I'm in school for digital design at the moment, and stuff like oscillators and frequency dividers are at the very base/root of almost all electronic circuits.
One guess could be that alignments of planets in specific ways could be used to generate specific impulses of gravitational waves, the way we generate signals in binary. Imagine an alien race who uses gravitational effects from orbiting bodies as the basic building block of their "mega processors" that are the size of galaxies. So one solar system that has a division cycle of "2/3, 2/3, 2/3, 3/4 and 3/4" could be their representation of a value/"bit pattern" but written with planets in orbital mechanics, just like how we represent decimal 10 in binary 1010.
as an aside, it is very easy to also ask "why would humans spend so much energy taking silicate sand and turning it into intricate patterns at the size of angstroms and nano meters just to consume power? wouldn't it be easier to just let the sand organize itself into components as needed?" of course, the answer seems obvious to us, but the question is analogous to yours.
If one alien entity/organism is actually the size of a galaxy, a single solar system would be on the scale of maybe a transistor at 20-30 nm to us.
At that scale it's no longer performance art, but maybe a small part of a engine of some sort.
What I'm saying is thought patterns like "what is it for" "this is inefficient" or "that would be way too big" ... etc is only defined from our point of view.
So there are these great big buildings in Egypt...
Moving planets out of existing orbit is another level. I can only imagine this is possible for a race who can plan multi million year projects and thus you can probably use rockets to do small gravitational slingshots each day and rely on some compounding effect.
Ok, I'll bite. Says who?
From the photos I have seen, the blocks look hand cut, not laser cut. I understand the blocks were cut with copper chisels and that archeologists found copper chisels in the quarries.
It is entirely believable that hundreds of men using ramps, ropes, grease and rollers could move these large blocks.
Maybe they built the system, and being lazy like we are they chose some simple numbers
> b) Isn't it vastly more likely to occur naturally as some sort of resonance effect?
Alien intelligence may be less likely than a natural effect, but alien intelligence in this system is much more likely than in a random system.