why is an object stable if its center of gravity is inside its area of support?
statically stable -- decrease potential energy by going back to static state, if
disturbed
when moving, steers itself under its own center of gravity... broom?
coin, when falling, will automatically steer itself 'under' its own center of gravity.
vector addition of torque and angular momentum!! ah, makes some sense now
radar: "shining" radio or microwaves at an object, instead of light
superposition of currents
both speakers are talking at the same time... and they hear each other speak! both voices
are going at once. the balancing network negates your own voice, so it leaves only their
voice. cool.
