@humy saidNo, you showed me links that made the claim with nothing to back it up. The link I presented explained in detail why relativity is not required for GPS to function. Nothing you presented challenged that explanation. It is like your hurricane myth I proved wrong. You still have a hard time accepting that all because you heard the rumor so many times.
We have given you the links. We have shown you the evidence. Who are you trying to kid here? Us?
Gossip is not proof.
https://www.physicsmyths.org.uk/gps.htm
@sonhouse saidI'm not eager to prove myself wrong about time dilation. Besides, I don't need to. Accepting the time dilation or not is irrelevant, there is no need for Relativity for GPS to function. You believe in a popular myth. Because the myth was repeated so many times from different sources you accepted it as fact. It is human nature. That is why propaganda is a science that is very effective. Propagandists use repetition and their control of multiple news networks to fool people into believing falsehoods. A high IQ does not make a person immune from it either. It has nothing to do with intelligence. It has to do with human nature. That is why many physicists are duped by gossip just like any other people. I know people would like to think they are too smart to be fooled, but the science suggests otherwise.
@Metal-Brain
So you deny the flow of time changes because of altitude and velocity?
https://www.livescience.com/1956-study-gossip-trumps-truth.html
@Metal-Brain
Find me something from a science journal saying relativity does not need to be taken into account to make GPS readings accurate to within the 6 foot range or so we see today.
You do realize the accuracy is totally dependent on the timing of whatever clocks are used, whether onboard or not right, there has to be a correction factor.
So if they don't take into account the relativistic effects of altitude above a gravity well and velocity, what do they do to make the clocks accurate?
This is what I found:
https://physics.stackexchange.com/questions/1061/why-does-gps-depend-on-relativity
In order to be accurate within 15 meters, the timing has to be accurate to within 50 nanoseconds.
Relativity puts the change in time flow at about 38,000 nanoseconds per day or about 10 nanoseconds PER SECOND. So ten seconds without compensation, the accuracy falls to 30 meters, not very good at all.
It seems relativistic effects are quite needed to be taken into account or the whole system will be less accurate than a map. That 50 nanosecond is just the time it takes a radio or light signal to go 15 meters, c is about 3 nanoseconds per meter, roughly.
So to be accurate to within 1.5 meters the timing needs to be accurate to within FIVE nanoseconds.
@sonhouse saidYou want me to prove a negative? I already proved GPS receiver's time is reset by the satellite atomic clocks. That proves you wrong. It isn't my fault you believe in a myth that you embrace like a religion. If you cannot accept facts I can't help you. You are bent on being dogmatic and refusing to believe facts. Live with it. It isn't my mental illness, it is yours.
@Metal-Brain
Find me something from a science journal saying relativity does not need to be taken into account to make GPS readings accurate to within the 6 foot range or so we see today.
You do realize the accuracy is totally dependent on the timing of whatever clocks are used, whether onboard or not right, there has to be a correction factor.
So if they don't take into ...[text shortened]... ects are quite needed to be taken into account or the whole system will be less accurate than a map.
Your article is not peer reviewed. You have abandoned your own standard.
@Metal-Brain
No matter what they do they have to account for the fact the clocks will be off by 36,000 nanoseconds per day and they can compensate for that by just adjusting the clock rates and that works to a certain extent but the fundamental work is compensating for changing time flow due to relativity. Equations don't have to be included, just a time correction factor predetermined but the bottom line is to get that correction factor, relativity has to be taken into account.
@metal-brain saidYou already have.
I'm not eager to prove myself wrong about time dilation.
@sonhouse saidSatellites measure GPS coordinates relative to each other. There is no need for relativity equations for accuracy. Time is adjusted to the satellite atomic clocks. The elliptic orbit has more variation than relativity. You are defending a myth.
@Metal-Brain
No matter what they do they have to account for the fact the clocks will be off by 36,000 nanoseconds per day and they can compensate for that by just adjusting the clock rates and that works to a certain extent but the fundamental work is compensating for changing time flow due to relativity. Equations don't have to be included, just a time correction factor p ...[text shortened]... mined but the bottom line is to get that correction factor, relativity has to be taken into account.
Gossip is not evidence. Give it up.
@Metal-Brain
The only myth is in your head. Clocks are off by 36,000 nano seconds per day and light travels about one nano second per foot so if not accounted for, GPS would be off by 36,000 feet in one day and 360,000 feet in 10 days.
That is a fact jack. If all the sat clocks were synced together there would still be a difference in sat time V ground time.
If you can't see that you need to go back to school. GPS is only as accurate as the clocks.
@sonhouse saidThere are numerous correction factors needed for GPS, the inaccuracy of the clock in the receiver the most obvious one. That one is corrected for by using 4 satellites three for the position and one for the clock bias. I suspect that the correction from GR in measuring the signal path length could be corrected for on a purely empirical basis.
@Metal-Brain
The only myth is in your head. Clocks are off by 36,000 nano seconds per day and light travels about one nano second per foot so if not accounted for, GPS would be off by 36,000 feet in one day and 360,000 feet in 10 days.
That is a fact jack. If all the sat clocks were synced together there would still be a difference in sat time V ground time.
If you can't see that you need to go back to school. GPS is only as accurate as the clocks.
The problem I have is that I don't understand the technology at all. Reading the Wikipedia page I found this sentence:
The C/A code, for civilian use, transmits data at 1.023 million chips per second, whereas the P code, for U.S. military use, transmits at 10.23 million chips per second. The actual internal reference of the satellites is 10.22999999543 MHz to compensate for relativistic effects.So the frequency of the Direct Spread Sequence Code [1] is chosen by the satellite so that it is at a frequency of 1.023 MHz (10.23 MHz for the military) when it reaches the receiver. What I'm left wondering about is whether the system relies on the precision of this frequency. Will an error of two parts in ten billion throw off the decoding?
https://en.wikipedia.org/wiki/Global_Positioning_System#Satellite_frequencies
[1] https://en.wikipedia.org/wiki/Direct-sequence_spread_spectrum
@sonhouse saidThe elliptic orbit has more variation than relativity. You are defending a myth.
@Metal-Brain
The only myth is in your head. Clocks are off by 36,000 nano seconds per day and light travels about one nano second per foot so if not accounted for, GPS would be off by 36,000 feet in one day and 360,000 feet in 10 days.
That is a fact jack. If all the sat clocks were synced together there would still be a difference in sat time V ground time.
If you can't see that you need to go back to school. GPS is only as accurate as the clocks.
For someone who claims to have worked for NASA you are very misinformed.
@metal-brain saidThe satellite knows where it is. It transmits its position as well as its clock time. This means the shape of the orbit has already been taken into account. This complicates the time dilation calculation a little as the satellite's clock's rate is then a function of where it is in its orbit.
The elliptic orbit has more variation than relativity. You are defending a myth.
For someone who claims to have worked for NASA you are very misinformed.
@deepthought saidDo you agree that GPS is not reliant on relativity to function?
The satellite knows where it is. It transmits its position as well as its clock time. This means the shape of the orbit has already been taken into account. This complicates the time dilation calculation a little as the satellite's clock's rate is then a function of where it is in its orbit.
@metal-brain saidYour question makes no sense because of your use of the word "reliant".
Do you agree that GPS is not reliant on relativity to function?
If relativity was (hypothetically) false then all that would mean is that the GPS sat clocks would have been designed to have the SAME 'tick' rate as the GPS-receiver clocks on Earth and then they would just fine with that SAME 'tick' rate therefore, at least in that narrow sense, GPS is NOT "reliant" on relativity to function and nobody here has claimed the contrary at least not in that narrow sense.
But that is IRRELEVANT to the fact if relativity was (hypothetically) false but, despite that, if the GPS sat clocks were STILL (and therefore erroneously) designed to have the DIFFERENT 'tick' rate as the GPS-receiver clocks on Earth and in accordance to relativity then clearly GPS would NOT function well enough. And yet they HAVE been designed to have the DIFFERENT 'tick' rate from the GPS-receiver clocks on Earth and in accordance to relativity and we can observe GPS DOES function well enough, which no relativity-theory-educated non-moron would expect if relativity was false, thus showing (PROVING, in fact) relativity correct.
@humy saidIn other words, no. GPS does not prove relativity correct, time dilation does. That is what I have been telling you all along. Why did you disagree with me?
Your question makes no sense because of your use of the word "reliant".
If relativity was (hypothetically) false then all that would mean is that the GPS sat clocks would have been designed to have the SAME 'tick' rate as the GPS-receiver clocks on Earth and then they would just fine with that SAME 'tick' rate therefore, at least in that narrow sense, GPS is NOT "reliant" on r ...[text shortened]... non-moron would expect if relativity was false, thus showing (PROVING, in fact) relativity correct.
GPS does not need relativity to function properly. It is a myth just like I have been saying all along. As you well know I never claimed relativity was wrong. That is why I put a question mark instead of omitting it.
Can you bring yourself to admit you were wrong?