Can someone explain what the wiggly diagonal lines are that are visible in
so many pcitures of nuclear bomb explosions?
These lines are almost always at a 45° angle and appear evenly spaced.
They do not appear to originate from the centre of the blast.
They are rocket trails. Used to give a sense of scale and measure the shock wave progress.
http://nuclearweaponarchive.org/Usa/Tests/SmokeTrails.html
Someone will probably have more detailed information, but basically those lines are smoke flares that are set off just before the explosion to act like lines on a ruler. The flares are set off at a known distance from the explosion (and from the observers), so that by looking at the photos of the explosion afterwards, one can make a good approximation of the size of the blast.
Many thanks to those who replied.
I have a much better picture of the rocket trails than those shown
in the link to the nuclear weapons archive. This pic was taken at
Maralinga in Australia.
However, I cannot see any way to post the pic to this forum, pity.
Thanks again people.
You have to post the pic elsewhere, and can then provide a link to that posting here.
A page with several photographs of the phenomenon mentioned at Maralinga can be found here