Sometimes nature has just the right tool, and our job is to figure out how to use it. The same way we use X-rays to see past skin to organ and bone, scientists have succeeded in using muons (MYOO-ons), produced when cosmic rays strike the upper atmosphere, to probe the inside of the Great Pyramid of Giza in Egypt built over 4,500 years ago. Muons are sort of like electrons — they have a negative charge — but they’re about 207 times more massive. Cosmic rays are fast-moving protons flung out from catastrophic events like supernovae, but they also get pitched by our very own sun during powerful solar flares.
When a cosmic ray strikes the nucleus of an air molecule, it produces a shower of muons. 10,000 of the little buggers traveling at nearly the speed of light reach every square meter of Earth’s surface every minute! Don’t worry, they’re too small to cause any harm.
Muons through both air and rock, but fewer make it through the denser rock compared to the air. An international team of scientists led by Kunihiro Morishima at Nagoya University in Japan placed special film within and around the pyramid that recorded the passage of muons as dark streaks. By measuring the number and the direction of muons picked up at these different locations, they essentially “X-rayed” the structure, revealing known an unknown cavities. No surprise, the technique’s called muon radiography.
Muons revealed the King’s and Queen’s chambers, the subterranean chamber and all the known connecting passageways, but also detected something brand new: a large hollow or void above the Grand Gallery that appears to be a tunnel at least 100 feet (30 meters) long and some 26 feet (8 meters) high. The group confirmed their finding with two additional tests for muons using other detecting methods inside and outside the pyramid.
Although the researchers are confident the chamber exists, they don’t know whether it’s horizontal or inclined or what might be inside. With no plans at the moment to access the sealed vault, its purpose remains unknown. The beauty of muon radiography is that we used the least invasive tool imaginable to get into the belly of Great Pyramid, but I suspect the mystery will get the better of archaeologists, who may be making plans even now to find a way in.
On somewhat different tack, high speed particles from the sun are expected to stoke minor to moderate (G1-G2) geomagnetic storms tonight and tomorrow night. Auroras are possible for the northern tier of states and Canada from about 9 p.m. till dawn Central time tonight and from 6 p.m. to 3 a.m. Wednesday night. With the moon rising later, we’ll have dark skies for looking.
Watch a video on the ScanPyramids project for more details on the discovery