speed of light correction

[en1940]

Hello folks,

In Cowan's intraday CycleTimer software there is ability to correct planetary position for speed of light.
Is it possible to use "correction for ether" in ephemeris properties to get same results?
If yes, what value should I use?

Regards,
Ev

Object Light-Travel Time (Measured from Sun)
Mercury 3.22 light-minutes
Venus 6.01 light-minutes
Earth 8.32 light-minutes
Mars 12.7 light-minutes
Jupiter 43.3 light-minutes
Saturn 1.32 light-hours
Uranus 2.66 light-hours
Neptune 4.16 light-hours

[earik]

Hi Ev,

The Ether correction will slow things down by one day for every AU. So you have to convert that to represent the amount of time it takes light to travel one AU, in units of days. It takes light 8min and 20sec to travel from the Sun to the Earth, which is 500 seconds. There are 86400 seconds in a day, so that gives us an Ether correction of 0.00578.

Unfortunately, the Ether algorithm is homegrown (and was a real pain in the butt to figure out), and not meant for that level of accuracy. It's meant for slow wave propagation, and not fast like you get with speed of light, so it's not going to be much help if you're trying to solve for second and third decimal place differences like you'll see when correcting for light travel.

Regards,

Earik