Subatomic particles reveal a mysterious structure inside Giza's Great Pyramid

A shower of subatomic particles has revealed the outlines of an empty cavity inside the Great Pyramid at Giza in Egypt — the first discovery of a new internal structure in almost two centuries. Scientists don’t know exactly what it is yet, or why it’s there. But the finding might help solve the mystery of how an ancient civilization constructed this imposing monument 4,500 years ago.The pyramids jutting out of Egypt’s Giza plateau are obvious landmarks — but even af