Question: How do you use science for defence?

John Welford answered on 28 Jun 2012:

Lots of great science has come out of work that governments have done for defence purposes!

To give you one example:
The GPS satellite network that allows sat-nav systems in cars all over the world to work, and probably even allows your mobile phone to work out where you are, was installed by the US Department of Defence.

In order to be able to protect itself during the Cold War the US government funded the launch of the satellites that orbit the earth. These could then be use to precisely guide nuclear missiles if they ever needed to be. It was a deterrent, basically saying “don’t mess with us we’ll be able to get you!”. Since then the GPS system has been opened up for the public to use, but it would never have been funded except for Defence purposes.

There are load of other examples of great science and technology that come out of defence research. Carbon fibre and Radar were both invented in UK government research facilities and have really important uses for the military protecting soldiers and detecting aircraft.

For non-military defence examples you could think about airport security, they have all sorts of clever technology to find out whether people are taking dangerous things on planes or trying to smuggle drugs. One of the really recent developments are millimetre wave scanners that airport staff can use to see if people are hiding anything dangerous under their clothes.