Comments on Next Big Future: $153 million city dome protection from nuclear wea...

If the wind pushes the dome against a building I w...

2009-05-17T11:38:00.000-07:00

If the wind pushes the dome against a building I wouldn't worry about the dome damaging the building but I think the building would rip the dome. It is after all, extremely thin. I think it might get holed easily by many things & since a hole is a weak point, rip apart after that.

Hmm, Wouldn't a film dome covering a city eventual...

2008-04-18T11:28:00.000-07:00

Hmm, Wouldn't a film dome covering a city eventually accumulate enough water vapor such that it would constantly be raining?

Dan, thank you for your kind thoughts!I have no do...

2008-04-17T23:25:00.000-07:00

Dan, thank you for your kind thoughts!
I have no doubt whatever that there is some wind intensity that would be able to overpower reasonably sized levitation fans. (Since a commercial installation would have to be paid for, there is some point at which the investor would put his foot down and say, "That ain't gonna happen and I ain't gonna pay to protect against it" http://en.wikipedia.org/wiki/Hypercane-- although you KNOW that in a movie, 'guess what' would happen about 2/3 the way through, and 'guess where' the reluctant investor would be!:)
And if you doubt that reluctance to pay, note that even the U.S. Congress, a freer spending body than which I know not of, had many years to provide an adequate sea wall for New Orleans before Katrina.

But even if flattened against a building, a smaller dome would probably not damage a large building with reinforced structure greatly relative to the damage such winds could inflict by translated (hurled) objects which are legendary in the Midwest where I grew up ie things spearing trees, etc
The key is that an unpierced dome distributes the load very evenly, deflecting slowly and gracefully in large sizes (though in a wierd pulsating motion which must be controlled) whereas in small ones change comes more quickly.(Smaller scale system reaction times.) But literally, air overpressure can suspend a buildings worth of materials, and if you don't believe me, see http://static.monolithic.com/construction/inflate/index.html
where they literally spray shotcrete on a simple hollow inflatable airform. Many tons of it. I know it is emotionally hard to believe because we think of air as light but those are the facts.
I personally would LOVE to see shielded small installations, particularly a swimming pool in lightning weather! Can you imagine swimming on your back, looking up, seeing the flashing and the rain splattering while feeling totally safe (better have a good grounding consultant first! :))

Joseph, this is very interesting. I'm still not 10...

2008-04-17T20:51:00.000-07:00

Joseph, this is very interesting. I'm still not 100% convinced though. Strong winds might still push the dome on one side, flattening it down onto buildings or whatever on that side and damaging it.

Since it apparently scales downward, why not build and demonstrate a small one? It might even have a practical use beyond just demoing it. How about enclosing a small outdoor baseball part, protecting games from getting rained out? Or some other sport. Or how about protecting an outdoor swimming pool from weather, for an even smaller scale application. Should work, right?

Hi, this is Joseph Friedlander, I am a sometime co...

2008-04-17T02:40:00.000-07:00

Hi, this is Joseph Friedlander, I am a sometime co-author of Professor Bolonkin's

http://arxiv.org/ftp/arxiv/papers/0802/0802.0315.pdf
a sometime volunteer editor (Russian English to more conventional English)

http://arxiv.org/ftp/arxiv/papers/0801/0801.4820.pdf
and I put Dan's question to Professor Bolonkin, who replied that a storm wind cannot put down the Dome. The storm

wind having a speed equal to 40 m/s produces a pressure of 980 Newtons/sq.meter, is less than 0.01 atmosphere. If

temporarily the inflating fans on the ground speed up to "puff up" the internal pressure into the Dome by about 10

millibars (totally normal range of pressure such as occurs in the normal range of yearly weather--google "synoptic map")

the Dome should resist the outside wind well.

To Brian Wang, I would like to thank him on the Professor's behalf for his kind coverage. As many people have noted, we

are living about at the tipping point when the majority of people are about to be urban for the first time (if it hasn't already

happened as I write this), and more and more technical possibilities are opening up for small groups to threaten people in

cities over the coming decades.
In the long term, space is the answer to the assured survival of human civilization, but it surely would not hurt to have a

means to make more expensive any assault on a city. If the price is raised for a "successful" attack, fewer independent

actors will be able to threaten a city, (or indeed trigger a war) and civilization may buy the time it needs to expand

beyond the planet.

Brian, if convenient I would like you to e-mail me at your convenience, jjfriedlander at gmail dot com, because I have an

interesting story to tell you, (maybe grist for the blog mill) but I don't want to go off topic here.

I wonder if you could have a rapid-deploy system, ...

2008-04-16T16:21:00.000-07:00

I wonder if you could have a rapid-deploy system, a silo in the middle of the city that could store a spare "dome" and deploy it using peel-off rocket leads for the edges after popping up the bulk material?

I don't think you could have the material as light as the slow-deploy system though.

Does he analyze the behavior of the dome in the fa...

2008-04-15T22:22:00.000-07:00

Does he analyze the behavior of the dome in the face of prevailing winds? Might tear it apart, or flatten it down on the windward side...