Sure, the material had not been produced yet, and still hasn't. Getting all those long nanotubes to line up parallel is another of the hard parts. It's just a theoretical result.
A key part of the design is for the glue to have a low enough melting point, so if the cable breaks, it melts on reentry and you don't get lots of little fluttery bits instead of a big super-strong cable wrapping around the planet.
A key part of the design is for the glue to have a low enough melting point, so if the cable breaks, it melts on reentry and you don't get lots of little fluttery bits instead of a big super-strong cable wrapping around the planet.