On 17/04/2008, at 3:14 AM, Dan M wrote: > The speed of sound barrier is rather > significant, and we have not found a way to develop efficient planes > that go > at Mach 1.1 almost 60 years after we first went above Mach 1.
So-called supercruise. The biggest problem with going over Mach 1 is political and legal, not technological - had Concorde not been killed by politics, its successor would have been an "efficient" supersonic plane. > > > > >> It's not the cost of energy. > > No, it's the cost of the system. Yep. >> Can you be specific about what you mean here? > > Sure, to be effective, power would have to be transmitted down in a > fairly > dense fashion. One needs mechanisms that provide feedback to turn > the power > off should the aim stray. Current designs seem to show a wide collection with a diffuse beam, so that it's relatively safe to be under the beam. >> >> There doesn't seem to be any reason a really huge throughput >> transport system should not be able to give you that much >> reduction. > > Then, why hasn't it happened with the scores of airline industries? > 747s > were brought online in the '60s....almost 40 years ago. 747s remain > competitive. The airline industry is huge, and we've only seen > incremental > improvements over the past 40 years. And 747s, beyond the basic airframe and control systems, are very different to what they were in the 70s. (by the way, they were "brought online" in 1970 - maiden flight was '69, but it wasn't delivered 'til the following year). There isn't a need for that many huge airliners, only around 1400 747s have been built, and it's taken 'til last year for the 747s size and efficiency to be surpassed by the A380 (which is an incredible plane) - improvements in the mid-size airliners have been marked, however, mainly because there's a lot more competition. Point on this part is that there is huge inertia when there's huge capital expenditure - if you've spent a few tens of millions on a plane in 1970 or 1980 you're going to keep using it as long as you can, 'cause a similar plane costs a few hundred million in 2008. All that said, I'd like to see you, Dan, try to put together a cost- analysis on a powersat project. You're very good at using your tenacious posting to naysay, so I'd like to see you attempt to solve the problem so I can see where the problems are. C. _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
