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The Real Trinitite Story

from Jim Eckles' new book

Just when you think you know some fact or truth – not believe it, but know it – often something comes along to rock your boat. That is the great thing about science. It allows for better explanations that only require better proof. No holy books need to be rewritten.

That happened to us in 2003 when we got involved with Robb Hermes and Bill Strickfaden from Los Alamos. Hermes was a polymer chemist with the lab at that time and Strickfaden was a retired physicist and independent investigator. Their work has rewritten the story of how Trinitite was formed.

They contacted us and asked for samples of sand from both GZ and an area outside the outer fence. They said they could use the comparative samples to recalculate the yield of the bomb.

And, by the way, they added, could they get some samples of anthill sand from GZ? We said sure, and on the next trip to Trinity Site we filled some quart plastic bags with the appropriate sand and mailed them to Hermes. Not long after, Hermes contacted us excited about the ant sand. He said there were small balls or spheres of glass mixed in with the sand. In other words, there were tiny beads of Trinitite mixed in. Some weren’t much bigger than a pinhead, but some were larger and clearly balls, not shards. People have found larger spheres that are about the size of pearls which are appropriately called “Trinitite pearls.”

To see color images of Trinitite beads, look at the back cover of this book. Hermes said that many of the sample chunks of Trinitite stored at Los Alamos were shiny and smooth on top but rough and irregular on the bottom. On some of the pieces, spheres were clearly embedded in the mixture. In fact, in some cases the rough bottoms were simply spheres stuck together.

The theory accepted for 60 years on the formation of Trinitite was that the fireball simply melted the surface of the crater and turned it to glass. Kevin Casey, who was in Public Affairs at the time, called it the “Trinitite crème brulee effect.”

This explanation did nothing to account for the spheres. Strickfaden said he modeled the explosion knowing the height of the tower at detonation, the bomb’s basic yield, and the kind of sand found at GZ. Using different models, he could not get any of them to generate enough heat on the surface to form Trinitite over a half-inch thick. The fireball just wasn’t there long enough.

That set them on a course looking for another mechanism to form the glass. When they looked at old reports and photos of the crater, as in the Groves account, they realized quite a bit of material was actually gouged out of the ground. The crater wasn’t simply smashed down and compressed forming a nice dinner plate surface.

The two quickly realized that if this material was thrown up into the fireball, the tremendous heat would have melted the sand and turned it to a mist of liquid rock. Maybe it was hot enough to turn some of it into a gas which, when cooled, would reform as a liquid.

At this point, it became something like raindrop physics. Droplets of liquid rock bumped into each other to form larger ones. Eventually, they fell back to the ground. In some cases, the tiny spheres were suspended long enough to solidify and remain beads after they hit. Other drops hit as a liquid and spread, forming puddles across the surface. “Much of the layer was formed not on the ground but by a rain of material injected into the fireball that melted, fell back, and collected on the hot sand to form the observed puddles of Trinitite, especially within the radius of the hottest part of the event,” they concluded in an article for the Fall 2005 issue of Nuclear Weapons Journal. “After falling to the ground, the top surface of the Trinitite layer was still heated somewhat by the fireball and thus developed a smooth surface . . . We calculated an average fireball temperature of 8,430 Kelvin,” they reported. That’s 14,710 degrees Fahrenheit.

Their theory nicely explains the spheres. It also explains why there was Trinitite found on top of the asphalted areas and on top of fence posts and rocks afterward.

It also explains a note in Reines’ 1945 report that asphalt roads within 150 feet of the tower were not destroyed in the blast. In fact, in the aerial photo taken 28 hours after the test and many other shots, the black asphalt is still very evident.

In this process of examining Trinitite, they were able to confirm that the green color of the glass is simply caused by the amount of iron found in the sand. Since ancient times, craftsmen knew how to add iron oxide to liquid glass to tint it green.

In one trip to Trinity with them, we discovered a few chunks of the very rare red Trinitite. Los Alamos analyzed one piece and Hermes reported the red is from copper mixed in with the glass. There were large copper coaxial cables running up the north side of the tower; that wiring is probably the source of the copper. Supporting that idea is the fact that the red glass was found north of GZ.

During the October 2011 Trinity open house, I was answering questions at GZ when a young boy and his father approached me. The man told his son to show me what he had found pawing around in the dirt. The boy held out a glob of Trinitite, not quite a sphere, that was mostly white with just a tinge of turquoise.

In visiting Trinity Site for more than 30 years, I had never seen such a color. I thanked the boy and tucked the Trinitite away for safekeeping. I then sent it to Hermes at Los Alamos for analysis. He reported their quick-look showed the white was caused by calcium, probably from the calcite or caliche in the soil.

Since the initial work on the green glass, Hermes has pursued his quest to learn as much about Trinitite as possible. He has even acquired a piece of glass from the first Soviet test site where Joe-1 was exploded. That glass is a deeper greenish black but has the same texture and qualities of Trinitite including the spherical inclusions on the bottom. Since Joe-1 was a carbon copy of the Trinity event, including a 100-foot tower, it means their glass was probably formed the same way.

Then in early 2010, Hermes discovered a buried Los Alamos report from 1947 that postulated the same theory he and Strickfaden had come up with for the dispersion of Trinitite. This document was classified as “secret” when written, so very few people were privy to the information. If the document had been available earlier, maybe the crème brulee theory never would have grown into the myth it has become.

In addition to their reformulation of the Trinitite story, Hermes and Strickfaden waded into the issue of the size of the GZ crater. Previously I have quoted diameter measurements presented by Groves (130 feet) and Reines (300 feet). Groves has to be forgiven for his lowball estimate as it was made from a distance right after the explosion. However, it should be noted that Bainbridge, in his Los Alamos report Trinity said the crater was 30 feet across.

Hermes and Strickfaden examined aerial photos taken of the crater the day after the test. The high-resolution negatives were perfect for enlarging – so much that they could clearly see the four tower footings protruding from the surface. From this and other information in the Los Alamos archives, they calculated the crater had a diameter of about 250 feet (close to Reines’ number) and the spread of Trinitite covered a circle with a diameter of close to 2,000 feet. They concluded many people, over the years, have confused the crater with the covering of Trinitite at the site which why you sometimes see the crater estimated at a quarter of a mile.

After all that work, Hermes and Strickfaden never did provide a firm yield for the Trinity plutonium bomb, as their calculations were derived from their observations of the available Trinitite. The result was a rather broad range of yields, including the generally accepted yield of 20 kilotons.