Somewhat OT: Long term design
in [Design]
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From: Sylvia Else on 14 Jan 2010 08:28 John Larkin wrote: > On Thu, 14 Jan 2010 19:21:43 +1100, Sylvia Else > <sylvia(a)not.at.this.address> wrote: > >> a7yvm109gf5d1(a)netzero.com wrote: >> >>> OR.... >>> >>> go all mechanical >>> >>> http://www.longnow.org/ >>> >>> (How long does a weight suspended in the air keeps its potential >>> energy? Makes a good battery, no?) >> Yes.... >> >> But now you have to design a mechanism to extract the energy that will >> work after 1000 years. >> >> Sylvia. > > Centuries-old weight-powered clocks still work. Surely we can do > better with modern materials. > > I don't think 1000 years is a long time for good materials. OK, you're just convincing me I should have said 10,000 years ;) Or indeed, the 48,000 years in the TV program. Though in Stargate Atlantis, they do have the advantage of using "naquita" (sp?) for their power source, which seems to be an element oddly overlooked in the periodic table. Sylvia.
From: Sylvia Else on 14 Jan 2010 08:43 > George Herold Inscribed thus: > >> On Jan 13, 9:31 pm, Sylvia Else <syl...(a)not.at.this.address> wrote: >>> A recent episode of Stargate Atlantis prompted me to think about how >>> would could design equipment that's intended to function far into the >>> future. The episode required stuff to function 48,000 years after >>> construction, but perhaps we could be less optimistic. >>> >>> Say 1000 years. >>> >>> Note, the requirement is not that the equipment function *for* 1000 >>> years, but that when it is turned on, 1000 years from now, that it >>> will work. >>> >>> It seems to me that semiconductors are out due to effects of difusion >>> and radiation. >>> >>> But how about thermionic valves? They're not very reliable, but do >>> they age when not in use? Would they hold a vacuum over that time? >>> >>> Obviously electrolytic capacitors are a no-no, but can resistors and >>> capacitors be made stable enough that they'd work? >>> >>> Would it help to enclose the entire circuit in a vacuum tube? Again, >>> could the tube sustain the vacuum over such a period? >>> >>> An energy source is a problem. Perhaps a cell where acid is added >>> (how?) at the appropriate time? >>> >>> Sylvia. >> What does the machine have to do? Mechanical stuff (gears, cams, >> punch cards) lasts a long time. It could be powered by gravity. >> >> George H. Well, if way take the TV program as an indication, and including my own interpretation of what happened (which wasn't that clear). It appears we need a radio receiver on some frequency that will be turned on after some number of thousands of years, and then run for perhaps one hundred years. If it detects a radio signal, it has to start up a computer, which is connected to a transmitter on that same frequency. The computer doesn't have to run continuously, but has to be able to run intermittently for a further thousand years. The transmitter is not required to be able to run for more than a few hours once turned on. There was also a signficant power supply that could be turned on after 48,000 years, and then actually run for a further 1000. I had thought this was a big ask, but perhaps not. U235 has a half life of 700 million years, but is clearly usable to produce power in nuclear reactors. I suspect that building a computer that would still be functional after even the first 1000 years would be a challenge, even if it were not running during that time. Sylvia.
From: Rich Webb on 14 Jan 2010 08:41 On Thu, 14 Jan 2010 13:31:08 +1100, Sylvia Else <sylvia(a)not.at.this.address> wrote: >A recent episode of Stargate Atlantis prompted me to think about how >would could design equipment that's intended to function far into the >future. The episode required stuff to function 48,000 years after >construction, but perhaps we could be less optimistic. > >Say 1000 years. Say 10,000 years? There's a group working on such a project now. http://www.longnow.org/clock/ -- Rich Webb Norfolk, VA
From: Sylvia Else on 14 Jan 2010 08:52 Rich Webb wrote: > On Thu, 14 Jan 2010 13:31:08 +1100, Sylvia Else > <sylvia(a)not.at.this.address> wrote: > >> A recent episode of Stargate Atlantis prompted me to think about how >> would could design equipment that's intended to function far into the >> future. The episode required stuff to function 48,000 years after >> construction, but perhaps we could be less optimistic. >> >> Say 1000 years. > > Say 10,000 years? There's a group working on such a project now. > http://www.longnow.org/clock/ > Not quite the same problem. They're looking at something that will run for 10,000 years, but with some maintenance, and a constant supply of power (from humans). I'm thinking of something that could be built now, and be secreted away from human interference, only to perform my biding a thousand years, or perhaps 10 thousand years hence. Sylvia.
From: Bit Farmer on 14 Jan 2010 09:25
Sylvia Else wrote: > A recent episode of Stargate Atlantis prompted me to think about how > would could design equipment that's intended to function far into the > future. The episode required stuff to function 48,000 years after > construction, but perhaps we could be less optimistic. > > Say 1000 years. > > Note, the requirement is not that the equipment function *for* 1000 > years, but that when it is turned on, 1000 years from now, that it will > work. > > It seems to me that semiconductors are out due to effects of difusion > and radiation. > > But how about thermionic valves? They're not very reliable, but do they > age when not in use? Would they hold a vacuum over that time? You just put them on the outside of the Space Ship. That way you would never lose the vacuum. > > Obviously electrolytic capacitors are a no-no, but can resistors and > capacitors be made stable enough that they'd work? > > Would it help to enclose the entire circuit in a vacuum tube? Again, > could the tube sustain the vacuum over such a period? > > An energy source is a problem. Perhaps a cell where acid is added (how?) > at the appropriate time? > > Sylvia. |