In nearly seventy years of deep-sea exploration, researchers compiled 43,681 submersible dive records — and found that humans have visually observed less than 0.001% of the deep seafloor, an area roughly the size of Rhode Island, according to a Science Advances study published in May 2025.
In 1991, eight people sealed themselves inside a glass world in the Arizona desert for two years, and the experiment nearly unravelled when the oxygen began disappearing from the air they were breathing