biologist and BBC Radio Four broadcaster

Some of your jump-start friends and colleagues seem to have ignored your (arbitrary?) cutoff date, so I will too. I think you'd have to go a long way to find a more important invention than the basket. Without something to gather into, you cannot have a gathering society of any complexity, no home and hearth, no division of labour, no humanity.

This is not an original insight. I ascribe it to Glyn Isaac, a sorely-missed palaeoanthropologist. The basket ranks right up there with hay, the stirrup, printing and what have you.

While we're about it, though, I'd like to take issue with Dan Dennett's choice of the battery. Granted it has enabled all the things he says it has (and I seriously considered nominating the Walkman — a bizarre idea, the tape recorder that doesn't record — as the invention with most impact on our lives) but at what cost? All extant batteries (though not fuel cells) are inherently polluting and wasteful. It takes something like six times more energy to make a Zinc-alkaline battery as the battery can store. I can't help but think that if a small portion of the effort that has gone into inventing "better" batteries had gone into, say, solar panels, our world and culture would be even more different.

Thanks for a stimulating time.