Royboy wrote:One of Wal thornhill's videos he states that light is instantaneous... Also Theoria Apophasis aka Ken Wheeler states the same.

https://www.youtube.com/watch?v=YcoYRofMtyk&t=905sHow then does the TBP explain the variations in the eclipse of Jupiter's moons ? which was used to calculate the speed of light. Also the light year has no meaning and the 'red shift' cannot be a Doppler effect. So how are space distances measured ?

There will have been a considerable quantities of distances measured in space using 'parallax' measurement. Here the object where the desired distance is to be measured has to be in-front of a background (so to speak), observation of the object from two positions yields a measurement of the change in the objects position with relation to the background, the change (in position) is directly proportional to the distance between the two observation points (perpendicular to the distance to be ascertained) while the distance to the object to be measured is inversely proportional to the change in the position of the object against the background while the distance between the observation points is constant. To maximise the observable 'parallax' (change in position of the object) it is desirable to ascertain two measurement positions with a maximum distance between them allowing the parallax over the two positions to become tangible for a distant object. The greatest distance (between observation points) we currently have available involves observation twice over the course of the year (where the distance is approximately twice the approximated distance to the sun), however utilising these measurement positions requires accurate information about the planets orbit which is a area for error with this method, a less significant area for error is the motion of the distant (background) object used to ascertain the measurement.

A alternative approach would be to have two observation points where the distance to the object is exactly perpendicular to the distance to the second observation point, then the angle created at the distant object can be ascertained and from that angle and the distance between the observation points using the arctan function the distance to the object.

For observation of distance objects where the two previously stated techniques are in-practical there are techniques employed which are dependant on the idea that light decays at the same rate through different mediums allowing a accurate distance to be measured from a brightness measurement. This is a assumption based on the idea that light propagates without any medium present. It is also dependant on the idea that fields can exist independently of any object.

Furthermore for measurement of extreme distances of barely visible objects theories of expansion of the universe have been birthed from a age of science which focuses more on the experiments than the interpretation of the experiments themselves leading to erroneous theories which do not withstand rigorous and clear reasoning and logic.

It can be said that as the distances measured increases the number of assumptions and poorly thought through theories associated with ascertaining these measurements likewise increases.

With relation to the speed of light again this is built from Maxwells concept of transverse solely electro magnetic propagation, there are several reasons as to why this theory is questionable, one is that transverse vibrations exist only with some kind of boundary condition, another is that there are several report of measurements which exceed the velocity of light, the idea of the velocity of light being some kind of universal constant again is also dependant on the idea that light exists independent of any medium and therefor its velocity cannot be manipulated by change in that mediums physical properties. Once the idea is presented that light is a longitudinal wave in a medium inducing field strength fluctuations of a certain intensity and frequency to result in this wave being categorised as light then the velocity of this oscillation becomes dependant on the medium therefor it can be any quantity. This is a more favourable suggestion as a product of both reasons given above; that transverse vibrations exist only with some kind of boundary condition and that there are several report of measurements which exceed the velocity of light. Furthermore the Maxwell idea of a constant ratio between magnetic and dielectric forces existing independent of any medium applied to the motion of bodies through space such that the same ratio applies to give a limiting speed to the propagation velocity of a object also contradicts laws associated with the motion of bodies. Light is a finite velocity so a finite quantity of force creating a constant acceleration over a determined period results in acceleration beyond the velocity of light (after a sufficient extension of the period) excluding any drag / external forces. However this is un-neccasary as it is adequate to replace the Maxwell idea at the point of there being no boundary condition existing in space in conjunction with the contradictory measurements; for a theory / suggestion which can logically exist.

Considering a theory of a eather propagating longitudinal waves the wave velocity becomes a function of density and stiffness while the motion of some body is arrested by the medium to a degree where by its velocity can be manipulated to any quantity as a product of applied force. Clearly the wave velocity and the velocity of the object are independent of one another when the objects velocity is modulated by the magnitude of the applied force.