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special relativity's second postulate is invalid



 
 
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  #1  
Old January 13th 13, 11:36 PM posted to sci.physics.relativity,sci.physics,alt.astronomy,sci.astro,sci.math
Koobee Wublee
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Posts: 815
Default special relativity's second postulate is invalid

On Jan 13, 10:06 am, Tom Roberts wrote:
On 1/13/13 1/13/13 3:33 AM, Helmut Wabnig wrote:


There is one thing to add to resolve a common misconception:
Ground based GPS users do not have atomic clocks in their
Garmins and GPS cell phones, therefore they need signals
from 4 satellites.


Only if a ground based receiver would use
an atomic clock and read the signals from 3 satellites only
then it would need a relativistic correction.
The GPS satellites clocks are synchronized with each other.
Therefore no correction whatever is needed to calculate the
position and height on ground. Regardless what clock rate
the satellites have, as long as they are synchronous,
there will be no geographical error from the calculations.
Any relativistic or other drift does not influence position accuracy.


You make the same mistake as several idiots around he geo-positioning is NOT
the only requirement on the GPS. The GPS is a REAL SYSTEM, and not some figment
of your imagination -- like those idiots, you are attempting to discuss a
fantasy system you imagine you are competent to design yourself. You aren't.

There are additional requirements on the GPS:

[rest of useless SR/GR scripture snipped]


Letís enjoy the following play between Tom and a GPS satellite.
Hopefully, the self-styled physicists would begin to understand why GR
is not necessary in designing the GPS. shrug

Satellite: Tom, every 24 hours, just send me your UTC time, and I
will adjust my calendar time to match the UTC time.

Tom: Donít bother. You need GR for that.

Satellite: No, not really. Please just do what I have asked you.

Tom: OK, that would be a waste of time. How would you meet the
specification of setting your calendar to within 1 usec of the UTC
time?

Satellite: My clock is 100MHz. This gives me a resolution of 10
nsec. It should be a piece of cake.

Tom: OK, at the time of beep, the UTC time will be
2,000,000,000.000000 sec.

Satellite: Thank you. Please beep me again in exactly 24 hours from
that beep.

[24 hours passed in uncle Tomís cabin]

Tom: OK, at the time of beep, the UTC time will be
2,000,086,400.000000 sec.

Satellite: Where the devil have you been? You are late, but that is
OK. Now, I have all the information I need to lock my calendar time
to the UTC time accurate to 1 usec. Now, that is an ideal situation.
Realistically, it will take several iterations to achieve that.

Tom: You need GR for that.

Satellite: Your 24 hours ago, when I first received that beep, my
calendar time showed 1,428,376,019.87725503 usec. 24 hours late, my
calendar time showed 1,428,465,254.68891273 sec at the time of beep.

Tom: You still need GR for that.

Satellite: No, I donít. From the information I have gathered, I know
my 24 hours is (1,428,465,254.68891273 - 1,428,376,019.87725503 =
89,234.81165770) sec to yours (86,400.000000 sec) which means my clock
is ticking (89,234.81165770 / 86,400.000000 = 1.0328103201) times too
fast. I can easily compensate for that through software by
subtracting (89,234.81165770 - 86,400.000000 = 2,834. 81165770) sec
every 89,234.81165770 sec. Also from the last beep, I know I need to
add (2,000,086,400.000000 - 1,428,465,254.68891273 =
571,621,145.31108727) to my own calendar time to match with the UTC
time.

Tom: You are an idiot. You still need GR for that.

Satellite: I have just demonstrated that you do not need GR to match
my calendar time to within 1 usec of the UTC time, and my clock does
not even have to be the same as yours.

Tom: You are still an idiot. You will never learn. There is no need
for me to communicate with you any further.

Satellite: shrug


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  #2  
Old January 14th 13, 12:27 AM posted to sci.physics.relativity,sci.physics,alt.astronomy,sci.astro,sci.math
Sam Wormley[_2_]
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Posts: 3,966
Default special relativity's second postulate is invalid

On 1/13/13 4:36 PM, Koobee Wublee wrote:
Letís enjoy the following play between Tom and a GPS satellite.
Hopefully, the self-styled physicists would begin to understand why GR
is not necessary in designing the GPS.


Koobee, Work through this resource for an understanding of why
relativity is necessary for GPS to work.

Reminder: Relativity in the Global Positioning System
http://relativity.livingreviews.org/...es/lrr-2003-1/


Article Abstract

The Global Positioning System (GPS) uses accurate, stable atomic
clocks in satellites and on the ground to provide world-wide position
and time determination. These clocks have gravitational and motional
frequency shifts which are so large that, without carefully accounting
for numerous relativistic effects, the system would not work. This
paper discusses the conceptual basis, founded on special and general
relativity, for navigation using GPS. Relativistic principles and
effects which must be considered include the constancy of the speed of
light, the equivalence principle, the Sagnac effect, time dilation,
gravitational frequency shifts, and relativity of synchronization.
Experimental tests of relativity obtained with a GPS receiver aboard
the TOPEX/POSEIDON satellite will be discussed. Recently frequency
jumps arising from satellite orbit adjustments have been identified as
relativistic effects. These will be explained and some interesting
applications of GPS will be discussed.


See:

http://relativity.livingreviews.org/...003-1Color.pdf




 




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