I didn't realise sprites could be several 10's of kilometres across.
See -
http://star.arm.ac.uk/press/2013/sprite.html
"The professional standards of science must impose a framework of discipline and at the same time encourage rebellion against it". – Michael Polyani (1962)
"If climate science is sound and accurate, then it should be able to respond effectively to all the points raised…." - Grandad
"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts". - Bertrand Russell
"Science is the belief in the ignorance of the experts" – Richard Feynman
"A consensus means that everyone agrees to say collectively what no one believes individually.”- Abba Eban, Israeli diplomat
Dave,Derby