Schneibster - questions

[Dorian Gray]

From this thread

On the concrete things, IIRC there was a Nazi project to detect incoming bombers by their sound. I thought I had come across something about some project like this that had been discovered, but I can't find the link now.

The show sounds like woo.

On the antigravity, technically, the suspending-aluminum-over-a-magnet thing, some people call it "maglev," is antigravity- as are electromagnets. However, as far as some new force that is the opposite of gravity, as positive electric charge is the opposite of negative, this is not possible if gravitons turn out to be spin-2 bosons, because a spin-2 boson has only an attractive interaction, not a repulsive one. Of course, we might be wrong, and gravitons might not be spin-2; but a lot of pretty well-known Standard Model stuff would be imperilled by that, so I guess most physicists don't expect it.

I kept the above as an indicator of why I am asking you this stuff now.

LiftPort Group (www.liftport.com) is attempting to build the first space elevator, using a ribbon made of a carbon nanotube composite, a good deal of which hasn't been finalized or even created yet. Lifters would climb up and down the ribbon, which would be millimeters thick, three feet wide, and 62,000 miles long. More details are on the site.

What is your impression of the feasibility of this project?

 

[Schneibster]

Technical, political, or financial feasibility? I'd say technically speaking, it's just outside our reach at the moment, but by the time anyone has managed to put financing in place for it, it's likely that we will have the remainder of the scientific knowledge we need. In the timeframe they have chosen, it is (IMO) just at the edge of what is technically feasible, and a fair bit outside what is financially feasible.

A massive engineering effort, preceeded by some fairly expensive and extensive experimentation to obtain figures that can be used to do the engineering in the first place, is likely to be required; as a result, I'm not sure that private financing is particularly likely. I'm not sure I can see this happening other than at the behest (and with the investment) of a national government, and I'm not sure that it's politically feasible to undertake a project that would take this long in the US today, given the political climate.

 

[Soapy Sam]

Perhaps if someone points out to the military the advantage of taking the high ground first?