ur ancestors have wondered for many years until finding a natural shelter which came in the form of a cave for millions of years. This natural housing is described as a safe haven from enemies and other predators made up of natural walls that were missing something to make this protective structure complete. Doors have not only offered protection but also encapsulated the warm inside structures or homes. You may think that this technology is very old, but not as old as some like to think. The first recorded history of doors was found in Egyptian tomb paintings 4000 years ago. No one knows who invented the door, only that it was first incepted somewhere in central Egypt.
Some of the heaviest doors in modern history are found inside bank vaults protecting huge sums of cash and even valuable jewelry worth millions. Despite this, the heaviest door in the world is not found in a bank, but actually in a laboratory.
The Lawrence Livermore National Laboratory houses a behemoth of a door weighing in at 44 tones (97,000 pounds) with a thickness of 2.5 meters (8 feet) and width of 3.6 meters (11.8 feet). You would think that such a heavy door would require a huge person to open, but due to the ingenious technology hidden in the hinges of the door, it only takes one person to open.
So what is behind the door? What is so valuable that it takes such a huge structure to protect it? Funny enough, the door is not made to protect the content inside the laboratory, but to protect the world from what is within the laboratory. The Lawrence Livermore National Laboratory has been used for many years to test various metals and other materials at a neuron level. The door is used to shield the Rotating Target Neutron Source-II (RTNS-II) — the world’s most intense source of continuous fusion neutrons. Scientists from around the world used it to study the properties of metals and other materials that could be used deep inside fusion power plants envisioned for the next century.
The power of this piece of technology involves a lot of radiation, that is why such a large and thick door is required, in order to stop the radiation from shooting out of the laboratory into the world.