Washington State Magazine

Spring 2005


Spring 2005

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In This Issue...

Features

Baseball is a Family :: We hear about his time with the Padres; about teammates Dave Winfield, Willie McCovey, and Tito Fuentes; how he'd faced Hank Aaron and Johnny Bench and Pete Rose and Joe Morgan; and how a tear of his rotator cuff had brought an end to his major league career.

The tie that binds :: No matter what you want to blame—predatory pricing, vertical integration, foreign competition, globalization, urban sprawl—the fact of the matter is, rural America is packing it in. At least the rural America of our memory or imagination.

{ WEB EXCLUSIVE—Recipe: Stuffed Peppers from the Harrah Café }

{ WEB EXCLUSIVE—Galleries: Washington Communities:Harrah and Pullman }

Where water meets desert :: Among locals, you occasionally hear the word "wasteland" used to describe sagebrush-studded lands that biologists prefer to call native shrub steppe. It's impossible to take such a harsh view when Robert Kent is your guide to the Columbia Basin Wildlife Areas.

{ WEB EXCLUSIVE—Gallery: Where water meets desert :: Photos of the Columbia Basin by Bill Wagner }

Panoramas

Departments

:: SEASONS|SPORTS: Meeting the challenge

Tracking

Cover: Former San Diego Padres pitcher Joe McIntosh '73 and his daughter Molly. Photograph by Robert Hubner.

Panoramas
An expectant crowd on the plaza breathlessly waits for the pumpkins to drop in a demonstration of Galileo's law of falling objects.

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An expectant crowd on the plaza breathlessly waits for the pumpkins to drop in a demonstration of Galileo's law of falling objects. Robert Hubner

Pumpkin Physics

by | © Washington State University

One way to raise awareness for an academic program is to arrange a seminar, invite an eminent faculty member to discuss her research, and hope people will show up.

Or, you could drop pumpkins from the tallest building in Pullman.

That was the route taken by the Washington State University Physics Club on Dad's Weekend at the end of October 2004. More than 200 people came to see it happen.

Though scholars now dispute it, Galileo is said to have dropped a 10-pound weight and a one-pound weight off the Leaning Tower of Pisa in 1621 to prove that objects fall at the same speed, regardless of weight. In truth, Galileo probably never dropped anything off the tower. Instead, he used pen and paper and an appeal to logic to convincingly disprove a belief held since the time of Aristotle.

Still, demonstrating Galileo's law of falling objects with a pencil and paper is not nearly as much fun as smashing pumpkins.

So on a blustery fall day, on the plaza between Webster Physical Sciences Building and the new Institute for Shock Physics, Galileo emerged from the past to serve as master of ceremonies for what physics department chairman Steve Tomsovic hoped would be "a very rigorous scientific experiment."

Dressed in a black robe for his 17th-century role, fifth-year graduate student Francis Morrissey told the crowd, "It was one of the deepest mysteries in all of physics." It was commonly believed that heavier objects fell faster than lighter ones, but Galileo devised a simple mathematical equation to refute that: d=1/2gt2. Sir Isaac Newton refined the idea into the law of gravity. It was further advanced by Albert Einstein to a theory of the mechanics of the cosmos. But it all started with an idea that can be elegantly demonstrated with a tall building and a few plump and plummeting pumpkins.

"For the pursuit of scientific knowledge, are we ready for the drop?" the young Galileo asked the crowd.

".Two, one, drop!" the crowd roared. The pumpkins fell. Breathless anticipation. . . and then the plaza resonated with the satisfying double thud of pumpkins landing nearly on top of each other.

Rind, pulp, and seeds went flying amid cheers and laughter.

"I've been hit!" said Sharon Fraser Allen, holding up a cookie-size piece of pumpkin, "but it's only a flesh wound." Allen was there with her five-year-old twins, Samantha and Katherine.

More pumpkins fell from Webster that day, along with cantaloupe and a watermelon (which seemed to have the widest pulp and rind trajectory). "Galileo" talked more about the physics of it all. Although the original Galileo described the phenomenon of falling bodies, it wasn't until the time of Einstein that it was finally understood.

In a nod toward that afternoon's WSU vs. USC football game, the last body to fall from the 12th floor window was a dummy Trojan. A gust carried the lightweight dummy toward the crowd massed behind a yellow caution tape. Gasps of alarm turned to laughter as the Trojan landed directly on Tomsovic.

Unharmed and smiling, Tomsovic said later he was pleased with the event. "But I like that kind of stuff, dropping stuff or blowing things up."

Tomsovic's own research focuses on understanding how chaos shows up in wave mechanics, with implications for nanophysics, nuclear physics, atomic molecular optical physics, and climate monitoring.

Maybe something as simple as smashing pumpkins was the way to bring out a crowd.

But, Tomsovic said, it wasn't that simple. Physics department members spent hours on the logistics, including removal of a light fixture from the path of the falling pumpkins, planning for the pumpkin parts pick-up, and complying with public safety regulations. A roof drop without a safety harness was nixed, but a window drop was okay. At some point the crew may have been tempted to go the way of Galileo's helpers (let's not do it, but say we did), but they persevered, and everything fell into place.

While everyone went away smiling, not all were convinced.

"They didn't prove it! They didn't prove it!" one young girl told her mother. "The pumpkins didn't drop at the same time."

Well, no, technically they didn't. According to Galileo, it had to do with the release time. It is impossible for two people-or even one person-to drop two objects at precisely the same instant. And, as the objects travel over a significant distance-like 12 stories-the difference becomes more pronounced. Air resistance also affects the drop. One way to truly demonstrate the law of falling bodies would be to conduct the experiment in a vacuum with a mechanical release.

"We knew that before hand," Morrissey said, "but we just thought people would enjoy watching the pumpkins smash."

And they did.

Categories: Physics |

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