If one were to completely solve aging, the "average" longevity would be 2000-3000 years (limited by ones hazard function). If one adds to that nanotechnology based "enhancements" one is probably pushing 10,000 years. Taking uploading into account, ones lifespan could be trillions of years. Ray pushes the envelope but he may have some problems with where the actual limits are.
Agreed and this is what Dyson actually suggested. But our abilities to observe in the infrared are so poor that it is difficult to imagine a situation in which we would observe them. As Minsky pointed out at the Byurakan conference the most advanced civilizations will radiate heat at a temperature slightly above the CMB. So how would you propose we detect them?
Dyson made one mistake due to the era in which he was thinking. He presumed that "intelligence" must be operating at a liquid water temperatures. Given our current understanding of computers it is quite reasonable for that restriction to be significantly relaxed. The range of "intelligence" operation is from several thousand degrees to nearly the CMB. Clearly computers do not currently span that range but we understand the principles that would allow them to do so. And we can enable such operation.
Ok, this is a great result. It does not however deal with the question of planets which have disappeared. Go read the Wikipedia entries on Dyson spheres and Matrioshka Brains. There should be an abundance out there of planets which we cannot see including some which may explain the "dark matter". I am *not* interested in the evidence that gets us to where we are. I am here, I know that works. I am interested in the evidence that suggests where we are going to go.
I like to consider myself a relatively aware TV viewer. I know who Buffy is. I even know who the major actors in MASH are and who Jay Leno and Conan are. But I don't have a friggen clue as to who you are talking about. Your audience has to be pretty small.
The recent software "upgrade" to/. raises the question of whether the software/site is taking a giant step back backward. The current/. pages do not display properly in Netscape 4.79.
This raises some interesting questions...
Are the people behind/. in league with the underground that seeks to eliminate legacy browsers (which tend to be more secure [security through obscurity] and faster than the so-called 'improved' modern browsers)? [I don't see Netscape 4.79 in *this* discussion of browser security problems!]
Do people pay any attention at all to HTML/HTTP efficiency? The current/. pages require 5 style sheets. Does anyone bother to consider the cpu cycles, network bandwidth, server log file space, electricity, etc. that 5 HTTP requests multiplied by the/. page download volume consume each day? Just because one has the resources doesn't mean that one should p*** them away when one doesn't have to.
Have CSS really enhanced the web browsing experience significantly from what it was when one used basic HTML 3.2? Or is it merely an invention (as so many of the "new" languages appear to be) which allows developers and/or page designers to "sell" their exclusive knowledge bases without significantly improving the final product?
Shouldn't all web page developers ask themselves whether or not their pages will distribute useful and reasonably formatted information even in Mosaic?
No, I'm not Ray, though I am very distantly related. So you don't feel I'm appealing to "inaccessible literature", I post the following from the source proceedings (edited by Sagan).
Dyson had made a set of points, one of which was:
"Point 3. If a society is very highly developed technologically, it must emit intense infrared radiation, not necessarily a planetary spectrum, but necessarily a large intensity of infrared radiation, whether or not this society wishes to communicate. Consequently, we should use infrared radiation, as a signpost indicating priority areas toward which we should direct searches by radio and other techniques."
There was some discussion which eventually led to the following exchange:
OLIVER: Why do you suggest civilizations must of necessity produce large amounts of infrared radiation? It seems to me that the infrared radiation that would be produced by even a very much farther advanced civilization than ours would be negligible compared to their primary star. For example, in California, which has a very high usage of electricity, the power generation at the present time is only 0.1 percent of the sunlight falling on the state.
DYSON: What I am saying is that the civilizations which are observable to us will have this character.
OLIVER: But you are suggesting, are you not, that the infrared emission will be an observable characteristic? I am suggesting it is far down in the stellar noise.
DYSON: No, I am saying that the generation of large amounts of infrared radiation is not necessarily an accompaniment of a high civilization at all. Only if it occurs is it something we can see.
MINSKY: Since radiation at any temperature above 3K is wasteful and a squandering of natural resources, the higher the civilization, the lower the infrared radiation. We should look for extended sources of 4K radiation. There should be very few natural such sources.
DYSON: I don't quite go along with this but to some extent you are right.
The reason that Dyson didn't go along with this is because he still tended to view "advanced" civilizations as those operating on the basis of "biological" systems (remember this is 1971!) rather than engineered computational systems which can function at a much wider temperature range (in fact Likharev's "Rapid Single Flux Quantum Logic" (based on Josephson junctions) *have* to operate at temperatures much closer to those Minsky suggests). Thus AIs constructed of such devices would emit IR at a temperatures much lower than "primitive" civilizations (i.e. "wet" brain based) which function at the liquid water temperatures that Dyson tended to prefer.
The theories behind Matrioshka Brains are in large part based on Minsky's observation, which are in turn related to Dyson's perspective reagarding Dyson "spheres" (really shells). They are however updated to recognize the fact that computational architectures which can support intelligence (and therefore advanced civilizations) can operate over a much wider temperature range (both higher and lower) than liquid water can provide.
This is such a '60s reply. The days when "people" will be doing things like construction are numbered. Read my Sapphire Mansions paper. By the 2nd half of this century it is highly likely that nanorobots will be performing all of the construction activities. One can consider nanorobots to be like bacteria. If one built self-replication capabilities into them and can supply them with sufficient resources they, like bacteria, could multiply to the mass of the Earth within 2 days. (But anyone who understands nanotechnology well does not suggest nanorobots should be given self-replication capabilities. The conclusion one reaches after reading this paper by Josh Hall is that nanorobots will be built in nanorobot factories which are more efficient (faster).)
In any case it will not be obsolete humans which go colonizing any stars. It will be complex nanosystems which support either uploaded "natural" intelligences or artificial intelligences or a combination of the two. Ultimately the entire framework that humans tend to view life from is flawed at the levels Matrioshka Brains operate at. Rather than replicate starting almost from scratch (using gametes), advanced civilizations are more likely to divide in half (as cells do). The problem is that due to the large amount of information advanced civilizations will have at their disposal they cannot easily transmit that quantity of information across large interstellar distances. Thus replication will only take place when developed star systems happen to orbit (or be navigated) to within close proximity of undeveloped star systems. Under normal circumstances this is a very slow development process. It is possible however that from time to time that the civilizations of a galaxy might choose to use the "seed" distribution (plant) approach to development, in which case it seems likely that the galaxy would "go dark" much more quickly. That may be the case for the galaxy associated with the "naked" black hole.
There are a couple of possibilities. First, if the black hole developed very early in galactic history (before there were any ATC) and accumulated a large amount of very distributed mass it may simply not be worth the expense to try and harvest the mass from a gravity well that deep. Second, because black holes do accelerate infalling matter to such great velocities most of the energy comes off in the UV and esp. X-rays which are very difficult to convert into more usable energy forms. The photons have sufficient energy to break chemical bonds. That requires that one expend a large fraction of the energy collected continually rebuilding whatever collectors you are using to collect it. (Photon energy collectors need to be fairly perfect at the atomic structure level in order to be efficient.) Third, the Black Hole environment has a very effective environmental temperature level. Matrioshka Brains want a very low environmental temperature level (for the thermodynamic computational efficiency reasons) so you have a significant transport problem of the energy from the black hole locality to the probably Matrioshka Brain locality (presumably orbiting the galaxy). Forth, if the Matrioshka Brains have been star-lifting (removing fuel from their star to lengthen its lifetime and burn more of the easily available fuel over a longer period (trillions of years) they have no need for the additional energy resources a black hole might provide.
One thing to keep in mind with respect to energy is whether or not one has access to enough mass to use it effectively and whether or not there are limits to computing, particularly the speed of light and heat removal constraints that would prevent any additional energy from being used productively.
An alternative explanation which is seldom discussed is that there could be a completely developed (mature) galaxy composed entirely of Kardashev Type II civilizations, also known as Matrioshka Brains. As was pointed out by Marvin Minsky at the Byurakan CETI conference in 1971 *advanced* civilizations, for thermodynamic efficiency reasons, will radiate their waste heat at slightly above the cosmic microwave background temperature. The VLT and HST which were used in these studies are incapable of detecting radiation at these wavelengths so any galaxies being managed by advanced civilizations would effectively be invisible.
A reasonable person might well consider an explanation that included the natural evolution of advanced technological civilizations before they resorted to the invention of new particles and laws of physics (as is typically a requirement as soon as you mention 'dark matter').
It is useful to keep in mind that several papers by Charley Lineweaver's group document that ~70% of the "Earth's" in our galaxy are significantly older than ours (perhaps billions of years older). It would not be that unexpected that from time to time we might encounter a galaxy where advanced civilizations had placed *all* of the reasonably available matter and energy "under management". (For the purposes of discussion we will assume that black holes do not constitute a "reasonably available" useful resource despite proposals from time to time that require rather creative physics to make them "useful".)
All of the cells of the body which are exposed to the external environment in some way (skin, intestines, lung, etc.) replicate to renew themselves. Excess replication leads to cancer which causes about 30% of all deaths. The Hayflick Limit (telomere shortening) is a cancer prevention mechanism.
But there is no inherent reason that cells cannot be designed so that they replicate more accurately (they probably do in elephants and whales which have many more cells than we do). Any programmer knows that you can design ECC codes that would protect the genomic information (the DNA code) in cells from errors. Nature has not done that because some mutation is actually useful (our immune systems for example depend upon it).
So a properly designed genome would allow cells to replicate accurately only when they are supposed to and would eliminate the need for a Hayflick Limit. One could increase genome redundancy (it isn't like the genome doesn't have room for it).
There are a whole host of solutions for the various aspects of aging that would require a long paper or a book to document.
I fail to understand *why* people are fixing things which are not broken. I use the web as an information resource. That means I want "Just the facts Mam". Those could have been presented to me in HTML 3.2 (which many readers may be too young to remember)...
Some sites have intelligent managers (Amazon and Google come to mind). They don't go overboard on overengineering their pages. They work with legacy browsers, etc.
How about an open-source app which plugs into standard proxy filters (e.g. squid) which removes all of the over-engineered crap web sites distribute? (I.e. No more Flash that I didn't request, no more Microsoft HTML'isms I didn't request, no more CSS, no more marketing crap I didn't request, etc.)
I.e. I get back to a world where I view what is important to *me* and not someone trying to sell me something I have no interest in. If that means a few information providers have to revise their business models -- hey thats life.
But I tend to come from the old school -- show me what I want to see -- when I want to see it. All of this overengineering of web pages defeats that.
The technology is only going to be useful if robust nanotechnology is *impossibly hard* -- Why? Because if it is possible it is highly probable that Mars *will not exist*.
Why? Because the probable time to disassemble Mars is 12 hours once the asteroids have been developed into an array to harvest the entire solar power output of the sun. [1]
So any work to "develop" Mars is either (1) assuming that nanotechnology is impossible -- which seems to fly in the face of physical laws as well as much NASA funding; or perhaps (2) that it will take a very very long time to become available (which would imply the people at NASA are *not* following the Moore's Law data...; or (3) that for some romantic reasons decisions will be made to not disassemble Mars -- and this is the realm of politics and requires a mandatory behavioral enforcement dictate unlike any humanity has been able to develop or dictate over thousands of years.
I for one would like to see the carefully reasoned and thought out discussions that Mars will still exist in 30-40 years. For NASA to be funding efforts involving growing life on Mars points out how short sighted they are and how poorly they are educating the students they are educating.
Instead of enzyme studies which will be pointless -- how about some studies of more advanced methods that might be used to disassemble Mars more quickly?
Precisely. As someone who has been involved in biotech and nanotech for more than a decade the comments above by karvind sum up the situation quite well.
Submissions to/. on these topics should be submitted to those who can evaluate them before they pass into the/. approval arena.
The situation with nanotube wiring can be summed up very simply -- how the fuck are you going to lay them down and connect millions (or billions) of them? If the topic cannot answer that then it is unlikely to be of interest to most/. readers.
That is the reality of current chip fabrication technologies -- unless you are presenting a technology which puts them down in an ordered fashion in parallel in a way which can be directed/managed you have nothing.
And I would hope that/. should not be presenting the hype as "progress".
You have a real problem about how to get it up to the speed required for orbit and then back down to a speed which can land. Planes deal with a significantly reduced set of velocities and acceleration and deceleration requirements.
For those of you who have not noticed, the URL cited in this comment maxes my CPU. While I realize that I am using an older legacy browser (Netscape 4.79) -- this is because I consider security through obscurity to be a reasonable path. This is a classic example IMO of people citing URLs where they have no idea *what* kind of code may end up being executed on their machine. (And this is with Java & Javascript disabled!)
Over the last couple of years I have sold most of my CDs (several hundred), not gone to a movie and have lived in a world where I listen to a few CDs (the Ally McBeal soundtrack and the Neil Diamond Jonathan Livingston Seagull CD) on an ongoing basis.
Guess what? It doesn't significantly impact the self-perceived quality of my life to any extent.
That would suggest that *much* of the entertainment media (movies & sound-tracks) are "add-ons" -- i.e. they must create the demand and the consumers buy into it.
From my perspective the entire copyright debate tends to boil down to a question of whether or not you are producing something which people are willing to pay to see/hear. From my rather jaded viewpoint the answer is no.
If an individual has a perspective that all copyrighted information will eventually be available for free (which is true to the best of my knowledge) *and* that human lifespan is only limited by our current lack of knowledge with respect to the biology of aging and how to prevent it, then the media producers have a significant problem... I.e. "How do I produce material which people are willing to pay to see now... vs. material which they will (legally) be free to see/hear sometime in the future?"
Even though the material producers have pushed laws which extend copyright protections far beyond their original intent -- the progress in extending the human lifespan has not been locked in stasis either. Unless copyright protections are pushed beyond the maximum feasible human lifespan I will eventually have *legal* access to all of the material for free.
So it would appear the entire "copying" debate is wrapped up in the question of whether or not one has access to it "now" or at sometime in the future. One could obviously draw analogies between the entertainment realm and other forms of self-gratification.
The "L" in BlueGene/L is for "Low" power. Given the amount of power it consumes that classification would appear to be bit of an oxymoron. The problem is that one is talking 100,000+ processors and the failure rate is not insignificant. It becomes a bit of a problem if the failures take out an important subset of the data of a simulation that takes weeks of time. This is one of the reasons that they run the processors at lower clock speeds than they are capable of (less heat) and focus a lot of attention on cooling.
The March/May 2005 issue of the IBM Journal of R&D has a complete set of articles on the architecture. Here is the URL for an overview by Gara et al.
Now what will be interesting is whether in order to solve the inter-CPU latency problems of these rather large machines they move from a 2-D computer room layout to a 3-D multi-floor layout. Though in most of the types of simulations that are run it isn't really necessary for the processors which are furthest apart to communicate with each other. Most of the simulations involved are recreations of real-world processes where one only needs to communicate with ones nearest neighbors. It is interesting to note however that brain architectures are arranged such that there is quite a bit of relatively long distance communication going on. That may offer an explanation as to why you aren't going to get "intelligence" out of these machines even with many more petaflops than a human brain. They need to solve a communications architecture/bandwidth problem -- not a raw CPU horsepower problem.
"There are no known potential customers for this chip."
Cough...
Have you looked at the Top500 supercomputer list recently?!? You do *not* build room-sized computers with chips that function as excellent coffee cup warmers. IBM for quite some time has realized that there will be a problem with heat removal (as there was with their mainframes based on ECL chips several decades ago). If you use chips producing large amounts of heat you cannot space them closely together and that becomes a problem for large clusters because many of the problems they deal with need to reduce inter-CPU communications delays as much as possible. There is also a MTBF problem. If the chips run hot they fail more frequently and that becomes a real up-time problem if it happens in the middle of a simulation that takes a couple of weeks. The overhead costs of creating fault-tolerant 100,000 node supercomputers is quite large. Better to engineer them so that there aren't any faults in the first place.
The questions to ask to understand this are what fraction of IBM's business Apple is now and what fraction of its future business did/does IBM expect it to be?
Does anyone out there (who has some inkling of the technical aspects of chip engineering and production) believe that IBM could not produce chips that run faster than Intel (or AMD) if it wanted to? If you check @ finance.yahoo.com you will find that while Intel's market cap is somewhat larger than IBM's it has only 36% of IBM's annual revenue.
This isn't about blogging. Its a somewhat rhetorical, outside-of-the-box question -- "What if the Chinese government is using the right approach?"
Their economic growth has been much better than ours over the last decade. Their top-down economy can decide to build new nuclear plants when they need them without having to deal with environmentalists interfering for a decade or more. [One of the best prospects for eliminating dependence on foreign oil is relatively cheap electricity combined with hybrid and eventually full electric cars.] They don't have to worry about the "networks" trying to slip "broadcast flag" ammendments onto appropriations bills. Their politicians don't have to worry about catering to the money. Etc.
In short, is a top-down command controlled political system (and economy) better than a system run by a bunch of special interests elected into place by people who vote based in large part on how someone looks [according to results of a recent scientific study]?
The real problem is a general lack of awareness of conforming technologies that do exist now or are likely to exist in the very near future which allow "science fictionish" stories without violating any laws of physics.
For example, I did the calculations a few days ago and it would appear current technologies allow the assembly of mammalian sized genomes *from scratch* in a few days using technologies that are available now (though the assembly of complete chromosomes needs some work it is a "methods" problem not a "technical infeasibility" problem). This doesn't violate any laws of physics. That means any complex life form can probably be assembled if you can design it. The problem is that most SciFi writers know relatively little about microbiology and biotechnology.
And *very* few SciFi writers really understand the implications of nanotechnology. I'm reasonably sure I can count them on less than 10 fingers. You don't go to the stars in "starships". You go to the stars by taking a planetary sized mind or an entire solar system. It doesn't move fast but since you've reengineered the power source (for "planets") or the sun (for solar systems) to last trillions of years who cares? Those of you who don't understand this haven't been following the/. discussions regarding the "Blinding of SciFi" or haven't read the background material on Matrioshka Brains.
Worth noting in passing is that the recent submission of astro-ph/0506110 which we hope to have published soon. Once it is completely grasped astronomers, physicists, SETI fans *AND* the Science Fiction authors will have little excuse for not seriously considering Life at the Limits of Physical Laws.
Why? Because the entire radio (and optical) SETI searches are based upon assumptions that are more than 40 years old which do not take into account advances in information science, microelectronics, biotechnology, nanotechnology, etc. that have taken place since the early assumptions were made. Almost all SETI efforts need to be reinvented in light of recent and anticipated future progress. Those searches would involve IR surveys (presumably space based), gravitational microlensing surveys and variable star surveys -- *not* radio or optical surveys looking for intentional communications. If you don't understand this you should go read the papers on Matrioshka Brains (mentioned on/. here).
Worth noting to the person who suggested that planets with advanced civilization migrate outward within the galaxy... The idea is on the right track but as the paper above points out -- advanced civilizations can migrate their solar systems anywhere they want. People who really want to understand galactic gradients and the probable location (and ages) of planets similar to Earth should research the papers by Charlie Lineweaver's group. Their work suggests that there are many many "Earths" in our galaxy. Many would be quite a bit older than ours if the intelligent civilizations they might have spawned chose for some illogical (nostalgic?) reason not to disassemble them.
All of this is not to say that the PicoCell or Bluetooth or other alternatives are not good ideas for airplanes for the simple reason of preventing radiotelescope interference (i.e. *real* radioastronomy rather than radioastronomy involving the questionable pursuit of ET. Of course having no-cell-phone zones (or even no-fly zones) in locations above radiotelescopes seems to be a much simpler solution. And then of course anyone who wishes to use a cell phone on a plane should be required to use a "cone of silence" (for those of you who remember "Get Smart").:-;
Ah, but master XanC you do not understand the power of nanotechnology. If you have the designs, then the construction of a second Death Star is a relatively trivial operation. As pointed out in the Planet Disassembly discussion taking apart massive objects isn't really that difficult (or time consuming). So once one has done it once doing it again isn't a very big deal. Far more difficult is navigating a Death Star from solar system to solar system. Unless you invoke magic physics the time required for this isn't going to change. So one can quite probably turn out Death Stars at a high rate -- but transporting them to "reluctant" to join the Empire systems may be quite a lengthy process.
So there may be no real barrier for "Death Stars" showing up on the door step of future worlds even in episodes VII-IX. They just got a late start in the interstellar travel queue.
The LN2 approach has been done. I believe it has been documented on/. if not elsewhere. It is 40+ year old technology (my father used to bring home LN2 from the lab to play with when I was a child). Of course really *real* men cool their CPUs with H2 ice-cubes circulating in LHe. They still meet the solid-to-liquid vs. liquid-to-gas phase change criteria which LN2 does not.
Real men use phase change coolers as defined by Drexler and Henson in US Patent #4,759,404 also briefly discussed in Section 11.5 of Nanosystems. That is because the heat capacity of solids going to liquids is higher than that of liquids going to gases. Of course the engineering of a system to circulate nanoscale ice cubes within ammonia (or methanol or ethanol) and refreezing the water back into ice cubes in the "condenser" is slightly more difficult than the engineering required for heat pipes.
Slashdot Mirror
If one were to completely solve aging, the "average" longevity would be 2000-3000 years (limited by ones hazard function). If one adds to that nanotechnology based "enhancements" one is probably pushing 10,000 years. Taking uploading into account, ones lifespan could be trillions of years. Ray pushes the envelope but he may have some problems with where the actual limits are.
Agreed and this is what Dyson actually suggested. But our abilities to observe in the infrared are so poor that it is difficult to imagine a situation in which we would observe them. As Minsky pointed out at the Byurakan conference the most advanced civilizations will radiate heat at a temperature slightly above the CMB. So how would you propose we detect them?
Dyson made one mistake due to the era in which he was thinking. He presumed that "intelligence" must be operating at a liquid water temperatures. Given our current understanding of computers it is quite reasonable for that restriction to be significantly relaxed. The range of "intelligence" operation is from several thousand degrees to nearly the CMB. Clearly computers do not currently span that range but we understand the principles that would allow them to do so. And we can enable such operation.
Ok, this is a great result. It does not however deal with the question of planets which have disappeared. Go read the Wikipedia entries on Dyson spheres and Matrioshka Brains. There should be an abundance out there of planets which we cannot see including some which may explain the "dark matter". I am *not* interested in the evidence that gets us to where we are. I am here, I know that works. I am interested in the evidence that suggests where we are going to go.
I like to consider myself a relatively aware TV viewer. I know who Buffy is. I even know who the major actors in MASH are and who Jay Leno and Conan are. But I don't have a friggen clue as to who you are talking about. Your audience has to be pretty small.
This raises some interesting questions...
Are the people behind /. in league with the underground that seeks to eliminate legacy browsers (which tend to be more secure [security through obscurity] and faster than the so-called 'improved' modern browsers)? [I don't see Netscape 4.79 in *this* discussion of browser security problems!]
Do people pay any attention at all to HTML/HTTP efficiency? The current /. pages require 5 style sheets. Does anyone bother to consider the cpu cycles, network bandwidth, server log file space, electricity, etc. that 5 HTTP requests multiplied by the /. page download volume consume each day? Just because one has the resources doesn't mean that one should p*** them away when one doesn't have to.
Have CSS really enhanced the web browsing experience significantly from what it was when one used basic HTML 3.2? Or is it merely an invention (as so many of the "new" languages appear to be) which allows developers and/or page designers to "sell" their exclusive knowledge bases without significantly improving the final product?
Shouldn't all web page developers ask themselves whether or not their pages will distribute useful and reasonably formatted information even in Mosaic?
Dyson had made a set of points, one of which was:
"Point 3. If a society is very highly developed technologically, it must emit intense infrared radiation, not necessarily a planetary spectrum, but necessarily a large intensity of infrared radiation, whether or not this society wishes to communicate. Consequently, we should use infrared radiation, as a signpost indicating priority areas toward which we should direct searches by radio and other techniques."
There was some discussion which eventually led to the following exchange:
OLIVER: Why do you suggest civilizations must of necessity produce large amounts of infrared radiation? It seems to me that the infrared radiation that would be produced by even a very much farther advanced civilization than ours would be negligible compared to their primary star. For example, in California, which has a very high usage of electricity, the power generation at the present time is only 0.1 percent of the sunlight falling on the state.
DYSON: What I am saying is that the civilizations which are observable to us will have this character.
OLIVER: But you are suggesting, are you not, that the infrared emission will be an observable characteristic? I am suggesting it is far down in the stellar noise.
DYSON: No, I am saying that the generation of large amounts of infrared radiation is not necessarily an accompaniment of a high civilization at all. Only if it occurs is it something we can see.
MINSKY: Since radiation at any temperature above 3K is wasteful and a squandering of natural resources, the higher the civilization, the lower the infrared radiation. We should look for extended sources of 4K radiation. There should be very few natural such sources.
DYSON: I don't quite go along with this but to some extent you are right.
The reason that Dyson didn't go along with this is because he still tended to view "advanced" civilizations as those operating on the basis of "biological" systems (remember this is 1971!) rather than engineered computational systems which can function at a much wider temperature range (in fact Likharev's "Rapid Single Flux Quantum Logic" (based on Josephson junctions) *have* to operate at temperatures much closer to those Minsky suggests). Thus AIs constructed of such devices would emit IR at a temperatures much lower than "primitive" civilizations (i.e. "wet" brain based) which function at the liquid water temperatures that Dyson tended to prefer.
The theories behind Matrioshka Brains are in large part based on Minsky's observation, which are in turn related to Dyson's perspective reagarding Dyson "spheres" (really shells). They are however updated to recognize the fact that computational architectures which can support intelligence (and therefore advanced civilizations) can operate over a much wider temperature range (both higher and lower) than liquid water can provide.
The complete proceedings from the conference can be purchased from Amazon for $3-7.
In any case it will not be obsolete humans which go colonizing any stars. It will be complex nanosystems which support either uploaded "natural" intelligences or artificial intelligences or a combination of the two. Ultimately the entire framework that humans tend to view life from is flawed at the levels Matrioshka Brains operate at. Rather than replicate starting almost from scratch (using gametes), advanced civilizations are more likely to divide in half (as cells do). The problem is that due to the large amount of information advanced civilizations will have at their disposal they cannot easily transmit that quantity of information across large interstellar distances. Thus replication will only take place when developed star systems happen to orbit (or be navigated) to within close proximity of undeveloped star systems. Under normal circumstances this is a very slow development process. It is possible however that from time to time that the civilizations of a galaxy might choose to use the "seed" distribution (plant) approach to development, in which case it seems likely that the galaxy would "go dark" much more quickly. That may be the case for the galaxy associated with the "naked" black hole.
There are a couple of possibilities. First, if the black hole developed very early in galactic history (before there were any ATC) and accumulated a large amount of very distributed mass it may simply not be worth the expense to try and harvest the mass from a gravity well that deep. Second, because black holes do accelerate infalling matter to such great velocities most of the energy comes off in the UV and esp. X-rays which are very difficult to convert into more usable energy forms. The photons have sufficient energy to break chemical bonds. That requires that one expend a large fraction of the energy collected continually rebuilding whatever collectors you are using to collect it. (Photon energy collectors need to be fairly perfect at the atomic structure level in order to be efficient.) Third, the Black Hole environment has a very effective environmental temperature level. Matrioshka Brains want a very low environmental temperature level (for the thermodynamic computational efficiency reasons) so you have a significant transport problem of the energy from the black hole locality to the probably Matrioshka Brain locality (presumably orbiting the galaxy). Forth, if the Matrioshka Brains have been star-lifting (removing fuel from their star to lengthen its lifetime and burn more of the easily available fuel over a longer period (trillions of years) they have no need for the additional energy resources a black hole might provide.
One thing to keep in mind with respect to energy is whether or not one has access to enough mass to use it effectively and whether or not there are limits to computing, particularly the speed of light and heat removal constraints that would prevent any additional energy from being used productively.
A reasonable person might well consider an explanation that included the natural evolution of advanced technological civilizations before they resorted to the invention of new particles and laws of physics (as is typically a requirement as soon as you mention 'dark matter').
It is useful to keep in mind that several papers by Charley Lineweaver's group document that ~70% of the "Earth's" in our galaxy are significantly older than ours (perhaps billions of years older). It would not be that unexpected that from time to time we might encounter a galaxy where advanced civilizations had placed *all* of the reasonably available matter and energy "under management". (For the purposes of discussion we will assume that black holes do not constitute a "reasonably available" useful resource despite proposals from time to time that require rather creative physics to make them "useful".)
All of the cells of the body which are exposed to the external environment in some way (skin, intestines, lung, etc.) replicate to renew themselves. Excess replication leads to cancer which causes about 30% of all deaths. The Hayflick Limit (telomere shortening) is a cancer prevention mechanism.
But there is no inherent reason that cells cannot be designed so that they replicate more accurately (they probably do in elephants and whales which have many more cells than we do). Any programmer knows that you can design ECC codes that would protect the genomic information (the DNA code) in cells from errors. Nature has not done that because some mutation is actually useful (our immune systems for example depend upon it).
So a properly designed genome would allow cells to replicate accurately only when they are supposed to and would eliminate the need for a Hayflick Limit. One could increase genome redundancy (it isn't like the genome doesn't have room for it).
There are a whole host of solutions for the various aspects of aging that would require a long paper or a book to document.
I fail to understand *why* people are fixing things which are not broken. I use the web as an information resource. That means I want "Just the facts Mam". Those could have been presented to me in HTML 3.2 (which many readers may be too young to remember)...
Some sites have intelligent managers (Amazon and Google come to mind). They don't go overboard on overengineering their pages. They work with legacy browsers, etc.
How about an open-source app which plugs into standard proxy filters (e.g. squid) which removes all of the over-engineered crap web sites distribute? (I.e. No more Flash that I didn't request, no more Microsoft HTML'isms I didn't request, no more CSS, no more marketing crap I didn't request, etc.)
I.e. I get back to a world where I view what is important to *me* and not someone trying to sell me something I have no interest in. If that means a few information providers have to revise their business models -- hey thats life.
But I tend to come from the old school -- show me what I want to see -- when I want to see it. All of this overengineering of web pages defeats that.
Re: who wants to know the random names on /.?
Someone who takes the time to investigate *who* the 'random names' are.
Sometimes you just might be surprised...
Why? Because the probable time to disassemble Mars is 12 hours once the asteroids have been developed into an array to harvest the entire solar power output of the sun. [1]
So any work to "develop" Mars is either (1) assuming that nanotechnology is impossible -- which seems to fly in the face of physical laws as well as much NASA funding; or perhaps (2) that it will take a very very long time to become available (which would imply the people at NASA are *not* following the Moore's Law data...; or (3) that for some romantic reasons decisions will be made to not disassemble Mars -- and this is the realm of politics and requires a mandatory behavioral enforcement dictate unlike any humanity has been able to develop or dictate over thousands of years.
I for one would like to see the carefully reasoned and thought out discussions that Mars will still exist in 30-40 years. For NASA to be funding efforts involving growing life on Mars points out how short sighted they are and how poorly they are educating the students they are educating.
Instead of enzyme studies which will be pointless -- how about some studies of more advanced methods that might be used to disassemble Mars more quickly?
1. Life at the Limits of Physical Laws
Precisely. As someone who has been involved in biotech and nanotech for more than a decade the comments above by karvind sum up the situation quite well.
/. on these topics should be submitted to those who can evaluate them before they pass into the /. approval arena.
/. readers.
/. should not be presenting the hype as "progress".
Submissions to
The situation with nanotube wiring can be summed up very simply -- how the fuck are you going to lay them down and connect millions (or billions) of them? If the topic cannot answer that then it is unlikely to be of interest to most
That is the reality of current chip fabrication technologies -- unless you are presenting a technology which puts them down in an ordered fashion in parallel in a way which can be directed/managed you have nothing.
And I would hope that
You have a real problem about how to get it up to the speed required for orbit and then back down to a speed which can land. Planes deal with a significantly reduced set of velocities and acceleration and deceleration requirements.
For those of you who have not noticed, the URL cited in this comment maxes my CPU. While I realize that I am using an older legacy browser (Netscape 4.79) -- this is because I consider security through obscurity to be a reasonable path. This is a classic example IMO of people citing URLs where they have no idea *what* kind of code may end up being executed on their machine. (And this is with Java & Javascript disabled!)
Over the last couple of years I have sold most of my CDs (several hundred), not gone to a movie and have lived in a world where I listen to a few CDs (the Ally McBeal soundtrack and the Neil Diamond Jonathan Livingston Seagull CD) on an ongoing basis.
Guess what? It doesn't significantly impact the self-perceived quality of my life to any extent.
That would suggest that *much* of the entertainment media (movies & sound-tracks) are "add-ons" -- i.e. they must create the demand and the consumers buy into it.
From my perspective the entire copyright debate tends to boil down to a question of whether or not you are producing something which people are willing to pay to see/hear. From my rather jaded viewpoint the answer is no.
If an individual has a perspective that all copyrighted information will eventually be available for free (which is true to the best of my knowledge) *and* that human lifespan is only limited by our current lack of knowledge with respect to the biology of aging and how to prevent it, then the media producers have a significant problem... I.e. "How do I produce material which people are willing to pay to see now... vs. material which they will (legally) be free to see/hear sometime in the future?"
Even though the material producers have pushed laws which extend copyright protections far beyond their original intent -- the progress in extending the human lifespan has not been locked in stasis either. Unless copyright protections are pushed beyond the maximum feasible human lifespan I will eventually have *legal* access to all of the material for free.
So it would appear the entire "copying" debate is wrapped up in the question of whether or not one has access to it "now" or at sometime in the future. One could obviously draw analogies between the entertainment realm and other forms of self-gratification.
The March/May 2005 issue of the IBM Journal of R&D has a complete set of articles on the architecture. Here is the URL for an overview by Gara et al.
Now what will be interesting is whether in order to solve the inter-CPU latency problems of these rather large machines they move from a 2-D computer room layout to a 3-D multi-floor layout. Though in most of the types of simulations that are run it isn't really necessary for the processors which are furthest apart to communicate with each other. Most of the simulations involved are recreations of real-world processes where one only needs to communicate with ones nearest neighbors. It is interesting to note however that brain architectures are arranged such that there is quite a bit of relatively long distance communication going on. That may offer an explanation as to why you aren't going to get "intelligence" out of these machines even with many more petaflops than a human brain. They need to solve a communications architecture/bandwidth problem -- not a raw CPU horsepower problem.
"There are no known potential customers for this chip."
Cough...
Have you looked at the Top500 supercomputer list recently?!? You do *not* build room-sized computers with chips that function as excellent coffee cup warmers. IBM for quite some time has realized that there will be a problem with heat removal (as there was with their mainframes based on ECL chips several decades ago). If you use chips producing large amounts of heat you cannot space them closely together and that becomes a problem for large clusters because many of the problems they deal with need to reduce inter-CPU communications delays as much as possible. There is also a MTBF problem. If the chips run hot they fail more frequently and that becomes a real up-time problem if it happens in the middle of a simulation that takes a couple of weeks. The overhead costs of creating fault-tolerant 100,000 node supercomputers is quite large. Better to engineer them so that there aren't any faults in the first place.
The questions to ask to understand this are what fraction of IBM's business Apple is now and what fraction of its future business did/does IBM expect it to be?
Does anyone out there (who has some inkling of the technical aspects of chip engineering and production) believe that IBM could not produce chips that run faster than Intel (or AMD) if it wanted to? If you check @ finance.yahoo.com you will find that while Intel's market cap is somewhat larger than IBM's it has only 36% of IBM's annual revenue.
This isn't about blogging. Its a somewhat rhetorical, outside-of-the-box question -- "What if the Chinese government is using the right approach?"
Their economic growth has been much better than ours over the last decade. Their top-down economy can decide to build new nuclear plants when they need them without having to deal with environmentalists interfering for a decade or more. [One of the best prospects for eliminating dependence on foreign oil is relatively cheap electricity combined with hybrid and eventually full electric cars.] They don't have to worry about the "networks" trying to slip "broadcast flag" ammendments onto appropriations bills. Their politicians don't have to worry about catering to the money. Etc.
In short, is a top-down command controlled political system (and economy) better than a system run by a bunch of special interests elected into place by people who vote based in large part on how someone looks [according to results of a recent scientific study]?
For example, I did the calculations a few days ago and it would appear current technologies allow the assembly of mammalian sized genomes *from scratch* in a few days using technologies that are available now (though the assembly of complete chromosomes needs some work it is a "methods" problem not a "technical infeasibility" problem). This doesn't violate any laws of physics. That means any complex life form can probably be assembled if you can design it. The problem is that most SciFi writers know relatively little about microbiology and biotechnology.
And *very* few SciFi writers really understand the implications of nanotechnology. I'm reasonably sure I can count them on less than 10 fingers. You don't go to the stars in "starships". You go to the stars by taking a planetary sized mind or an entire solar system. It doesn't move fast but since you've reengineered the power source (for "planets") or the sun (for solar systems) to last trillions of years who cares? Those of you who don't understand this haven't been following the /. discussions regarding the "Blinding of SciFi" or haven't read the background material on Matrioshka Brains.
Worth noting in passing is that the recent submission of astro-ph/0506110 which we hope to have published soon. Once it is completely grasped astronomers, physicists, SETI fans *AND* the Science Fiction authors will have little excuse for not seriously considering Life at the Limits of Physical Laws.
A preprint discussing some of these problems is available in the preprint archive Galactic Gradients, Postbiological Evolution and the Apparent Failure of SETI.
Worth noting to the person who suggested that planets with advanced civilization migrate outward within the galaxy... The idea is on the right track but as the paper above points out -- advanced civilizations can migrate their solar systems anywhere they want. People who really want to understand galactic gradients and the probable location (and ages) of planets similar to Earth should research the papers by Charlie Lineweaver's group. Their work suggests that there are many many "Earths" in our galaxy. Many would be quite a bit older than ours if the intelligent civilizations they might have spawned chose for some illogical (nostalgic?) reason not to disassemble them.
All of this is not to say that the PicoCell or Bluetooth or other alternatives are not good ideas for airplanes for the simple reason of preventing radiotelescope interference (i.e. *real* radioastronomy rather than radioastronomy involving the questionable pursuit of ET. Of course having no-cell-phone zones (or even no-fly zones) in locations above radiotelescopes seems to be a much simpler solution. And then of course anyone who wishes to use a cell phone on a plane should be required to use a "cone of silence" (for those of you who remember "Get Smart"). :-;
So there may be no real barrier for "Death Stars" showing up on the door step of future worlds even in episodes VII-IX. They just got a late start in the interstellar travel queue.
The LN2 approach has been done. I believe it has been documented on /. if not elsewhere. It is 40+ year old technology (my father used to bring home LN2 from the lab to play with when I was a child). Of course really *real* men cool their CPUs with H2 ice-cubes circulating in LHe. They still meet the solid-to-liquid vs. liquid-to-gas phase change criteria which LN2 does not.
Real men use phase change coolers as defined by Drexler and Henson in US Patent #4,759,404 also briefly discussed in Section 11.5 of Nanosystems . That is because the heat capacity of solids going to liquids is higher than that of liquids going to gases. Of course the engineering of a system to circulate nanoscale ice cubes within ammonia (or methanol or ethanol) and refreezing the water back into ice cubes in the "condenser" is slightly more difficult than the engineering required for heat pipes.