When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
Pure water (H2O) does not conduct electricity on its own.
46
One 75-watt bulb gives more light than three 25-watt bulbs.
57
Sound travels fifteen times faster through steel than through air.
134
The brain case [of Neanderthals] on the average was more than 13 percent larger than that of the average of modern man
61
Iron weighs more after it rusts.
68
Stannous fluoride, which is the cavity fighter found in toothpaste is made from recycled tin.
65