Stellar abberation has always been explained as star light arriving in the inertial solar frame with the earth moving through the incident light wavefronts. Although generally this works, when applied to the water filled telescope the light appears to move slower in the inertial frame and a different angle of abberation is predicted. But not observed. This left the ground open to the claims by SR supporters that only a relativistic calculation can explain all the observations of stellar abberation. However what has been ignored since the effect was first observed is the fact that the abberation angle can be observed by naked eye using a mural quadrant!
In other words the light must already be arriving at an angle in the earth observer frame. Contrary to erroneous assumptions it arrives vertically. Which in turn creates the imaginary problems with, for instance, the water filled telescope. To take into account this important fact one must calculate the angle of aberration by using the following very simple calculation:
Earths speed around the sun is 30 ks and lightspeed arriving is 299792 ks.
So that's a horizontal speed of 30 against a vertical speed of 299792ks.
Putting this information into a right angle triangle to represent starlight arriving at earth from vertically above. Opposite and adjacent sides of the triangle are:
Opposite is 299792ks Adjacent is 30ks (see illustration below)
In other words every second earth moves across 30ks the starlight travels down 299792 ks
This gives an angle of adjacent/ hypoteneuse as approximately 0.00573 degrees
Compare this to the observed 'angle of aberration constant' of 20 arcseconds. 20 arcseconds is 20/3600 = 1/180 degree = 0.00555 degree
The calculated value very closely matches the observed angle of abberation.
In the earth frame the light is therefore arriving at an angle of approximately 0.00573. And to take this into account the telescope must be set at that angle. If the telescope is water filled the slower speed of light in water will not effect the abberation angle as the light is ALREADY arriving at an angle.
The only conclusion is that a classical model can fully explain the observed effects of stellar abberation.
This shows how if one uses the earth observer frame to explain abberation, the light now is seen to be arriving at an angle. The telescope then only needs to be tilted in the right direction, as calculated using the method described above. Furthermore if the telescope is filled with water the slower speed of light in water does not effect the path of the light through the telescope barrel. And still arrives at its correct position at the eyepiece. What is remarkable is how Bradley in the 18th century did not realise this simple explanation. Probably one reason for this misunderstanding was their assumption of an imaginary aether to help them explain how lightwaves propagate. However there never was neccesity for aether in a classical wave emission model of light. Quite why aetherists supported the need for an aether is vague. Probably a lack of understanding of physics. But it must be noted that the same people who supported the need for an unneccesary aether went on to support another unneccesary theory...Spacetime and relativity.
This illustration shows how to calculate abberation angle using a simple triangle method of earth speed horizontally against light speed arriving vertically.
This is the traditional frame used to explain abberation. The starlight arrives vertically and the earth, shown here by the telescope cross section, travels from right to left. The light moves down the tube to the bottom if the angle of the telescope is positioned correctly.
Theorists from Bradley through to current relativists illustrate the water filled telescope moving in the heliocentric frame. However they erroneously assume that the water in the telescope doesn't move in that frame! This is an absurd conclusion as they admit the telescope does move. Ignoring the waters motion and calculating the lightspeed for the water in the inertial heliocentric frame, theorists have erroneously concluded that the light actually moves faster than c for water in the telescope. They do this by assuming the light travels straight down in the inertial frame. Which can only mean it is travelling faster than c through the water as the water is moving in this frame.
A correct calculation should have the light always travelling at c relative to the moving water filled barrel of the telescope. Which means it has to travel diagonally across the inertial frame rather than straight down.
The path of the light through the water is bent forwards in the direction of the motion of the telescope.
As with refraction the light has to travel this path of least resistance. As it is the only path that it can take to travel at c. To deviate means it must travel either slower or faster than c in water. Something it cannot do as the light source does not move closer or farther relative to the telescope
