Balsa wood is classified as a hard wood!
41
Hot water can freeze faster than cold water.
181
The smell of freshly cut grass is actually a plant distress call.
31
The average temperature at 40,000 feet above sea level is -60 F.
56
Sound at the right vibration can bore holes through a solid object.
134
When you walk down a steep hill, the pressure on your knees is equal to three times your body weight.
199
The bark of an older redwood tree is fireproof.
65