What happens when you replace the sand in an hourglass with the liquid metal, mercury? You can see that fluids do not work very well in hourglasses because it doesn't "breathe" properly. Despite being almost 14 times denser than water, it still behaves like a liquid, bubbling and dribbling along.
Frequently asked questions:
--------How long did it take for the mercury to fall through the hourglass?----------
A: It took about 10 minutes. However, the mercury would start and stop and a few times it stopped for a minute or so and required me to nudge it to get it going again.
How did you seal up the hole?
A: I just used an epoxy putty.
For more interesting mercury videos, please check out my "Mercury Playlist".