With no muscles in our fingers or toes, how come humans are able to climb every mountain? Or, climb some of them anyway!
They have slept suspended in bivouac-style tents attached to the rock, which towers above Yosemite Valley and is some three times as big as France's Eiffel Tower and even bigger than world's tallest building, the Burj Khalifa in Dubai.
"This is not an effort to conquer. It's about realizing a dream," Jorgeson tweeted on Tuesday, ahead of the final push.