I do think so George

Sorry I do not know

Sorry I do not know

The explanation is given by Kepler law number 2; the laws governing motion of planets are formulated as follows:

”(1) planets move in elliptical orbits with the Sun as a focus, (2) a planet covers the same area of space in the same amount of time no matter where it is in its orbit, and (3) a planet’s orbital period is proportional to the size of its orbit (its semi-major axis)”.

https://solarsystem.nasa.gov/resources/310/orbits-and-keplers-laws/

George Stoica

Thank you very much for your multidimensional answer to my RG discussion question, which confirms Isaac Newton's gravitational theory and laws while, at the same time, emphasizing the interrelationship between the Sun and the planets in the solar system. I am also very grateful for, and I greatly appreciate your kind recommendations.

With my ver best regards and best wishes.

Dear Nancy Ann Watanabe and Readers,

Please consider also the following lecture:

https://youtu.be/xdIjYBtnvZU

that explains all nuances of planetary motions with unparalleled beauty and clarity.

In order to establish correctly the relation between Kepler and Newton please consult:

https://earthobservatory.nasa.gov/features/OrbitsHistory/page2.php

Bushra Mahmood Alwan ,

Thank you for your interest in the discussion topic! I appreciate your kind reply and especially I would like to thank you for your recommendation.

Bazar Dzhumaevich Ulugov ,

Thank you for your participation in this discussion thread, and I am also grateful for your kind recommendation. Best regards.

Janusz Pudykiewicz ,

Thank you so much! I really appreciate your answers to my RG discussion question, especially the tying together of Newton with Johannes Kepler, who also contributed several laws, including, as you mention, the elliptical orbits of planets. Even today, most Internet descriptions of the planets in our solar system only emphasize that the planet Mercury has a rather elliptical orbit about the Sun and so they usually do not make any mention of the other planets having elliptical orbits! In fact, the notion that Newton's view is mechanical and mechanistic is not really accurate, in view of the variability of the orbital paths of all of the planets, which are following orbital paths which are influenced by a number of different extenuating circumstances.

With my best regards.

I thought about this for a long time since I believe it's actually an excellent and complex question. The temptation to reply that it can be completely answered by quoting Newton's laws of gravitation and motion, or Kepler's laws of planetary motion, or even Einstein's view of space-time curvature being gravity, is indeed great. But we need to revert to the classic situation in which a child keeps asking "why" in response to everything he or she hears. The first part of my answer is a proposal that we live in a mathematical universe (though they might or might not agree with the details I propose, this opinion is shared by the scientists Max Tegmark, Erik Verlinde, Ed Fredkin, John Wheeler, and others).

BITS AND TOPOLOGY

Electronics' binary digits can be used to draw a two-dimensional computer image of a Mobius strip. Two united Mobius strips create a three-dimensional figure-8 Klein bottle

Polthier (2003). Polthier, Konrad, "Imaging maths - Inside the Klein bottle", http://plus.maths.org/content/os/issue26/features/mathart/index

that acts as a building block of space, time, forces’ bosons and matter’s fermions. This creates a supersymmetry (linkage) between fermions and bosons. A recent paper

Afshordi (2017). Afshordi, N. & Corianò, C. & Delle Rose, L. & Gould, E. & Skenderis, K. From Planck Data to Planck Era: Observational Tests of Holographic Cosmology. Phys. Rev. Lett. 118, 041301. https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.04130

says that in a holographic universe, all of the information in the universe is contained in two-dimensional packages trillions of times smaller than an atom. Therefore, "Extracting Energy From Black Holes" (10.13140/RG.2.2.20941.05609) proposes this - If it's assumed from supersymmetry that the Mobius contains all the information in both fermionic and bosonic particles, trillions of Mobius strips could form a photon and trillions of more complex figure-8 Klein bottles could form a more complex graviton (suggesting union of electromagnetism and gravitation).

You need to journey round a Mobius twice (make 2 revolutions) to return to the starting point. So if 1 anyon (a 3rd type of particle that occurs only in two-dimensional systems, was discovered in 2020, and is possibly a Mobius strip or figure-8 Klein bottle according to this discussion) moves round another, return to the original quantum state can only occur after 3 revolutions - the 2 required to return a Mobius to its start plus the complete revolution of one moving around the other. If the particle under study is a figure-8 Klein bottle, then the revolution of one about the other is supplemented by 4 revs (you go round each of the 2 combined Strips twice), and 5 revs must be completed before return to the original quantum state is achieved. (Physics' theories about anyons predict these numbers of revs regarding the quantum state.)

Figure 1 - Mobius strip, Wick rotation, figure-8 Klein bottle

Referring to the figure-8 Klein bottle aka the Mobius doublet: Note that the reddish positive curvature fits together with the bluish negative curvature to produce the outline of a doughnut which is technically flat. When many doublets are placed together, binary digits can fill in any gaps or voids in the same way that computers can morph a picture on a screen and extrapolate a small patch of blue sky to make a sky that's blue from horizon to horizon. Morphing by bits can also delete a single doublet's central "hole", making the doublet simply (not multiply) connected. A flat universe that is also simply connected implies an infinite universe,

Luminet (1995): "Cosmic Topology" by Jean-Pierre Luminet and Marc Lachi`eze-Rey, Physics Reports 254 [3]: 135–214, www.arXiv:gr-qc/9605010

The physicist and science historian Abraham Pais wrote that “In 1924 the scientist Wolfgang Pauli was the first to propose a doubling of electron states due to a two-valued non-classical "hidden rotation".

Pais (1991). Pais, A. Niels Bohr's Times. Oxford: Clarendon Press, p. 201 (1991).

Extending the ideas of “doubling”, “two-valued” and “hidden rotation” from the particle spin Pauli had in mind to the Mobius strip being a basic, fundamental unit of reality; it can be seen that Pauli’s proposal has an analogy to this article. The doubled Mobius strips (doubled to form a figure-8 Klein bottle) could be produced by the two-valued binary-digit system used in electronics. The bottles possess a hidden rotation, now identified as adaptive Wick rotation, which gives a fourth dimension to space-time. Using the photoelectric effect to explain that the so-called imaginary numbers and imaginary time of the Complex Number Plane's y-axis can be real,* this Wick rotation - after a short section on imaginary computers - is shown to be consistent with Special Relativity’s slowing of time (a.k.a. time dilation).

* At the start of last century, physicist Max Planck assumed that electromagnetic radiation can only be emitted or absorbed in discrete packets, called quanta. Albert Einstein postulated that Planck's quanta were real physical particles (what we now call photons), not just a mathematical device as Planck and most scientists believed for years. From there, Einstein developed his explanation of the photoelectric effect.

PROGRAMMING

(It's a good thing my comments are being read by scientists. You'll give my next words a fair hearing, and you won't respond with a knee-jerk, emotional reaction that fits in with traditional beliefs and with preconceptions.)

The section above logically shows that the universe is composed of mathematics (base-2 maths - the bits or binary digits of 1 and 0 used in electronics) form the Mobius strips which are a foundation of all the information in the universe and its particles. Therefore, the universe is programmed like a computer. This does NOT mean the traditional God created us because we'd then have to ask where that God came from.

The clue is that our origin may be electronic. Eons from now, human electronics will be unimaginably advanced and we're forced to cast aside our bias that men and women will forever be incapable of such a miracle as creation of the universe. If any one of you can absolutely prove people will be similar to today's population in millions or billions of years (not mere centuries or millennia), I'll discard these ideas. If you can't prove we'll be the same, it's only fair to the search for truth that you consider these ideas.

Even an infinite space and eternal time might be created, perhaps by incorporating infinite numbers like pi into electronic calculations of the remote future - and also by transmitting portions of Virtual Reality throughout different times (this would be distantly related to present Augmented Reality). These transmissions show that at least some of the current ideas concerning time travel are on the right track.

So the kid who asks "Why do Kepler's laws of planetary motion work?" just might find a satisfactory answer when told that the universe is programmed. Meanwhile, all the "intelligent" and "scientific" adults will be appalled by such nonsense. It might be a good idea to open your Bible to Matthew 19:14 where Jesus says, "Suffer little children, and forbid them not, to come unto me: for of such is the kingdom of heaven."

Dear Nancy, this is a simple question on the surface. It can be interpreted in the classical way if we refer to Kepler or Newton, more argumentative if we consider, for example, the ethereal theory. Perhaps, the angular momentum could be a clue to follow to investigate the problem.

Dear Nancy Ann Watanabe,

Thank you for your comment. The orbit of Mercury is an excellent example to be considered. It is very well known that the motion of the perihelion of of this planet is greater by 38” per century that it should be from the perturbation due to other planets in the solar system (in the sense of all calculations within the framework of classical mechanics). The explanation of this fact is provided within the framework of the Relativity Theory; see for example Silberstein (1917):

http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1917MNRAS..77..503S&defaultprint=YES&filetype=.pdf

We should only admire the precision of all calculation performed in 1845 by Le Verrier in the era without excess of all computing devices that we take for granted in our time.

Dear Rodney Bartlett,

Your comments are indeed very stimulating and provoking to search for the underlying principles that are not considered in the regular textbooks. Fortunately Professor Luminet's blog addresses some of the issues potentially relevant to topology and Kepler's laws

https://blogs.futura-sciences.com/e-luminet/

Dear Valentino Straser

This suggestion is correct; second Kepler's law express conservation of the angular momentum:

https://openstax.org/books/university-physics-volume-1/pages/13-5-keplers-laws-of-planetary-motion

The closer a planet is to the Sun, the stronger the Sun's gravitational pull on it, and the faster the planet moves. The farther it is from the Sun, the weaker the Sun's gravitational pull, and the slower it moves in its orbit. https://howthingsfly.si.edu/flight-dynamics/kepler%E2%80%99s-laws-orbital-motion

As Earth rotates, the Moon's gravity causes the oceans to seem to rise and fall. (The Sun also does this, but not as much.) There is a little bit of friction between the tides and the turning Earth, causing the rotation to slow down just a little. https://spaceplace.nasa.gov/review/dr-marc-earth/earth-rotation.html

The speed at which a planet orbits the Sun changes depending upon how far it is from the Sun. When a planet is closer to the Sun the Sun's gravitational pull is stronger, so the planet moves faster. https://public.nrao.edu/ask/do-planets-change-speed-when-orbiting-the-sun/

Analyzing the micro-gravitational variations caused by the passage of the meridian of the Sun and the Moon, it is often noted that there is not much difference between the two gravitational effects.

> What accounts for the fact that the planets have been observed to quicken or to retard their motion?

Chinaza Godswill Awuchi Your first & third answers are basically correct for this question. Your second answer, referring to tides on the Earth, is the answer to a different question to the one posed by Nancy Ann Watanabe - because tides like these alter a planet's spin (rotation) speed, not its orbital speed.

Another effect which does change the orbital speed of the planets, and which has not been mentioned yet, are the Milankovitch cycles, specifically the variation in orbital eccentricity. In the case of the Earth, this cycle takes around 100,000 years.

In fact, when the body moves in orbit, three forces act on the body:

1. Gravity Ft = m * g;

2. Centrifugal force Fc = m * V ^ 2/R;

3. The force of inertia due to the vector difference in gravity forces.

In a circular orbit, the centrifugal force fully compensates for the force of gravity, the body moves only under the influence of inertia.

In elliptical orbit, there is a difference between centrifugal force and gravity. This difference alternately becomes either positive or negative - shown in the graphs in the attached article (sorry that the article is in Russian). However, the body in such an orbit also moves by inertia

Sun has more gravitational pull.so, the planet closest to the sun it has more gravitational pull and also rotate at different speed than other planet,and the distant planet will have less gravitation pull to the sun so it rotates slowest and that's why there is no living animals and plants.but our earth in perfect distance from sun so, it rotates at correct speed and have perfect gravitational pull.

Between 1609 and 1619, Johannes Kepler, had a remarkable 10 years. He published the first two of his laws of planetary motion in 1609, used the dark sky and lack of infinite stars to argue for an infinite universe in 1610, and published his third and final law of planetary motion in 1619. He was an assistant of Tycho Brahe for a while, and subsequently had access to all his astronomical data, which he used to come up with his laws. If you’re not familiar with his 3 laws, which are all corrections to Copernicus’s model, they’re;

1.) *All planets move about the Sun in elliptical orbits, having the Sun as one of the foci. (Doing away with the notion of the “perfect” circular orbits)

2.) A radius vector joining any planet to the Sun sweeps out equal areas in equal lengths of time. (Showing that the orbital radius and angular velocity of the planet in the elliptical orbit will vary. Or put more simply, a planet travels faster when closer to the sun, then slower when farther from the sun)

3.) The squares of the sidereal periods (of revolution) of the planets are directly proportional to the cubes of their mean distances from the Sun. (Capturing the relationship between the distance of the planets from the sun, and their orbital periods). Upon the publication of his third law, Kepler wrote; “I first believed I was dreaming...But it is absolutely certain and exact that the ratio which exists between the period times of any two planets is precisely the ratio of the 3/2th power of the mean distance."

So Look at *Kepler's Laws of Motion*

And also In Newtonian mechanics, gravity is a centripetal force.Assume a circular trajectory. Set the formula for the centripetal force equal to the formula for the gravitational force. What can you say about the orbital speed then? I have also give some beyond information about ur question ...

Sun, being a moving body, it is physically impossible for any other body (including the planets) to orbit around the sun in any type of geometrically closed path. Planets' real orbits about the sun's median path are wavy with the planets alternately moving to the front and back of the sun. Variations in the speeds of planets are due to mutual gravitational attraction between neighboring bodies, including the sun. See: http://vixra.org/abs/1311.0018 , http://vixra.org/abs/1008.0010

Nainan.

When we decide to refine our comments on the problem of the movement of heavenly bodies, no discussion can be complete without the reference to the seminal contribution of Henri Poincaré discussing foundations and deep implications of celestial mechanics. For a brief discussion please see

https://projecteuclid.org/journalArticle/Download?urlid=bams%2F1183407387&referringURL=https%3A%2F%2Fwww.google.ca%2F&isResultClick=False

The full text of the Poincare book is available for free download on many internet sites.

It is just a natural movement of the bodies in the gravitational field, where the Sun dominates with its huge mass. Planets are generally orbiting the Sun on elliptical orbits. Most primitive explanation: The gravitational pull (vector) and the centrifugal force (vector) are mutually compensated, so the closer to the Sun, the gravitation is stronger and the velocity is higher. Most advanced explanation: Einstein's General relativity that explains the movement of the planets in the space-time deformed due to the Sun mass.

I have read and reread the books of Poincarè and his thought is of a surprising modernity in addition to the splendid considerations on celestial mechanics.

Jan Balaz ,

Thanks so much for your nice answer to this ResearchGate discussion thread question, and congratulations for your scientific research achievements in astrophysics, space exploration, and related subjects!

Valentino Straser ,

I appreciate your insightful suggestion to consult Pointcare's works pertaining to celestial mechanics. I am grateful to you for your important scientific accomplishments, especially in geological dynamics, seismology, and related areas. Earth is always changing, and, sometimes, natural events can have unexpected impacts, so it is extremely helpful to provide access to current information to meteorologists and officials in earthquake-prone locations.

Dear Nancy,

thanks for your comment. To retrace Poincarè's thought regarding natural systems, it is necessary to remember the concept of deterministic chaos, very useful for reading terrestrial dynamics.

Regards,

Valentino

One of the best stories behind the discovery of chaos is featured in the article

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3202497/

The passage from Laplace determinism to the statistical reasoning of the present day is presented in a very convincing manner. The important conclusion concerns the role of a timescale. In planetary movements, we can theoretically observe chaotic behavior, but for all practical reasons the planetary system is stable. The different situation is in the chaotic behavior of atmospheric systems as discovered by E. Lorenz, this problem is also briefly discussed in the suggested article.

Dear Janusz Pudykiewicz,

I am grateful to you for this report which I appreciate very much.

Regards,

Valentino

Janusz Pudykiewicz ,

Thank you very much for your contribution of a LINK to the history of chaos theory, which is applied differently by biological sciences and medical sciences specialists than by specialists in the material sciences, including physics, with particular reference to Step One, which uses the empirical methodology based on observation.

I especially appreciate the LINK because it indicates that, to date, chaos theory is not yet complete!

With my very best regards and wishes.

Nainan Varghese ,

Thank you for your answer to this RG question in which you focus on the trajectories of the different planets being influenced in their orbital paths by their locations relative to the Sun and to on another. This factor reminds me of the way political scientists have observed the way politicians "waver" from one point of view to another point of view, which frequently is the opposite of what they stated in the first place. I suppose that in this case, the position of the Sun is analogous to "the voice of the people"; in other words, politicians, including governmental officials have to be flexible in accordance with their perceptions of what their constituents (and detractors) think when they voice their differing opinions. It seems that the principles of political science may really be deemed "scientific" because they must follow the principles that are observed by planetologists, astronomers, and earth scientists about the way the cosmos of the solar system is regulated, relative not only to the central heavenly body, the Sun, and relative to everything else in the solar system, including their own ideas about the way government should be conducted.

All of this line of reasoning suggests, to me at least, that our world, whether in local and state government affairs or in astronomical configurations, is essentially not mechanistic, but "relative"!

Jan Balaz ,

Thanks so much for your answer to this ResearchGate discussion question! However, it makes me wonder when I see your assertion that "the gravitation is stronger and the velocity is higher" for the inner 'rocky' planets than for the outer "gaseous' planets' because they are "closer to the Sun"! Does not Jupiter, which, in a sense, rivals the Sun in terms of sheer size, represent an exception; in other words, does the relative size and mass of the planets have an influence on the extent to which they may "waver" as they orbit the Sun?

Does Mercury really have a stronger gravitational pull of attraction to the Sun than does Jupiter? When the planets were first forming more than 4.5 billion years ago, Jupiter was on a collision course with Mars and Earth, but then Jupiter was prevented from colliding ith Mars and Earth by Saturn when its orbital path brought it closer to the orbital path of Jupiter, and therefore, Saturn's gravitational pull brought Jupiter to a halt in its movement toward Mars and Earth.

To this very day, it may well be the case that the cosmos of the solar system is relatively stable because, each of the planets settled into a fairly regular orbital path, as a result of their gravitational attraction to the Sun, as well as to one another.

It seems that it is easier to discuss the gravitational attraction and Isaac Newton's gravitational laws of motion for large bodies that constitute the solar system than it is to discuss the velocities of the different planets, relative to their respective distances from the Sun and relative to one another. But talking about the velocities of the planets in their orbital paths might be more of a cosmological area of inquiry. Maybe the velocities of each one of the planets in the solar system was already determined when the Sun itself was forming and taking its position at the center of the system.

Yours are interesting reflections Nancy. Among the questions you ask, it would remain to be established, especially in your final considerations, whether the rocky or gaseous planets were formed first, or all at the same time. Cosmologists will answer this question, although it seems reasonable to me to assume that the inner planets of the Solar System may have formed first.

Nancy Ann Watanabe "Does Mercury really have a stronger gravitational pull of attraction to the Sun than does Jupiter?"

It does not. The formula for gravitational force ( [GMm] / [r^2] ) scales with the planet mass (m) in the numerator and the planet-Sun separation squared in the denominator...it's a classic example of an inverse-square law in physics.

Jupiter is 5750 times more massive than Mercury.

Mercury's r^2 is 180 times smaller than Jupiter's r^2 - not enough to cancel out the mass disparity.

So the Jupiter-Sun force is indeed higher than the Mercury-Sun force - almost 32 times higher.

But all of this is a red herring as far as orbital velocities go, because they essentially do not scale with mass, due to the dominant mass of the Sun.

A tiny asteroid, with the same orbital size (semi-major axis) as Jupiter, would have virtually the same orbital period & average velocity as Jupiter - they would differ from each other by only ~ 0.05%. That is how little difference their masses make to the calculation.

According to a fairly recent article published in the Popular Mechanics magazine, the largest planet in the solar system, Jupiter, was formed first.

"New Evidence Points to Jupiter as the Solar System's Oldest Planet"

" According to a new study, the great gas giant likely formed only a million years after the sun, roughly 50 million years before Earth."

Jun 14, 2017📷By .Jay Bennett

"Which planet in our solar system formed first? The question has long been one of the great unsolved mysteries of planetary science. The first planet was almost certainly one of the gas or ice giants, but with no samples from anything beyond the asteroid belt, determining which planet is in fact the oldest has eluded researchers for decades.

But now, an international team of scientists from the Lawrence Livermore National Laboratory (LLNL) thinks it's finally solved the mystery. According to a new paper in the Proceedings of the National Academy of Sciences, the oldest planet in the solar system is Jupiter.

"We do not have any samples from Jupiter, in contrast to other bodies like the Earth, Mars, the moon and asteroids," said Thomas Kruijer, lead author of the paper and a researcher at LLNL, in a press release. "In our study, we use isotope signatures of meteorites (which are derived from asteroids) to infer Jupiter's age."

"Related Story"

"It might seem odd that scientists used meteorites to determine the age of Jupiter, but the findings present a clear line of deduction that identifies Jupiter as the oldest planet. Meteorite samples analyzed fall into two distinct groups with different isotope signatures. The differences in composition indicate that the meteorite groups formed in two distinct clouds of gas and dust, both surrounding the sun but separated from each other. Through models, the LLNL team has demonstrated that an explanation for these two distinct sources of meteorites is that Jupiter formed, and then the new planet cleared a path through the dust and debris surrounding the sun, known as an accretion disk, creating two distinct areas of planet and asteroid formation.

A timeline for the evolution of the solar system can be inferred. Our sun ignited into a star about 4.6 billion years ago, and at the time it was surrounded by an accretion disk of gas and ice and rock. Jupiter's rocky core formed as the first planet, only about one million years after the sun's first light, and it cut a gap in the accretion disk following its orbit. As Jupiter grew and the other planets started to form, asteroids also coalesced in both the inner and outer part of the accretion disk, separated by Jupiter. These asteroids have different isotope compositions, according to which area they formed in.

Fast forward some 4.5 billion years, and the asteroids that formed beyond Jupiter have all been shoved into the asteroid belt by the gas giants. The asteroids collide with each other, bits break off, and the bits reach us on Earth as meteorites, where we analyze them."

"Jupiter is the oldest planet in the solar system, and its solid core formed well before the solar nebula gas dissipated, consistent with the core accretion model for giant planet formation," said Kruijer.

The findings indicate that Jupiter formed only one million years after the beginning of the solar system as a rocky core, and the planet grew to about 20 Earth masses over the next million years. Over the course of an additional three to four million years, Jupiter's core grew to 50 Earth masses. The new study aligns with the prevailing theory that Jupiter formed as a rocky core and then accumulated large amounts of gas to become the giant planet we have today.

"Our measurements show that the growth of Jupiter can be dated using the distinct genetic heritage and formation times of meteorites," Kruijer said.

There is still work to be done to confirm, without a doubt, that Jupiter is the oldest planet in the solar system. That said, many have long suspected that the Jovian beast formed first, and the new findings present a convincing argument that this the case."

Here is my perspective:

The formation of the solar system is rather theoretical. For example, a book titled STELLAR EVOLUTION published by the MIT Press contains a chapter in which a Russian scientist postulates that before the formation of the Sun, Jupiter was a protosun which gave its hydrogen and helium to a younger protocore planet which, in turn, evolved into the largest body and eventually assumed its current central position. Jupiter's smouldering core of fire was then covered over with other gaseous material and became a satellite of the much younger Sun. The other gaseous planets, Saturn, Uranus, and Neptune, helped to pull Jupiter into its current orbital path, but not without a struggle because Jupiter was so much larger than they were. At one point, Jupiter was subjected to a boomerang effect and after it ejected hydrogen and helium and pulled away from the Sun, this gigantic satellite to the Sun turned around and headed back toward the Sun. By that time, the rocky inner planets had formed, and might have been impacted by Jupiter, except that Saturn was transiting and so Saturn pulled Jupiter toward itself, which saved Mars and Earth from being decimated in a collision with Jupiter.

Jupiter is not only the largest planet, it is also the hottest; moreover, unlike the other planets, which do not generate heat but which are warmed by the Sun, Jupiter is heated primarily by its hot core, which I believe suggests that Jupiter was originally an old star whose gravitational attraction was weaker than the much younger orb that is now our Sun. The old star Jupiter had lost its grip and, in effect, bequeathed its fuel burning energy production to the Sun.

In ancient Greek mythology, Zeus (Roman Jupiter) was the king of the pantheon of gods, and Apollo, the sun god, was the son of Zeus. Likewise, Hermes (Roman Mercury) was the messenger god, while Aphrodite (Roman Venus) was the goddess of love. In classical Roman mythology, the outermost planet, Neptune, is the god of the sea. Greek and Roman mythologies portray the divinities as directly influencing life on Earth. Ancient narratives tell stories in which the lives of epic Greek and Roman heroes and heroines are directly influenced by the super-lives of the divinities, specifically by their thoughts and desires. The ancients probably interpreted the speeding up and slowing down, or wavering, of the planets in terms of the whims of the divinities in their pantheistic theologies. The telling of action stories about the Greek and Roman gods strongly suggests that the ancient peoples of Greece and Rome were capable of observing waverings and changes in the velocities of the planets with the naked eye!

Thanks for the important report that responds to my curiosity.

Nancy Ann Watanabe "Maybe the velocities of each one of the planets in the solar system was already determined when the Sun itself was forming and taking its position at the center of the system."

Whether one agrees with this statement depends on what is understood by "already determined":

• One physicist would say that given the role of chaotic, non-linear motion associated with gravitational resonances, it is not possible for us to look at the state of the solar system (or any exoplanet system) at its formation, and from that predict/determine the exact future motions of all its constituent bodies. Chaotic motion appears random - but actually it is deterministic; however it is highly dependent on the initial conditions.
• Another physicist would say that if we had complete, deity-like knowledge of the initial conditions of the solar system constituents, then application of the laws of physics would determine their exact future.

Stephan C. Mann ,

Just a note to say "Thank you" for your recommendation!

Valentino Straser ,

You are welcome! I am glad to know your nice reply! Best wishes!

Ray Butler ,

I appreciate your futuristic answer; indeed, there are some scientists today who share your glimpse into the future. Very best regards!

For the review of main problems related to the formation and evolution of the planetary system please see

“Turbulence-Assisted Planetary Growth“

Hydrodynamical Simulations of Accretion Disks and Planet Formation

by

WLADIMIR LYRA

http://www.diva-portal.org/smash/get/diva2:173154/FULLTEXT01.pdf

The theory outlined in this thesis shows how significant the progress was after the introduction of Kant and Laplace groundbreaking ideas. In the same way, we can imagine that progress will make our ideas rather inadequate from the point of view of future generations. The role of turbulence mentioned in one of the previous comments posted by Ray Butler will likely remain to be paramount and unchallenged.

There is no such a continuously monitored motion for planetary orbits. However, positions and speed of planets can be calculated using Newtons theory gravitation (NTG). Speeding up and slowing downs can be explained considering total energy of the planetary motion as kinetic potentials.

Furthermore, one can be determined if any difference in the planetary orbits (Example- orbit of Mercury). Also, this difference of Mercury lead to confirms Ernestine theory of general theory of relativity (GTR) experimentally. However, the Newton's theory of gravity can be considered as limiting case of complete picture of gravity and good approximation model for most cases of serastrial bodies.

The concept of turbulence represents an achievement of science and I agree that in the near future it can explain many problems currently under debate.

Manoj Sithara ,

Thank you very much for your answer to this Research Gate discussion thread question! Best regards!

Valentino Straser ,

I am grateful for your reply to my Research Gate discussion thread question! Thank you and best regards!

There seems to be little consensus about what causes the planets to speed up and slow down, which is not surprising in view of the fact that there are a number of different factors to consider and different groups of scientists are working on different aspects of the problem. Some focus on Newton's gravitational theory and non-baryonic dark matter, while others concentrate on electric and magneto influences. I am surprised that I have not yet found much of anything about retrograde motion, which I originally had surmised would be the answer to this question. Of course, even if retrograde motion is the dominant influence, one might then ask what causes retrograde motion.

Dear Nancy, unfortunately the problem does not have an immediate answer and this is demonstrated, for example, by the concept of the "electric universe". Probably we should not limit ourselves to a purely mechanical or other physical fact, but look for a potential interaction between the various processes.

Regards,

Valentino

Dear Valentino Straser ,

Thank you very much for your answer to my Research Gate discussion thread question; I agree with you!

Best regards.

it is not clear if Sir. Isaac Newton knew about relation between sun and earth or vis versa on his era 1700s.

On the other hand nothing in the universe is working mechanically as Sir. Newton thought. Sadly I must say that, his theory on earth's gravity is incorrect by far.

https://www.academia.edu/48986830/Earth_gravity_is_not_Newtonian

best regards.

Thank you for sharing this interesting analysis.

gravitation.

Any statement that Newton did not know how the planets moved is ridiculous, since Kepler discovered their motions nearly a century beforehand. The reason that they move faster as they get closer to the Sun is that they are "falling" relative to their previous distance, so just as any falling object moves faster as it falls, so do the planets; the exact reverse applies to greater distance, and the slowing speed of objects that are rising.

However, although that is all that is required to explain WHY they move faster or slower, the exact details of how MUCH faster or slower involve conservation of angular momentum, which requires faster motion when closer to the central body, and slower motion when further from it. Kepler's Second Law, which exactly explains the increasing and decreasing motions, is mathematically equivalent to the law of conservation of angular momentum.

In other words, this is a problem that would be given to a physics major taking their very first semester of college physics, and does not require any of the half-dozen or two kinds of voodoo science proposed in some previous answers. All of those answers should be viewed not as real-world answers, but as advertisements for the particular axe their proponent has to grind, and are not even fit to be called good science fiction (perhaps Loony-Tunes fiction, in which Wile E. Coyote doesn't fall to the ground until after he realizes he is standing on thin air, but that's about it).

Nancy Ann Watanabe "I am surprised that I have not yet found much of anything about retrograde motion, which I originally had surmised would be the answer to this question. Of course, even if retrograde motion is the dominant influence, one might then ask what causes retrograde motion."

Retrograde motion is simply a perspective effect. You see it in everyday life. As you overtake a slower moving vehicle on the highway, although both vehicles are actually moving in the same forward direction, the slower vehicle appears to be moving backwards (retrograde) with respect to your faster vehicle's reference frame. That's all there is to it.

Planets and asteroids in smaller orbits (closer to the Sun) move at higher velocity than planets and asteroids further out (from Kepler's Third Law), so they are constantly overtaking the outer bodies, when they are at the same side of their orbits with respect to the Sun.

Javad Fardaei ,

I wish to thank you for your answer to this ResearchGate discussion thread question! Sir Isaac Newton actually does not subscribe to such a mechanistic view of the solar system as you are suggesting. He is more of a "law and order" philosophical thinker. In fact, he earned a living as Warden of the Mint. He was also quite a Biblical scholar, which indicates that he believed in God; furthermore, he spent a great deal of effort in trying to discover the symbolical significance of the final book in the Holy Scriptures, i.e., Revelations. Best wishes.

Dear Nancy Ann Watanabe

I agree with you in many occasions on Sir Isaac Newton, specially personality or philosophical autodidact, and as good person, but as far as science, he is NOT " law & order" in fact, he miss-lead us, and himself.

He was perfect for his era by describing earth's gravity when an apple hit his head.

But, I wish he could expand his thought in a raining day, why raindrop are not pointy to the ground if earth has g= 9.81 force or why earth with it strong gravity force let mass of water goes up!

Simply if earth had Newtonian gravity, earth never would have rain by his formula, or his philosophical explanation. It is sad that we are following his pseudoscience gravity while UFO or UAP are coursing in our space without following Newtonian gravity.

Sir. Newton fool Mr. Einstein as well, as result everything in last century sitting on heroical bench. Our universe become a mechanical and accidental phenomenon, atom become mechanics.

It is very sad that our teachers brainwashed by teaching the most unscientific subject of gravity and mechanics atom in our universities.

PS: My research is not peer-review phenomenon that can be evaluated. Thus, if you are teacher and want to find the truth how earth's gravity work, please read this unprecedented article and find question, also it is totally rejecting Newtonian gravity scientifically empirical evidence.

best wishes

Article Earth Gravity is not Newtonian

Ray Butler ,

I would like to thank you very much for your answer to this ResearchGate discussion thread question! With respect to retrograde motion, I appreciate your reference to Kepler's Third Law. Also, for some reason, I had thought that Venus, Uranus, and Pluto are actually considered to be retrograde planets! For example, Venus is exceptional in that it spins in an opposite direction from all of the other planets, and plausibly for this reason, it sort of always appears to be "moving backwards," as it were. Best regards!

Courtney Seligman ,

I would like to thank you for your expert opinion in reply to this ResearchGate discussion thread question and I also appreciate the humor! I am grateful for your estimation that this RG question may be appropriate for an examination administered during a first-year college course. Best regards!

Javad Fardaei ,

I would like to call your attention to the fact that the legendary story about Newton and the apple is more of a humorous spoof. In point of fact, Sir Isaac Newton, who wrote the monumental volume titled "Mathematica Principia," is still studied because his gravitational laws of motion pertain to the macrocosm of the solar system. Therefore, it is inappropriate for you to discount Newtonian gravitational laws on the basis of examples such as the way raindrops fall from the clouds to the ground. The ground to which you refer is a noun spelled with a lower case, i.e., "earth," while Newton is providing scientific and mathematic factual information with respect to a noun spelled with an upper case letter which refers to the planet Earth. Best wishes.

Zachary Knutson

Thank you for trying to contribute to this ResearchGate discussion thread; however, I am unable to decipher the fragments you wrote ("coinciding gravitation.... and momentum imposed on spacetime..., Newtonian physics") and so if you have a moment, it would be good if you were to transform these phrases into complete sentences! Again, I thank you for trying! And please accept my best wishes!

Not many comments on my suggestion about the physical impossibility of circular/elliptical planetary orbits. No free body can revolve around another moving body in any type of geometrically closed path. This can be easily proven by observing a person moving around another person walking along a defined path. Real planetary orbits are wavy about the mean path of the central body, the planets alternately moving to the front and to the rear of the central body. Under the actions of mutual gravitational attraction, planets slow down when they are in front of the central body and they accelerate when they are at the rear of the central body.

Nainan

Nancy Ann Watanabe Thanks for your kind comments.

"I had thought that Venus, Uranus, and Pluto are actually considered to be retrograde planets!"

One needs to be careful not to mix up 3 things: retrograde motion, retrograde orbit and retrograde spin/rotation.

This is a brief scientific explanation for why a planet in the cosmos of the solar system increases its velocity as stated by a Bachelor of Science in Physics at the Ramakrishna Mission Residential College, Narendrapur Mrinmoy Mukherjee:

"The velocity of the planet increases as it gets closer to sun because of the law of conservation of angular momentum.

According to this law,

Iw=constant

Where, I = moment of inertia

and w = angular velocity

As radius, that is the distance between the sun and the planet decreases, the value of I(= mr²) decreases. In order to keep the total value constant, the value of angular velocity increases.

In other words,

I is inversely proportional to the angular velocity.

Hope this helps:-):-)

[End of quote].

@Nancy Ann Watanabe: The answer you quoted today from Mrinmoy Mukherjee - Conservation of Angular Momentum - is correct. Courtney Seligman also gave this correct answer (in words rather than equations) back in July.

Let me fill in some mathematical detail:

Definitions: L = angular momentum, I = moment of inertia, w = angular velocity, v = linear velocity, m = orbiting mass, T = orbital period, r = orbital radius [varies with location in orbit], (2.pi) = orbital circumference in angular units [radians], (2.pi.r) = orbital circumference in linear units;

L = I.w

where I = m.r² for an object moving around a central point

and w = 2.pi / T

-> L = (m.r²)(2.pi / T)

L = (m.r)(2.pi.r / T)

L = (m.r)(v)

L is conserved -> m.r.v is conserved -> r.v is conserved, as the mass of the body does not change. So what the conservation of angular momentum boils down to is that in an elliptical orbit, the product of the distance times the velocity (r.v) stays constant. As r reduces, v must increase; so planets move faster in the part of their orbit that's closer to the Sun.

Kepler's 2nd Law, cited by a few other people answering, is also a good answer, but it is a consequence of the law of Conservation of Angular Momentum, rather than a mechanism of its own. The concept of "angular momentum" was unknown in Kepler's time (early 1600s); several scientists from Newton onwards seemed to recognize aspects of it and its conservation, but it was not truly pinned down and given its present name until the 1800s.

Another way to prove this is using Conservation of Energy.

Dear Ray Butler,

using the method of conservation of energy I consider it more adequate to explain these dynamics. Thank you for your interesting dissertation.

Regards,

Valentino