The centrifugal fishtank consists of a squat toroid of Perspex. It can be spun at high speed via a central hub.
All the gravel, ceramic model divers, little houses, lumps of coral etc. are glued to the outer circumference of the torod, which is rectangular in cross section. The fishtank is provided with the usual air bubblers, etc.
The tank starts from a rest position and over a period of many minutes increases its speed until the water is flung outwards by the roatational forces. The acceleration needs to be very, very gentle to ensure the whole water mass is affected by viscous coupling and the fish don't get bashed about.
The tank is intended to be viewed from below; "down" for the fish will be along the radius of the tank, so they can swim round and round forever, with some of their compatriots "above" them. Because of buoyancy effects, they should be relatively unaware of the increase in "gravity".-- 8th of 7, Sep 18 2002 Heath Robinson drawings http://www.btintern.../~a.ghinn/heath.htmha ha [FarmerJohn, Sep 18 2002, last modified Oct 21 2004] Rube Goldberg http://www.rgmc.com/Heath Robinson * US / Britain [jutta, Sep 20 2002, last modified Oct 05 2004] Turn it vertical and you have a fish treadmill.-- FarmerJohn, Sep 18 2002 Won't the fish suffer from coriolis forces when they try to move sideways? I don't know whether fish can get seasick....but think about being on those twirly platforms in playgrounds & what happens when you move your head.-- pfperry, Sep 18 2002 Today's random [angel] factoid: fish can get seasick.-- angel, Sep 18 2002 This is certainly this week's most elaborate nothing accomplisher.
(Has Heath Robinson been adopted as a kind of HB atua / patron saint?)-- General Washington, Sep 18 2002 [angel] are you sure that those wobbly, vomiting, dizzy seasick fish aren't just plain drunk?-- po, Sep 18 2002 The fish are bouyant, so they will move to a point where there are zero net forces acting on them and then stay there. Wouldn't coming in to feed rip off their lips?-- reensure, Sep 18 2002 But the fish would go 'round too fast to look at them. Fish blurs are no fun.-- my-nep, Oct 21 2003 No. Stupid.
Need I really post my usual fishkeeping info link yet again?-- squeak, Oct 22 2003 Sometimes I wonder about the mental health of some people - why would someone want this?-- BennyS, Nov 16 2003 Rats! I wrote this up and then found 8th beat me to it. Anyway, I was thinking you could keep deep-sea fish in there, because of the high pressure you could generate. Strobe lighting timed to the rotation would illuminate the contents, so it would be as if they were standing still.-- ldischler, Aug 30 2004 Perhaps it is the viewer who should be rotated. Around the circular tank is a circular viewing platform; if the little fishie swims into its little fishy fortress, it triggers the platform to revolve. If the fish is clever/lucky enough to make repeat visits the platform could spin ever faster, until the aquarium gazer is flung off. In a heap at the foot of the wall, he can ponder on his decision to own fish.-- sabretooth, Aug 31 2004 I was going to bone as all you could see is blurry fish circles... but then a strobe light was mentioned, and now I can see the fish. And you can see a bun instead.
If you flash the light at the right speed you can make it look like you have more fish than you really do-- eulachon, Aug 31 2004 You could keep those little blue ones that light up under UV and use a UV strobe.-- wagster, Aug 31 2004 Thanks for bringing this to the top of "recent" [eulachon].It's cOool.-- 2 fries shy of a happy meal, Aug 31 2004 With the addition of a strobe light and little blue shiny fish this could be well cool. Especially when the fish start having epileptic fits. Mwahaha. +-- spacemoggy, Sep 01 2004 Can we have it with a horizontal axis? As long as the tankoid is spinning fast enough the water will stay in it 'upside down'. Like the thing you can do with a bucket of water on a string. In a big impressive corporte building atrium, a fishy ferris wheel 50m across would need to spin at a little over 800rpm... (bit of a challenge to clean the tank though)-- ATP, Sep 02 2004 If it was big enough, you could swim in it and experience the dual pleasures of high G and weightlessness. (You’re weightless in the water, but just try to do the backstroke!)-- ldischler, Sep 02 2004 Has anyone tried this in the two years since it inception?-- brodie, Sep 02 2004 random, halfbakery