# How to make a bottle that rolls in "slow motion"

Originally published at: http://boingboing.net/2017/06/28/how-to-make-a-bottle-that-roll.html

4 Likes

6 Likes

Ack! Why is the hand so slow? Let the honey drip in the table! Put the balls in faster! Made me shiver with hatred watching the prep work here. Slow and careful people piss me off.

3 Likes

Peanut butter will do this, too. But it moves very very slowly.

1 Like

I’m doing a demonstration on density and viscosity for some kids coming up. I think you just found me another experiment!

I can even end the demo by pointing out you can use some of the leftover materials to make a tasty sandwich!

Ooh! I wonder how a non-Newtonian fluid like ketchup would do…

It’s time to

5 Likes

Where does one obtain glass balls? At the toy store, you say?

1 Like

by very very slowly, I mean: hours or an entire weekend

1 Like

Works for the demo. I would want one that seems to defy gravity entirely. Could even shoot a time lapse beforehand to prove it really does move.

1 Like

Ketchup is a Bingham fluid – you have to give it a shove before it even starts to move. That’s why you have to bang on the bottom of the jar to get some out, but once it has started flowing, it flows OK. So I imagine the same thing would be true in this case – the bottle would just sit there, until you gave it a shove? But that may not be enough to keep it moving. In fact I’m not sure it would move at all – it may be like giving the ketchup bottle a light tap.

I suspect a non-newtonian fluid that’s not a Bingham fluid would just roll a constant speed, so wouldn’t look much different than the honey. Be fun to have races though – glycerine, honey, molasses, etc. And there are all sorts of biological fluids you could experiment with if you’re not careful.

2 Likes

All the marbles.

This would rock for a grade-school science class!

A real honey of a trick. “Let the bar bets begin!” I’d glue the top on first to deny easy examination.

This topic was automatically closed after 5 days. New replies are no longer allowed.