Re Pascal's idle thought about whether there only needs to be one time travel convention, more to the point, would they start by reading the minutes of next week's meeting?
Chris Kenny, Southampton, England
It has been theorised and already proven that time travel is possible. It all becomes less exciting, though, when you realise that you can only travel forwards in time. And even then at a rate of about one second per second.
Colin Main, Berkhamsted
Re 10 things we didn't know..., the UK has the most post offices in Europe. This may be true in absolute numbers but per capita, Switzerland has far more and has no intention of closing any of them.
David M Roberts, Clachamish, Isle of Skye
Must be a British thing, but as soon I saw the picture of the 10 limpets my first thought was "spot the 2 limpets that don't know how to queue".
Christian Cook, Epsom, UK
I don't want to be mean, but, as this article is currently generating a lot of letters, I'd like to point out that we could really do with a (L) and (R) in the caption to the main photo.
Greg Hoover, London, UK
Re "Australian pub bars heterosexuals", couldn't you have said bans? I thought there was a new kind of pub-themed trendy bar.