============================================================================== Yvan Bozzonetti wrote : >Let see if I have understood something about "respirocytes": They are >micrometer sized spherical diamond tanks able to store gazeous oxygen at high >pressure with the help of a centrifugal pump using a 10 nanometer rotor... It does not use a "centrifugal pump" but a "Molecular Sorting Rotor". It does not seperate molecules by using centripal acceleration, but it rotates relatively slowly and it uses binding site "pockets" (along the rim) to seperate molecules (by Van der Waals force). >First, why diamond? graphite sheet are nearly as strong and there is a well >established technology to make them in the bulk. Nope, a graphite sheet is only one layer of atoms thick, a diamond wall can be made as thick as you want, and can thus be made much stronger. (In this case about 10nm thick.). See paragraph 3.6 : "Each storage tank is constructed of diamondoid honeycomb or a geodesic grid skeletal framework for maximum strength. Thick diamond bulkheads separate internal tankage volumes. Available structural mass is equivalent to a 10-nm thick (~60 carbon atoms) 2.2 micron x 2.2 micron diamond sheet, enough material for 1000 compartments ~(40 nm)3 in size for all tanks. Compartment walls are perforated with sufficient holes of varying sizes to allow gas to flow easily between them, with larger compartments nearest the rotors graduating to smaller compartments more distant from the rotors to encourage isobaric entrainment." >Second, What is a submicrometer gas? At that scale, surface effects are >dominant. Surface effects are not dominant, but they are not negligible either. (The compartments are of 40 nm size.) But I guess, surface effects will only lower the effective pressure, so they should even lessen the strength requirements. >What about using capillarity to load a cylindrical bottle made from >a nanotube? And how is the capillarity going to be attached to the bottle? How is the device controlled ? The pressure can not be made as high, so this kind of device has a much lower capacity. (Maybe even less than a standard red blood cell.) Furthermore you would need real MNT anyway, even to make a device like this work. >It seems that has been done for hydrogen, why to build atom by a atom a >diamond structure? Diamond or not, carbon and high pressure oxygen are a >noxious mix. Didn't you read : O2 and CO2 are stored in seperate tanks. >Do you really would try to make such a complex, unstable, costly >thing Yes, because they will not be costly to fabricate using real MNT ! ( Using reproducing systems, exponentional production and convergent assembly systems.) And it will not be unstable : in the design an extremely conservative 100-fold structural safety margin is used. Maybe I should add : All conservative approaches do assume that any nano-system with a self-reproducing capacity will never be used inside the body. They assume that the fabrication of the biological repair or enhancement systems will take place outside the body. >when fixing an ahemoglobin molecule to a carbon nanotube would do the >same work at some $/kg? The artificial respirocyte would be several hundreds of times more efficient per unit volume than natural red blood cells... I guess you didn't read the complete article (or you didn't understand it?). Next time do not read the abstract only. And if you want to criticize the fundamental basics of MNT, read "Nanosystems" first and then focus your critic on the assumptions and derivations made in this book. Cheers, >Hkl ============================================================================== From: "Henri Kluytmans" <> To: Subject: Nanotech / MNT Date: Mon, 26 Jan 2003 10:06:43 +0200 I wrote : >> it rotates relatively slowly and it uses binding site "pockets" >> (along the rim) to seperate molecules (by Van der Waals force). Azt28@aol.com replied : >and it releases them how?... A rod in the center of the binding site will protrude when it's part of the rim is located inside the reservoir and will mechanically press the molecule out off the binding site. (Of course this operation requires some energy.) >> Nope, a graphite sheet is only one layer of atoms thick, a diamond >> wall can be made as thick as you want, and can thus be made much >> stronger. (In this case about 10nm thick.). >Nanotubes can be produced with multiple sheets, same for buckyballs. I'm familiar with nested nanotubes, but I never heard about nested buckyballs. They seem to me much harder to produce. But anyway, a nested structure of graphite surfaces of irregular shape is more complicated to produce (im assuming advanced MNT is being used for manufacturing) and less strong than a diamondoid structure of the same thickness (when more than 10nm thick). >> "Each storage tank is constructed of diamondoid honeycomb or a geodesic >> grid skeletal framework for maximum strength. Thick diamond bulkheads >> separate internal tankage volumes. >Do you think one second to the complexity of that 3D structure? To think a >(perfect) gas can flow freely in it is beyond my understanding, at best >you'll have a kind of very non linear liquid with strong surface effects. Even when the surface effects are strong that shouldn't interfere much with the planned functioning of the device. When the storage tank is filled the pressure in it will be very high (1000 bar when completely filled). >The problem is that diamond (carbon) + O2 = CO2 + energy + destruction. Indeed, that could be a problem. But the inside surface of the tank can be coated with molecules/atoms that are more inert to O2. >bad molecule in the rotating part and the system grind to halt or the motor >is sufficient to overcome that and you have the activation energy to start >the combustion process. When that energy is located inside a motor or a sorting rotor that shouldn't be able to start a combustion process. The energy will quickly be conducted away anyway. >It may be worse: This system has nearly no thermal sink so any >concentrated energy input, for example a cosmic ray particle, >could start the fire. On the contrary, the device is located inside the bloodstream in the human body, a very large heat sink indeed (compared to the device itself). The device is mostly constructed of diamondoid which serves as an excelent thermal conductor to lead the heat to the outside of the device. At microscales it's more of problem to contain heat than to loose it, because of the great ratio of surface to volume. >Even thermal energy is a bad concept at that scale, you >may have to speak about discrete mechanical vibrations or phonons. >Resonance effects may concentrate energy in a particular zone and >set a fire. The device can be tested and designed to avoid this. >To make such a structure would be very costly, to make it >safe would be quite another challenge. Wrong!!! One of the main inherent advantages of advanced MNT (i.e. using self-reproducing systems) is the low costs of anything produced using this technology. >> And it will not be unstable : in the design an extremely >> conservative 100-fold structural safety margin is used. >The problem here is that you think on a classical physics basis, not a >semi-quantum one as you should. Only for some exceptions it's is neccesary to use quantum-mechanical models (e.g. the reaction to covalently bind a molecule), but for most processes in MNT everything can be moddeled using non quantum-mechanical models. >A simple radiography would set fire in all your respirocites for >example, simply because you assume there is a bulk, >macroscopic thermal sink where there is not. But as I explained above, there is a very large heat sink! >I have read far more than the abstract, but I am not sure it was >a good time investment. Then, I guess you haven't read enough yet. But as I told before, when you want to criticize the MNT concept, then you should start with atacking the fundamentals described in the book "Nanosystems". (Read "Engines of Creation" first, but only as an introduction.) >True nanotech is at the scale of atoms or a small group of them, most >progress seen here are simply biochemistry or plain chemistry in disguise to >attract more money. Indeed, you're right, if you're talking about all the research going on in "nanotechnology" these years. But the systems we are talking about can only be produced using "real MNT". There is indeed little research going on concentrating on real MNT. >Theoretical large schemes lack the quantum thinking they desserve. Nope, not necessary. >Assemblers for billion parts systems are no more than dream pipe. Nope. There seem to be no theoretical arguments against them. >Self assembly is not best at that scale. You can probably have a self >assembly system working on at most ten parts, no more. Ribosomes may do more >but they are limited to 20 different building block assembled into a string. >Nano systems seem to have far more than 20 different parts and need 3 >dimensional work, not one. You're talking about un-controlled self-assembly, in MNT the assembly process is controlled. Even much more controlled than in biological reproducing systems like cells and bacteria. And I think these are constructed from more than 20 parts. >To make that (or a small part of that) a reality, you'll need tens of >billions dollards/year for one century or so. Where did you find that money? Technological development is leading toward MNT anyway, with or without direct investment into research concerning "real MNT". (Read "Engines of Creation".) >I have never seen a strategy to go from zero to that astounding level of >activity. Is it possible, if the market is so great than nobody find in each >case a simpler, cheaper solution? I guess we will have to wait for a couple of decades (without substantial investments into real MNT research). >To a cold eye, nano capacities seem largely overstated. The reality one >generation from now may be somewhat biter. There seems to be no theoretical barrier, even better, biological systems seem to be a proof of concept (like birds where for flying machines). Grtz, >Hkl ============================================================================== ( MNT = Molecular Nanotechnology = Molecular Manufacturing, etc... ) I wrote : >> A rod in the center of the binding site will protrude when it's >> part of the rim is located inside the reservoir and will >> mechanically press the molecule out off the binding site. >> (Of course this operation requires some energy.) Yvan Bozzonetti replied : >This is mere sci-fi. Nope. >I dislike profoundly sci-fi ( many years ago I have read a lot of >them, so I know about their -lack of- value). I am not religious >neither. Here, I find both: sci-fi and religious (mere faith) >thinking in thechnological disguise. Hmm, ... ehh ... sigh... :( By the way, I'm not religious too, and I always try to avoid religious thinking. Furthermore, the term science-fiction implies that the science does not exist (yet). So far I have not yet encountered any valid scientific arguments against MNT, therefore I keep assuming that the MNT concept is scientifically correct. But of course, the technology does not exist yet. Therefore you could call it "techno-fiction". I preserve the term "science-fiction" for things like time-travel, faster-than-light, parallel worlds, etc... >Your explanation above prove only one thing: you see a nanodevice as a >classical object, not a quantum one. At that scale, everything is sticky, >vibrating, soft, not well localized. A rod, hard and rigid is a bad fiction. This only demonstrates that you didn't look into the nano-MNT concept very well. You utter the same invalid arguments like many "so-called" experts did (e.g. Prof. Whitesides, ). They only show a misconception of MNT and also a misunderstanding about things at the molecular scale. Maybe you should read this debate, it's about an article in the Scientific American that contained some of these same misconceptions and invalid arguments (and also a lot of non-scientific critic) : http://www.foresight.org/SciAmDebate/SciAmResponse.html#locBG And this : http://www.zyvex.com/nanotech/nanocritics.html === You can read the explanation about why these issues are not good arguments against MNT in the online book : "Engines of creation" (this is meant for the layman). And if you want an explanation in scientific terms, you can find it in the book "Nanosystems"/ But I will explain it anyway : You say that at the atomic scale ( 0.1 - 10 nanometer) : 1) "everything is vibrating" Yes, everything is vibrating. But that should not interfere with MNT concept of building things from molecular parts with atomic precision because the internal structural components have relatively high stiffness, For a diamond rod of 10nm length and 1 nm width at 310 Kelvin the resulting positional uncertainty from thermal vibrations is about 0.02 nm. The size of a C-atom is about 0.3 nm, and the smallest atom, the H-atom is about 0.1nm. Because the inaccuracy is much less than the size of the atoms, thermal vibrations therefore should be no real obstacle against placement of molecular parts with atomic precision. 2) "everything is sticky" Nope. There do exist very sticky type of molecules indeed, for example free-radicals. But even for most of these molecules the stickyness is localized, so it is still possible to handle the molecule without interfering with the sticky part. Remember that the internal environment of nanosystems will be made inert (i.e. vacuum) and the location of every atom and molecule will be known, no loose atoms/molecules should linger around. And two objects made of diamond, with their surfaces terminated with hydrogen atoms, will not stick together. At atomic scales not everything is sticky. 3) everything is soft / not well localized The fuzzyness of a particle is inversely proportional to its mass. For example light particles like electrons are indeed quite fuzzy. But the atomic nucleus is not. Indeed the border of an atom is a little fuzzy, but this fuzzyness is less than it's diameter. Therefore this fuzzyness forms no obstacle in manipulating atoms and molecules as building blocks. The fact that atomice force / scanning tunneling microscopes can show surfaces with atomic detail already demonstrates that atoms as a whole are not fuzzy at these scales. ==== >I am a strong advocate of both, avdanced science and >technology, but as good sci-fi (if it exist), nothing >must contradict known facts. ... The MNT concept doesn't contradict any known facts. >And thinking about nanoscale objects as macroscopic classical ones >is plainly wrong. Certain aspects of macroscale engineering can be down-scaled and some aspects cannot. For example, electromagnets are far less attractive for nanoscale systems, since magnetic fields do not scale down to nanoscale very well. The corresponding magnetic forces become minute in nanoscale systems (e.g. compared to chemical bond strength). But nanosized motors could be built based on electrostatic forces in stead. Electric circuits cannot be downscaled to nano-scale without taking into account the quantum nature of electrons. However most mechanical mechanisms can be downscaled. Except for the frictional force which doesnt scale down at all, but mechanical nano-systems can be designed and produced in such a way that frictional force is not applicable. For example chemical computer analysis of molecular gears have been made (by Nasa) and seem to indicate that they should work as expected. See Merkle's page for more info http://www.zyvex.com/nano/ (To circumvent electronics at nanoscales Drexler proposed using computers that operate by using mechanical logic. Because it's functioning is based on the movement of molecular structures, in stead of electrons, quantum effects are less of an issue.) But you can take a look at chapter 2 of nanosystems yourself, it's about "Scaling Laws" and it's online!, see : http://www.foresight.org/Nanosystems/toc.html#c2 >When I speak about nanoscale devices built on a clay crystal >surface, I know what material to use, how to handle them, >where to buy the tools for that, how to find money to finance >this. To me, this idea looks not so much different from what current lithographic is accomplishing now and in the near future. However MNT is totally new concept for building objects with some inherent characteristics (atomic building blocks, self-replication ) that will make it revolutionize our world completely. >Clearly, we have not the same idea of reality :-) Maybe you don't see clearly yet. :) I suggest you take a better look at the MNT concept, and also at the scientific arguments for it (i.e. Nanosystems). >Well, as said Johnny Burnette 40 years ago, keep on dreamin'. Yes, I do like to dream. But MNT is not a dream, it's a foreseeable technology with a scientific basis. ============================================================================== Thomas Donaldson wrote : >I believe I pointed out that chemists were already studying ways to >make hydrogen more compressed and more manageable in a previous >message. Think borohydrides. Ehh ... where did I mention the storage of hydrogen ? Yvan and me were debating an hypothetical artificial device made by advanced MNT and which should be able to function as a replacement for the human red blood cells. Such a device will need to store oxygen and carbondioxide in storagetanks on board. >As for nanotechnology, living systems can only be used so far. >They do not extend to the systems you (or NANOSYSTEMS) envision. Did I imply that ? >Perhaps your NMT will someday really come, perhaps living things >when examined carefully will tell us why it will never come. There is no 100% guarantee that MNT concept will be possible exactly in the way as it is foreseen in current conceptual designs. It could be that certain details will have to be altered to make them functional. But that the complete principle of an artificial technology using systems that can build atomically precise objects from molecular building blocks (including self-reproduction) is impossible seems highly unlikely to me... It would be extra-ordinary exceptional if the biological way would be the only way, or even the most efficient way. Especially because biological systems developed themselves by undirected mutation and selection. And directed design, in principle, will almost always be able to make a better system. ======== >Among other points, if you have LOTS of molecules ways to use >randomness to change them to suit may turn out much more efficient >than devising special systems which move every one where you want it. Are you trying to explain here that biological systems are more efficient in building objects from molecules than future artificial systems? And that this is due to the fact that biological systems employ brownian movement of molecules whilst artificial systems will use mechanically controlled systems to transport molecules. You forgot to mention in what ways they are more efficient, but I guess you are referring to the energy usage. Indeed, it seems obvious that biological systems are more efficient regarding energy usage in building objects from molecules. Already only the fact that the current MNT designs are using much stronger chemical bonds (e.g. diamandoid instead of proteins) seems to make that likely. However future artificial systems will certainly be more compact, faster, stronger, etc... than biological systems (i.e. more efficient in volume, time and stiffness). The research Robert Freitas has done in investigating artificial replacements for some biological functions seem to show an improvement of many hundreds or even thousands of times in performance of specific functions (see his examples of artificial respirocytes and clottocytes at : http://www.foresight.org/Nanomedicine/index.html ). Although it seems clear that biological systems are more efficient (regarding energy usage) in building objects from molecules it is not clear that they also more efficient in performing their specific function. ==== For example the human brain is using about a 100 watt to perform it's function. The computational power of the human brain can be estimated at 2 * 10^16 cps (conservative estimate by Ray Kurzweil). A computing system based on nanomechanical rod-logic of this same processing power will consume only about 2 Watt. (10 Watt for a 10^11 MIPS computing system, see Nanosystems.) And I didn't even take into account : 1) that the computing power estimate for the brain used here was a very conservative one, there are estimates as low as 10^13 cps, which would result in an MNT equivalent systems using only 1 MicroWatt !!! 2) the usage of more efficient architectures and reversible logic (not for all computations) to reduce energy usage even more. So it's not that clear that biological systems are more efficient in energy usage in a general sense. ================== Furthermore MNT systems could be designed that would use different kinds of building blocks than current designs (which mostly use diamondlike C-C bonds). Building blocks using the same or even lower energy per bond than proteines are possible. Also transport-systems using Brownian movement could be implemented. Of course such transport-systems will be much slower, because the system will have to wait until the required part arrives at the desired place. However an artificial MNT system, building atomically precise objects from molecular parts, using less energy than biological systems seems feasible. ============================================================================== Yvan Bozzonetti wrote : >the nanomanipulator case as an example. >At near atom scale, there is no rigid, well defined objects and surface, at >least when simple atom stacking is used. To move atom and molecules with some >efficacity, tools must have a control system finner than the atom scale they >want to move. This can't be done with a minute robot arm, even built frm >single molecules. That it can be done with a macroscopic "robot arm" has already been proven by the placement of atoms and molecules using scanning tunneling microscopes. (For example the famous IBM logo made of 35 xenon atoms in 1989.) For example, applying 1 volts across a 750 micron thick piezoelectric crystal causes it to deform by ~0.4 nm. PZT crystals are commonly used to provide movement of samples being examined in scanning probe micros- copes such as STMs and AFMs. AFMs can achieve a resolution of 10 pm. -- Why do you claim that movements of less than atomic scale can't be done using a microscopic robot arm ? For conceptual MNT designs of possible microscopic positional devices see : http://www.zyvex.com/nanotech/6dof.html ============================================================================== Yvan Bozzonetti told me that the MNT concept is mere sci-fi. I said it is only techno-fiction, because there seem to be no valid scientific arguments against it. Yvan Bozzonetti replied : >have a realist view. You have to work with soft >proteins, not diamond rods. Hey, that is not a rational argument, only an opion. I tried to explain in detail why it is not **science**-fiction but only techno-fiction. >>And two objects made of diamond, with their surfaces terminated >>with hydrogen atoms, will not stick together. >And you want to pump oxygen under high pressure with a carbon >structure coated by hydrogen? You didn't read correctly, I stated : "And two objects made of diamond, with their surfaces terminated with hydrogen atoms, will not stick together." So the termination with hydrogen was to prevent the two diamondoid structures from sticking together, not to prevent a reaction with oxygen. To prevent a reaction with oxygen I wrote : "But the inside surface of the tank can be coated with molecules/atoms that are more inert to O2." And that certainly doesn't mean hydrogen atoms. But for example silicium-oxide or aluminium-oxide would do a much better job. Please read better next time, and try to avoid constructing statements I didn't make... :( >That in a device with no room to dump excitation energy? As I explained before, thermal energy will be led away very fast. (Reread my earlier postings, or do I have to keep on copying and pasting ??) >How many microseconds before an explosion? Not applicable. >>At atomic scales not everything is sticky. >... Noble gas are not, beyond that everything or so, is. If really everything was sticky many biological systems shouldn't be able to work too. Nothing would be able to move because al the parts would stick together. So biology is already a living proof that not everything does stick together... Furthermore, regarding MNT designs, computational simulations using molecular mechanics methods seem to confirm that these designs should work as expected and that the parts do not stick together. The molecular mechanics algorithms have been widely in use in the field of chemistry for many years and have already proven themselves to be a reliable way to predict behavior of chemical structures. For example see : http://www.zyvex.com/nanotech/bearingProof.html For an explanation why molecular bearings will not stick together. Or see : http://www.zyvex.com/nanotech/compNano.html#molecularmechanics For an explanation about computational methods. >Don't forget the van der Waals force. They didn't, the van der Waals force is implemented in the molecular mechanics method. >now a test to see if you see MNT clearly: (A story about lettuce was included.) >If you can't produce a convincing scheme, I'll conclude that >your nano ideas are bad sci-fi and you have no idea how to >make them real. Therefore I agreed, they are "techno-fiction", but not science fiction. I still haven't seen any valid scientific argument against the concept of MNT. If I, or somebody else had a detailed idea of how to realize the first assembler, the world would already have known by now. But the fact that the path to get there is not known yet, does not constitute a proof that it is scientifically impossible. All research done so far seems to confirm that the concept of MNT should be possible. Please tell me a **valid** scientific argument against the MNT concept. ============================================================================== Subject : Cost of MNT objects Thomas Donaldson wrote : >I was not, at least directly, claiming that biological systems >would be more efficient. But you seemed to suggest it. :) >Your message said that biological systems provided a proof >of principle for the existence of nanotechnological >systems. I pointed out one way in which they were quite clearly >different from nanotechnological systems, Yes, you are right about that. I said : "There seems to be no theoretical barrier, even better, biological systems seem to be a proof of concept (like birds where for flying machines)." I was meaning to say here, that biological systems are a proof of the two fundamental things which the MNT concept and biology have in common, and which are : "molecular building blocks" and "self-reproduction" Indeed, biological systems cannot be used as proof that the MNT concept as a whole is possible. When I made this statement I was only having in mind these two central issues of MNT and biology. ( This was because Yvan was questioning the possibilty of "self assembly" of objects made of more than 20 components. ) The two main differences between the way biology works and the way MNT should work are that : 1) Biology uses molecular building blocks that are weakly bonded (e.g. Van der Waals interaction) to each other (e.g. proteins) while the MNT concept want to use very strong (covalent) bonds between its building blocks (mostly diamondoid). 2) Biology uses transport of molecules mostly based on Brownian movement while the MNT concept will use mechanically controlled systems. The first will result in MNT producing stronger objects than biology, the latter will result in MNT producing atomically precise objects. (Similarly, birds are only a proof that flying objects heavier than air are physically possible, and not, of course, that a yet-engine or propeller driven flight is possible. ) ================ >I raised the question of >whether or not living systems might tell us that the kind of >nanotechnological devices you envisioned just wouldn't be >so easily made that they could compete. I raised a question, >but did not directly answer it. And I tried to make clear that current research into MNT designs (or as Robert Freitas calls it "Exploratory Design") seems to indicate that they will compete, and by a very large margin indeed. >I WILL point out that in real life at least one factor which >you don't mention in your message becomes quite important: the >energy cost of making a device in the first place. Sure, the >device when made may use far less energy than a living cell, >be packed more tightly, etc etc. But how much will it cost to >make? Hmm, this is a fairly straight forward calculation. I will try to do it here for two examples : the MNT computing device with a processing power equal to the human brain, and the artificial red blood cells (i.e. respirocytes). The energy released when following materials are burned : 1 KG of lipids = 38 megajoule 1 KG of proteins = 17 megajoule 1 KG of glucose = 16 megajoule 1 KG of diamond = 33 megajoule 1 KG of methane = 50 megajoule 1 KG of gasoline = 44 megajoule 1) MNT computing device of 10^16 cps (calculations/second) Merkle made following estimate in "Molecular Repair of the Brain" : "Given that there are 100 grams of protein and 175 grams of lipid in the brain, this means there is almost 2,000 kilocalories of chemical energy stored in the structure of the brain, or about 8 x 10^6 joules" Regarding the MNT computing device based on nano-rod-logic : A 10^16 cps device, uses 1 watt , size 10^-11 m^3 (cube with 0.22 mm sides) which would contain a chemical energy of about 1 joule when made of solid diamond. (Of course, the actual device will contain much less total chemical energy in its bonds because it's not a solid block of diamond. I guess maybe more than 2 or 3 times less chemical energy.) A less conservative human brain processing power estimate would result in a 10^13 cps device, that uses 1 microwatt , and has a size of 10^-14 m3 (cube with 0.022 mm sides), and it would contain less than 0.001 joule of chemical energy !!! (These estimates are based on chapter 12 in Nanosystems) I did not include the cooling part of the device, but on the other hand, I took the chemical energy for a volume-equivalent mass of diamond, which should make more than good for the omission of the cooling part. Also the energy cost for transportation of molecules, inefficiencies, computation and entropy reduction together are almost ten times less than the chemical energy. 2) Artificial red blood cells (or respirocytes) From the article about respirocytes by Freitas : - the operational lifespan of respirocyte is about 20 years. - 1% per day of all red cells are destroyed naturally - baseline respirocytes can deliver 236 times more oxygen to the tissues per unit volume than natural red cells - density of red cells = 1100 kg/m3 - a 1-micron respirocyte has a density of 679 kg/m3 with tanks empty Assuming a human lifespan of a 100 years : Every 100 days, all red blood cells must be replaced. Thus for a 100 years that's 365 times total replacement for red blood cells. For the respirocytes only 5 times total replacement is required in 100 years. For 1 milliliter of blood the chemical energy is = ~30 Kilojoule (assuming a 50%/50% proteines/lipids proportion for red cells) For 1 milliliter of respirocytes chemical energy is = ~22 Kilojoule For a 100 years, the chemical energy for producing red bloodcells or an equivalent mass of respirocytes compare as 2*10^4 :: 1 === CONCLUSION : The energy cost of making a device, and also the operational energy usage of device made using MNT should be several orders of magnitude better than for biological systems. If these examples are typical, then it seems that biological systems are not very efficient in ANY WAY . === I didn't even take into account that : 1) Of course, as I said before, MNT systems could be designed that would be based on building blocks with lower bond energies and Brownian movement transportsystems. Such systems should use less energy for building atomicely precise objects than biological systems do. 2) Furthermore it's to be questioned if the energy consumption for creation of objects is a valid general reference for efficiency or economic cost. Energy will be much cheaper in the future when solar power collectors can be manufactured much cheaper and better than now. One should also consider the fact that an enormous amount of energy is being wasted in our solar system. More than 99.999999% of the energy the sun is producing is radiated into space without being used at all. 3) Also, as Drexler notes in Nanosystems, when organic feedstock molecules are used as raw material (in stead of CO2) then a reasonably efficient molecular manufacturing process will be net energy producer!! >to make more nanosystems. The construction process you propose >(not that I think you are alone) COULD turn out to be expensive >enough that it just isn't practical when compared with how >living things are made. Regarding the "economic price" of MNT produced objects, they should be VERY CHEAP indeed, compared to the price of currently manufactered products. Current products vary between 10-10000 $/Kg (tv,cars,furniture,airplane,etc..) Drexler estimated a price for MNT produced objects of : 0.1 $/Kg but here he assumed obtaining raw materials from agricultural resources. ==== The basic price of a product is determined by the cost of energy, raw materials and development of the design blueprints. Because the cost of design can be neglected when large series of a product are made, the price will be determined primarily by the cost of energy and raw materials. (And there will probably be a lot of designs that will be available as open-source, like there are for computer software now.) The raw materials are mostly molecules containing C atoms (and some H and/or O). On Earth, at this moment, the easiest source to obtain these raw materials is the atmosphere (CO2 and H2O). These resources are for free. Energy can be obtained from solar power collectors, those in turn will be produced using MNT. Raw material and energy cost for creating the solar power collectors themselves can be neglected in the long term. The cost of surface area seems to be the principal remaining cost! Merkle made a crude estimate in "Molecular Repair of the Brain" : "The land cost $100 [for 1 year], so the cost per joule is 0.9 nanocents and the cost per kilowatt hour is 3.3 millicents. Solar power, once we can make the solar cells cheaply enough, will be over several thousand times cheaper than electric power is today." Making 1 KG of diamond out of CO2 would require about 33 MegaJoule, so the energy cost would only be about 0.03 cents! (Hmm, looks like the price Drexler estimated is very conservative.) Furthermore, still cheaper would be, creating floating solar panels in international waters (or in space), this should eliminate the cost of surface area. >(Not that if this were so, we could >not use similar reactions to those of living things to make >our nanodevices!). Indeed. But for the moment, it still looks like MNT systems based on covalent C-C bonds and mechanical transport systems producing atomicaly precise objects seem feasible. And also that the products made using this technology will not be expensive at all. >Basically I was pointing out one issue which some proposals >for making nanodevices don't consider. Hmm, I seem to recall many articles/books where production and energy costs were considered (by Drexler and Merkle). >In any case, if YOUR proposed systems are too costly compared >to the kinds of nanodevices based on chemistry and biochemistry, >then no one will buy them. From the examples available it looks like it will be the opposite : objects manufactured using MNT should be dirt cheap! (Even compared to products based on biochemistry.) >If they are put out to compete with >living things, living things will win, not by being more >efficient or superior, but simply by numbers alone, When considering self-reproducing systems, starting numbers are not relevant, in the long term reproduction efficiency is the only thing that counts. >while your nanodevices struggle to reproduce themselves only >a few times. Ehh ... why will they struggle to reproduce only a few times ? Cheers >Hkl ============================================================================== Thomas Donaldson wrote : >The energy used to make an object is not the same as the energy >which may be stored in the object. Yes, but in this case the chemical energy stored in the object accounts for the bulk of the energy required to make the object, and I did mention that somewhere. Quote : "I did not include the cooling part of the device, but on the other hand, I took the chemical energy for a volume-equivalent mass of diamond, which should make more than good for the omission of the cooling part. Also the energy cost for transportation of molecules, inefficiencies, computation and entropy reduction together are almost ten times less than the chemical energy." (Although I made a mistake here, entropy reduction is not an energy cost...) >You discuss diamonds as materials for nanotech devices. Fine. I did use diamond for simplicity, because a solid block of diamond will certainly require more energy to make than a diamondoid nanodevice of the same volume. >What chemical (and other) energies are used in making those >diamonds, remembering that some of that energy will be lost >and not recoverable from the diamonds themselves? I'll try to give a more complete list of energies involved in every part of the manufacturing process in another posting. (Because it will take some time.) Of course you could gather that information yourself by obtaining the book Nanosystems and looking it up. >You do not cite any work which looks at this question. To be fair, we The book "Nanosystems" of course !!!! ( See chapter 13 & 14 ) >have no nanotech devices of the kind you envision which would let >us use experiments to work out this energy. Indeed, there are no functioning devices yet. But theoretical calculations should produce good estimations, because the science behind the processes is all very well known. >A valid argument for nanotech substitutes for red blood cells >would calculate the energy needed to make them, not just the >energy that remains with them after they're made. The total energy required for all other operational steps is about a factor 10 less (and this could probably be improved, for example by slowing down the process). Even if these other manufacturing operations would take a 100 times more energy then assumed, the MNT devices would still cost much less energy to make then their functional biological equivalents ! Remember that the manufacturing energy cost was 10^4 (respirocytes) to 10^7-10^10 (computing device) times better for MNT devices. Furthermore the human body uses biological feedstock molecules (almost completely produced directly or indirectly by plantlife). When MNT devices use organic feedstock molecules they can be net-energy producers! So maybe, this whole discussion is going a little too far. Especially concerning the fact that cost of energy in the MNT era will be negligible compared to now. But nevertheless I will dig into Nanosystems and try to make a more complete list of all the energy costs involved. ============================================================================== Thomas Donaldson wrote : >As for replacing our body parts with nanotech devices, it's >appropriate to consider red blood cells as an example. The first >thing I would ask is that of just what evolutionary pressures >caused us to make only red blood cells with the lifespans they >have. I don't claim to be an expert on red blood cells and would >be interested in what such an expert might say. However I will >suggest that, given their role, making red blood cells capable >not just of self-repair but also of fending off external threats >from viruses, bacteria, etc etc turns out to require more energy >and leave the red blood cells less efficient as carriers of O2 >to our other cells. Another reason could be that a red cell looses functionality over time ? >Finally, I will point out that if all our red blood cells are >replaced by nanotech substitutes, it would not take long (say >no more than 50 years) for bacteria, funguses, and other such >life forms to start growing on them. Very unlikely! Biological organisms do not possess the necessary chemical tools to disassemble a protective outer shell made of diamond(oid). (However, artificial attackers could.) I should also mention that all these discussions about biological applications are mostly academic anyway. (Although they do serve very well to show that artificial MNT systems will perform orders of magnitude better than biological systems.) But basically all MNT applications for biological enhancements are probably only of temporary use. We can expect that not very long after MNT devices of this kind are possible, the whole biological body will be out-dated .... (I.e. uploading to an artificial brain (and/or body) seems the way to go if you want to keep up with the ...) >So just where would THAT put us? As I explained above, attack by biological organisms is not applicable. We are talking about a future 50 years after the first advanced MNT devices have been produced. It seems very likely that by that time there will be a complete artificial ecology with artificial sentient beings, artificial virusses etc... Biological ecology will be "out-dated" and only of value from a historical and cultural perspective. (And maybe the Earth will then be considered a reservation for organic biological beings.) (And we're speaking, maybe a hundred years from now.) >Think of what's happened with all the antibiotics we've made. >Any good nanotech device of ANY kind would basically have to >contend with how everything in our world will change in response to it. Yes, indeed, there will be virusses that have to be taken into account, but not the ones based on organic biology. ============================================================================== Yvan Bozzonetti explained that a macroscopic system with many atom lengths can have a precision better than a nanometer, but that downscaling reduces stiffness and increases positional uncertainty. He is right about that of course. And my example of a piezoelectric crystal was a bad one. Bending stiffness scales down proportional with size. And positional uncertainty due to thermal noice is inversely proportional to the square root of the stiffness. But because MNT devices will be made from materials with very high stiffness (Young's modulus of diamond = 10^12 N/m2 ) 100 nm sized manipulator arms with atomic positional precision (<0.1nm) are still feasible. The robotic arm example in Nanosystems (although not optimal) is 100 nm long and 35 nm diameter. Although it is hollow and contains joints, it still has an overal stiffness of 25 N/m. (For comparison, a solid rod of diamond 100nm by 35nm diameter would have a stiffness of 9000 N/m ) Positional uncertainty due to thermal noice is : sigma^2 = kT / ks at room temp. sigma = sqrt( 4×10^-21 / 25 ) = ~0.01 nm This is only a modest fraction of an atomic diameter, and quite enough to allow placement with atomic resolution. However one should have to add positional uncertainty due to workpeace (the object) and the tool (i.e. reactive moiety). But overall the total positional uncertainty can be kept under 0.03 nm, still enough for atomic resolution. ============================================================================== I wrote : >>Therefore I agreed, they are "techno-fiction", but not science >>fiction. I still haven't seen any valid scientific argument >>against the concept of MNT. Yvan Bozzonetti replied : >You could as well said that about interstelar travels. Even in this case >there have been published technical schemes to get here. For MNT, you have >only one idea and no proof it is impossible, a weaker position. The MNT concept is a little stronger than you seem to suggest : There is a roughly detailed idea of how the concept should function. There are existing proofs of some of its basic principles (self-reproduction, building objects out of molecular building blocks). There is theoretical proof (based on well known science) of all other parts (even some theoretical experiments). Indeed, there is no physical experiment to demonstrate the complete concept in practice yet, but then it wouldn't be a concept anymore, would it. >It is similar to a religious faith: If you can't give a >mathematical poof it is false, then I chose to think it is true... Nope. It is TOTALLY DIFFERENT !!!! Do you really want me to explain this ????? :( >>Please tell me a **valid** scientific argument against the MNT >>concept. >Science is about testable observational or experimental facts. NOPE. Science is about making theoretical models that can predict observational or experimental facts. Those models can then be used to theoretically analyse unbuild technological designs. Only when new models are made, or old models are adapted, then confirmation by experiments is required, therefore models need to be testable to be of any use (and thus religious beliefs are not scientifically acceptable models). However, MNT does not require new models (i.e. new science) ! (Oops, I think I just accidentally answered your question why MNT is not similar to religious faith.) ============================================================================== Yvan Bozzonetti wrote : >For me it will be techno-fiction when it will be as man on Mars: >Not yet done, but each step to go here is defined. Money is then >what is requested to make it technical reality. Then I think we're using different definitions, because I don't call "space travel to Mars" techno-fiction. Because in this case the technology is not fictional, however because there is no money to do it, I would call it : "financial-fiction" Hmm Yvan, I'm curious : You call it "techno-fiction" when the technology exists but there is no finance. You call it "science-fiction" when the science exists but not the technology. What do you call something when the science does not exist yet ??? For example : time-travel, faster-than-light travel, etc... Cheers, >Hkl ============================================================================== ============================================================================== ============================================================================== ============================================================================== ============================================================================== 1 cubic centimeter volume of gates can deliver 10^29 cps. a 1 cubic millimeter volume of gates can deliver 10^26 cps. a 1 cubic micron volume of gates can deliver 10^15 cps. 300,000 calories = 1,254,000 joules "When protein is burned, it releases about 4 kilocalories per gram." *Size of a single "lock" (gate) plus overhead (power, etc.): 100 cubic nanometers = 10^-21 m3 *Volume of gates that can deliver 10^37 operations in three years (a larger volume will in fact be required to accommodate cooling requirements): 10-6 m3 = 10^15 gates = 10^37 i/3year = 10^29 ips (3 jaar = 10^8 sec ) ======== 1cm3 = 10^12 cpu scale systems = 10^21 ips = 10^5 watt --> 1 cpu scale system = 10^9 ips 10^17 ips = 10^1 watt 1 cpu scale system = (400 nm)3 = 10^6 gates = 1ghz = 60*10-9 watt -> 6*10^8 ips (want 10^16 ips = 1 watt ) ====== 10^16 ips , uses 1 watt , size 10^-11 m3 = ~ cube of 0.22 mm sides 10^13 ips , uses 1 microwatt , size 10^-14 m3 = ~ cube of 0.022 mm sides ----------- Lets consider the energy to create a diamond lattice of equal weigth : energy to make 1 Kg of diamond out of CO2 = ( 2*CO2 --> C-C and 2*CO2 ) C(diamond) --> C(graphite) : dH = -1.88 kJ/mole =~ 157 kJ/Kg burning of 1KG graphite (C->CO2) = 33 MegaJoule =------------- - the average male human body has 3 x 10^13 red blood cells - full duplication of human blood active capacity requires deployment of 5.36 x 10^12 devices [respirocytes] 5.36 x 10^12 * bol 1 micron = 5.4*4/3*3.14*(0.5^3)*(10^-6) = 3 * 10^-6 m^3 = 3/1000 liter = 3 ml!!! 1 m^3 = 10^3 liter blood cells = X 236 = - 1 respirocyte = kg