Question Regarding the variable size of mars retrograde loops

Why are some of the orbital loops thin and narrow and other wider? How is this explained?
I imagine it is due to the fact that it is dependent on the binary dance of Mars and the Sun, but I would like clarification if possible on the issue because I am talking with people about the Tychos and the question has come up.

Dear MUU,

My short answer would be: Because that is precisely how Mars is empirically observed to behave.

In fact, even Kepler once drew a (little-known) ‘geocentric’ diagram based on the observed motions of Mars - as recorded by his master Tycho Brahe - over a period of 16 years (1580-1596). It shows Mars retrograding in alternating thinner or wider loops - exactly as traced by the digital Tychosium 3D simulator :

My longer answer would be: Because the plain laws of geometry say so. If you have an "object B "(Mars) revolving around another revolving “object A” (the Sun), “point B” will naturally generate ‘retrograde loops’ (i.e. so-called “trochoids”). In other words, an observer located at the center of the orbits of objects “A” and “B” will see the motion of “object B” periodically reversing direction. Now, if the circular path of “object B” isn’t perfectly centered around “object A” (i.e. if it’s eccentric / off-center in relation to “object A”), these loops will be alternately thinner or wider. It’s just a matter of plain geometry - no ‘magic’ involved! Please buy a children’s spirograph set and check it for yourselves. :slight_smile:

On the other hand - as thoroughly expounded and illustrated here - the heliocentric model’s explanation for the different lenghts of Mars’s observed retrograde motions is fundamentally flawed.

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There is something magical about trochoids…! I am one of the few who didn’t come across a spirograph as a child but remember the lights people would put on the spokes of their push-bikes…and all for fun(spirit of delight). Five minutes researching Trochoids is worth the effort.


And remember: there is nothing strange or exceptional about these trochoidal / spirographic motions of our planets. As illustrated in Chapter 2 of my book, modern astronomers are now empirically observing all sorts of - even more complex - spirographic trajectories in other star systems. Of course, in Tycho Brahe’s and Kepler’s times, this was not known - nor even remotely imagined. Hence, Kepler - who couldn’t make any ‘physical sense’ out of his own drawing (see my above post) simply discarded this (correct) hypothesis which is, in fact, to be found in the first pages of his famous opus "Astronomia Nova".


Above image from p.6 of “The barycentric motion of exoplanet host stars”(opens in a new tab) by M. A. C. Perryman and T. Schulze-Hartung (2010)

So the question becomes: “why would our planets NOT revolve around spirographic orbits, since this is what is observed in many (or quite possibly all) other star systems?”

Allow me to state once again: the TYCHOS model is founded upon plain, rational logic - common sense - and solid statistical probability.

Make that sink in. :slight_smile:

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Thanks for all the reply’s.
I find it a great challenge to introduce people to the TYCHOS. I am learning and studying it every day. I am finding that it pays not to overwhelm people with too much information all at once. So my current method is to put it out in small incomplete fragments until i hit upon a factoid that makes them take interest, then I expand slowly from there. sort of like fishing. It is funny to me how even though I send links to the book, people don’t look at it, and the more they know about science, the less they want to have anything change what they think they know. They need to be guided through the concepts because the Heliocentric model is so ingrained in everyone’s reality. etc.,

This is the response i sent to my friend. Thanks again for your support and help. etc.

"We don’t know what causes the solar system to stay exactly tuned for thousands of years. Maybe speculate its magnetically balanced along with gravity… not sure why BUT.
It is what is observed…
It is what is observed
If you look at the picture (above with the orange border marked 8:04) on the right is Kepler’s drawing of what he and Brahe observed, you will see that it matches what is in the Tychosium. It may be because Mars is orbit is not centered exactly around the sun because of its binary relationship.


Muu, I hear what you are saying, but I might add that a very intelligent friend of mine replied exactly the same response to me when he was confronted with the non-physical description of earth’s so-callled orbit around the sun. “It’s exactly what we observe.”

Well, not actually. Number one, “we” haven’t observed anything, “we” were taught that in school and “we” live in a city and cannot ever even see the stars. Number 2, what “we” observe is not even observable at all, and I know because I went outside and started regularly looking and observed something completely contrary to what “we” were taught.

So I caution everyone on here, that before you tell anyone it is what “we” observe, be sure that you actually have spent the time and actually have observed it. The preponderance of my questions came after I had moved to a rural area and began to see things that I had never taken note of in the past.


Yes, very good point. It is what they say about the heliocentric model also. How can you question it? Its what we see.

The cool thing to me in this answer to my friend, is the case where Kepler has drawn out the same shape that the Tychosium draws for those dates of 1596 and 1580. Similar to all the historical information about Haley’s comet and all the confusion about it for instance, and the work Simon has done to correlate that with the Tychos model. All these past observations were made.
As far as me actually observing with enough accuracy to be meaningful, I am not the person to make those observations. I can, and have crossed checked many things in the Tychosium with other star map programs over the past 3 years and learned enough that I have been convinced that this model is a more rational explanation for the movements of the solar system. So,I am for now, treating the Tychos as if it were the true configuration, unless something comes along that changes my mind.
I think spreading the word about the Tychos is super important. Perhaps someone with the ability and skill will be able to seriously test this model out and prove once and for all that: rationality rules. I personally think Simon has already found that proof.


One thing that everyone can do is pay attention to the moon and it’s even observable during the day quite a lot. I always get a kick out of watching the full moon rise. It has so many different “characters” almost, it moves around on the horizon, it grows and shrinks, it is a very enigmatic object. It really has a strong influence on us but most people aren’t aware of it. When you know what it is doing it is easier to understand it’s effects on you and plan accordingly and I don’t just mean gardening. It’s a powerful force.