Changing Earth's axis suddenly or gradually?

Question

First post, if it isn't completely obvious. I've discovered this site by trying to "google" that question. Here's what I'm investigating:

Long ago, pre-deluvian civilizations built ancient megalithic structures that line up geographically on an axis offset from our equator by nearly 30 degrees. Science gives these people no credit for having sufficient technology to sail the seas or contact other civilizations at great distances. That said, it seems that these people had measured the earth, made these giant megalithic structures on an equatorial line around the planet, and left no clues about how they did it, and we still couldn't do it today.

Here's the question: If the Earth were aligned to this "equator" long ago, what could have moved this axis? I've already read how much energy it would take, and that seems unlikely to occur. Is there a physical principle (aside from just raw energy application) that can accommodate this shifting? Could something apply a force to this mass at a "perfect" angle, even if unlikely, that could over time, relocate this axis? Could redistribution of mass on the surface apply enough force to affect in this way? Involving a sphere, there are other principles like gyroscopic precession that involves applying a force and the resulting reaction is 90 degrees away from the application, such as with a helicopter rotor disc. Are there any other rules and properties when dealing with spheres? Is this question too "out there"?

Edit: These are real archaeological sites. The alignment follows a 25,000-mile long line around the globe, offset of our current equator by nearly 30 degrees. The places it crosses are (among others) Easter Island, Machu Picchu, The Great Pyramid at Giza, Persepolis in Iran, Mohenjo Daro Pakistan, Angkor Wat, and many others. There's a video about it. What I'm looking for is a scenario that could make this possible, with physics, astronomical events, or anything, really.

Answer 1

Changing the rotation axis of the Earth by a substantial amount would require a colossal amount of energy. A rough calculation suggests that it would require on the order of $10^{29}$ Joules to effect a change of that size. The only thing that could deliver that much energy is a collision with a dwarf planet. Such a collision would result in the end of life on Earth.

The forces required are similarly huge even if you suppose some other mechansim, enough to rip huge cracks in the Earth's crust, cause mega-volcanism and probably the end of complex life on Earth.

As you mention Easter Island, which was first populated about 900 years ago, we would have to suppose that this occurred in the past 900 years. Even though astronomy wasn't well developed in the 12th century, someone would have noticed if the sun changed its path by a substantial amount.

Your list of sites includes locations that did not overlap in time. And your hypothetical line misses a great many ancient sites of equal importance: Stonehenge, Great Zimbabwe, Ise Jingu, Tenochtitlan. There are enough ancient sites that it is not surprising that several happen to be roughly on a great circle

Answer 2

There is one reason that comes to mind here: Axial Tilt The axis cycles between 22.1 and 24.5 degrees every 41000 years or so. This in turn causes significant changes in the climate of the more extreme regions of the planet over time and of course, the inclination of the different latitudes, which again may account for why these antediluvian structures are so far off from our equator, since at some point of time a few thousand years ago, the latitude along which they built their structures may have lined up with where out equator is now.

Here is a Quora link that discusses the Earth's axial tilt.

PS: I'll edit this as I find more info.

Answer 3

Distrubution of Mass

This could work in theory, but in practice you'd need such a ludicrously large mass to have an effect, sort of more than the weight of a continent amounts of mass...

Orbital Mechanics

for 2 seconds i'm going to ignore the structures but bare with me, if a sufficiently large object entered Earths gravitational sphere of influence, an orbited a few times, on a highly eccentric orbit, then it could effect the axial tilt. just thinking outside the box, but as you've already said that the structures can't be explained and even modern humans couldn't built them... perhaps you civilization saw what was happening and built the structures as part of a way to expel the orbiting body from Earth's sphere of influence???

Edit: As you said you thought this section could be expanded just my simplistic idea: Perhaps there was this sufficiently large asteroid/rogue body, that over the course of a few years managed to tilt the planet by a degree, when this advanced civilization realized what was happening, they decided to build this energy weapon which took many many years (allowing for further tilt) that gently pushes the asteroid away, i say gently so that the equal and opposite thing doesn't come into play and change the orbit of Earth Drastically, this worked however the device emitted harmful radiation or [insert plot device to have the civilization end], so the civilization had to abandoned the site, spreading out far and wide, but lacked the tools to continue at their technology level, so they regressed and spawned several other tribes that eventually grew and grew into modern humans, the lack of tech meant they couldn't hold onto the records for so long, the only thing left of the civilization is the large energy Weapon.

EDit 2: perhaps the monolith is actually the remains of a space elevator, that broke off thousands of years ago when it was struck by the rogue body.

Newton's Third law of Motion

For every action, there is an equal and opposite reaction

if the structures could generate a force (most likely by expelling material like a rocket) and this was used in the correct direction then it could adjust the axial tilt, as you've said the energy required to do this is a bit extreme though

Answer 4

It would probably make a lot more sense if instead of the entire Earth tilting on its axis, the plates which these megaliths were built on shifted around, so that they no longer on top of the equator. I believe the tectonic plates we have are not actually moving in those directions right now, but they could have contributed.

Alternatively, if a large enough asteroid passed by the Earth it could have messed with its axis of rotation, causing the "equator" to shift, but I don't think that could account for a 30 degree change.