So I was in the shower today...

[Agamemnus]

Not at all. The pressure at the center of the earth is incredibly high because there's a planet on top of it, the fluid is forced to become a solid.

Pressure is "the force applied to a unit area of surface". If there is little gravity in the center of the Earth, there would be little pressure, since that is the only force in play there. Unless you want to tell me about some other force..?

Just because "there is a planet on top of it" does not increase the pressure. "Top" is not an absolute term, and your statement implies that the force of gravity is very high there, and it isn't... or are you going to side with Aetherfox's ridiculous argument?

The same idea is taken advantage when a valve is physically placed at a lower elevation to eliminate flashing and cavitation -- the lower elevation increases the pressure head, which lowers the temperature at which the liquid moving through the pipe turns to gas, eliminating cavitation.

I'm not quite following you. Whatever the lower elevation does, at that elevation there is a high amount of gravity. In the center of the earth, the amount of gravity would be very small.

In my example with the drill, the gravitational pull increases indefinately as you approach the COM of Earth.

In this scenario, you don't just simply "plug in" the numbers into the formula. You have to take the limit as the radius approaches by zero. As a result, I am right.

No, as a result, you are wrong. You are plugging in the numbers for one equation: the particle and the earth, when it should be the particle and all the other particles.

And Aga: to disprove your example to disprove me:
If something were in the center of your hollow sphere (it would have to get there somehow, it wouldn't come to rest there naturally unless some serious lucky throwing happened), it would sit there. The attraction from all sides would be equal. If this is -not- what you meant, let me know.

Well, now you are simply contradicting yourself. You admit that gravity moves any object not at the exact center towards the crust, which means that you do not count the mass of the super-sized object as one entity. (Otherwise everything would fall towards the center.) But you also forget that there is no way that you can ever have 0 gravity. There is always some imbalance, unless the universe is and acts perfectly symmetrical from the point of that particle. So, it would always fall towards the crust from the center.

Also, Aga: Your technique for travelling faster than light is not new. Yours is a basic example of what people thought would be the first way to do it. In practice it is impossible, because we have no way to move black holes, and we aren't even imaginably close to creating an electromagnetic force generator strong enough to rip through space-time once, let alone three times.

Practice makes perfect.

I should further add that according to relativity, infinite energy is possible. As a mass approaches the speed of light, it's (sic) relative mass increases, approaching infinity. e=mc^2...

Of course, mass never approaches the speed of light, hence why the speed limit of mass is thought to be slightly less than the speed of light, and why infinite energy doesn't exist...