Concentrated light can be incredibly powerful and useful. Learn how laser beams are produced by controlling how atoms emit photons of light. Physics - Waves - Learning Points. Lasers are photons of the same frequency going in the same...

Hand grenades are small bombs that function like firecrackers. They are filled with gunpowder or explosive filler and a fuse. Hand grenades are activated via a mechanical device rather than requiring a person to light them with a match....

VS CU soldier holds rifle / rear shot two soldiers with heads sticking out of foxhole look at snowy field beyond / soldiers dig with shovel and pickaxe / soldier sits atop tank camouflaged with hay / VS soldiers place tree branches on...

VS young women on assembly line put together parts for small Browning 9mm automatic pistols / CU Canadian seal on gun / Chinese Major Y. L. Chen puts pistol on long stock up to his shoulder and aims / woman's hand pulls small case with...

CU captured German General Ernst Mattern, Commander of German troops in Poland / Soviet cavalry riding past camera / two shots of sign in Polish on side of road going into town / CU Soviet soldier smoking cigarette / two close ups Soviet...