Somewhat OT: Long term design
in [Design]
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From: Paul Hovnanian P.E. on 14 Jan 2010 21:30 Sylvia Else wrote: > > Michael A. Terrell wrote: > > Joel Koltner wrote: > >> "WangoTango" <Asgard24(a)mindspring.com> wrote in message > >> news:MPG.25b96ab48fc5c5b698ae28(a)news.east.earthlink.net... > >>> I've watched TV and not only do those guys instantly recognize > >>> millennium old devices, they recognize millennium old ALIEN devices, and > >>> they all invariably function. > >> I've always been most impressed with how readily humans seem to be able to > >> pick up on how to run, e.g., an entire alien spacecraft despite said aliens > >> not speaking any known language, not necessarily resembling human > >> physiologically (e.g., the wavelengths you use in displays is going to be > >> tuned to the individual species), and of course so often coming from planets > >> with gravities and atmospheres highly compatible with human life. :-) > > > > > > They don't have to. The cast all read their scripts, and know what > > to do. ;-) > > > > > > And the aliens in many cases not only speak English, but do so with an > American accent. > > Sylvia. Evidently you haven't been watching Dr Who. -- Paul Hovnanian mailto:Paul(a)Hovnanian.com ------------------------------------------------------------------ "There's something vewy scwewy going on awound here." -- Elmer Fudd
From: Robert Baer on 15 Jan 2010 06:41 John Larkin wrote: > On Wed, 13 Jan 2010 21:20:58 -0800, Robert Baer > <robertbaer(a)localnet.com> wrote: > > >>> I'd expect that most semiconductors and passives would last 1000 >>> years, given a conservative design. There's not much radiation around >>> at sea level. The gadget could be stored in vacuum or dry nitrogen to >>> prevent corrosion and wiskers and such. > > >> * Sorry, NASA has seen whisker growth in their satellites.. > > Well, you'd have to do whatever works best. Leaded solder comes to > mind! > > John > > Woe, Hoss!
From: Robert Baer on 15 Jan 2010 06:46 John Larkin wrote: > On Wed, 13 Jan 2010 21:19:12 -0800, Robert Baer > <robertbaer(a)localnet.com> wrote: > >> 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? >>> >>> 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. >> Thermionic valves are very reliable if used well within >> specifications. Running the filaments at 90 percent of spec increases >> apparent lifetime by a factor of 100 (or so it seems). >> >> Electrolytic capacitors are also quite reliable; i have seen the old >> wet electrolytics working near spec up to 30 years later even without >> addition of electrolyte. As far as the most "modern" reliable aluminum >> electrolytics go, the Sprague TE series outperform anything else i have >> seen. >> >> Film and wirewound resistors have a similar long life reliability, as >> long as they are used within ratings. >> >> ** Expect possible 30 to 100-year continuous reliable use if these parts >> are made with high quality production methods using high grade >> materials, and if run well within specifications. >> ** Expect your possible "immediate" usability 1000 years from now with >> the caveat that aluminum electrolytics (even of the Sprague TE series >> quality) would need "forming" (which could be designed in the circuit). > > Aluminums fail by drying out, through water vapor leakage through the > rubber seals. That's a wearout mechanism. > > John > > > A number of the original Tek tube scopes (517? do not remember numbers it has been too long) still work only needing capacitor forming via slow increase of AC via triac.
From: Robert Baer on 15 Jan 2010 07:01 Sylvia Else wrote: >> 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. > > > > > <grumble>.."functional"..guess one better start to define (nominal) capabilities of that computer first. That way, one has an idea as to the complexity of design: 4 banger? 4004? Z80? 6805? PowerPC / Transmeta? brain of mouse? brain of human? 10^20 q-bits? More than that?
From: Robert Baer on 15 Jan 2010 07:05
Sylvia Else wrote: > 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. I thot i covered that as being possible with (at least) vacuum tube technology and i am guessing possible using solem-strate shelectroniks. |