Gallery: Hands-On With Baseball's Biggest Scientific Mysteries
01whats-inside-a-baseball
Sure, baseball's origins date back to the [early 19th century](http://joeposnanski.si.com/2010/11/08/history-lessons-with-bud/), but it's still the ultimate geek sport. Split-second decisions, weird physics and ever-evolving equipment permeate all facets of the game. There's a seemingly endless laundry list of questions that surround the sport: *Does a curveball really curve? Why don't I hear the crack of the bat right when it happens? Do bats really have a "sweet spot"?* Of course, science can answer all of these questions and more, and San Francisco's Exploratorium museum has dedicated prime space on its main show floor for its [Science of Baseball exhibit](http://www.exploratorium.edu/baseball/index.html), which runs through Sept. 5 and features a dozen interactive installations that'll bring out the baseball geek in all fans. __Above:__ What's Inside a Baseball? ------------------------- Sun Tzu said that, in war, you must [know your enemy](http://en.wikipedia.org/wiki/The_Art_of_War#Quotations). When a major league hitter steps in the batter's box, his enemy is the baseball, which is actually an incredibly precise and complex sphere. With a heart of cork that must weigh exactly half an ounce, each sanctioned baseball measures roughly 2.9 inches across, although that diameter can fluctuate on account of humidity and other environmental factors. Around the cork are two layers of rubber that weigh a combined seven-eighths of an ounce. Four different kinds of string, which would measure 1,107 feet if laid out in a line, encircle the outer rubber layers. Topping it off is a white cowhide cover kept on by rubber cement. Throw in 216 outer stitches made from 88 inches of red thread and you've got an official major league baseball.
02why-curveballs-curve
Why Curveballs Curve -------------------- It's one of the most-asked questions in baseball: *Why does a curveball curve?* Well, the reason why a baseball does anything it does after it leaves a pitcher's hand has much to do with the stitches that encircle the ball. A curveball, specifically, can rotate at speeds as high as 1,900 rpm, and the stitches around the ball grab the air passing by — represented here by the water rushing past the disk — and the reactive force "pushes" the ball in the opposite direction. (Chalk up another one for [Newton's Third Law](http://www-istp.gsfc.nasa.gov/stargaze/Snewton3.htm).) In some cases, with the right amount of speed and rotation, a curveball or sinker can "break" as much as 17 inches from the perspective of the helpless opposing batter. If that doesn't [buckle your knees](http://www.post-gazette.com/pg/11156/1151573-63.stm), you're made of sterner stuff than the rest of us.
03sound-delay
Sound Delay ----------- It can be jarring sitting in the stands and seeing things happen before you *hear* them happen. That's because while light travels at 186,000 miles per second, sounds only travels at 1,100 feet per second. This 200-foot-long echo tube strung high above museum goers provides a fifth-of-a-second delay when you clap into the open end. (It also makes your clap sound like some sort of DARPA-funded laser coming back at you.) The delay is even more pronounced if you're, say, sitting in the upper deck of a baseball stadium, where the crack of the bat will hit your ears a third of a second after your eyes see it.
04energy-transfer
Energy Transfer --------------- When a ball hits the bat, its 5 1/8 ounces of mass explodes off the bat with considerable energy, but every bounce in the field of play reduces that energy significantly. It's all rooted in core principles of materials science. Bounce a baseball off a steel plate and it only maintains only about 32 percent of its energy after the first bounce. (It's no wonder that with all that wear and tear, the average baseball only lasts for some six pitches in a major league game.) However, bounce a little steel ball off the same steel plate and it only loses some 2 percent of its energy.
05pro-geek
Pro Geek -------- Little known fact: San Francisco Giants hitting coach Hensley Meulens is a geek at heart, and that's not just because he's slated [to go into space](http://hardballtalk.nbcsports.com/2011/05/04/hensley-meulens-is-going-to-be-an-astronaut-kinda/) in 2014. (Thanks, Curacao!) Meulens, whose work with the Giants' offense last year helped lead the team to its first World Series title since 1954, has seen all sorts of tech advancements since he broke into the majors back in 1989. Back then, he was just a [22-year-old third basemen](http://www.baseball-reference.com/players/gl.cgi?id=meulehe01&t=b&year=1989) for the New York Yankees. Today, he works with the Giants to let them know what they're doing wrong at the plate. "Scouting wasn't as great back then," Meulens told Wired.com after showing a group of kids how to swing more efficiently. "Technology has provided the players with a lot more these days. They can be more prepared. The information provided to the players nowadays, it prepares them better for the game. "I know that for a fact."
06playing-the-short-hop
Playing the Short Hop --------------------- Imperceptible changes on the playing surface can make all the difference between whether an infielder successfully snags a ball on the short hop or whether it scoots on through his legs. In this installation, museum-goers set up a series of miniature metal hoops and drop a steel ball through a chute, seeing if they can successful get it to bounce through the makeshift course. For real-life infielders, the trick here is to position yourself so that you're set to catch the ball before it radically changes trajectory. The exhibit might look like [a scale-model Quidditch field](http://stag-komodo.wired.com/playbook/2010/11/gallery-quidditch-world-cup/) run amok, but it's baseball-based physics in action.
07visual-perception
Visual Perception ----------------- Even though the exhibit mostly deals with baseball, there's a bit of basketball thrown in for the hoopheads. In "Hoop Nightmares," fans put on a pair of goggles outfitted with prisms and then try to throw a small basketball through a square hoop. At first, the forced shift in perspective makes your throws go in every possible direction, but after 15 throws or so, your eyes adjust to the distortion and suddenly you're shooting free throws like [Mark Price](http://www.nba.com/cavaliers/history/mark_price.html). All due respect to Malcolm Gladwell, but at least you don't have shoot mini-hoops [for 10,000 hours](http://www.gladwell.com/outliers/outliers_excerpt1.html) before you master this skill.
08the-sweet-spot
The Sweet Spot -------------- Two metal rods stretching up toward the Exploratorium roof help illustrate how hitting the ball on the "sweet spot" of a bat can help [maximize power output](http://www.exploratorium.edu/baseball/sweetspot.html) and launch balls farther than if you hit the ball with weaker part of the bat. As the RPMs of the rods goes higher, you can discern an area just beyond midway up where the rods don't appear to be vibrating. These spots are called "nodes," and if you can envision the bat in your hands as one of these tall vibrating rods, that's a spot between two nodes, just about four inches from the end. *That's* where you want the ball to make contact, but you better swing fast: A 90-mph fastball reaches home plate in only 400 milliseconds.
