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.

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.

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

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

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*

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.

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

" 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*

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

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.