Quote: "Again, it's more complicated than that.
There are no permanent magnets in an MRI, they're all electromagnets with alternating fields at high frequencies. Those kinds of magnets don't attract other permanent magnets."
Yes, it's not a simple "it
will attract your fingers", but MRIs DO pull metal objects very strongly sometimes and have killed people before by doing so. It's just madness to take any kind of metal into the machine.
Quote: "NEE-sahn, of course. Even the company pronounces it that way. I have yet to hear a single soul pronounce it the second way."
Only in America (they did say it your way on Top Gear a few times but I think Jezza may have been making fun of the Americans - I'm not sure about the UK pronunciation). The whole of Australia pronounces it NISS-en, including the company when running ads here.
Quote: "Oh, so you need the air resistance for the spinning thing to counteract the main rotor?"
Pretty much, but it's not the air resistance that counteracts the other rotor per se. It's the fact that the air is trying to slow down the blades, so the engines have to apply constant rotational force (torque) to keep them spinning. A disc (or heavy weight) inside the craft, no matter how fast it's spinning, wouldn't work because the engine that's spinning it barely has to do any work once it's up to speed - there's nothing trying to slow it down. On the other hand, if you constantly added more torque to the disc, it would work, but it would also constantly accelerate until it spun so fast it flew apart.
Quote: "Awesome! Is that a real cow though?"
No.
EDIT: C'mon, I did 4, someone do 5!
