. S*

Why is that interesting? He was wrong.

From the same data Newton calculated 310 000 km/s. But it was for the Earth
the Sun (the hottest region).

Newton died almost 300 years ago and we have much better data since then, you
babbling idiot.



--
Jim Pennino

Remove .spam.sux to reply.

Radio waves faster than light
 

U¿ytkownik napisa³ w wiadomo¶ci
...
Szczepan Bialek wrote:

" napisa? w wiadomo?ci
...
On Tue, 15 Mar 2011 09:53:41 +0100, Szczepan Bialek rearranged some
electrons to say:


It is interesting that Roemer has measured 220 000 km/s. S*

Why is that interesting? He was wrong.

From the same data Newton calculated 310 000 km/s. But it was for the
Earth
the Sun (the hottest region).

Newton died almost 300 years ago and we have much better data since then,
you
babbling idiot.

You have? Where I can find them?
S*



--
Jim Pennino

Remove .spam.sux to reply.

Radio waves faster than light
 

"Jim Lux" napisal w wiadomosci
...
Szczepan Bialek wrote:
Uzytkownik "Jim Lux" napisal w wiadomosci
...
Speed of light in space is known thanks Roemer.s method. Now are radio
transmitters on the Mars and is possibility to use the Roemer's method
for radio waves. NASA know the results. Are thy pulished?

Of course, they're published. Widely. I would check Journal of
Geophysical Research or similar publications.

As a practical matter, precise measurements of the time of flight
to/from a spacecraft is used to figure out where the spacecraft is and
its radial velocity.

Typical range accuracy is on the order of a few meters, velocities good
to a few cm/s, for something at the orbit of Neptune or Uranus.

Precise doppler measurements are used for radio science experiments,
e.g. to determine the internal structure of a planet or moon by
precisely measuring the orbit of a satellite. A typical performance for
such a measurement is 1 part in 1E15 over 1000 seconds at 32 GHz or
8GHz.

Roemer's method is the one way measurement. See:
http://www.mathpages.com/home/kmath203/kmath203.htm

We know where Jovian is so the one way measurement is possible. With
spacecraft it is impossible.

not true. We do one way measurements from spacecraft all the time. A high
quality oscillator (aka USO)is used to generate a set of phase coherent
signals at different frequencies.

Look at PN ranging or Sequential Ranging.

But the Mars is the best. Are available data for the Mars?

Lately the one way is possible with the Mars. But independently for radio
waves and light. Mars has the satellite and radio transmitter.

As do Jupiter, Saturn, and outer planets

"The Rocky Planets a
a.. Mercury
b.. Venus
c.. Earth
d.. Mars


The Gaseous Planets a
a.. Jupiter
b.. Saturn
c.. Uranus
d.. Neptune"
S*

Radio waves faster than light
 

Szczepan Bialek wrote:

U?ytkownik napisa? w wiadomo?ci
...
Szczepan Bialek wrote:

" napisa? w wiadomo?ci
...
On Tue, 15 Mar 2011 09:53:41 +0100, Szczepan Bialek rearranged some
electrons to say:


It is interesting that Roemer has measured 220 000 km/s. S*

Why is that interesting? He was wrong.

From the same data Newton calculated 310 000 km/s. But it was for the
Earth
the Sun (the hottest region).

Newton died almost 300 years ago and we have much better data since then,
you
babbling idiot.

You have? Where I can find them?
S*

In stuff written recently, you babbling moron.


--
Jim Pennino

Remove .spam.sux to reply.

Radio waves faster than light
 

Szczepan Bialek wrote:

"Jim Lux" napisal w wiadomosci
...
Szczepan Bialek wrote:
Uzytkownik "Jim Lux" napisal w wiadomosci
...
Speed of light in space is known thanks Roemer.s method. Now are radio
transmitters on the Mars and is possibility to use the Roemer's method
for radio waves. NASA know the results. Are thy pulished?

Of course, they're published. Widely. I would check Journal of
Geophysical Research or similar publications.

As a practical matter, precise measurements of the time of flight
to/from a spacecraft is used to figure out where the spacecraft is and
its radial velocity.

Typical range accuracy is on the order of a few meters, velocities good
to a few cm/s, for something at the orbit of Neptune or Uranus.

Precise doppler measurements are used for radio science experiments,
e.g. to determine the internal structure of a planet or moon by
precisely measuring the orbit of a satellite. A typical performance for
such a measurement is 1 part in 1E15 over 1000 seconds at 32 GHz or
8GHz.

Roemer's method is the one way measurement. See:
http://www.mathpages.com/home/kmath203/kmath203.htm

We know where Jovian is so the one way measurement is possible. With
spacecraft it is impossible.

not true. We do one way measurements from spacecraft all the time. A high
quality oscillator (aka USO)is used to generate a set of phase coherent
signals at different frequencies.

Look at PN ranging or Sequential Ranging.

But the Mars is the best. Are available data for the Mars?

Lately the one way is possible with the Mars. But independently for radio
waves and light. Mars has the satellite and radio transmitter.

As do Jupiter, Saturn, and outer planets

"The Rocky Planets a
a.. Mercury
b.. Venus
c.. Earth
d.. Mars


The Gaseous Planets a
a.. Jupiter
b.. Saturn
c.. Uranus
d.. Neptune"
S*

The babbling idiot is:
a.. Szczepan Bialek



--
Jim Pennino

Remove .spam.sux to reply.

Radio waves faster than light
 

Szczepan Bialek wrote:
"Jim Lux" napisal w wiadomosci
...
Szczepan Bialek wrote:
Uzytkownik "Jim Lux" napisal w wiadomosci
...
Speed of light in space is known thanks Roemer.s method. Now are radio
transmitters on the Mars and is possibility to use the Roemer's method
for radio waves. NASA know the results. Are thy pulished?

Of course, they're published. Widely. I would check Journal of
Geophysical Research or similar publications.

As a practical matter, precise measurements of the time of flight
to/from a spacecraft is used to figure out where the spacecraft is and
its radial velocity.

Typical range accuracy is on the order of a few meters, velocities good
to a few cm/s, for something at the orbit of Neptune or Uranus.

Precise doppler measurements are used for radio science experiments,
e.g. to determine the internal structure of a planet or moon by
precisely measuring the orbit of a satellite. A typical performance for
such a measurement is 1 part in 1E15 over 1000 seconds at 32 GHz or
8GHz.
Roemer's method is the one way measurement. See:
http://www.mathpages.com/home/kmath203/kmath203.htm

We know where Jovian is so the one way measurement is possible. With
spacecraft it is impossible.
not true. We do one way measurements from spacecraft all the time. A high
quality oscillator (aka USO)is used to generate a set of phase coherent
signals at different frequencies.

Look at PN ranging or Sequential Ranging.

But the Mars is the best. Are available data for the Mars?

I don't know why Mars would be the best..

But you might start with googling "ranging Mars radiometric" or
something like that.
Or the usual tracking down the papers thing starting with one that talks
about it, and will have references.
http://seismo.berkeley.edu/~manga/folkner.pdf might give a start.
One of the footnotes mentions Viking data at S-band.

Journal of Geophysical Research (aka JGR) is where a lot of this seems
to show up.

You could search for works by authors who do this kind of thing, too.
Folkner, Asmar, Oudrhiri, Iess, Armstrong are all worth searching for.
I'd do a search for the author name AND "ranging"



For more "raw data" try the NASA Planetary Data System archive
http://pds.nasa.gov/

You're going to be on your own to find the relevant data files. Try
"radio science" as a search term.

Radio waves faster than light
 

"Jim Lux" napisal w wiadomosci
...
Szczepan Bialek wrote:
"Jim Lux" napisal w wiadomosci

Speed of light in space is known thanks Roemer.s method. Now are
radio transmitters on the Mars and is possibility to use the Roemer's
method for radio waves. NASA know the results. Are they published?

Of course, they're published. Widely. I would check Journal of
Geophysical Research or similar publications.

As a practical matter, precise measurements of the time of flight
to/from a spacecraft is used to figure out where the spacecraft is and
its radial velocity.

Typical range accuracy is on the order of a few meters, velocities
good to a few cm/s, for something at the orbit of Neptune or Uranus.

Precise doppler measurements are used for radio science experiments,
e.g. to determine the internal structure of a planet or moon by
precisely measuring the orbit of a satellite. A typical performance
for such a measurement is 1 part in 1E15 over 1000 seconds at 32 GHz
or 8GHz.
Roemer's method is the one way measurement. See:
http://www.mathpages.com/home/kmath203/kmath203.htm

We know where Jovian is so the one way measurement is possible. With
spacecraft it is impossible.

not true. We do one way measurements from spacecraft all the time. A
high quality oscillator (aka USO)is used to generate a set of phase
coherent signals at different frequencies.

Look at PN ranging or Sequential Ranging.

But the Mars is the best. Are available data for the Mars?

I don't know why Mars would be the best..

Probably is possible to measure the optic signal from the Mars satellite. If
yes, we have the direct comparison light - radio waves.
Radio transmitter can be installed only on the Mars.

But you might start with googling "ranging Mars radiometric" or something
like that.
Or the usual tracking down the papers thing starting with one that talks
about it, and will have references.
http://seismo.berkeley.edu/~manga/folkner.pdf might give a start.
One of the footnotes mentions Viking data at S-band.

Journal of Geophysical Research (aka JGR) is where a lot of this seems to
show up.

You could search for works by authors who do this kind of thing, too.
Folkner, Asmar, Oudrhiri, Iess, Armstrong are all worth searching for. I'd
do a search for the author name AND "ranging"


For more "raw data" try the NASA Planetary Data System archive
http://pds.nasa.gov/

You're going to be on your own to find the relevant data files. Try "radio
science" as a search term.

For me will be enough your steatment if speed of light and radio waves were
measured in different regions of the Solar System.
Katz: http://ipnpr.jpl.nasa.gov/progress_report/42-65/65I.PDF
wrote that the electron temperatures are from 10^4 to 10^6. Look at Fig 2.
Place the Mars instead a spacecraft. Between (a) and (c) should be some
differences.

You wrote: " NASA knows the results. Are they published? Of course, they're
published. Widely."

What the conclusion are?
I do not need the quantitative data.
S*

Radio waves faster than light
 

Szczepan Bialek wrote:

But the Mars is the best. Are available data for the Mars?
I don't know why Mars would be the best..

Probably is possible to measure the optic signal from the Mars satellite. If
yes, we have the direct comparison light - radio waves.

I don't think that there is any way to "see" a satellite at Mars.
Perhaps if one did some sort of Moon/mars occultation?

Radio transmitter can be installed only on the Mars.

There are precision transmitters suitable for this kind of measurement
at many places in the Solar System.
You're going to be on your own to find the relevant data files. Try "radio
science" as a search term.


For me will be enough your steatment if speed of light and radio waves were
measured in different regions of the Solar System.
Katz: http://ipnpr.jpl.nasa.gov/progress_report/42-65/65I.PDF
wrote that the electron temperatures are from 10^4 to 10^6. Look at Fig 2.
Place the Mars instead a spacecraft. Between (a) and (c) should be some
differences.

You wrote: " NASA knows the results. Are they published? Of course, they're
published. Widely."

What the conclusion are?
I do not need the quantitative data.

I'll assert that propagation through interplanetary space is moderately
well understood and matches all modern models of electromagnetic behavior.

Radio waves faster than light
 

Jim Lux wrote:
Szczepan Bialek wrote:

But the Mars is the best. Are available data for the Mars?
I don't know why Mars would be the best..

Probably is possible to measure the optic signal from the Mars
satellite. If yes, we have the direct comparison light - radio waves.

I don't think that there is any way to "see" a satellite at Mars.
Perhaps if one did some sort of Moon/mars occultation?

Radio transmitter can be installed only on the Mars.

There are precision transmitters suitable for this kind of measurement
at many places in the Solar System.
You're going to be on your own to find the relevant data files. Try
"radio science" as a search term.


For me will be enough your steatment if speed of light and radio waves
were measured in different regions of the Solar System.
Katz: http://ipnpr.jpl.nasa.gov/progress_report/42-65/65I.PDF
wrote that the electron temperatures are from 10^4 to 10^6. Look at
Fig 2. Place the Mars instead a spacecraft. Between (a) and (c) should
be some differences.


Are you asking if the calculations in Katz's paper for the two paths
have been experimentally verified? I don't know..
Certainly he predicts that the temporal dispersion is going to be 0.1ps
for near IR, which is, shall we say, challenging to measure.

You wrote: " NASA knows the results. Are they published? Of course,
they're published. Widely."

What the conclusion are?
I do not need the quantitative data.

I'll assert that propagation through interplanetary space is moderately
well understood and matches all modern models of electromagnetic behavior.

Radio waves faster than light
 

On Thu, 17 Mar 2011 12:52:28 -0700, Jim Lux
wrote:

Certainly he predicts that the temporal dispersion is going to be 0.1ps
for near IR, which is, shall we say, challenging to measure.

Why?

73's
Richard Clark, KB7QHC

Radio waves faster than light
 

Richard Clark wrote:
On Thu, 17 Mar 2011 12:52:28 -0700, Jim Lux
wrote:

Certainly he predicts that the temporal dispersion is going to be 0.1ps
for near IR, which is, shall we say, challenging to measure.

Why?


measuring things to tenths of a picosecond, repeatably, can be tricky..
That's like measuring the phase difference between two 10 GHz signals
to 0.3 degrees. Or, another way to look at it is 1 picolightsecond is
about a third of a millimeter.

You're looking at
a) figuring out how to generate two signals at near IR that has a
frequency offset that can be accurately controlled. Probably some sort
of heterodyne mixing scheme would be easiest.
b) sending those two signals over the optical path through
interplanetary space.
c) recovering the signals, measuring the propagation time variation
(say, by looking at the phase difference between the modulation
signals), and then removing atmospheric effects.
d) it's probably going to be a pretty weak signal, so you'll need to
average. That means your measurement system has to be picosecond stable
over the averaging interval.

None of those steps are particularly simple or easy.

I've worked on systems to measure the (microwave) distance to Jupiter
and back with an accuracy of around 1 part in 1E15 at 32 GHz,
integrating over 1000 seconds. That's tenths of a picosecond out of 1000
seconds. It's challenging.

http://en.wikipedia.org/wiki/Juno_%28spacecraft%29
http://juno.wisc.edu/spacecraft_instruments_GSE.html

Radio waves faster than light
 

"Jim Lux" napisal w wiadomosci
...
Szczepan Bialek wrote:


For me will be enough your steatment if speed of light and radio waves
were measured in different regions of the Solar System.
Katz: http://ipnpr.jpl.nasa.gov/progress_report/42-65/65I.PDF
wrote that the electron temperatures are from 10^4 to 10^6. Look at Fig
2. Place the Mars instead a spacecraft. Between (a) and (c) should be
some differences.


Are you asking if the calculations in Katz's paper for the two paths have
been experimentally verified? I don't know..

They were verified because there is a radio transmitter on the Mars. We do
not know the results.
S*

Radio waves faster than light
 

On Thu, 17 Mar 2011 17:19:09 -0700, Jim Lux
wrote:

Certainly he predicts that the temporal dispersion is going to be 0.1ps
for near IR, which is, shall we say, challenging to measure.

Why?

measuring things to tenths of a picosecond, repeatably, can be tricky..
That's like measuring the phase difference between two 10 GHz signals
to 0.3 degrees. Or, another way to look at it is 1 picolightsecond is
about a third of a millimeter.

A third of a millimeter is no big deal and for an optical (or
sub-optical) signal - trivial. Perhaps, when stated in terms of two
10 GHz signals, "near IR" is being vastly over stated.

You're looking at
a) figuring out how to generate two signals at near IR that has a
frequency offset that can be accurately controlled.

Controlled? This is dreaming in technicolor (or near IR color) if the
source is celestial.

I thought the discussion was about dispersion, the characteristic of
the medium, not sources.

Probably some sort
of heterodyne mixing scheme would be easiest.

Heterodyning is extremely commonplace and accurate - why would it be
pondered as an alternative method?

b) sending those two signals over the optical path through
interplanetary space.

This blurs my understanding of celestial where two signals is a
poverty of what is available from ANY celestial source.

c) recovering the signals,

If there is a problem of recovery, it seems it is more a practical
matter of source selection. Given the billions of celestial sources
available, I don't understand the problem.

measuring the propagation time variation
(say, by looking at the phase difference between the modulation
signals), and then removing atmospheric effects.

Why worry about the atmosphere when you can get above it?

d) it's probably going to be a pretty weak signal, so you'll need to
average. That means your measurement system has to be picosecond stable
over the averaging interval.

OK, so I am lost. This laundry list of difficulties seems to be
prepared to anticipate failure.

Name the near IR source and defend its choice in light (no pun) of
these intractable difficulties.

None of those steps are particularly simple or easy.

I've worked on systems to measure the (microwave) distance to Jupiter
and back with an accuracy of around 1 part in 1E15 at 32 GHz,

32 GHz is what photonics would call far-far IR at roughly 3 to 4
orders of magnitude distant from "near IR."

integrating over 1000 seconds. That's tenths of a picosecond out of 1000
seconds. It's challenging.

No doubt - like trying to push a peanut up Pike's Peak with your nose.
That too has been done with challenge in mind.

How did this slip from "near IR" to 32 GHz?

73's
Richard Clark, KB7QHC

Radio waves faster than light
 

On 3/18/2011 1:16 PM, Richard Clark wrote:

How did this slip from "near IR" to 32 GHz?

Hello Richard!

I'm back, and I see the old neighborhood hasn't changed much, although I
haven't seen anything from Art - hopefully the chap hasn't had a bed turn.

Here is a question or two for those who have some doubt as to the speed
of light.

A probe recently inserted itself into orbit around Mercury. How does
some presumed superluminal velocity affect the insertion?

The idea that "we" have a transmitter on Mars notwithstanding, Jupiter
has been transmitting RF for a long time. There are enough other
spacecraft running around in our solar system, and certainly if radio
waves traveled at some other velocity than what we thought they did, it
would mean a strange and useless conspiracy to hide that fact.

Cue up the twilight zone music and grab your aluminum foil hats everyone.

- 73 de Mike N3LI -

Radio waves faster than light
 

"Mike Coslo" napisal w wiadomosci
...
On 3/18/2011 1:16 PM, Richard Clark wrote:

How did this slip from "near IR" to 32 GHz?

Hello Richard!

I'm back, and I see the old neighborhood hasn't changed much, although I
haven't seen anything from Art - hopefully the chap hasn't had a bed turn.

Here is a question or two for those who have some doubt as to the speed of
light.

A probe recently inserted itself into orbit around Mercury. How does some
presumed superluminal velocity affect the insertion?

The idea that "we" have a transmitter on Mars notwithstanding, Jupiter
has been transmitting RF for a long time. There are enough other
spacecraft running around in our solar system, and certainly if radio
waves traveled at some other velocity than what we thought they did,

Not we but you.

it would mean a strange and useless conspiracy to hide that fact.

Somebody wrote that the data from the Mars are available. But it is not easy
to find them.
S*

Radio waves faster than light
 

Szczepan Bialek wrote:

Somebody wrote that the data from the Mars are available. But it is not easy
to find them.
S*

Since data from Mars is less than 150 years ago I doubt you would read it
and I know you wouldn't understand it if you did.


--
Jim Pennino

Remove .spam.sux to reply.

Radio waves faster than light
 

On Sat, 19 Mar 2011 07:51:45 -0500, Mike Coslo wrote:

On 3/18/2011 1:16 PM, Richard Clark wrote:

How did this slip from "near IR" to 32 GHz?

Hello Richard!

Hello Mike,

Welcome back to the Land of Odds.

The idea that "we" have a transmitter on Mars notwithstanding, Jupiter
has been transmitting RF for a long time.

Jupiter was one of my first DX goals back in the early 60s. However,
to expand upon your offering (I was wondering when anyone would
mention these sources), Earth, too, is a natural RF source (to
distinguish from the unnatural - such as stations carrying Fox Noise).

Quoting Wikipedia on Jupiter (nothing much said of the other planets
other than Earth):
"The intensity of Jovian radio emissions usually varies smoothly with
time; however, Jupiter periodically emits short and powerful bursts (S
bursts), which can outshine all other components. The total emitted
power of the DAM component is about 100 GW, while the power of all
other HOM/KOM components is about 10 GW. In comparison, the total
power of Earth's radio emissions is about 0.1 GW."

("emissions in the range 3 to 40 MHz are referred to as the decametric
radiation or DAM")

This decametric radiation would put us (returning to my quoted
question above) another several orders of magnitude beneath "near IR"
and into the "frigid IR" (a distinct irony with temperatures hovering
in the hundredths of a degree K).

73's
Richard Clark, KB7QHC

Radio waves faster than light
 

On Mar 18, 11:16*am, Richard Clark wrote:
On Thu, 17 Mar 2011 17:19:09 -0700, Jim Lux
wrote:

Certainly he predicts that the temporal dispersion is going to be 0.1ps
for near IR, which is, shall we say, challenging to measure.

Why?
measuring things to tenths of a picosecond, repeatably, can be tricky..
* That's like measuring the phase difference between two 10 GHz signals
to *0.3 degrees. Or, another way to look at it is 1 picolightsecond is
about *a third of a millimeter.

A third of a millimeter is no big deal and for an optical (or
sub-optical) signal - trivial. *Perhaps, when stated in terms of two
10 GHz signals, "near IR" is being vastly over stated.

The reference to 10 GHz was to try and relate the problem at Near IR
to something more familiar (since I suspect that most r.r.a.a are more
familiar with RF than light) (since speed of *light* was being
discussed, and the reference cited referred to optical communications
at Near IR)




You're looking at
a) figuring out how to generate two signals at near IR that has a
frequency offset that can be accurately controlled. *

Controlled? *This is dreaming in technicolor (or near IR color) if the
source is celestial.

The figures in the referenced paper showed a manmade source,
presumably with some sort of source which could be designed to make
measuring dispersion easier.



I thought the discussion was about dispersion, the characteristic of
the medium, not sources.

Precisely.. but if you're going to measure dispersion, you've got to
have a way to do it, and sending out two signals that are coherent
with each other at a known offset seems to be a fairly straightforward
approach.


Probably some sort
of heterodyne mixing scheme would be easiest.

Heterodyning is extremely commonplace and accurate - why would it be
pondered as an alternative method?

For optical signals, there could be other ways to generate multiple
signals at different frequencies that are coherent with each other. I
don't know enough about optical measurement techniques. I *do* know
that you can modulate near IR with RF signals using a variety of
techniques.



b) sending those two signals over the optical path through
interplanetary space.

This blurs my understanding of celestial where two signals is a
poverty of what is available from ANY celestial source.


Back to the figure reference.
And, of course, getting coherent signals from a celestial source might
be a challenge. I don't know.. maybe some sort of clever correlation
technique in an interferometer would do. Not really my field.
c) recovering the signals,

If there is a problem of recovery, it seems it is more a practical
matter of source selection. *Given the billions of celestial sources
available, I don't understand the problem.

Precision detection of a man made signal from across the solar system
is a challenge.



measuring the propagation time variation
(say, by looking at the phase difference between the modulation
signals), and then removing atmospheric effects.

Why worry about the atmosphere when you can get above it?

Indeed. That would make things easier, and is something that people
want to do. But so far, we're stuck with just sending the transmitter
out there.



d) it's probably going to be a pretty weak signal, so you'll need to
average. That means your measurement system has to be picosecond stable
over the averaging interval.

OK, so I am lost. *This laundry list of difficulties seems to be
prepared to anticipate failure.


Not so much failure, but that the original question asked for
experimental data to confirm a fairly well understood effect. My
point is to show that collecting that experimental data is non-
trivial, and not something that you can just rig up in your backyard
with baling wire and sealing wax.


Name the near IR source and defend its choice in light (no pun) of
these intractable difficulties.

There has been more than one optical comm experiment from deep space.


None of those steps are particularly simple or easy.

I've worked on systems to measure the (microwave) distance to Jupiter
and back with an accuracy of around 1 part in 1E15 at 32 GHz,

32 GHz is what photonics would call far-far IR at roughly 3 to 4
orders of magnitude distant from "near IR."

integrating over 1000 seconds. That's tenths of a picosecond out of 1000
seconds. It's challenging.

No doubt - like trying to push a peanut up Pike's Peak with your nose.
That too has been done with challenge in mind.

Well.. yes, it *is* hard, but if you want to know the internal
structure of another planet, it does take some work.




How did this slip from "near IR" to 32 GHz?


The example of 32 GHz is to illustrate that I am not just speculating
about the difficulties of doing it at IR. I have personal knowledge
of how hard it is at 32GHz, and I'm pretty sure it's harder at Near
IR.

So someone on a listserv or usenet group who's looking for a "hey I
did the experiment yesterday, and sure enough, dispersive media have
dispersion" isn't going to get it. Nor are they likely to find the
results of someone who might have done it for real without digging a
bit.

Radio waves faster than light
 

On Mar 19, 12:07*pm, Richard Clark wrote:
On Sat, 19 Mar 2011 07:51:45 -0500, Mike Coslo wrote:
On 3/18/2011 1:16 PM, Richard Clark wrote:

How did this slip from "near IR" to 32 GHz?

Hello Richard!

Hello Mike,

Welcome back to the Land of Odds.

The idea that "we" have a transmitter on *Mars notwithstanding, Jupiter
has been transmitting RF for a long time.

"The intensity of Jovian radio emissions usually varies smoothly with
time; however, Jupiter periodically emits short and powerful bursts (S

It would be difficult to make measurements of dispersive propagation
in the interplanetary media using the natural emissions of Jupiter,
since you don't have knowledge of the relative phases/timing of the
emissions at different frequencies, so you have nothing to compare
against on earth.

If you had two receivers in space separated by some distance along a
line from Jupiter, maybe you could do it. If they're on earth, I
think the ionospheric variation would dominate your measurement.

That said, at least you can get a big frequency ratio so the 1/f1^2-1/
f2^2 term would be large.

Maybe the folks building LOFAR have some clever ideas on compensating
for the ionosphere and they will be able to use Jupiter as a source
for this sort of measurement (if they're interested.... I suspect
they're not..)

Radio waves faster than light
 

On Sat, 19 Mar 2011 18:36:11 -0700 (PDT), Jim Lux
wrote:

It would be difficult to make measurements of dispersive propagation
in the interplanetary media using the natural emissions of Jupiter,
since you don't have knowledge of the relative phases/timing of the
emissions at different frequencies, so you have nothing to compare
against on earth.

Hi Jim,

We would first have to agree what "dispersion" means.

If it conforms to optical dispersion (this having started, at least
for me, in the near IR, which is optical as far as I am concerned),
then the wide bandwidth (offering us with many time coherent sources)
through a frequency dependent media would present different phase
shifts which could then be cross-correlated. Modal dispersion might
present a problem because even though Jupiter is far away, it still
presents a significant arc of span across space (i.e. not even close
to being a point source).

73's
Richard Clark, KB7QHC

Radio waves faster than light
 

On Sat, 19 Mar 2011 18:29:43 -0700 (PDT), Jim Lux
wrote:

How did this slip from "near IR" to 32 GHz?


The example of 32 GHz is to illustrate that I am not just speculating
about the difficulties of doing it at IR. I have personal knowledge
of how hard it is at 32GHz, and I'm pretty sure it's harder at Near
IR.

Hi Jim,

The display and measure of Newton's rings is exceedingly trivial for
optical time/phase/freq/distance differences far shorter in shift (nm
to um) than what is being described here (in mm).

73's
Richard Clark, KB7QHC

Radio waves faster than light
 

On 3/19/2011 11:45 AM, Szczepan Bialek wrote:


The idea that "we" have a transmitter on Mars notwithstanding, Jupiter
has been transmitting RF for a long time. There are enough other
spacecraft running around in our solar system, and certainly if radio
waves traveled at some other velocity than what we thought they did,

Not we but you.

No, not at all. The problem with all the folks who have these strange
desires to debunk basic physics is this:

Things are connected.

When people come up with theorys/conspiracies or whatever that
sopmething we thought we knew is so completely wrong, it is a mark of
thier ignorance that they don't realize that there is more than one
thing negated if they are correct. Want a different speed of radio
compared to light - or rather I should say faster than C ? Better be
prepared to abandon most of what we already know.

So in the end, we're left with either a remarkable ignorance, willful
stupidity, a creationist agenda, or else that ever loving fun
interactive game of arguing with the computer.

- 73 de Mike N3LI -

Radio waves faster than light
 

On 3/24/2011 8:34 PM, Mike Coslo wrote:
Things are connected.

When people come up with theorys/conspiracies or whatever that
sopmething we thought we knew is so completely wrong, it is a mark of
thier ignorance that they don't realize that there is more than one
thing negated if they are correct. Want a different speed of radio
compared to light - or rather I should say faster than C ? Better be
prepared to abandon most of what we already know.

So in the end, we're left with either a remarkable ignorance, willful
stupidity, a creationist agenda, or else that ever loving fun
interactive game of arguing with the computer.

- 73 de Mike N3LI -

Wait. Are you saying Science Fiction isn't real?

Next thing you'll pull out of your hat is Divining Rods can't locate water!

Or, Bog forbid, Vaccines don't cause Autism.

tom
K0TAR

Radio waves faster than light
 

"Mike Coslo" napisal w wiadomosci
...
On 3/19/2011 11:45 AM, Szczepan Bialek wrote:


The idea that "we" have a transmitter on Mars notwithstanding, Jupiter
has been transmitting RF for a long time. There are enough other
spacecraft running around in our solar system, and certainly if radio
waves traveled at some other velocity than what we thought they did,

Not we but you.

No, not at all. The problem with all the folks who have these strange
desires to debunk basic physics is this:

Things are connected.

When people come up with theorys/conspiracies or whatever that sopmething
we thought we knew is so completely wrong, it is a mark of thier ignorance
that they don't realize that there is more than one thing negated if they
are correct. Want a different speed of radio compared to light - or rather
I should say faster than C ?

We have the two C. One of them is a constant in the wave equation.
The second is a speed of light. It is different in different media and the
frequency dependent. Also in space. An example Pulsars are spinning neutron
stars that emit pulses at very regular intervals ranging from milliseconds
to seconds. Astronomers believe that the pulses are emitted simultaneously
over a wide range of frequencies. However, as observed on Earth, the
components of each pulse emitted at higher radio frequencies arrive before
those emitted at lower frequencies. This dispersion occurs because of the
ionised component of the interstellar medium, which makes the group velocity
frequency dependent.
S*

Good afternoon.
We are a group of volunteers who care about the fate of those who got into trouble.
We urge all people to help the citizens of Japan. In the Czech Republic we have organized a fundraising drive. They are very necessary for those who remained without a roof over your head. Hope very much for your help. One we can not cope with this tragedy. All the money will pass to the Embassy of Japan.
Provide a report on the use of money.
Requisites for conversion to U.S. dollars:

Account name:
Sergey Timofeev
Account number:
600 617 50 01
Bank code:
5500
IBAN:
CZ77 5500 0000 0060 0617 5001
SWIFT/BIC:
RZBCCZPP
Bank address:
Raiffeisenbank, a.s.
Hvezdova 1716/2b
Prague
Czech Republic

Answer all questions. Write to
Thank you all for your help.