My design for a very simple water-rocket

Despite the rain, yesterday's test launch in the park was an impressive success. The only modifications to a 2-litres plastic bottle were a tennis ball taped to the front and four small, stiff fins attached with Gaffer (Duct) tape. Adding weight to the front makes a huge improvement to stability in flight. The fins must be stiff and 'swept-back' or they will be ripped off during the launch. The bottle accelerates to a measured 100 miles per hour - 160 kilometres per hour - in a small fraction of a second. (I once calculated the velocity by analysing video frames.)
No special 'nozzle' is needed for this design, if a suitably tight-fitting bung can be found for the tube from the air pump. It means that children can build and launch their own rockets.
Notice the important safety feature: the rocket is launched at a child's head-height. It must NOT be possible for it to hit anyone on it's way up...

Two nice exhibits nearly finished...

One that inflates and deflates plastic nappy bags to show how our lungs work, and one that gives you a magnified view of your eye with a pushbutton-controlled light to make your iris contract. Slightly larger than our standard Mini-interactives, these have 60cm diameter bases.
I especially love how the 'lungs' model whistles and wheezes asthmatically as it breathes...


Science Communication in the Post-Truth World

This thought-provoking and rather startling article shows how a limited focus on improving people's scientific knowledge and understanding can actually increase their resistance to scientifically validated truth. The author concludes that we must cultivate curiosity as an end in itself, not merely as a useful aid to 'learning'.

My live microscopic creatures at the Ecsite Conference

I have just set myself the challenge of taking living cultures of microscopic creatures to this year's Ecsite Conference in Portugal and setting up a microscope with a video camera and screen, to present some demonstrations from my Blown-up Biology Show. This will be at the so-called 'Grand Bazaar' session.

Astronomy session with New Mills Scouts

With New Mills Scouts last night: I sat for a long time answering astronomy questions from a hushed circle of visibly awestruck young people