^okay: gravity and acceleration are the same thing. (Accelerate,
   you get heavier / decelerate, you get lighter. More gravity on
   jupiter=heavier, less gravity on moon=lighter). Now: When sound
   or light or any wave passes through something of a different
   density, it changes SPEED (accelerate/decelerate suddenly) and
   DIRECTION. == Gravity/acceleration "pulls" us 'down' or towards
   the "center of gravity". SO: What if gravity/acceleration
   changes our direction not 'down' but rather in a different
   DIMENSION? Up/down, left/right, forward/backward are 3D -
   gravity/acceleration would be the next geometrical dimension?
   And isn't this what Einstein was talking about with spacetime
   fabric? Wow. We feel (and measure it) as "heavier" but its just
   a change in direction in a dimension we can't SEE directly.
   Thanks Einstein! == I barely get it myself. I mean, even the
   idea that we get heavier when we go faster blows my mind. I
   guess you could make an analogy that when you run really really
   fast, you feel like you're gonna fall over - but that's more due
   to running out of emergency "quick burn" calories, heart beating
   faster than the lungs taking in oxygen can cope with (we can
   breathe only so fast til we pass out)... Although... The same
   thing would happen to our bodies if we were put in a higher
   gravity environment... So actually, it DOES work. Run faster,
   get heavier   == Then you also have to add in the time thing
   too. Hmm. Actually, it might not be too hard. Use toy cars. I
   had a play session with my nephew when he was 5 and 'somebody
   turned off gravity' - I made the toy car I had float around like
   an astronaut. Kids "get" how things move in outer space quickly.
   You could have a gravity game where you go in circles around a
   small rubber ball slowly then faster and faster like going down
   a whirlpool, then use a big yoga ball for BIG gravity - start
   fast then faster and faster. And the ultimate? A black hole. Not
   sure if 4 yrs will get it - 5s would, so they might.