The Linear Accelerator

Egr Chebbi, Morocco

photo by Susan Owhadi






Scott Sturman


It's not Mt. Everest or CERN's particle beam accelerator, but it was the site of some ground breaking scientific discoveries in the early 1970s.  Could a boulder of sufficient mass be dislodged from the summit of Colorado's Eagle Peak and mow down every tree in its path until coming to rest?

Eagle Peak soars 9368 feet above sea level and is located in the Rampart Range just west of the United States Air Force Academy campus.  Its eastern face is quite steep but technical equipment is not required to access the summit.  One autumn day a select group with ample liquid refreshment hiked 2000 vertical feet from the campus to enjoy the view.  Along the way we pushed some rocks weighing less than 100 pounds down the slope to see what would happen.  Accelerating rapidly down the 45+ degree incline, they began to bounce like rubber balls as they repeatedly struck the uneven ground beneath them.  Every so often one of the projectiles would strike a massive granite outcropping with a violent smash.  It was pulverized into gravel sized fragments and emitted a distinctive, acrid odor which we could smell after impact.  Rocks that passed through the granite section entered the tree line and caromed off large tree trunks and came to rest nearby.  Inquisitive minds wondered what would occur if a large group of "scientists" returned and placed some really large boulders in motion.

At the dormitory that evening we organized a team for the following weekend.  My classmates S.R. and Mark, both mechanical engineering majors, and Goodie, a physics major, volunteered to consult on technical issues, while seven or eight liberal arts majors were recruited to dig, lift, and pull. As long as there was free wine and a lot of it, it didn't take much to entice a history, political science, or economics major to join the expedition.

Next Saturday afternoon after completion of military training lectures, twelve of us grabbed a couple of shovels and headed toward Eagle Peak.  Along the way we found several logs about ten feet long and a foot in diameter and hauled them with us. As we neared the top, we saw a number of huge boulders weighing by our estimation several thousand pounds apiece perched above a steep incline which extended uninterrupted to the tree line below.  While S.R., Mark, and Goodie supervised launch preparations, it was my job to keep the liberal arts majors from drinking all the wine.  Archimedes would have been proud.  Using (F1)x(D1) = (F2)x(D2), we set a fulcrum and placed the end of a log beneath the uphill side of a relatively round boulder, which would roll easily once put in motion. With ten of us pushing down on the lever and the other two undermining the downhill side of the boulder furiously, it started to move.

As soon as the boulder's center of gravity extended beyond the ground supporting it, its mass and acceleration produced an imposing force.  No one knew what to expect, but within three seconds it was traveling nearly 60 miles per hour and bouncing 10 feet into the air.  Suddenly, it impacted an enormous rock embedded in the ground on the canyon floor. There was a massive explosion sounding like a howitzer as the boulder disintegrated. We started laughing, screaming, and slapping each other on the back and began looking for a bigger boulder.

The next candidate was larger and rounder than the first but its base was buried deeply in the ground. After what seemed like hours of digging and prying, we dislodged and sent it down the canyon. This time the boulder avoided the large rocks lining the canyon and entered the tree line.  It hit the base of a giant pine tree and snapped it like a match stick.  If the collision slowed the boulder's progress it was not apparent as it continued down the mountain mowing down every tree in its path.  As the bounding mass passed out of sight, all we could see were the tops of trees disappear from view.

As we returned home and descended along the boulder's path, our mood changed.  The power of the falling boulders and potential danger to anything in the way was a sobering thought.  Young men with time on their hands and much to drink do crazy things, and we were relieved our antics had not caused any permanent damage.  To mark the occasion the canyon was renamed the Linear Accelerator, but it was the last day a physics experiment was conducted in this unusual laboratory.