... You don't necessarily need high power, modern silicon is now up to gigahertz speeds anyway, this bit is if anything getting easier. Some designs just stick...
8448
Andreas
awnd329
Oct 1, 2008 7:35 pm
... True. Spectral purity seems to rule out ordinary Klystrons. Silicon devices are much less efficient than tubes, AFAIK. Traveling wave tube (TWT) amplifiers...
8449
Ian Woollard
wolfekeeper
Oct 1, 2008 8:32 pm
... Well, notably the E-M physics is identical to that of laser power beaming, so if you really don't think this will work, your laser space elevator climbing...
8450
Andreas
awnd329
Oct 2, 2008 1:35 am
... The SE laser beaming is expected to have not much better than 1% overall efficiency (yes, 99% losses), which is what makes it (sort of) realistic. Even so,...
8451
Ian Woollard
wolfekeeper
Oct 2, 2008 2:25 am
... No, that's a different problem completely. I actually tried to design a laser beaming system for a rocket. It seemed to work great, but the rocket was...
8452
Andreas
awnd329
Oct 2, 2008 3:05 am
... I have made another attempt to dig up evidence on useful wireless power transmission. What keeps cropping up is these lines from Wikipedia: Wireless Power...
8453
Robert Munck
bobmunck
Oct 2, 2008 4:23 am
A point that's been mentioned but not emphasized is that end-to-end efficiency isn't the be-all and end-all of the analysis here. DIE SONNENLICHT SIND FREI up...
8454
Andreas
awnd329
Oct 2, 2008 2:03 pm
... True. But there is plenty of free sunlight on the ground, too. Any chance of economic viability vanishes when transmission losses cancel the insolation...
8455
Andreas
awnd329
Oct 2, 2008 2:18 pm
... year old ... I was trying to make the point that building an efficient WPT system requires a little more than doing the maths. People like Brown have tried...
8456
Ian Woollard
wolfekeeper
Oct 2, 2008 2:31 pm
... That's simply a total mischaracterisation of the technology, and an insult to Brown, he was in no way at all unsuccessful. He was flying helicopters, and...
8457
Andreas
awnd329
Oct 2, 2008 2:46 pm
... I don't know if your design included adaptive optics, but it is quite clear for the reasons you mention that AO is a must when beaming from the ground....
8458
Andreas
awnd329
Oct 2, 2008 2:51 pm
... Browns experiments were great and very successful. But neither he not anyone else succeeded in transmitting power over more than a few meters at more than...
8459
Ian Woollard
wolfekeeper
Oct 2, 2008 4:20 pm
... The short range transmitters show that the transmitters can be reasonably efficient, and the long distance transmission shows that the receivers are...
8460
Andreas
awnd329
Oct 3, 2008 11:11 am
... reasonably efficient, and the long distance transmission shows that the receivers are efficient. Everything in between is standard beam physics. ... Both...
8461
csceadraham
Oct 3, 2008 2:45 pm
... "Plenty of incentive for decades" -- please elaborate. What was the incentive in the 1970s, the 1980s, and the 1990s? ... http://www.eagle.ca/~gcowan...
8462
Ian Woollard
wolfekeeper
Oct 3, 2008 3:44 pm
... I'm just glad we have you here to tell us what is hard and what is not. DIffraction limited microwave transmission is considered to be hard? That's news to...
8463
Tony Rusi
marsbeyond
Oct 3, 2008 6:08 pm
have you guys read these? http://www.physorg.com/news140438326.html http://focus.aps.org/story/v20/st19 ... From: Ian Woollard...
8464
Andreas
awnd329
Oct 3, 2008 9:46 pm
... The ability to efficiently transmit power without wires has plenty of applications. In particular, supplying energy to inaccessible areas. All the research...
8465
Andreas
awnd329
Oct 3, 2008 10:20 pm
... Are you seriously saying that we don't need to build a functioning system because our computer models tell us it is trivial? Why, then, would Brown and...
8466
Bill Haught
wlhaught
Oct 4, 2008 2:58 pm
How about using tethered aerostats? Bigger, higher floating versions of these: Balloon technology could cut cost of solar energy 90% by 2010 ...
8467
Ian Woollard
wolfekeeper
Oct 6, 2008 5:28 pm
... You know, I've always considered it to be a really, really bad idea. However it would solve most of the windshear problems if you put a large balloon at...
8468
Robert Munck
bobmunck
Oct 6, 2008 6:13 pm
... go horizontal in low winds; which otherwise has no solution that I'm aware of. Make the bottom 30 km of the SE circular in cross-section rather than thin...
8469
Ian Woollard
wolfekeeper
Oct 6, 2008 6:33 pm
... That would be one massive, *massive* elevator. For a 1cm diameter, with useful working strength of 65 GPa CNT, the payload carrying capacity would be over...
8470
Robert Munck
bobmunck
Oct 6, 2008 7:30 pm
... Whoops, meant to say "pencil LEAD." And admittedly, I didn't give any consideration to accuracy, was just trying to convey the impression "thin." ... I'd...
8471
Herbert Murray
hcm1955
Oct 6, 2008 10:22 pm
From http://nextbigfuture.com/2008/09/advance-in-separating-carbon- nanotubes.html Carbon nanotubes are very strong and light and can be 100 times stronger...
8472
Herbert Murray
hcm1955
Oct 6, 2008 10:44 pm
You can download the paper at http://www.geocities.com/hcm1955/cnt_B2_seperation.pdf Bert ... until ... nanotubes ... in ... With ... figures...
8473
Ian Woollard
wolfekeeper
Oct 7, 2008 3:10 pm
... You want a high ballistic coefficient, not a low ballistic coefficient. Thin is bad because it has a low sectional density. Cylindrical shapes aren't very...
8474
csceadraham
Oct 8, 2008 3:49 am
... You're at 100,000 feet? Events are unfolding with greater rapidity than I had anticipated ... ... http://www.eagle.ca/~gcowan...
8475
Ian Woollard
wolfekeeper
Oct 8, 2008 1:38 pm
... I'm not, but these guys pretty much are (>96,000 ft): http://www.jpaerospace.com/pongsat/away25.html ... Yeah, right. ... -- -Ian Woollard We live in an...
8476
Andrew Swallow
am4987
Oct 8, 2008 9:44 pm
... Those wires sounds like cheese cutters. One way of removing the wings from terrorist planes trying to fly into the space elevator....
