The solar system, a messy harmony
The solar system and celestial mechanics in general are sometimes portrayed as something precise, rhythmic, organized, or in a nutshell: “perfect”, and arguing that this is proof of a “divine” origin of the universe.
If in a sense certain phenomena of resonance and regularity can leave one perplexed as to their beauty, they are also explainable by the simplest laws of physics. But above all, we usually forget to mention another facet of the same sun system: the chaos – in the popular sense – which reigns there!
You just need to take the time to take a closer look at the stars that are in the solar system and you quickly discover that nothing is regular.
In truth, the solar system is a mess!
What we observe
If the set were regular, the planets would be evenly spaced, right? Obviously this is not the case (on a log scale, however, it was much more consistent, although not exactly).
We can already see that the order of the planets arranged by size is not the same order as the classification by mass: Neptune, more massive than Uranus, is smaller than the latter. This is explained by the internal composition of Neptune, which is richer in much denser metals.
Same remark as for the masses: there is no real consistency either. Uranus has the most rings but has few known moons. Saturn has more moons than all the other planets combined, and only has 7 rings: fewer than others, therefore, but much larger…
So if you talk to me about “divine mechanics”, I ask you: where is the “divine” in all of this? There is no regularity, no harmony!
Second, the planets are not organized by mass or size. Not by number of moons either.
In addition, even if we allow ourselves to distinguish terrestrial planets from gas planets, again the groups are neither alike nor organized.
Each planet has several characteristics that make it unique compared to all the others:
Mercury sees its equinoxes shifted every year and looks like our Moon;
Venus is spinning in the opposite direction of all the other planets and it is raining acid;
Earth is home to life;
Mars is red and small, with no magnetic activity;
Jupiter is more massive than all the other planets combined and its speed of rotation is such that it is no longer even spherical;
Saturn has a ring system that is unique in size and overall density less than that of water;
Uranus has an axis of rotation inclined at almost 90 °;
Neptune has its origin which is still subject to debate but would come from the Kuiper belt (and therefore would have migrated);
Finally Pluto (coupled to Charon), even if it is no longer considered a planet, has an orbit inclined with respect to the ecliptic (much more than the planets)!
No organization at all!
Seeing what is above, can you really call it organizing? perfection? I doubt. Can a supposed creator, creating something like this , be called intelligent? Or at least organized, perfect, harmonious?
Also, if we classify these stars in the category of “planets”, we could also classify them all in a dedicated category. So, can you really qualify the planets as a single whole? There are more differences than commonalities in their characteristics.
It is this last point, moreover, that Pluto lacks. If it was size only, and if Pluto is not a planet compared to Earth, then Earth would be even less so compared to Jupiter. And then the Moon, larger than Pluto, would also be a planet?
All this is not to mention asteroids (filled with gold, of course), comets, hundreds of moons and all the rest of the scattered debris that struts around inter-planetary space …
If the solar system were really organized by a somewhat rigorous entity, it would more likely have been made up of planets with similar, if not identical, characteristics.
Instead, the position, composition, speed and other parameters of each planet are explained very well using basic laws of physics.
At the end of the life of giant stars, that is to say when the heart has consumed all the hydrogen and helium after having transformed it into carbon, oxygen, nitrogen, etc., the other layers of the star (again rich in hydrogen) collapse and the star explodes, throwing all of its matter into space.
The ejected matter ends up accreting and forming stars. The material that has remained in the center falls back and forms a star again. Our Sun exists thanks to this.
Heavy elements (oxygen, silica, iron, nickel, carbon, calcium …) were not thrown very far from the old star. When they accrete, they form dense, rocky planets close to the central star.
The light elements (hydrogen, helium) are ejected much further. These elements ended up forming packets, later becoming the gas giants.
Obviously, part of the material ends up escaping this accretion, but it is in the minority. This dust is what will form the small distant stars, like Pluto, Eris and the entire Kuiper belt (formed mainly of frozen gas ices), beyond Neptune. These objects, which sometimes come close to the Sun, are comets, whose gaseous evaporation forms the tail.
Is the asteroid belt between Mars and Jupiter made up of small rocky debris: it is the substantial mass of Jupiter that is believed to have regularly destabilized the region and prevented the formation of a planet there.
No organization, really?
If you look even closer, you can still see things at a steady pace.
Because despite the differences, these planets have one thing in common : the laws of gravity. Thanks to them, there are particularly regular phenomena.
Thus, when the Earth makes exactly 8 revolutions around the Sun, Venus makes exactly 13. And when it is Mars which makes 8, then the Earth makes 15. The remarkable fact is that there is a couple of numbers {A; B} as it is A revolutions of one planet corresponds exactly to B revolutions of the other. This is absolutely not something systematic: one can very well have two orbits such that they are not connected in this way at all.
In the case of Earth and Venus, with 8 and 13 revolutions respectively to find an identical planetary configuration, we say that there is a 13: 8 resonance.
And yet , in our solar system, all the planets are related to each other as well. This is due to the gravitational influences between each couple of planets. The two stars are in different orbits: consequently they have different periods of rotation. Of course, there is a time when the two planets are closest to each other and at another time they are further away.
When they are closest, the two planets attract each other: they deviate very slightly from their normal orbit. The planets return to their normal position when the planets move away from each other. A planet therefore oscillates in its orbit during a revolution, thanks to the attraction of other planets.
If the alternation “near planets / far planet” is identical to the period of oscillation of the planet in its orbit (which depends on the mass of the stars), then the two oscillations come into resonance: they are accentuated and the whole stars tend to remain in this oscillating configuration.
This is clearly a resonance, like that of a swing or RLC circuit. The solar system is therefore the seat of oscillations of planets: masses of billions of tons oscillating with periods measuring in years or centuries!
Moreover, this principle is responsible for other things in the solar system: thus, when the massive Jupiter passes as close as possible to small asteroids, according to the period of revolution of the asteroid (therefore according to its orbit), the amplitude of the resonance of the asteroids can be such that the rock is ejected from its orbit!
