Sports Science: Football

The fourth Thursday in November is the perfect time to spend time with family, eat some home-cooked comfort food, and watch grown men throw around an inflated pig bladder.

That’s right, folks; the world’s first American football was actually an inflated pig bladder, hence the nickname “pigskin.” Don’t worry, modern footballs are made of leather or vulcanized rubber, but the shape of a football remains the same as it’s ever been, lending itself to an interesting discussion of physics.

My sophomore year of college at Washington University in St. Louis, my physics professor’s lecture the week of Thanksgiving featured two balls, a red rubber kickball and an American football. She asked us to predict how the balls would bounce. The spherical kickball was easy; the American football was not.

Football shape

The ovoid shape combined with the two sharp points at each end mean that the ball can bounce in just about any direction at any angle depending on its orientation as it is falling and what part of the football makes contact with the ground. That’s why every football coach I ever had drilled us on just falling on the ball instead of trying to catch it or scoop it up; it is extraordinarily difficult to predict just which way the ball will bounce! These bounces often manifest on plays when a bouncing ball is live, like a fumble, an onside kick or following a punt.

As the game evolved, so did the football itself. As you can imagine, inflating animal bladders can be inconsistent; now, the NFL football is standardized at about 11 inches long from tip to tip and a circumference of about 28 inches around the center. Those bladders could also be difficult to grip, so the modern football has a coarse, pebbled texture as well as white laces in the center.



Because of its shape, the football cuts through the air most easily when spinning around its longest axis, called a spiral. This spiral minimizes air resistance and allows the ball to move in a more predictable parabolic motion.

A common misconception is that the spiral motion allows the ball to travel farther, but this idea falls apart with basic physics. When a ball is initially thrown, there is a set quantity of total energy in the system. That set amount cannot be increased or decreased, just changed from one form to another according to the Law of Conservation of Energy. The spinning motion of a football in the air requires kinetic energy, so every Joule of kinetic energy required to keep the ball spinning is less energy dedicated to the football’s motion.

Instead, the spiral is important because of a concept called angular momentum. A spinning football behaves like a gyroscope; a ball will maintain roughly the same orientation while travelling. This makes the football’s movement from point to point easier to track and predict for a player.step0So when tossing around the ol’ pigskin Thanksgiving Day, make sure you grip the ball with the laces as you throw! What works best for me is to put my middle finger, ring finger and pinkie finger on alternating laces at the front of the ball (as pictured above).

When throwing a football, it is important to generate the force for the ball from your legs. If you are right-handed like me, stand sideways with your right leg behind you. Push off against the ground with your back leg and turn your body to throw as you do so. Bring the football backwards and then forwards over your shoulder, allowing the ball to roll off of your fingers straight. No need for any wrist twisting, as the ball should naturally move in a spiral. (See proper form below.)step1Step one: feet shoulder width apart, hands meet on the ball.step2Step two: weight on your back foot, bring the ball back, wrist out.step3

Step three: throw the ball, wrist in. Allow the ball to roll off of your fingers, but keep your wrist straight and stable. Release the ball over your shoulder. Remember, it’s not a baseball. step4Step four: follow through after the release.

Whether you’re facing the New Orleans Saints or the neighbors across the street, the principles of physics are crucial to your football team coming out on top. May the forces be with you! Happy Thanksgiving!

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From HMNS to Your Family…



Holiday Hours:

The Houston Museum of Natural Science will be closed Thanksgiving Day, but will be open for extended hours from 9 a.m. to 6 p.m. over the weekend. Regular hours of 9 a.m. to 5 p.m. will resume Monday, Nov. 30.

If you’ve got room for seconds, come see our wild turkey specimen (Meleagris gallopavo) and other outstanding Texas species at the Farish Hall of Texas Wildlife.

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The (Real) First Thanksgiving: the Wampanoag Perspective

Most of us know the story. Seeking a place to establish a Puritan church, the Pilgrims arrive on the Mayflower at Plymouth Rock in 1620 and have a hard winter, so the Indians teach them how to grow their own food over the next year. The following harvest, they hold a huge feast to honor the Indians with turkey and dressing and pumpkin pie and celebrate their new-found friends and the peace between them, and we’ve kept that tradition ever since. But most of this isn’t true, and every tale has more than one perspective.


Our storybook version, featuring a giant turkey, grapes, and a majority of Pilgrims.

To the Wampanoag, the Native American people who aided the Pilgrims, things happened in a very different way. Their story begins like this. The Wampanoag had seen whites before, but when the English Pilgrims arrived with women and children, they didn’t see them as a threat. The winter was hard, that is true. From hiding, the Wampanoag watched 46 of the original 102 settlers perish from cold and hunger. March 16 the following year, a Monhegan from Maine named Samoset made contact with the Pilgrims, and the next day returned with Tisquantum, better known as Squanto, a Wampanoag who had learned English. Squanto befriended the English and taught them how to fish, how to plant corn, and how to hunt for nuts and berries. As a result of their friendship, the Pilgrims entered into a peace treaty with Massassoit, the Wampanoag chief, and heeded the advice of their new friends.

In September or October, their crops had a good yield, and they decided to hold a traditional English harvest feast. Historians draw the story of the first thanksgiving from two accounts, one of which was written by Pilgrim Edward Winslow. His account mentions the Pilgrims “sent four men on fowling,” meaning bird hunting, and that “we exercised our arms,” meaning gun fire. These men did hunt for “turkey,” but the word referred to any kind of bird, not necessarily the centerpiece of the contemporary Thanksgiving table.


A more accurate representation, but still featuring a turkey at the center of the table and just six Wampanoag.

The Wampanoag weren’t invited to this feast originally, according to Tim Turner, Cherokee, manager of Plimoth Plantation’s Wampanoag Homesite and co-owner of Native Plymouth Tours.

“Most historians believe what happened was Massassoit got word there was a tremendous amount of gun fire coming from the Pilgrim village,” Turner said, “so he thought they were being attacked and he was going to bear aid.”

Massassoit came with 90 of his warriors, prepared to do battle. Since there was none, the Pilgrims invited their new friends to their feast. However, there wasn’t enough to feed everyone, so the warriors went out and brought back five deer, their contribution, according to Kathleen Wall, Colonial Foodways Culinarian at Plimouth Plantation.

The feast lasted three days and likely included pumpkin, fish, berries, watercress, lobster, dried fruit, clams and plums in addition to the poultry and venison. There was no flour, so likely no pies or pastries. We can and should imagine a warm, three-day feast between the Wampanoag and the Pilgrims, a picture of unlikely togetherness and a celebration that marks a large part of the American identity, but consider that there were 91 Indians and around 50 Pilgrims. Re-think that long table surrounded by settlers with a few Indians thrown in, and forget that it was annual tradition.


This representation is the most accurate, featuring a majority of Wampanoag, no turkey, and a large gathering.

Thanksgiving had been proclaimed by governors and presidents in the 13 colonies at one time or another, but as the country grew, many U.S. citizens didn’t feel it was appropriate. It wasn’t until magazine editor Sarah Josepha Hale campaigned for the national holiday in her writing, an effort bordering on obsession. For 40 years, Hale pushed for the establishment of a Thanksgiving Day, publishing editorials in Boston Ladies’ Magazine and Godey’s Lady’s Book. (Incidentally, she is also the author of the children’s song Mary Had a Little Lamb.)Finally, in 1863, President Abraham Lincoln proclaimed the last Thursday in November as a national day of thanksgiving, but it still wasn’t what we celebrate today.


Sarah Josepha Hale

During Franklin D. Roosevelt’s presidency, the holiday was pushed forward a week to create a longer Christmas shopping season, but public uproar convinced him to move it back to its original date. In 1941, Congress named Thanksgiving Day a legal holiday, the fourth Thursday in November.

This Thanksgiving, and every Thanksgiving following it, give gratitude for this wonderful country we live in. Enjoy your family. Enjoy your friends. Enjoy the fruits of your labor and all the things and people you have in your life. Give thanks for whatever fortune has bestowed upon you this year. Give thanks to those who fought and died to build this nation. Give thanks for being American, a wonderful, unique identity. Love your neighbor. Offer second chances. Make a new friend. Try to understand someone better. Buy things. Watch football. Because that’s what this holiday is all about.

But most of all, remember the whole story.

For more about the lives of indigenous Americans, visit the John P. McGovern Hall of the Americas. From our table to yours, Happy Thanksgiving!

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Staff Picks: Best of the Cockrell Butterfly Center

The Cockrell Butterfly Center (CBC) is most well known for its free-flying butterflies inhabiting a three-story indoor rainforest. But there are many other cool things to see and experience at the CBC! We checked with staff members and asked them about their favorite sections of the center, and this is what they said:

Lauren – Lauren is the butterfly entomologist and she takes care of the 800 to 1,000 imported butterflies we receive every week. Her staff picks are the chrysalis emergence chambers. The emergence chambers showcase thousands of live chrysalids of every size, shape and color imaginable! Many have gold spots or flecks. The word “chrysalis” comes from the Greek word for gold, “chrysós.” If you watch carefully you can even observe butterflies emerging, leaving an empty chrysalis shell behind, which they cling to while their wings stretch and dry.

lauren with chrysalids

Lauren stands next to the chrysalis chambers where you can watch butterflies as they emerge.

Erin – Erin is a board certified entomologist and is the insect zoo manager. She cares for all the non-butterfly bugs in the CBC. Her staff pick is the eastern lubber grasshopper sculpture found at the entrance of the entomology hall. The larger-than-life sculpture shows the anatomical details of the grasshopper’s body parts on one side, like the head, thorax, abdomen, wings and antennae. On the other side it shows a cross-section, displaying the insect’s internal organ systems. It’s a great visual introduction of what makes an insect, an insect. 


Erin with the Eastern Lubber grasshopper sculpture you can enjoy in the CBC entomology hall.

Nancy – Nancy is the director of the CBC. Her staff-pick is spicebush caterpillar sculpture found in the entrance of the butterfly center. The giant caterpillar welcomes each visitor into the butterfly center and is a great opportunity for photos! It may seem cartoon-ish, but the sculpture is actually a very realistic representation of the caterpillar that can be found right here in Houston! The large eye-spots on the back of the caterpillar function to trick or scare away predators by making it appear like a bigger animal. 

nancy on caterpillar

Nancy with the spicebush swallowtail caterpillar that greets guests as they enter the CBC.

Soni – Soni is the horticulturist that grows and cares for all of the plants in the CBC rainforest. Her staff pick is the Pride of Trinidad tree in the rainforest. The Pride of Trinidad (Warszewiczia coccinea) is native to Central and South America and the West Indies and is the national tree of Trinidad. The best part of this tree are its showy, flowering branches. Each flower cluster is accented with a red bract and is loaded with nectar. Inside the CBC rainforest, the Pride of Trinidad is in bloom year round and is constantly feeding a variety of butterflies! 


Soni shows off a cluster of flowers on the Pride of Trinidad that feeds many of the butterflies in the CBC rainforest.

Ryan – Ryan is the CBC Bugs-On-Wheels outreach presenter. He travels to schools, day-cares, camps, and clubs to present a variety of bug-related topics (check them out here: Bugs-On-Wheels). His staff pick is the vinegaroon (Mastigoproctus giganteus). This scary looking arachnid is actually quite harmless and easy to handle. They get their name from their defense mechanism. If threatened, glands near the rear of the abdomen can spray acetic acid which has a vinegar-y smell and may dissuade predators from making the vinegaroon their lunch!

ryan with vinnie

Ryan holds a vinegaroon showing their relatively docile nature.

Farrar – Farrar is the curatorial entomologist. He identifies and documents the thousands of species in the CBC’s entomology collection. His staff-pick is the beetle specimen display in the entomology hall. Beetle species make up almost 25 percent of all known animal species. They are found in almost all major natural habitats and are adapted to practically every kind of diet. The British biologist and atheist J.B.S. Haldane once said, when asked whether studying biology had taught him anything about the Creator: “I’m really not sure, except that He must be inordinately fond of beetles.” This quote lines the top of the beetle display in the CBC. 


Farrar stands next to the beetle specimen display you can visit in the CBC entomology hall.

Celeste – Celeste is the butterfly rearing coordinator. She breeds and raises butterflies for the CBC. Her staff pick is Charro, the CBC’s resident iguana! Charro is a Green Iguana (Iguana iguana). Despite this name, he is actually bright orange! Green Iguanas can be a variety of colors depending on what region they come from. Charro can be found relaxing in his enclosure in the rainforest or sunning himself outside the butterfly center by the demo garden. After hours, Charro gets to wander the entire rainforest freely. Don’t worry about the butterflies; Charro is strictly vegetarian. 


Celeste sits with Charro the iguana who resides inside the CBC rainforest.

Next time you visit the CBC make sure to check out all these staff picks, and take time to pick YOUR favorite part of the CBC!

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