An astronomical symphony

oriel36

https://sol24.net/data/html/SOHO/C3/96H/VIDEO/

The reason the stars change position from left to right of the central/stationary Sun is due solely to the Earth's orbital motion using a satellite tracking with our orbit around the Sun. On December 26th, this is what can be seen until a few days later Mercury comes into view traveling in direct motion behind the Sun as seen from a slower moving Earth -

https://www.theplanetstoday.com/

Soon Jupiter will emerge from behind the stationary Sun traveling from left to right but also in direct motion against the background stars. The reason for this is that Jupiter's motion is slower than the Earth's so will always be seen moving from left to right whereas Mercury and Venus will alternatively move from right to left (direct motion) and from left to right (retrograde motion) as seen from a slower moving Earth.

Saturn will soon enter the time lapse also moving from left to right of the stationary Sun but will take a shorter time to enter and exit the time lapse as its motion is slower than Jupiter's.

This perspective is new so it takes a little getting used to but the symphony always changes depending on which planets come into view and whether they are travelling faster or slower than the Earth.

ps200306

oriel36 wrote: »

Soon Jupiter will emerge from behind the stationary Sun traveling from left to right but also in direct motion against the background stars. The reason for this is that Jupiter's motion is slower than the Earth's so will always be seen moving from left to right whereas Mercury and Venus will alternatively move from right to left (direct motion) and from left to right (retrograde motion) as seen from a slower moving Earth.

It's true that Jupiter will always be seen in direct motion against the stars in a SOHO picture when, by definition, it's within a few degrees of the Sun. It moves in retrograde at other times of year.

oriel36

ps200306 wrote: »

It's true that Jupiter will always be seen in direct motion against the stars in a SOHO picture when, by definition, it's within a few degrees of the Sun. It moves in retrograde at other times of year.

The SOHO camera does something extraordinary by allowing observers to look towards the inner solar system and the central/stationary Sun along with the change in position of the background stars from left (evening appearance) to right (morning appearance) due to the orbital motion of the Earth minus daily rotational inputs.

The original heliocentric astronomers used a 'fixed star' background* to resolve the direct/retrograde motion of the slower moving planets seen from a faster moving Earth -

https://apod.nasa.gov/apod/ap011220.html


An entirely separate framework is required to account for the direct/retrograde motions of the faster moving Venus and Mercury seen from a slower moving Earth. These planets move in direct motion while travelling behind the Sun and in retrograde motion when they pass between the slower moving Earth and the central Sun representing a back and forth motion of faster moving planets in smaller orbital circumferences.

https://sol24.net/data/html/SOHO/C3/96H/VIDEO/


While Jupiter, Saturn , Mars and the rest of the slower moving planets further from the Sun will always enter the time lapse moving from left to right, the faster moving inner planets Venus and Mercury will be seen moving from right to left and left to right depending on whether they are moving behind the Sun or in front of our central star.


It is a wonderful project to split what our astronomical ancestors called direct/retrograde motions into two distinct perspectives depending on whether the planets are slower/ further from the Sun or faster/nearer the Sun than our moving planet. I assume that anyone who is interested would focus on the change in position of the stars using the orbital motion of the Earth and the Sun as a central stationary reference whereas the first heliocentric astronomers used a framework inherited from Ptolemy where the Sun moves through the stars while the planets 'wander' in direct/retrograde motion .

* ". . . the ancient hypotheses clearly fail to account for certain important matters. For example, they do not comprehend the causes of the numbers, extents and durations of the retrogradations and of their agreeing so well with the position and mean motion of the sun. Copernicus alone gives an explanation to those things that provoke astonishment among other astronomers, thus destroying the source of astonishment" Kepler

ps200306

oriel36 wrote: »

The original heliocentric astronomers used a 'fixed star' background... An entirely separate framework is required to account for the direct/retrograde motions of the faster moving Venus and Mercury...

Not it's not. The same heliocentric framework does quite nicely.

oriel36 wrote: »

While Jupiter, Saturn , Mars and the rest of the slower moving planets further from the Sun will always enter the time lapse moving from left to right, the faster moving inner planets Venus and Mercury will be seen moving from right to left and left to right depending on whether they are moving behind the Sun or in front of our central star.

That's a limitation of the field of view of the SOHO coronagraph, and not true in general. The switch in direction happens at maximum elongation, when the inferior planets are still "in front of" the Sun, that is they are in front of a plane that bisects the Sun normal to the Earth-Sun line. But maximum elongation is never seen in the SOHO C3 coronagraph which only has an FOV of 30 solar radii.

oriel36

ps200306 wrote: »

Not it's not. The same heliocentric framework does quite nicely.

To be fair, most people nowadays enjoy the spectacle and have enough presence of mind to let the astronomical symphony play out so when they look safely in the direction of the central/stationary Sun presently, the satellite picks up what our eyes cannot -

https://sol24.net/data/html/SOHO/C3/96H/VIDEO/

Mercury enters the time lapse dazzling as it travels behind the central Sun and is greatly diminished in luminosity as it travels between our slower moving planet and the Sun because it shows its dark side mostly to us.

A whole individual opus can be enjoyed across a year where observers become accustomed to how we see the faster and slower planets moving relative to the motion of the Earth and the stationary Sun and it never repeats itself from year to year with something new to watch and interpret -

https://www.youtube.com/watch?v=-g5JkGzALNc

https://www.youtube.com/watch?v=oQSmFbh64QQ&t=23s


In order to account for the motions of Venus and Mercury as they race back and forth behind and in front of the Sun like cars on a track, the Earth's orbital motion accounts for the change in position of the stars from left to right of the Sun thereby setting our star up as a stationary reference in order to enjoy the motions of Venus and Mercury and their actual loops of the Sun.

The original heliocentric astronomers would have understood and accepted the need to split the perspectives but then again, they did not have the engineering marvels of satellites that we now have as it sets up permanent solar eclipse conditions by artificial means as we look towards the central solar system. It takes nothing away from those astronomers but adds a new facet to observing for people with a genuine interest in astronomy today.

ps200306

oriel36 wrote: »

The original heliocentric astronomers would have understood and accepted the need to split the perspectives but then again, they did not have the engineering marvels of satellites

Copernicus, the original heliocentric astronomer as far as the Copernican revolution went, did not rely on any visual perspective but took an explicitly mathematical approach. In De Revolutionibus he set out, by way of chord geometry and tables, a method of predicting the observed positions of the planets. Early modern heliocentric astronomers had their own engineering marvels. Within a century or so there were physical computers in the form of Huygens' "heliocentric planetary machine" (based on gear trains calculated off Earth's year of 365.25 days), and later orreries. It was the use of mathematics and computers which freed heliocentric astronomers from needing purely earth-bound perspectives. In exactly the same way, I don't need SOHO's cameras as I have Stellarium.

oriel36

This project, and it is a project, is for those who share the same excitement for perspectives that the original heliocentric astronomers like Kepler and Galileo did for a moving Earth and planets in a Sun centred system -

https://apod.nasa.gov/apod/ap011220.html

"Now what is said here of Jupiter is to be understood of Saturn and Mars
also. In Saturn these retrogressions are somewhat more frequent than in
Jupiter, because its motion is slower than Jupiter's, so that the Earth
overtakes it in a shorter time. In Mars they are rarer, its motion
being faster than that of Jupiter, so that the Earth spends more time
in catching up with it. Next, as to Venus and Mercury, whose circles
are included within that of the Earth, stoppings and retrograde motions
appear in them also, due not to any motion that really exists in them,
but to the annual motion of the Earth. " Galileo

While getting the resolution for the slower moving planets right as the resolution relies on relative speeds between the faster moving Earth and the slower and further planets, an entirely new perspective is required for Venus and Mercury.

Their direct/retrogrades motions represent back and forth motions behind and in front of the Sun like witnessing cars on a race track with their own traits such as size and luminosity variations -

https://www.popastro.com/images/planetary/observations/Venus-July%202010-January%202012.jpg

It is why Venus presently appears so bright close to the moon yesterday as it begins to swing in front of the Sun as an evening appearance.


As is customary, observers can enjoy the symphony right now as it is happening as we look inwards to the central Sun and the foreground and background details -

https://sol24.net/data/html/SOHO/C3/96H/VIDEO/

https://www.theplanetstoday.com/


It is not for everyone, however, Venus will come into view traveling in retrograde motion in a number of months as it passes between the slower Earth and the stationary Sun. Once again, most people stay quiet as opposed to contending with the split perspectives of direct/retrogrades (in old astronomical language) rather than share the excitement of a new project in the making and that is fine.

ps200306

oriel36 wrote: »

This project, and it is a project, is for those who share the same excitement for perspectives that the original heliocentric astronomers like Kepler and Galileo did for a moving Earth and planets in a Sun centred system -

https://apod.nasa.gov/apod/ap011220.html

"Now what is said here of Jupiter is to be understood of Saturn and Mars
also. In Saturn these retrogressions are somewhat more frequent than in
Jupiter, because its motion is slower than Jupiter's, so that the Earth
overtakes it in a shorter time. In Mars they are rarer, its motion
being faster than that of Jupiter, so that the Earth spends more time
in catching up with it. Next, as to Venus and Mercury, whose circles
are included within that of the Earth, stoppings and retrograde motions
appear in them also, due not to any motion that really exists in them,
but to the annual motion of the Earth. " Galileo

While getting the resolution for the slower moving planets right as the resolution relies on relative speeds between the faster moving Earth and the slower and further planets, an entirely new perspective is required for Venus and Mercury.

...Once again, most people stay quiet as opposed to contending with the split perspectives of direct/retrogrades (in old astronomical language) rather than share the excitement of a new project in the making and that is fine.

It is customary to provide references and context for your quotes. Had you done so, we would see that your Galileo quote is from Day 3 of his Dialogue Concerning the Two Chief World Systems. In the sentence immediately following your extract, Galileo goes on to say: "This is acutely demonstrated by Copernicus, enlisting the aid of Apollonius of Perga, in Chapter 35 of book V in his Revolutions".

Turning to that chapter of De Revolutionibus, we find Copernicus elaborating on the very general explanation of nonuniformity in planetary motion that he has already set out in chapter 3. While in both chapters 3 and 35 he provides separate diagrams for the inferior and superior planets, he outlines an entirely general explanation for retrograde motions. I quote from chapter 35 here without reproducing the diagrams, as the implications are obvious:

But if the ratio of the half-segment within the aforesaid inner circle to the remaining outer segment exceeds the ratio of the earth’s speed to the velocity of Venus or Mercury, or the ratio of the motion of any of the three outer planets to the earth’s speed, the planet will advance eastward. On the other hand, if the first ratio is smaller than the second, the planet will retrograde westward.

Even though Copernicus mentions the situation for inferior and superior planets separately, it's quite clear he understood the reason for retrograde motion by way of a mathematical model. Moreover, he could have applied the same mathematical model to predict retrograde motion of any planet from the perspective of any other. As I said, far from "an entirely new perspective [being] required for Venus and Mercury", the power of the mathematics was to free the astronomer from any vagaries of visual perspective. And indeed, if any such perspective was desired, Copernicus' mathematics were soon used to "program" analogue physical computers that could place the observer's eye anywhere.

oriel36

ps200306 wrote: »

As I said, far from "an entirely new perspective [being] required for Venus and Mercury", the power of the mathematics was to free the astronomer from any vagaries of visual perspective.

The power of mathematics indeed !, mathematical modelers following Copernicus and Galileo couldn't even get the resolution for the direct/retrogrades of the slower moving planets right as that resolution is based on relative speeds where the faster moving Earth causes the slower moving planets to temporarily fall behind in view just as Galileo described -

https://apod.nasa.gov/apod/ap011220.html

This infers a central Sun indirectly because the direct/retrograde loops are illusory when gauged against a fixed background of stars so that only by assigning an orbital motion to the Earth can the loops disappear -

https://apod.nasa.gov/apod/ap181108.html

https://upload.wikimedia.org/wikipedia/commons/e/e9/Kepler_Mars_retrograde.jpg

"Copernicus, by attributing a single annual motion to the earth,entirely rids the planets of these extremely intricate coils,leading the individual planets into their respective orbits,quite bare and very nearly circular. In the period of time shown in the diagram, Mars traverses one and the same orbit as many times as the 'garlands' you see looped towards the center, with one extra, making nine times, while at the same time the Earth repeats its circle sixteen times " Kepler Astronomia Nova 1609


The loops of Venus and Mercury are actual as the run faster and smaller circuits than the slower moving Earth with Mercury presently running behind the stationary Sun -

https://sol24.net/data/html/SOHO/C3/96H/VIDEO/

This is a new astronomical project that anyone can join in for what else is astronomy other than a visual exercise with magnification,satellites and animated graphics acting as helpful tools to enjoy the spectacle.

For your sake, this type of interpretation is not for everyone nor is it against anyone as the symphony plays out in the eyes who really enjoy astronomy.

ps200306

oriel36 wrote: »

The loops of Venus and Mercury are actual as the run faster and smaller circuits than the slower moving Earth with Mercury presently running behind the stationary Sun

Yes, but the retrogrades of Venus and Mercury are of exactly the same nature as those of the superior planets. On your previous go at this, you suggested that the inferior planets were in retrograde for half their orbits until you were corrected.

oriel36 wrote: »

This is a new astronomical project that anyone can join in for what else is astronomy other than a visual exercise with magnification,satellites and animated graphics acting as helpful tools to enjoy the spectacle.

For your sake, this type of interpretation is not for everyone nor is it against anyone as the symphony plays out in the eyes who really enjoy astronomy.

It's new since 1543 as was pointed out to you last time. And, ah yes, I remember the "animated graphics acting as helpful tools" until they started contradicting what you were saying. Then you told people they had to get out under the night sky and stop living in an RA/Dec bubble.


You've been doing this under various usernames since at least 2011, but here's one of the more extraordinary ones from 2014 as gkell11, in which you were repeatedly destroyed yet kept coming back for more. And since the current thread will now follow the trajectory of all those others, I will bid you adieu.

oriel36

ps200306 wrote: »

Yes, but the retrogrades of Venus and Mercury are of exactly the same nature as those of the superior planets. On your previous go at this, you suggested that the inferior planets were in retrograde for half their orbits until you were corrected.

I suggested no such thing, the back and forth motions of Venus and Mercury in their actual circuits of the Sun require they move in one direction against the stellar background and then the other using the central Sun as a stationary reference.


I shrug as the visual symphony is enjoyed in silence by many people. When Venus and Mercury pass between the slower moving Earth and the stationary Sun, they move faster than the change in position of the stars to the central Sun as they move faster than the Earth. The time lapse from a satellite tracking with the Earth motion shows Mercury in retrograde motion in January 2003 as it moves rapidly between the stationary Sun and the slower Earth -

https://www.youtube.com/watch?v=oQSmFbh64QQ&t=249s

Everything else can wait as observers become accustomed to the two frameworks which account for the motions of the planets depending on whether they are moving faster or slower than the Earth.

https://www.youtube.com/watch?v=oQSmFbh64QQ&t=249s

It is not for everyone so good luck to you.

ps200306

oriel36 wrote: »

ps200306 wrote: »

Yes, but the retrogrades of Venus and Mercury are of exactly the same nature as those of the superior planets. On your previous go at this, you suggested that the inferior planets were in retrograde for half their orbits until you were corrected.

I suggested no such thing, the back and forth motions of Venus and Mercury in their actual circuits of the Sun require they move in one direction against the stellar background and then the other using the central Sun as a stationary reference.

This is gibberish. Either you are using the Sun as a stationary reference or you are using the stellar background as a stationary reference. If the former, then the inferior planets move back and forth with respect to the Sun between maximum elongations. If the latter then the inferior planets move in direct motion with respect to the stars except for retrograde loops exactly like all the other planets.

oriel36 wrote: »

Everything else can wait as observers become accustomed to the two frameworks which account for the motions of the planets depending on whether they are moving faster or slower than the Earth.

Only one framework is required. I just quoted it to you from Copernicus.

oriel36 wrote: »

It is not for everyone so good luck to you.

It's not for anyone who knows the basics of astronomy and the actual history of the Copernican revolution.

oriel36

This is for people who like the symphony provided by a satellite that can look towards the central Sun and create permanent solar eclipse conditions. The stars actually do change position from left to right of the Sun due solely to the Earth's orbital motion around our parent star so it provides a simple way to reference the faster moving Venus and Mercury around the Sun in actual loops/ circuits. It takes nothing to realise that Mercury is now moving behind the Sun as seen from a slower moving Earth as it moves in the opposite direction to the background stars -

https://sol24.net/data/html/SOHO/C3/96H/VIDEO/

The 'fixed stars' background by which the illusory loops of the slower moving planets further from the Sun than the Earth doesn't require the stars to change position as their motions rely solely on relative speeds between the faster moving Earth and slower motions which give the illusion they are moving backwards against the stars -

https://apod.nasa.gov/apod/ap011220.html


People have the ability to work through the two different perspectives and enjoy the astronomical symphonies as best they can using all the help they can find -

https://www.theplanetstoday.com/

They can see Mercury and Jupiter as we see them presently although one planet is moving faster while the other is moving slower than the Earth and put the perspective in context by scrolling forwards with the dates.


The wider world has clued into the differences in perspectives but is rather slow to develop it as a project. That is fine because ultimately the visual symphony is for those who can get excited or are curious enough to explore this new approach to heliocentric astronomy for the visual exercise it is.