Friday, October 29, 2010

GPS, Relativity & Geocentrism

This is in response to Rick DeLano comments on GPS and relativity, originally posted in the comments of John Hartnett's Cosmos. 1. Introduction.

For this analysis, I will define Physical Geocentrism as a system which claims that the Michelson-Morley experiment (MMX) makes the Earth a fixed, motionless frame of reference.  This seems to be consistent with the claims Mr. DeLano makes in his earlier comments and below.

Just how well tested is relativity?
DeLano: "We are only now beginning to be in a position to determine whether the behavior of “c“ is as predicted in non-Earth reference frames."
False. 

We've pretty much had the capability since space flight - and especially interplanetary flight.  We've been able to measure newer predicted relativistic effects since the 1960s, such as the Shapiro Delay (Wikipedia

In addition, there are currently at least two satellite instruments flying in space, moving relative to the Earth, AND to the object they're imaging, where the optical configuration used is similar to the Michelson-Morley experiment.  The system is used for precision Doppler velocity measurement.  They use 'c' for the velocity of light when removing Doppler effects from the spacecraft velocity relative to the target.  

As high-bandwidth transmissions become common in space, we will have to include the relativistic effects there as well to keep precise timing.  Physics Today: Time dilation seen at just 10 m/s.

But Doesn't GPS Use Geocentric Coordinates?
The GPS system uses several different coordinate systems, including an inertial system with an orientation fixed to the distant stars.  Computations transform to a geocentric system when needed to compute locations physically on the Earth.  For more details and references, see Scott Rebuttal. I. GPS and Relativity.
DeLano: "The early evidence is shockingly unsupportive of Relativity (JPL time correction built into GPS software, for example, which renders “c“ constant in only one frame. Hint: it ain't the solar system barycenter)."
That can only be a credible statement to an audience that knows NOTHING about relativity.

According to relativity, provided you do ALL your calculations in a given frame, you can always use 'c' as the speed of light in that frame. 

That is what frame-independence of the speed of light MEANS. 

If you transition between reference frames you must do the appropriate relativistic transformation and then do all your calculations based on measurements in THAT frame.  Then you can use 'c' in that frame as well. 

If You Want to Know About GPS, Read the Spec!
But here is the real killer for the claim of no relativistic effects in the GPS system. Back during the system's development, the contention over the reality of relativistic effects was so severe, a frequency synthesizer was installed to alter the system clock frequency to the relativistically-corrected value - just in case. Neil Ashby describes how the required clock synchronization could not be achieved until the corrected synthesizer was turned on (see General Relativity in the Global Positioning System by Neil Ashby). A copy of the original paper, from 1978, describing the launch and initial testing of the first GPS satellite, is available online: INITIAL RESULTS OF THE NAVSTAR GPS NTS-2 SATELLITE.

Today, the relativistic correction is described in the GPS specifications. It's available at the Navigation Center of the U.S. Coast Guard, under GPS References, see Interface Specification (IS-GPS-200E, 8 June 2010). The relativistic corrections are described in Sections 3.3.1.1 and 20.3.3.3.3. (Note that the USCG site layout has changed so these links are different than the earlier article.)

So I ask the question, could Physical Geocentrists have built a working GPS system?

But the implications of an absolute reference frame like Physical Geocentrism requires goes far beyond what is covered here.

Coming Soon: More technology implications (more things that would NOT work if Physical Geocentrism were valid) AND APPLICATIONS (what WOULD work if Physical Geocentrism were valid) of Physical Geocentrism!

4 comments:

Robert B said...

Tom B: ..... We've been able to measure newer predicted relativistic effects since the 1960s, such as the Shapiro Delay (Wikipedia)

Dr. Irwin I. Shapiro's talk titled OBSERVATIONAL TESTS OF RELATIVITY gave the illusion that the Venus radar data was consistent with Einstein's general relativity theory. ...in the comment session that followed, he admitted that all his calculations were based on a constant speed of light c (the wave in ether model), and he had not tested c+v (the particle model). ... He admitted that the published radar analysis showed very large impossible variations in the calculated value of the astronomical unit (the mean distance between the earth and the sun), that were far larger than their maximum estimate of all possible errors. ......The variations in the calculated value of the astronomical unit are what one would expect to find if the speed of light was c+v, and the [Shapiro] calculations were based on c.
http://bourabai.kz/wallace/farce06.htm

Tom B: In addition, there are currently at least two satellite instruments flying in space, moving relative to the Earth, AND to the object they're imaging, where the optical configuration used is similar to the Michelson-Morley experiment. ....

1- Relativity is inconsistent in its 2 premises which state that physical laws are the same for the states of systems in constant relative motion and physical laws are the same for photons in constant absolute motion.
Inconsistent (internally contradictory) theories are unscientific; they can prove anything is true and false.
2- What are the names/references for the 2 Doppler-effect satellites?


Tom B:As high-bandwidth transmissions become common in space, we will have to include the relativistic effects there as well to keep precise timing. Physics Today: Time dilation seen at just 10 m/s.

If there is a relativistic time dilation how are the same predictions of other theories eliminated? How is time dilation necessary and sufficient to explain the effect?

Tom B:The GPS system uses several different coordinate systems, including an inertial system with an orientation fixed to the distant stars. Computations transform to a geocentric system when needed to compute locations physically on the Earth.

1. These several different coordinate systems..... which ones are not geocentric(GC)?
2. GPS also uses ECEF(the geocentric system) as a valid frame of reference. The ECI system is just a rotation of ECEF westward with period of a sidereal day.
3. How about an airplane or satellite, Tom? They do not have locations on the Earth, but a GC system is used to locate them...

Tom B:According to relativity, provided you do ALL your calculations in a given frame, you can always use 'c' as the speed of light in that frame.

1. If light speed is an absolute constant, why the restriction to one frame? Isn't light speed c in every frame?
2. Sagnac used the ECEF frame to measure light speed and obtained c +/- v , where v is the rim speed of a nearby rotor. Ruyong Wang found the same for linear motion of a light beam in the ECEF. If Sagnac used c, his calculations would always be wrong.

Robert B said...

Tom B:If you transition between reference frames you must do the appropriate relativistic transformation and then do all your calculations based on measurements in THAT frame. Then you can use 'c' in that frame as well.

Sagnac measured c +/- v in the rotor frame, also. Another contradiction.

Tom B:..... Neil Ashby describes how the required GPS clock synchronization could not be achieved until the corrected synthesizer was turned on (see General Relativity in the Global Positioning System by Neil Ashby).

Ashby: "The atomic clock was first operated for about 20 days to measure its clock rate before turning on the synthesizer. The frequency measured during that interval was 442 * 10^12 parts in faster than clocks on the ground; if left uncorrected this would have resulted in timing errors of about 38,000 nanoseconds per day.".....

This shift could be due to the Sagnac effect alone, depending on the component of radio signals in the E-W direction.

Tom B:Today, the relativistic correction is described in the GPS specifications. ......

"One of the characteristics of clock behavior clearly evident in GPS is that all clocks in the earth-centered inertial (ECI) frame at sea level run at the same rate. On the equator they should run slow according to SRT due to its speed in the ECI frame. However, on the equator they should run fast according to GRT due to the spin-induced equatorial bulge which causes the clock to be higher in the earth's gravitational potential. These two effects, explained by two disjoint theories, are of exactly equal magnitude but opposite sign".

"SRT and GRT theories sometimes exhibit clock effects of equal magnitude which cancel and sometimes exhibit clock effects of equal magnitude which are additive. This cannot be coincidence, yet there is nothing within the two disjoint relativity theories to suggest an underlying mechanism. Since clock effects are a function of velocity squared (kinetic energy) and gravitational potential energy, it would seem that the common factor is related to the energy of the particle. But SRT treats kinetic energy as relative and GRT treats gravitation as a geometric effect of an orbiting body following a force-free trajectory completely independent of energy considerations. SRT/GRT has no valid explanation for this phenomenon. Thus, both Einstein theories are invalid"


Tom B:So I ask the question, could Physical Geocentrists have built a working GPS system?

The above quotes are from GPS consultant Ron Hatch, who did help build a working GPS system....

Rick DeLano said...

Tom:

There are now four comments in response to three of your posts awaiting the light of day.

Should we assume that these will not appear?

W.T."Tom" Bridgman said...

Quote: Rick DeLano said...
Tom:

There are now four comments in response to three of your posts awaiting the light of day.

Should we assume that these will not appear?


You should assume that I have more to do in my life than hover around this blog 24/7...

In spite of your beliefs, the universe DOES NOT revolve around you.

So...What Happened?

Wow.  It's been over eight years since I last posted here... When I stepped back in August 2015,...