For generations cave guides have been telling cave visitors that the stalagmites and stalactites that they see around them grow at incredibly low rates. The figure that is usually given is one inch per century for stalactites (they are the ones that hang down). Now a group of scientists who believe in young Earth creationism has studied the chemistry of stalagmite and stalactite formation in actual cave conditions. They discovered that there are many variables in the growth of these formations.