[#] "unobtainium"

So I'm reading this story about the Space Elevator, and I scoll down to the last comment (at that time) and I read this:
This is a classic in material science classes. Most real engineers look at this problem and laugh at it, myself included. The material science involved in this issue are light years ahead of where we are right now. Even then its not likely that a matierial exists that could provided the following characteristics: Light weight, incredible tensile stength, toughness, abrasion resistance, nonexistant ductility. In short, unobtainium. If you used our currently most extreme materials the weight of the material while in atmosphere before it was under the influence of the tensile force would be enough to destroy the material at nearly any point higher than a mile. The weight of the cable would literally be too much for the cable to hold up.

50 years would be a magical shot in [bleep]. We'll be using brain waves to lift things to the heavens before a material that can do this is synthesized.
There is nothing more dangerous than an engineer with a decent vocabulary.