Is our solar system weird? our planets don't hit each other (Introduction)

by David Turell , Thursday, May 11, 2023, 17:04 (352 days ago) @ David Turell

The orbits are slightly chaotic but very stable:

https://www.livescience.com/space/cosmology/scientists-discover-secret-symmetries-that-...

"Earth probably shouldn't exist.

"That's because the orbits of the inner solar system planets — Mercury, Venus, Earth and Mars — are chaotic, and models have suggested that these inner planets should have crashed into each other by now. And yet, that hasn't happened.

"New research published May 3 in the journal Physical Review X(opens in new tab) may finally explain why.

"Through a deep plunge into the models for planetary motion, the researchers discovered that the motions of the inner planets are constrained by certain parameters that act as a tether that inhibits the system's chaos. Besides providing a mathematical explanation for the apparent harmony in our solar system, the new study's insights may help scientists understand the trajectories of exoplanets surrounding other stars.

"Planets constantly exert a mutual gravitational pull on each other – and these little tugs constantly make minor adjustments to the planets' orbits. The outer planets, which are much larger, are more resistant to little tugs and so maintain comparatively stable orbits.

"The problem of inner planet trajectories, however, is still too complicated to solve exactly. In the late 19th century, mathematician Henri Poincaré proved that it is mathematically impossible to solve the equations governing the motion for three or more interacting objects, often known as the "three body problem." As a result, uncertainties in the details of the planets' starting positions and velocities balloon over time. In other words: It is possible to take two scenarios in which the distances between Mercury, Venus, Mars and Earth differ by the slightest amount, and in one the planets smash into each other and in another they veer apart.

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"Delving through the math, Laskar and his colleagues then identified for the first time "symmetries" or "conserved quantities" in the gravitational interactions that create a "practical barrier in the chaotic wandering of the planets," Laskar said.

"These emergent quantities remain nearly constant and inhibit certain chaotic motions, but don't prevent them altogether, much like the raised lip of a dinner plate will inhibit food falling off the plate but not prevent it completely. We can thank these quantities for our solar system's apparent stability.

'Renu Malhotra(opens in new tab), Professor of Planetary Sciences at the University of Arizona who was not involved in the study, highlighted how subtle the mechanisms identified in the study are. Malhotra told Live Science that it is interesting that "our solar system's planetary orbits exhibit exceptionally weak chaos."

"In other work, Laskar and colleagues are searching for clues as to whether the number of planets in the solar system ever differed from what we currently see. For all the stability evident today, whether that has always been the case over the billions of years before life evolved remains an open question."

Comment: we still are a priveleged planet protected by a tiny bit of chaos in our neighboring planets motions. Earth needs this stability. God, as designer, provided it. Why some chaos? If God did it, it was required.