2002 Chicago Review Press

 Excerpt from Chapter 12, page 157-160
 

In 1955, a group of scientists and engineers at Los Alamos National Laboratory was given the task of reducing the amount of radioactive material expelled into the atmosphere resulting from nuclear testing. Astrophysicist Robert Brownlee headed up this project, named Bernalillo after a New Mexico county near Los Alamos. 

Dr. Brownlee and his team were testing the feasibility of moving nuclear testing underground. In order to achieve a number of scientific objectives, they needed to explode several nuclear devices underground. Doing so involved building the equivalent of a giant, nuclear powered potato cannon. The cannon was a 400-foot deep well lined with thick steel pipe, capped by a steel plate instead of a potato, and powered by a nuclear bomb instead of a squirt of hair spray.

Forty stories below the scrubby tangle of mesquite trees and creosote on the desert surface, researchers tried to determine if they could safely test the effects and design of nuclear devices while reducing the release of radioactive materials to a minimum, maybe even completely.

The Bernalillo team placed a small (by high-energy physics standards) nuclear device in the well and capped the well off with a big steel plate. The four-foot diameter steel manhole cover was 4 inches thick and weighed in the nearly half a ton.

The puny nuclear device had the explosive equivalent of less than one kiloton of high explosive. However, small in nuclear terms is still incredibly large. The effects of letting lots and lots nuclear energy loose are sometimes hard to predict.

The scientists working on the Burnalillo series of tests were trying to figure out what happens during the few micro-moments of the nuclear explosion. The Los Alamos team wanted to know what kind of nuclear particles were emitted, how many there were, and where they were going. The data they needed to collect had to be measured in the first few "shakes" after the explosion begins. (A "shake" is the amount of time it takes light to travel 10 feet. Since light travels at 186,000 miles per second, that makes a shake an exceedingly short time interval.)

The scientists put all sorts of detectors and sensors in and near the well. They also placed speed cameras some distanced from the top of the well to film the explosion. Normal cameras take about 16 frames of film every second. The high speed Los Alamos cameras were 10 times faster.

When the device was triggered, the scientists got a bit more than they bargained for. The bomb emitted high energy particles of light, called photons. Within a few shakes, the photons, or in Alamos lingo, the "shine", bombarded the steel pipe vaporizing it into superheated iron gas. About three hundredths of a second after detonation, the shock wave of gas, light, and radiation blasted against the steel cover plate at the top of the well.

The high speed cameras recorded the blast effect on the plate. In one frame it is there. In the very next frame, 1/160th of a frame later,  it is gone.  Where did the 4-foot diameter, half-ton steel plate go? The area was searched carefully, but the plate wasn't found. In fact, in the 40-plus years since project Bernalillo, no trace of the plate has ever been found, anywhere.

The project team felt they knew where the plate went. Prior to the actual test, Dr. Brownlee’s boss asked him what would happen to the plate covering the test hole. He thought about it for a while.. “I guess I don’t really know,” said Brownlee. “Find out,” said the project director.

Brownlee performed some preliminary calculations. Based on the expected bomb yield, the shape and depth of the test hole, and so forth, he figured the initial velocity of the plate would be somewhere in the neighborhood of 41 miles per second. That’s moving mighty fast. He made many slide rule calculations and reported back to his director. The manhole would probably wind up on a collision course with the distant starts, shoved by a nuclear push through the Earth’s atmosphere and into outer space.

In 1687, Isaac Newton, figured out some interesting things about gravity and velocity. He deduced that there is one particular speed, one if you throw something hard enough and fast enough, you can make it through the gravitational attraction of the earth and break free into outer space.  Newton called that speed "escape velocity" and is calculated to be just less than seven miles per second on earth. When the Bernalillo team calculated the plate’s velocity just after detonation, they estimated it was in the rough neighborhood of five times escape velocity!

A few years later,  in 1959, a team of Soviet scientists launched what they claimed to be the first man made object into outer space, the satellite called Sputnik. Many at Los Alamos think Sputnik was the second object to travel to outer space, preceded by a full two years by an American made steel manhole cover.