Brain Fertilizer

Who is claiming that we have changed orbital path?

There are only a few things that can alter an orbit (I'm talking about any size item here.)
1) A loss or gain of mass. (While an earthquake is catostophic, we didn't lose mass.)
2) Some sort of impact from another object. (nope that didn't happen either) - This event was self contained. (It has the same effect of trying to pick yourself up and leave the ground.)
3) Some sort of propulsion. (This was an earthquake, not a volcano.) There was no ejecta (if there were, it be a black cloud of dust in the sky right now.)
4) In space travel, we have harnessed a "slingshot maneuver", in which we "steal" some energy from a planet's gravity to propell us faster into deeper space. (In this process the planet loses energy in its rotation/revolution energy, but the effect is so minimal it cannot be measured, especially about large objects like Jupiter/Saturn.) (This didn't happen either)

Now, we MAY have affected our planetary tilt, if anything its fractional. This would change how harsh or mild our seasons are. The tilt is somewhat determined by the equilibrium of the Earth's core in relation to its rotation. But seeing that we here on the other side of the world didn't feel anything, I'm skeptical.

But what do I know?

Yeah, trying to find the article I had seen earlier, I found all these.

What threw me off was that the various headlines say, "rattled in its orbit," "jolted in its orbit," "wobbled in its orbit," and "shaken in its orbit," leaving me with the impression that it was the orbit itself that was affected.

But none of the articles discuss orbits at all.

My bad. Well, and the bad of the headline writers making misleading headlines...[grumble, grumble]

The claim might -- indeed, probably is -- nonsense, but the possibility exists, nonetheless.

A body in a closed orbit -- in the case of a planet, a roughly circular orbit around its primary -- could be changed if its moment of inertia, sometimes also called its rotational mass, were to change. The moment of inertia of a point mass in a perfectly circular orbit about its primary is:

m*r*r

where m is the mass of the object and r is the radius of the orbit.

For a non-point mass, the moment of inertia depends on the shape and three-dimensional density graph of the object. So it is possible to alter Earth's orbit by altering its shape or density distribution, without any application of force from outside. Granted that unless the change were really dramatic, the effect would be negligible, possibly not even measurable.

The physicist in me comes out at the oddest times.