Math enthusiasts around the world, from college kids to rocket scientists, celebrate Pi Day on Thursday, which is March 14 or 3/14 B次元官网网址� the first three digits of an infinite number with many practical uses.
Around the world many people will mark the day with a slice of pie B次元官网网址� sweet, savory or even pizza.
Simply put, pi is a mathematical constant that expresses the ratio of a circleB次元官网网址檚 circumference to its diameter. It is part of many formulas used in physics, astronomy, engineering and other fields, dating back thousands of years to ancient Egypt, Babylon and China.
Pi Day itself dates to 1988, when physicist Larry Shaw began celebrations at the Exploratorium science museum in San Francisco. The holiday didnB次元官网网址檛 really gain national recognition though until two decades later. In 2009, the US to be the big day B次元官网网址� to hopefully spur more interest in math and science. Fittingly enough, the day is also Albert EinsteinB次元官网网址檚 birthday.
HereB次元官网网址檚 a little more about the holidayB次元官网网址檚 origin and how itB次元官网网址檚 celebrated today.
WHAT IS PI?
Pi can calculate the circumference of a circle by measuring the diameter B次元官网网址� the distance straight across the circleB次元官网网址檚 middle B次元官网网址� and multiplying that by the 3.14-plus number.
It is considered a constant number and it is also infinite, meaning it is mathematically irrational. Long before computers, historic scientists such as Isaac Newton spent many hours calculating decimal places by hand. Today, using sophisticated computers, researchers have come up with trillions of digits for pi, but there is no end.
WHY IS IT CALLED PI?
It wasnB次元官网网址檛 given its name until 1706, when Welsh mathematician William Jones began using the Greek symbol for the number.
Why that letter? ItB次元官网网址檚 the first Greek letter in the words B次元官网网址減eripheryB次元官网网址� and B次元官网网址減erimeter,B次元官网网址� and pi is the ratio of a circleB次元官网网址檚 periphery B次元官网网址� or circumference B次元官网网址� to its diameter.
WHAT ARE SOME PRACTICAL USES?
The number is key to accurately pointing an antenna toward a satellite. It helps figure out everything from the size of a massive cylinder needed in refinery equipment to the size of paper rolls used in printers.
Pi is also useful in determining the necessary scale of a tank that serves heating and air conditioning systems in buildings of various sizes.
NASA uses pi on a daily basis. ItB次元官网网址檚 key to calculating orbits, the positions of planets and other celestial bodies, elements of rocket propulsion, spacecraft communication and even the correct deployment of parachutes when a vehicle splashes down on Earth or lands on Mars.
Using just nine digits of pi, scientists say it can calculate the EarthB次元官网网址檚 circumference so accurately it only errs by about a quarter of an inch (0.6 centimeters) for every 25,000 miles (about 40,000 kilometers).
ITB次元官网网址橲 NOT JUST MATH, THOUGH
Every year the San Francisco museum that coined the holiday organizes events, including a parade around a circular plaque, called the , 3.14 times B次元官网网址� and then, of course, festivities with lots of pie.
Around the country, many events now take place on college campuses. For example, Nova Southeastern University in Florida will hold a series of activities, including a game called B次元官网网址淢ental Math BingoB次元官网网址� and event with free pizza (pies) B次元官网网址� and for dessert, the requisite pie.
B次元官网网址淓very year Pi Day provides us with a way to celebrate math, have some fun and recognize how important math is in all our lives,B次元官网网址� said Jason Gershman, chair of NSUB次元官网网址檚 math department.
At MicheleB次元官网网址檚 Pies in Norwalk, Connecticut, manager Stephen Jarrett said itB次元官网网址檚 one of their biggest days of the year.
B次元官网网址淲e have hundreds of pies going out for orders (Thursday) to companies, schools and just individuals,B次元官网网址� Jarrett said in an interview. B次元官网网址淧i Day is such a fun, silly holiday because itB次元官网网址檚 a mathematical number that people love to turn into something fun and something delicious. So people celebrate Pi Day with sweet pies, savory pies, and itB次元官网网址檚 just an excuse for a little treat.B次元官网网址�
NASA has its annual online, offering people plenty of games and puzzles, some of them directly from the space agencyB次元官网网址檚 own playbook such as calculating the orbit of an asteroid or the distance a moon rover would need to travel each day to survey a certain lunar area.
WHAT ABOUT EINSTEIN?
Possibly the worldB次元官网网址檚 best-known scientist, Einstein was born on March 14, 1879, in Germany. The infinite number of pi was used in many of his breakthrough theories and now Pi Day gives the world another reason to celebrate his achievements.
In a bit of math symmetry, famed physicist Stephen Hawking died on March 14, 2018, at age 76. Still, pi is not a perfect number. He once had this to say:
B次元官网网址淥ne of the basic rules of the universe is that nothing is perfect. Perfection simply doesnB次元官网网址檛 exist. Without imperfection, neither you nor I would exist.B次元官网网址�
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