## Happy Pi Day

March 14 (3.14) is Pi Day. As we all know, Pi (symbol: $\pi$) is a mathematical constant which is the ratio of the circumference of any circle to its diameter.  That means that if we measure the circumference of a circle and divide it with its diameter, then the quotient is always $\pi$. The constant $\pi$ is an irrational number; it starts with 3.14 and continues forever.

Pi Day was created 1988 by Larry Shaw, a physicist at the San Francisco Exploratorium.

## Is mathematics an exact science?

In many sciences, we conduct experiments many times and hypothesize or  make conclusions. We can grow two groups of plants, place one group in a room with no sunlight, and place the other group outdoors. The plants inside a dim room die, and the plants in the garden live. We conclude that plants need sunlight.

But are we absolutely sure that our conclusion or hypothesis true? What about the plants under the caves that live despite the lack of sunlight? What about the plants under the sea? » Read more