That's what they tell us. Light can travel through a vacuum with nothing in it. And maybe so but what is the evidence?
So I looked up the best vacuum on planet Earth. It contains 2.5 million molecules of air per cubic cm. This is said to replicate conditions between stars. So how then can we say we've ever tested light waves going through "nothing". We haven't.
To test the validity of my suspicions I've asked the science guys on reddit if they have an answer for this. The first few responses have already been hostile and that usually indicates this is one of those issues they simply don't have a good answer for. I was very polite in my question btw, so no I didn't provoke anybody, this is all on them.
We'll see how it goes. I'm open to a good explanation of why this is a valid test, but this light has 2 million molecules to interact with ever cubic cm it propagates, so you didn't rule out matter.
No, they don't.
GPS, just like any known GNSS system is differential, not absolute.
Receiver doesn't use absolute time data from satellites, it measure differences of time in signals received from different satellites (phase) and use only that differences to find out position.
GPS clocks on satellites do slowed slightly IIRC not 1.024 MHz clock signal, but 1.02399...whatever MHz to satisfy special and general relativistic time distortion prediction (-7μS/day special, +45μS/day general, total +38μS/day) to make satellite clocks appear running at same pace as clocks on Earth, but this does not make any real sense, since any absolute error is cancelled by differential nature of measurement (not a frequency or time on satellite matters, but phase offset between different satellites, that is measured ), so any relativity corrections will give position error in order of millimeters. This shift was done purely to satisfy relativists marketing demand, not for solving any real problems. Also, in any case satellite clocks are forcefully synchronised with Earth UTC every 24 hours .
Take a look at GPS position calculation math, it is pretty clear that relativistic effects if any, could not give any noticeable error.
For GPS positioning syncronicity between satellites is orders of magnutude more important than any possible relativity effects.
Major GPS error comes from atmospheric interference, ephemeris precision and so on, potential relativistic effect errors are at the very bottom of the list, even lower than short-term instability of atomic clocks.
PS: that often pushed statement that unaccounting for relativistic effects in GPS will give 11km/day error is a pure lie. Idiots who made this statement (300000km/S * 38μS) to show importance of Einshtein just have no any clue about how GPS really works. In reality such error will be absolutely negligeable (millimeters in a worst case), much lower than other ineradicable errors and it will not accumulate at all.
That's interesting. I'm going to have to look into GPS math when I can make some time / energy for it.
I'm confused by that statement. So you said they don't use Lorentz, but then you are saying the clocks do see a slow down which satisfies relativity but is negligible. Are you claiming they are adding this slow down deliberately? I don't understand.
It seems like even if the effect is small, as you allege, they are still using the Lorentz equations.
They do that "just in case", because "scientists insisted" or for whatever other reason, but definitely not because it is really necessary for positioning.
They use Lorenz equations on GPS satellites, but Lorenz equations are not used for GPS positioning, because their effect is unnoticeable.
Also, in any case once a day staellite clocks synced with Earth UTC time from ground stations.
So, statement that existence of GPS impossible without relativivty and GPS is a proof of relativity is a bullshit. Not because GPS disprove relativity or prove something different, but because whole system designed to minimize or completely exclude influence of clock instability or drift of whatever reason on positioning.
During finding position following happens in receiver: To determine position on one coordinate receiver need 2 satellites. Receiver measure static delay (phase shift) between signals from satellites. This way receiver find out by what distance it is closer to one of satellites. Pay attention to that - receiver does not measure absolute distance to satellite by comparing local time and received satellite time where Lorenz transforms matter, but local phase shift between signals from two satellites. What matters here is syncronicity between satellites which is not subject to Lorenz, not their absolute times or frequency drifts. Knowing absolute positions of both satellites from ephemeris (almanac) data and how it is closer to one or another, receiver calculate its absolute position. To calculate 3D position receiver need 4 satellites in view. With 3 satellites in view you will see empty field for altitude (height) value in NMEA sentence from GPS receiver and only longitude and latitude will be shown.
Say, receiver get 3.333 mS shift between signals from two satellites. This means receiver is 1000km closer to one of satellites. 38 μS/day is 38e-6 / 86400 = ~4.4e-10 adjustment to clock and so to position measurement, because receiver clock synced with received satellite frequency signal and is used to measure phase shift. On the distance of 1000km it is 0.44 millimeter difference. Could you tell that 0.44 millimeter on 1000km is anywhere practical or significant? Was it really necessary to make this Lorenz adjustment to the staellite clock, especially taking into account that other things add meter order errors?
Point of GPS and relativists who lie about it is very simple - Why relativists need this lies if their theory so cool and correct? Why do they need to pose GPS positioning example as a proof of relativity theories, when principle of GPS positioning made in the way it just cancels relativity effects if any? They slowed clocks on GPS satellites to some value, yes, but this value could be arbitrary, not -38μS/day, but, say -70 or +10 or 0 μS/day and this still will have no any noticeable effect on precision of GPS positioning.
Meanwhile, time shift is not the only possible relativistic effect. F.e. engineers examined other cases where relativistic effects could have some influence on positioning - https://archive.org/download/DTIC_ADA516975/DTIC_ADA516975.pdf about using GPS from high-speed plane or another satellite, i.e. when receiver moves too and this probably could add some relativistic effects.
Conclusion was: (see p197)
It is really amasing that GPS engineers created a system that cancels out all possible uncertainites and minimize possible errors as much as possible fundamentally, by design. But still some use GPS that is designed to cancel out errors of different kind including relativity as a proof of relativity. It's just plain dishonesty in a nutshell. Why relativists ever have to use such dishonesty in attempts to support and propagandise their theory?