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Not a good start... What you have described is speed, not velocity. Velocity has direction too.The speed can easily be measured from either frame, they just won't be the same.

Quote from: Centra on 16/01/2022 10:45:38Under that definition, Einstein's "theories" would not be theories.Einstein's works have been tested extensively, and found to be correct within the limits of experimental error.They meet the definition as given in the wiki article.Why say things like that?Why be so obviously wrong?

Under that definition, Einstein's "theories" would not be theories.

I disagree, name the experiments. I just cited one that contradicted it.

within the limits of experimental error.

I have modified that par of the post to read "First I will give my definition of velocity: the quantification of motion based on the parameters of distance, time and vector.

Quote from: Centra on 16/01/2022 11:54:18 I have modified that par of the post to read "First I will give my definition of velocity: the quantification of motion based on the parameters of distance, time and vector.Did you realise that you changed it to something meaningless?

Are you serious?For a start, sat nav works.

Abstract – The implementation of GPS systems has allowed the understanding of important facts about the true meaning of time and simultaneity. In fact GPS has became a fundamental source for the understanding of clock behaviour and synchronization, through the considerations of the relativistic effects affecting it. Among these, a very important role is played by the Sagnac effect, influencing the clocks readings. The correct consideration of such effect is fundamental in every synchronization process where the receiver is moving with respect to the source. In this paper we show how GPS system demonstrates that the explanation of Sagnac effect given by the commonly accepted version of Special Theory of Relativity is not correct and the use of an alternative formulation based on Inertial Transformations must be used. This implies the adoption of a new synchronization procedure, the renounce to the relativity of simultaneity and a novel meaning of physical time. The Sagnac effect in GPS, absolute simultaneityand the new meaning of timeLuigi Maxmilian CaligiuriAmrit Sorli2

In an inertial frame, a network of self-consistently synchronized clocks can be established either by transmission of electromagnetic signals that propagate with the universally constant speed c (this is called Einstein synchronization), or by slow transport of portable atomic clocks. On the other hand it is well-known[3] that in a rotating reference frame, the Sagnac effect prevents a network of self-consistently synchronized clocks from being established by such processes. This is a significant issue in using timing signals to determine position in the GPS. The Sagnac effect can amount to hundreds of nanoseconds; a timing error of one nanosecond can lead to a navigational error of 30 cm. To account for the Sagnac effect, a hypothetical non-rotating reference frame is introduced. Time in this so-called Earth-Centered Inertial (ECI) Frame is adopted as the basis for GPS time; this is discussed in Section 2. Of course the earth’s mass encompasses the origin of the ECI frame and has significant gravitational effects. To an extremely good approximation in the GPS, however, gravitational effects can be simply added to other effects arising from special relativity. In this article gravitational effects will not be considered. Even time dilation, which is an effect of second order in the small parameter v/c, where v is the velocity of some clock, will be neglected. I shall confine this discussion to effects which are of first order (linear) in velocities. The Sagnac effect is such an effect.THE SAGNAC EFFECTIN THE GLOBAL POSITIONING SYSTEMNeil AshbyDepartment of Physics, UCB 390.University of Colorado.Boulder, CO 80309-0390 USA.Quote

Those portable cesium clocks are simply not highly accurate,

Quote from: Bored chemist on 16/01/2022 12:06:28Quote from: Centra on 16/01/2022 11:54:18 I have modified that par of the post to read "First I will give my definition of velocity: the quantification of motion based on the parameters of distance, time and vector.Did you realise that you changed it to something meaningless?Okay, please define velocity.

Quote from: Centra on 16/01/2022 13:07:17Those portable cesium clocks are simply not highly accurate, Yes they are.They are sufficiently accurate that they had to be set to run at the ""wrong" rate here on the ground so that they would run at the right rate when in orbit.The extent to which the rate changes is exactly what was predicted by GR.So, you seem to be denying reality here.

the GPS clocks are not adjusted based on GR, it's based on the Sagnac effect

"The velocity of an object is the rate of change of its position with respect to a frame of reference, and is a function of time."Fromhttps://en.wikipedia.org/wiki/VelocityWhy couldn't you do that for yourself?

That very Sagnac effect actually contradicts Einstein's theories

What do you think "rate of change of its position with respect to a frame of reference, and is a function of time" is that is different from " the quantification of motion based on the parameters of distance, time and vector"?

Did you realise that you changed it to something meaningless?

Quote from: Centra on 16/01/2022 15:24:04 the GPS clocks are not adjusted based on GR, it's based on the Sagnac effectNo.There are three main contributions. The Sagnac effect is one of them.The others are relativistic.https://en.wikipedia.org/wiki/Error_analysis_for_the_Global_Positioning_System#RelativityShouldn't you have researched this before telling everyone that they were wrong?

The Operational Control System (OCS) of the Global Positioning System (GPS) does not include the rigorous transformations between coordinate systems that Einstein's general theory of relativity would seem to require - transformations to and from the individual space vehicles (SVs), the Monitor Stations (MSs), and the users on the surface of the rotating earth, and the geocentric Earth Centered Inertial System (ECI) in which the SV orbits are calculated. There is a very good reason for the omission: the effects of relativity, where they are different from the effects predicted by classical mechanics and electromagnetic theory, are too small to matter - less than one centimeter, for users on or near the earth.GPS AND RELATIVITY: AN ENGINEERING OVERVIEW Henry F. Fliegel and Raymond S. DiEsposti GPS Joint Program Office The Aerospace Corporation El Segundo, California 09245, USA

Shouldn't you stop using Wikipedia as a reliable reference?

Quote from: Bored chemist on 16/01/2022 15:41:51What do you think "rate of change of its position with respect to a frame of reference, and is a function of time" is that is different from " the quantification of motion based on the parameters of distance, time and vector"?You couldn't understand that? What do you think the following quote "rate of change of its position with respect to a frame of reference, and is a function of time" is... are you with me so far? That is different from this quote " the quantification of motion based on the parameters of distance, time and vector"? You seriously couldn't understand that? Wow.

the quantification of motion based on the parameters of distance, time and vector"?

Speaking of references, you should try reading the one you cited.

At high altitude, where the GPS clocks orbit the Earth, it is known that the clocks run roughly 46,000 nanoseconds (one-billionth of a second) a day faster than at ground level, because the gravitational field is thinner 20,000 kilometers above the Earth. The orbiting clocks also pass through that field at a rate of three kilometers per second — their orbital speed. For that reason, they tick 7,000 nanoseconds a day slower than stationary clocks.To offset these two effects, the GPS engineers reset the clock rates, slowing them down before launch by 39,000 nanoseconds a day. They then proceed to tick in orbit at the same rate as ground clocks, and the system “works.” Ground observers can indeed pin-point their position to a high degree of precision. In (Einstein) theory, however, it was expected that because the orbiting clocks all move rapidly and with varying speeds relative to any ground observer (who may be anywhere on the Earth’s surface), and since in Einstein’s theory the relevant speed is always speed relative to the observer, it was expected that continuously varying relativistic corrections would have to be made to clock rates. This in turn would have introduced an unworkable complexity into the GPS. But these corrections were not made. Yet “the system manages to work, even though they use no relativistic corrections after launch,”https://medium.com/@GatotSoedarto/top-4-reasons-why-gps-doesnt-need-einstein-s-relativity-895cabc6e619