Dear Sean,

I have some (very) good news and some (mildly) bad ones for you. Let me start with the latter so as to get over and done with them. I shall be a bit âharshâ with you in this first part of my reply - but please do not take offense, after all thereâs nothing personal about debating the workings of our Solar System and of Mother Nature! Again, I sincerely appreciate your time and efforts reviewing the Tychosium simulator but, in order for our dialogue to be useful I must first clarify for you some fundamental aspects of the model â lest we indeed keep communicating with each other âin circlesâ. So here we go with the âmildly bad newsâ, that is to say your poor interpretation of some figures in the model and your general (mis)understanding of it:

For instance, you wrote:

*There is a 20.4 minute delay between tropical and sidereal year. In those 20.4 minutes the sun would have travelled (according to your number 107,226 km/h, I think it is slightly less): ~36.500 km. In that time the Earth has moved by 14,036 km (your number).*

*That would mean the movement of the earth, would have a ~2.6423 effect on the sun (your number). So letâs say the earth moves 1 km in year, the delay in the sunâs movement is 2.6423 km.*

*The sun is 23,454.79 times further away.*

No! The Earth doesnât move by 14036 km in 20.4 minutes! Thatâs the distance we cover *in one year*, a crucial figure that Iâve called the EAM (Earthâs Annual Motion) and is cited dozens of times throughout my bookâŠ Have you even spent a few minutes reading it? And how on Earth do you conclude that the *âsun is 23,454.79 times further awayâ?* Good Heavens, Sean â you certainly seem to be âat seaâ with regards to some fundamental tenets of the TYCHOS model.

But letâs move on. I canât believe that you actually wrote this line:

*âTotally neglecting all scientific proof about determined standards (like the size of 1 AU) and coming up with alternative numbers doesnât really make much sense.â*

Surely, you must have missed this explanatory paragraph to be found in Chapter 4 of my book:

*âThe Tychosium simulator is built upon the official astronomical tables compiled over the centuries by our worldâs best astronomers. That is to say, all of the orbital sizes, relative distances and empirically verifiable sidereal periods within our Solar System have been rigorously respected. In the Tychosium, all the planets and moons revolve around uniformly circular orbits - and at constant orbital speeds. This is in stark contrast with the elliptical orbits and variable speeds that Kepler had to postulate in order to make the heliocentric model âagreeâ (mathematically) with empirical observations. In all logic, I have therefore used the mean/average values estimated for our planetsâ orbital velocities - and disregarded their supposed âmaximumâ and âminimumâ values, as computed by Kepler.â*

Ever since day one of my TYCHOS research, I have scrupulously observed all the planetary parameters (sizes / distances/ orbital periods/ etc) and astronomy tables laboriously compiled by our worldâs best observational astronomers over the centuries. Not one single parameter integrated in the Tychosium simulator is the result of âguessworkâ, of pure chance or - worse still - of any sort of fudging or confirmation bias. All the orbital speeds of our Solar Systemâs bodies, for instance, were quite simply computed relatively to the speed of the Sun (107226 km/h) which, in the simulator, is set to 2Ï (i.e. 6.283185307179586).

In fact, the only âlibertyâ I have taken is to ignore / do away with Keplerâs proposed *variable* orbital speeds and *elliptical* orbits. Yet, and âin spiteâ of this, the Tychosium (a work in progress and constant refinement) can already account for â to an excellent degree of accuracy - a vast number of âmemorable eventsâ (recorded in astronomy tables) in the last centuries (e.g. all solar and lunar eclipses / all Mercury and Venus transits across the solar disk / all Jupiter-Saturn conjunctions/ etc). Admittedly though, until the other day, I wasnât quite satisfied with the LONG TERM behavior (in the Tychosium) of the Mars oppositions. I had noticed that, over the millennia, the Martian orbit seemed to âwobbleâ a tad too much (with respect to all the other orbits), thus causing some Mars oppositions to occur a bit too close to the Earth. And hereâs where we get to the (very) good news that I have for you, dear Sean: as you justly pointed out that Mars came (unrealistically) as close as 0.25AU around the year 22001 AD, I decided to give the fine-tuning of Marsâs parameters in the Tychosium another go. In about a dayâs work, I managed to substantially improve Marsâs long term motions â as I will describe in a separate post. I thank you for linking to that Jean Meeus paper which was certainly a useful resource towards refining Marsâs long term motions. The Tychosium simulator is now updated with the new, improved Martian parameters.

Now, what you must appreciate and understand is that, whenever performing fine-tuning / micro-adjustments of any planetâs secular, LONG TERM positions (i.e. over many thousands of years) a certain amount of âguessworkâ (trial & error) is necessary. This, because available & reliable astronomy tables only go back a few centuries and thus, all LONG TERM predictions (whether heliocentric, geocentric or geo-heliocentric) are based upon relatively short time spans and will therefore always be subject to some degree of approximation.

As for your reckoning that the TYCHOS Great Year should be considered as lasting for 25345 solar years (rather than 25344), you are absolutely correct â and you deserve a huge hat tip for this realization, dear Sean! As the Earth completes a â25344-yearâ revolution around its PVP orbit, it will obviously âsubtract ONE revolution from the Sunâ which will therefore need ONE more turn to complete a full Great Year! Now, get this: as I tested the Tychosium in successive steps of 25345 years, it now turns out (to my utter delight) that our Moon returns to very nearly the âsame placeâ every 25345 years! This is a wonderful confirmation of the TYCHOS modelâs tenet that our Moon acts as the âcentral driveshaftâ of our entire Solar System. Moreover - and better still â it also elegantly corroborates my proposed 811000-year Mega Cycle (see Chapter 20), and hereâs how you can verify it for yourself :

In the Tychosium, set the date at 2001-06-21 (on that day, there was a solar eclipse and we thus see the Moon and the Sun aligned at 6h of RA â or at â12 oâclockâ, if you will). Next, start moving the date forwards in steps of 25345 years. You will see that the Moon will gradually âtick around the PVP clockâ (in clockwise direction) and, after 405500 years or so (i.e. half a 811000-year Mega Cycle â or about 16 âstepsâ of 25345 years) it will find itself at â6 oâclockâ. Then, after another 16 such steps, it will return to where it was on 2001-06-21 (i.e. 811000 years earlier).

All this to say, dear Sean, that if you have decided to âabandon shipâ and to leave this forum for good, please know that I will always fondly remember your fine contributions to the TYCHOS model, in spite of your rather fuzzy grasp of the same.