As stolen from one of my other guilds. Figured this would be interesting to post here. This is excerpted from one of the games being run there ("A or B?") in which the question I came in on was "Philosopher's stone or perpetual motion?"
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...I'm going to opt for perpetual motion. Also because I read somewhere a rather entertaining explanation of portal teleportation
mad d Say you have a set of portals on opposite sides of the Earth, each one sealed in a vacuum and setup such that what's dropped into one will fall into the portal that leads right back to the other portal.
Like so. (Excuse the crappy artistic skills
sweatdrop )
So what happens with a setup like this? Why, you get objects falling at an ever increasing speed! Since they're falling through vacuum, there's nothing to slow them down. Optimally, this yields an ever increasing amount of energy as the objects gain momentum and generate an ever larger magnetic field. There's just one problem with this: As an objects momentum increases, its mass also increases relative to its surroundings. (This is why solar wind can be used as a means of propulsion, even though the particles are subatomic.)
While you have perpetual motion doing this, you also end up generating a massive gravity well that will eventually destroy the equipment and probably have extremely adverse affects on the Earth itself (like massive tectonic shifts, extreme tidal forces, pulling the moon out of orbit, possibly tearing the planet apart, and (if the equipment holds out long enough) a black hole).
Ok. Science lesson for the day is done now
sweatdrop