Hey - who’s that guy on the ladder prising the ceiling tiles off the Planet Science workshop? It’s ok, it’s only Jonathan Sanderson, our in-house science tv producer, getting his bits together in order to demonstrate his latest scientific activity …

Ready?

”For those moments when you absolutely positively have to make something fly, a paper aeroplane is a perfectly good stop-gap. But if you've a little more time, why not try something a little more ambitious? Particularly when it's even simpler to make, since there's no folding or creasing involved.

What you need:

• A polystyrene ceiling tile. You can buy these in packs of ten from DIY shops - they're quite cheap, and each tile makes two gliders. Go for as smooth a surface as you can find - some tiles have ghastly patterns on them.
• A few paperclips.
• Sticky tape.
• A cutting mat (or large sheet of cardboard), craft knife, long ruler or straight edge, and a responsible adult who doesn’t have shaky hands …

What you do:

1. Cut the tile from corner to corner. Be very, very careful here …
2. Equally carefully, cut a large triangle out of the middle of the long edge. Each side of the triangle should be about 10cm long, but it's not critical. You'll end up with a shape that looks a bit like a stealth bomber, only much smaller, white, made of polystyrene, and costing about $2bn less. The 'front' is the right-angle corner, so the 'wings' are the... er... bits sweeping back on either side.
3. Here's the tricky bit: you need to bend up the last 10cm of the wings, just a little bit. You'll find you can gently curl them against the table - gently, to avoid snapping them. Half a centimetre of bend is plenty, but try to get it even on both sides.
4. Now tape three or four paperclips under the nose of the glider. You'll need to experiment to see how many works best for you.
5. To launch the glider, hold it from the triangle cut-out, pinched between your thumb and forefinger. Point the nose just slightly down, and gently push the glider away from you, along the line of its nose. With luck, it'll waft gracefully off across the room.

What's going on:

If your glider flies at all, you'll probably notice that it flies spectacularly well. Head to a school hall or gym, and see just how far it'll go. Quite likely, it'll go much further than a paper dart would, and possibly it'll go further than the room does.

A flying wing is a remarkably efficient aerodynamic shape. The wing area is huge and the weight is low, which means it can fly quite slowly - which causes less drag. Also, your glider is stable not because of a clumsy tail or fins, which would add drag, but because of the way vortices of air form over it. Bending the wingtips up is crucial to help shape those vortices.

Here are some small but useful pictures of the glider from The Big Bang tv show.

We also made a winch launch system for the gliders, which you'll find here.

And if you want to know more about flying wing designs, this is a good place to start.

And staying with the gliding theme, we have this week’s Mouses offer …

“The Inheritance of Aquired Characteristics’ is a Wrong Idea that’s given a good kicking in the evolution chapter of many a biology textbook. Which is a shame, as Jean-Baptiste Lamarck’s concept of species gradually changing (transmuting) over time is spot on - he just got the reasoning behind it wrong.

Like others, Lamarck had noticed how different domesticated animals had become from their wild animal roots, and he correctly sussed that species change over time. What he suggested was that that bits that aren’t used much wither and disappear over the generations, and bits that are used more get better developed over the generations - a bigger human brain perhaps. This idea sounds reasonable enough. It’s when he goes on about explaining the change by the inheritance of acquired characteristics that his Idea gets Wrong. 

Lamarck imagined an animal or plant striving, perhaps subconsciously, to ‘perfect’ itself - through a giraffe stretching its neck to reach higher up to feed, or a predatory cheetah urging its legs to move faster when on the chase. The slightly longer neck or fleeter feet were then, he theorised, inherited by the next generation of giraffes or cheetahs. While undoubtedly wrong, this idea has attracted undeserved ridicule by the suggestion that an organism could acquire a characteristic against its will (like having its tail chopped off) and go on to give birth to tail-less offspring.

Charles Darwin’s take on evolution proposed natural selection with the environment not causing change directly, but by weeding out those less suited to it. Victorians keen to better themselves were left with the uncomfortable idea that you could strive as much as you like but if you were born with limited intelligence you probably would have appropriately dim children too. Lamarckism gave rise to the (false) hope that your studies could benefit your children, even before they were born.

Evolution by natural selection stamped mercilessly on the idea of evolution progressing by the inheritance of acquired characteristics, relegating it to an also-ran in the history books. As a PS though, we should note that a form of Lamarckism prospered for a while in the former Soviet Union. It fitted in well with the ideology of the rulers but had devastating results on agricultural production resulting in widespread starvation.