Maybe nitpicky, but this is not quite true. As soon as the marble falls below the surface of the Earth, the rock above the marble will be pulling the marble backup. That upwards force cancels some of the downward pull, and the math works out so that all the layers above the marble (on all sides of the Earth) cancel out, so the marble is only being pulled by the layers of Earth closer to the center than the marble.
So as the marble gets closer to the center of the Earth, the force actually gets smaller, and at the exact center of the Earth there’s no force at all on the marble.
Big picture, I agree that this wouldn’t be a disaster (I’m talking about the magic ‘one-way gravity’ marble that feels gravity but doesn’t attract anything itself). The marble-sized hole leading into the Earth will have no effect on anything more than a couple feet away (any more than pounding a one-inch stake into your lawn will cause a disaster). There will be a hole in the dirt, but before getting too far down, there will be enough pressure to push the hole back closed again; you won’t have magma shooting out of the hole or anything.
Also, without thinking very deeply about it, I imagine the friction at the center of the Earth won’t be completely negligible. After all, the core is supporting an entire Earth’s weight, so the pressure’s got to be significant, even compared to Everest or even two Earths in a marble. Though I’d concede to anyone with actual numbers saying different.
Speed??? This thing is massive. Two whole Earths worth. The energy of this thing punching its way towards the core is fantastic.
The core can’t handle this level of energy very well. Yeah, it’s hot. But we’re adding a tremendous amount of energy very quickly.
The difference in effects between being released from 1000ft, ground level, etc. is insignificant. Do the Math on Potential Energy for a massive object.
I think too many people are taking simple “Tower of Pisa” Physics and trying to apply it to something entirely different. The mass involved means the everyday stuff you’re used to does not remotely apply.
I think this is the first post that understands the logic of where I’m coming from. In the sense that most people are using physics to explain why the scenario is stupid and wouldn’t work in reality - I know this… but that isn’t why I asked the question.
Maybe the ‘realistic’ physics applies to this too… I get that, but essentially, what I’m doing is adding a supernatural element to a natural world.
In the tv show ‘True Blood’, the vampires had ridiculous speed and strength, more so than is physically possible with something of that mass and weight. In a more realistic scenario, we have created bombs, and explosions… a force so far beyond what a living organism is capable of receiving… and we’ve seen what happens when the two meet…
My marble is basically a vampire punching a human face, or a bomb shockwave, well, hitting a human face…
Physics can predict, but surely there must be an element of ‘who the hells knows’.
If you want to consider the ultra-magic marble - one with one or two Earth masses, no gravitational field, but inertial mass and follows the space-time curvature of other masses, the answer is different, but curious.
As far as the marble is concerned the Earth may as well not exist apart from its gravitational field. The Earth looks like a vacuum as far as it is concerned. It will oscillate back and forth every 90 minutes essentially forever. The amount of energy it loses each oscillation will be infinitesimal compared to potential energy it holds. Each oscillation it will drag a marble sized path through the Earth. That path will dissipate exactly the energy any marble travelling at what is a quite pedestrian speed (it will be subsonic in the magma) and add tiny tiny bit to the Earth’s intrinsic self heating. But not enough to actually measure.
If you dropped it from 1000 feet above sea level, it will top out at 1000 feet above sea level every oscillation. Having a marble smash out of the ground somewhere on the Earth every 45 minutes only to drop in again nearby, is going to make life amusing. It will be quite easy to predict where these points are, and real estate values in these areas will suffer. Anyone living higher than 1000 feet will never need to worry. The sun will go cold before much changes.
Early in the thread I mentioned a book called The Doomsday Effect–it has essentially this scenario. A Hawking black hole is captured by Earth’s gravity and spends most of the book oscillating through the Earth, growing a little more massive and destructive with each passage. It is eventually
captured by using a series of steps involving using asteroids like billiard balls to knock one of the moons of Mars into Earth orbit and intercept the black hole when it is at the peak of it’s orbit, capturing the black hole at the center or the moon.