concave mirror with hole

I recall a story from a friend years ago who worked at an underwater weapons research facility. They had a large pool in which they occasionally tested things that went bang. Any time there was a test scheduled, there was much scurrying around, gathering up previously prepared formers and sheets of aluminium. These would be placed in the pool, and the shock wave from the explosion would "form" the aluminium sheets to the shapes of the moulds.

I've no direct knowledge whether this really happened, but it did seem plausible.

Regards Ian

versus

How can they make no difference ? ive already explained why, and before you were saying they had to be perfectly clean first surface mirrors, also they have to be made payed for, installed, aligned, tested etc. hardly makes no difference.

This is a LIDAR, the laser isnt just used for pointing/aiming, the phase delay of the modulated laser light thats reflected off the target is what is measured, therefore the laser light IS the light that is being quantified.

double Duh

Colin =^.^=

weapons

tested

Sounds an exciting line of work.

Colin =^.^=

In message , dated Fri, 8 Sep

Submariners wouldn't agree!

If they didn't get into trouble, they would have still been real Marines. ;-)

In message , dated Fri, 8 Sep 2006, Michael A. Terrell writes

The US doesn't have any Real Marines. Only British marines can carry the 'RM' badge.

Tell them that to their face, if you dare. ;-)

RM = Royal Marines?

The old joke over here is, "They send in the submarines when the Marines fail!" Of course submarines don't go inland where Marines fight hand to hand combat. It generally means that its the only way to get supplies and reinforcements to a battle.

if aluminium was the bulk material used it'd only need polishing, that's almost the sort of thing that can be done in a garage using a propane torch.