The number of pi is irrational, meaning it has an infinite number of unique decimal places. However, NASA scientists typically only require the first 15 decimal places of pi to solve most of their mathematical problems. Even when dealing with tasks on a cosmic scale, scientists rarely need more than a few dozen additional digits.
Many people are familiar with pi from their school days. It represents the ratio of a circle’s circumference to its diameter. Put simply, pi equals the circumference of a circle divided by its diameter, allowing for the calculation of a circle’s circumference if the diameter or radius is known. Pi is commonly approximated as 3.14, and Pi Day is celebrated on March 14.
Currently, thanks to a supercomputer that worked for over 100 days, we know the first 62.8 trillion digits of pi. However, the remaining digits beyond this point remain a mystery.
Scientists do not require more digits of pi in their calculations because the numbers involved, even on a planetary or stellar scale, are too small for additional decimal places to significantly affect the results, according to NASA research labs.
For instance, the Earth’s diameter is approximately 7,900 miles (12,700 kilometers), resulting in a circumference of about 24,900 miles (40,100 km). When calculating this precise circumference using the first 16 digits of pi (3.14159…) compared to a highly accurate version with hundreds of digits, the difference in answers is roughly 300 times smaller than the width of a human hair, as per NASA.
While the error margin increases with more digits used, it remains insignificant for most practical calculations required by NASA scientists.
The spacecraft Voyager-1, located in interstellar space, has traveled over 15 billion miles (approximately 24 billion kilometers) from Earth. If scientists needed to calculate the circumference of a circle with such a radius, the difference between using the first 16 digits of pi and hundreds of digits would be smaller than the width of a pinky finger.