Hello Martin
Pseudo peer review can be unforgiving rigorous, itself straying somewhat toward fringe in the quest of ultimate... whatever such may be, of course, is not certain, since only that which is known lends itself to being defined. This domain is not for mere alternative history, surviving here -- an impossibility -- paves the way to tutoring in the esoteric, whereupon real knowlege is imparted by no-one in particular, yet, the initiate stands to tap bottomless enlightenment. That, in part, is realization that everything ever taken for granted is up for question... Like a memory wipe - whereupon the candidate is ready to embark on the real work and an exciting journey of discovery, albeit only to find himself :-) a winner in terms of Giurdjeff philosophy - the bone is not so much lost as the dog seeking it... Thus, heed the instruction of Thoth (Barbelo is just a nom d'plume) - keep digging :o)

Quote
MS
The forces required to make any substantial change to Earth's orbit would be immense.

Indeed, after all it's charging like a raging bull at some 30km/sec. which is nothing to scoff at since we rip one another apart with high velocity bullets that zip around at under 1km/sec. - grim analogy I realize, however, this is the Age of High Civilization -- the best in a long time I'm told -- in which the arms industry is one of the driving forces that make the financial World go around - yeah, pretty #@$ up!

Non-withstanding our World trying to fly free into oblivion, our Sun has the last say in the matter, with a very firm grip keeping Earth in check. Yep, with Sol around middle age still, its fate in terms of orbital parameter is pretty much contained. That said, Earth has had its share of showdowns to which the scars bear testimony.

One wrinkle in particular - on land, stretching from the Himalaya to the Pyrinees was acquired in a head on charge with a challenger of unprecedented proportion. The trauma unleashed on that day very nearly could have ended it... Ironically, it also brought new components to life. The blow was a glancing one - with its own consequences: the momentum transfer commenced a revolution.

That rotation has never ceased, nor abated -- it advances the equinox -- the orbit of our planet has zero sway in the matter. Contrary to what the textbooks proclaim, Earth's Polar axis does not precess by means of Solar-Lunar exerted gravity. For our day & age, Earth science is lacking stunning facts - surpassing even MiddleAges deprivation. Those who seek, stand to gain what few can comprehend.

Should the thought of such resonate, volumes of empirical evidence lurk - mere hyperlink clicks away.
H:D