Quote:
Originally Posted by Weiss Pinguin
Wasn't night vision technology first developed during WWII?
|
Yes and no.
They had active infra-red systems like "vampire" and the tank equivalents.
These work by shining a bright, invisible, infra-red light at what you want
to see and turning the resulting image into visible light.
The drawback for military use is that the bright IR light you need to
shine will give away your position to the enemy if they have a method of
seeing IR light also.
You can't always see very far just by shining IR either; like you can't
see that far in the dark with a torch.
This is still the most common form of night vision for civilian use.
Modern military night vision also works, in part, with IR light, but it is
sensitive enough to pick up the very low levels of light (inc. IR light)
that are about at night. It does not need it's own light source.
This does, however, illustrate the steady progression of technology.
No aliens needed.