Imagine a ribbon roughly one hundred million times as long as it is wide. If it were a meter long, it would be 10 nanometers wide, or just a few times thicker than a DNA double helix. Scaled up to the length of a football field, it would still be less than a micrometer across — smaller than a red blood cell. Would you trust your life to that thread? What about a tether 100,000 kilometers long, one stretching from the surface of the Earth to well past geostationary orbit (GEO, 22,236 miles up), but which was still somehow narrower than your own wingspan?
Via Dr. Stefan Gruenwald