Why are people using infrared to look for new chambers and passages? Muon detectors, using cosmic rays for the source, were used in the 1960s to conclude:<p>> We can say with confidence that no chambers with volumes similar to the four known chambers in Cheops's and Sneferu's pyramids exist in the mass of limestone investigated by cosmic-ray absorption. The volume of the pyramid probed in this manner is defined by a vertically oriented cone, of half-angle 35 degrees, with its point resting in the Belzoni Chamber. The explored volume is 19 percent of the pyramid's volume. We hope that with minor modifications to the apparatus the complete mass of limestone can be searched for chambers. - <a href="http://www2.lns.mit.edu/fisherp/AlvarezPyramids.pdf" rel="nofollow">http://www2.lns.mit.edu/fisherp/AlvarezPyramids.pdf</a><p>That's one of the reasons we know for certainty there is no large, unknown grain storage chamber in those pyramids.