[kens]

No, it does not take the pen 6 times longer to fall down on the Moon compared to Earth. Not even close. That's not how acceleration works. [I can give the equation, but I think it's more instructive if people think about it themselves :-) ]

Also, actually try dropping a pen, like right now. Gravity "kicks in" immediately - there's no perceptible delay. (Unless your perception is way different from mine.)

[dennisgorelik]

I suspected that time difference between falls would be not linear, but I was not sure about actual ratio.

Playing with freefall distance equations showed that time to fall difference is square root of 6. Here we are:

  Height = gEarth*timeOnEarth^2/2 = gMoon*timeOnMoon^2/2
  gEarth = gMoon * 6
  6 * gMoon * timeOnEarth^2/2 = gMoon * timeOnMoon^2/2
  6 * timeOnEarth^2 = timeOnMoon^2
  timeOnMoon = sqrt(6 * timeOnEarth^2)
  timeOnMoon = sqrt(6) * timeOnEarth = 2.45 * timeOnEarth