A black moor swims around in a fish bowl discovering a road sign every half lap, indicating a curve ahead.

Given that goldfish are alleged to have very bad short-term memories, perhaps their bowls or tanks should be equipped with road signs as reminders of the environment ahead. To save a fish from going too fast and grinding against the side of the bowl because it was ill-informed of the bowl curvature (even though it has seen it hundreds of times before), small signs could be installed to indicate a curve over a given distance.

I’ve given an illustrated example above for a fish in a bowl. The sign in this one may be a little small to read, but it implies there is a curve to the right for the next 0.00044 km. I have based this figure on a fish bowl of radius of 14cm. Hopefully my calculations are correct.

There are a few assumptions here for this illustration to work:

  1. The fish is in a circular bowl of radius 14cm.
  2. The fish is not visually impaired.
  3. The fish can read.
  4. The fish can interpret the sign’s meaning, understand and apply the knowledge.
  5. The fish swims only in a continual circle in a clockwise direction (for this sign, but other signs may allow for the opposite direction).
  6. The fish’s memory of the previous sign has gone before it travels 44cm around the edge of the bowl.
  7. The fish doesn’t become giddy and nauseous.

I’d never tried to draw refraction before, so this was new territory for me. Alas, I didn’t have a fish bowl to go by, so I used a glass of water with an icy-pole stick and extrapolated. I think it turned out ok.

I had completed this one and uploaded it to its destination where, after viewing it a few times, I realised I had drawn the scales on the fish back to front. Poor moor (and grrrrr). I had to do some editing to turn them around and then re-upload. It may be a bit hard to see the scales in the image at this size, but they are quite noticeable in the larger print version.