This is a thing so mind-boggling that it quite literally makes me giddy to think about it. There are many more complex creations of the human mind- in fact the space elevator is a remarkably simple idea- but I think it is true that nothing that approaches its breathtaking scale has ever been seriously imagined. Imagine a cord so strong that it can resist the tension over tens of thousands of miles. Imagine a vast block of concrete flouting in the ocean somewhere with this cord attached to it. Just imagine what it would look like for a moment. Imagine climbing up that cord, hand over hand for tens of miles, out of the Earth's atmosphere, then for thousands more miles into orbit, and then some part of the way to the Moon. At the end of that cord is a giant counterweight, circling the Earth exactly once a day, a man-made moon fixed in the sky, 60,000 miles above the equator. Imagine feeling your weight pulling away from the Earth and towards that great block of metal. I defy anyone not to feel vertigo at contemplating this. My head spins, and I have to hold onto something. When what you are holding onto is a bicycle, this is a problem, so I only think about it when I'm sitting safely in a comfortable armchair.
2 hours ago