Secrets of The Pyramid - Empty Space Found Great Pyramid

The heart of the Great Pyramid of Giza is empty. It's now the fourth known cavity in the pyramid, along with the king and queen's chambers and the "Grand Gallery." Scientists used muon radiography and found a void that's at least 100ft long.

Muons are subatomic particles (smaller than atoms) that are produced when cosmic rays hit the Earth's atmosphere. Striking the Earth at such a fast speed, the particles are able to pass through hundreds of feet of rock. Even though we can't see them with the naked eye, muons are constantly passing through the Earth.

Scientists use special detectors to spot muons. The more they can count, the more empty space there is within a structure. The Great Pyramid was built during the ruling of Pharaoh Khufu 4,500 years ago. Some researchers say the cavity isn't a new discovery.

Zahi Hawass Archaeologist, Egyptologist said "If you understand how the pyramid was built, you will know that inside the pyramid there is many hollows and many gaps. A void doesn't mean a room, a void doesn't mean a discovery."

It's still unclear what lies within the space and what its purpose may have been. While drilling holes and inserting cameras aren't allowed. the Egyptian Ministry of Antiquities is encouraging scientists to find new ways to verify and study the void.