[Phys-l] Oobleck

["John B. Laird" <laird@tycho.bgsu.edu>]

We did a large-ish scale version a couple of times for campus events. Our
oobleck was about 8 ft long, 3 ft wide, and 2 ft deep. We rented a portable
cement mixer to mix smaller batches before dumping it into the main pool.
(It was still pretty messy!) A couple canoe paddles were useful to help
with the dumping and to keep the pool well mixed. We left it completely
uncovered and had no trouble with evaporation over the course of 4-5
hours.

Here are a few things we did that I would recommend.
- For both convenience and safety, we rented a platform to surround the
  main pool at the height of its top, so people step down about a foot
  onto the oobleck. We covered the platform with rubber squares to improve
  traction. We kept two spotters at the sides to steady people if they
  needed it. Lining the inner edge of the platform with foam (e.g. pool
  toys) would prevent injury if someone falls, though we had no falls with
  100's of students. Nevertheless, we had everyone sign a waiver.
- A water hose is essential for cleaning people off.
- Our events were intended to attract passers-by. We carried some cups of
  oobleck around with pencils to poke it with. These were very effective
  at getting people interested.
- Think about disposal. The final pool of oobleck is obviously very heavy.
  We used a forklift to load it on a truck, which took it to a suitable
  place to dump it.

We found that the whole event took a lot of work plus some money for the
platform and cement mixer, but it was a big hit with the students on
campus.

Good luck.

John Laird


John B. Laird
Department of Physics and Astronomy
Bowling Green State University
Bowling Green, OH  43403-0209
phone: 419-372-7244  
FAX:   419-372-9938
email: laird@bgsu.edu


> ----- Original Message ----- 
> From: "Craig David" <craigda@lemoyne.edu>
> To: <phys-l@carnot.physics.buffalo.edu>
> Sent: Monday, February 23, 2009 9:25 PM
> Subject: [Phys-l] Oobleck
>
>
> Our Physics Club is excited to take on the challenge of setting up a
> large-ish scale demonstration of a non-newtonian fluid for an annual
> spring bacchanalian affair that is a tradition at Le Moyne.
>
> I have some limited experience with smaller-scale demonstrations with
> your basic corn-starch & water oobleck.   I have found it to be a
> giant PITA to mix and KEEP mixed.   The Club is interested in any and
> all advice and wisdom from anyone who has put on a larger scale demo ?
> best proportions, advice on how best to mix the stuff and KEEP it
> mixed for a stretch of at least a few hours, and so forth.
>
> Anyone done this?
>
> Thanks,
> David Craig
>
>
> <http://web.lemoyne.edu/~craigda/>