Five Things to Know Today, March 14

Welcome to Wednesday. Here are some things to know today.

The weather: Wear short sleeves today -- the high will be about 81 degrees. We'll have some fog before 9 a.m., but the sun will burn it off and it'll be mostly sunny all day. The low tonight will be around 54.

Gas prices are little changed. The lowest price for a gallon of regular in Lilburn reported to www.georgiagasprices.com on Tuesday was $3.62 (at Murphy USA, 3950 Lawrenceville Hwy, and three other places). The highest was $3.69 (at Shell, 722 Harbins Road at Dickens Road, and at two other places).

Pi Day: Not cherry or apple, as in pie. Today is a national and global observance in honor of the mathematical idea of pi, a very long number that starts with 3.14 and therefore resembles the month and date 3/14. Pi represents the ratio of a circle’s circumference to its diameter. The number is used in all kinds of mathematical formulas. Speaking of math and its cousin, physics, today also happens to be the birthday of Albert Einstein, born in 1879.  

Crowning King Cotton: This was the day in 1784 when inventor Eli Whitney received the patent for the cotton gin, the device that would change agriculture in America and especially the South. The gin (short for ‘engine’) made the labor-intensive process of deseeding cotton automatic and affordable. That changed the economics of farming and of slavery. Historians have argued the gin helped preserve and expand slavery in the 19^th century by making cotton profitable. The fiber became America’s biggest agricultural export from 1820 to 1860 and survived the Civil War to reign as King Cotton long after that.  

Trees: The Gwinnett Environmental & Heritage Center has reopened its adventure and education attraction Treetop Quest. Combining climbing, ziplines and the forest, there are courses for all ages from 4 to 6 year olds, who can stay near ground level so parents can help and cheer, to teens and adults who want to fly along between the trees. Prices vary for kids, students and adults. Could be a fun day trip to Buford, near the Interstate 85/985 split.