It takes up to 1000 years for a stalactite to grow 1/2 inch.

How old is the Earth ?

Geologists believe that the Earth is about four and a half billion years old. By studying rocks from meteorites which landed on the earth, scientists have been able to conclude this. Most meteorites that have hit the Earth are about 4.5 billion years old. A process known as radiometric dating is used to determine this. Radiometic dating involves the measurement of radioactive isotopes of certain elements that are found in rocks. These radioactive isotopes which are known as radioisotopes, gradually change into more stable isotopes in a process known as radioactive decay. Rocks are dated by taking a measurement of the ratio of a radioisotope to its decay products.

Did you know?

Sound travels about 4 times faster in water than in air.

Diamonds are the hardest substance known to man.

There is a high and low tide because of our moon and the Sun.

The moon is 27% the size of the Earth.

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