New era in ultra-hard materials imminent: arbitrarily large diamonds. And with it routine space access, the hydrogen economy, room-temperature superconductivity and ultra large telescopes.

Very interesting article here reporting on researchers who had previously announced a rapid means of producing synthetic gem sized
diamonds, now believe their methods will work to produce diamonds of arbitrary size:
Artificial diamonds - now available in extra large. 18:11 13 November 2008 by Catherine Brahic. "A team in the US has brought the world one step closer to cheap, mass- produced, perfect diamonds. The improvement also means there is no theoretical limit on the size of diamonds that can be grown in the lab. "A team led by Russell Hemley, of the Carnegie Institute of Washington, makes diamonds by chemical vapour deposition (CVD), where carbon atoms in a gas are deposited on a surface to produce diamond crystals. "The CVD process produces rapid diamond growth, but impurities from the gas are absorbed and the diamonds take on a brownish tint. "These defects can be purged by a costly high-pressure, high- temperature treatment called annealing. However, only relatively small diamonds can be produced this way: the largest so far being a 34-carat yellow diamond about 1 centimetre wide. Microwaved gems "Now Hemley and his team have got around the size limit by using microwaves to "cook" their diamonds in a hydrogen plasma at 2200 C but at low pressure. Diamond size is now limited only by the size of the microwave chamber used. "The most exciting aspect of this new annealing process is the unlimited size of the crystals that can be treated. The breakthrough will allow us to push to kilocarat diamonds of high optical quality," says Hemley's Carnegie Institute colleague Ho-kwang Mao." http://www.newscientist.com/article/dn16036
Original research article:
Enhanced optical properties of chemical vapor deposited single crystal diamond by low-pressure/high-temperature annealing. Yu-fei Meng, Chih-shiue Yan, Joseph Lai, Szczesny Krasnicki, Haiyun Shu, Thomas Yu, Qi Liang, Ho-kwang Mao, and Russell J. Hemley Published online before print November 12, 2008, doi: 10.1073/pnas. 0808230105 PNAS November 18, 2008 vol. 105 no. 46 17620-17625 http://www.pnas.org/content/105/46/17620 [abstract]
I had discussed the earlier research that showed they could make synthetic diamonds of perhaps 50% greater hardness than natural diamond. From this I suggested this should mean the strength should also be increased by this amount and could result in ultra large telescope mirrors, perhaps to 30 meters across, if the process could be scaled to arbitrary sizes, as now appears likely:
Newsgroups: sci.astro, sci.physics, sci.optics, sci.materials
Date: 11 Dec 2004 12:48:10 -0800 Local: Sat, Dec 11 2004 3:48 pm Subject: Re: Can diamond now be used for telescope mirrors? http://groups.google.com/group/sci.astro/msg/8d2744a0b5fa94b4?hl=en
Here I suggested that use of ultra high strength microspheres or microfibers would be able to solve the problem of finding lightweight storage tanks for the hydrogen fuel on the VentureStar reusable launch vehicle:
Newsgroups: sci.astro, sci.space.policy, sci.physics, sci.energy
Date: Fri, 5 Sep 2008 20:32:39 -0700 (PDT) Local: Fri, Sep 5 2008 10:32 pm Subject: High strength microspheres for hydrogen storage (was: High strength fibers for hydrogen storage on the VentureStar.) http://groups.google.com/group/sci.astro/msg/4bddfa864aa04056?hl=en
If the high strength material at the microscale were diamond, the weight of the propellant tanks could be reduced by a factor of 100, which would make feasible not only the VentureStar but also the other competing NASA reusable launch vehicle proposals. With the newly announced process now being able to make diamond in bulk sizes, the tanks would not need to consist of numerous microspheres or microfibers but a single macrosized tank. Note that such lightweight, high strength tanks would also solve the storage problem for hydrogen for the hydrogen economy. Not only could the diamond be used for the propellant tanks but also for the strength bearing structures of the entire craft since diamond also has ultra high compressive strength as well as tensile strength. The weight of the vehicles could conceivable be reduced by a factor of 100: instead of 200,000 lbs., only 2000 lbs.
Metallic hydrogen has been considered an ideal rocket fuel if it could be produced because it is of high density yet it's energy content would give it a fuel efficiency of 4 times that of the best chemical propellants now used. Theoretical modeling also suggests it could be stable at room temperature once produced and would be a superconductor. Experimental and theoretical work suggested metallic hydrogen would be produced at pressures of 4.5 megabars, 450 GPa:
Apr 10, 2002 Hydrogen metal on the horizon. "Scientists have long expected solid hydrogen to become a metal when it is compressed, but so far electrical conductivity has only been detected in liquid hydrogen. Now an experimental study of solid hydrogen at pressures up to 320 GPa predicts that it will become metallic at a pressure of 450 GPa over four million times atmospheric pressure. Ren LeToullec and co-workers at the CEA in France also found that solid hydrogen becomes opaque or black under compression (P Loubeyre et al 2002 Nature 416 613)." http://physicsworld.com/cws/article/news/5307
Attempts to create ultra high pressures in the megabar range frequently involve using diamond anvils at the microscale. However, natural diamond has maximum compressive strength of about 400 GPa. If it is indeed the case that the 50% increase in hardness of the new synthetic diamonds over natural diamond also indicates a corresponding increase in compressive strength, this would put diamond anvils using these synthetic diamonds within the compressive strength range required to produce metallic hydrogen.
Bob Clark
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Dear Sam Wormley:
Robert Clark wrote:

...
Diamond is 1*10^-6 @ 20 degC Pyrex is 3.2*10^-6 "Glass" is 8*10^-6
Diamond has n of 2.418
Pyrex has n of 1.474
Of course it burns... I am not sure how "long lasting" a lens or mirror would be with monatomic oxygen bombarding it. Might "anneal" just fine...
David A. Smith
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The aluminum alloy liquid hydrogen tank used for the space shuttle is on the order of 10 meters wide, with a skin thickness in the range of 5 to 10 millimeters. To use a similar sized tank for liquid hydrogen using diamond while reducing the weight by a factor of 100, you would need to reduce the thickness to only about 100 microns. That is quite thin for a macro sized tank, about the thickness of a sheet of paper. The research team producing the synthetic diamonds have already created diamonds of size a cm across. The analogous thickness for a LH tank 1 cm across would be one with a thickness of only 100 nanometers. It would be interesting to find out if the researchers hollowed out one of their cm-sized diamonds to make a LH container out of it of only 100 nanometer thickness, would it have comparable strength to the LH tanks now used.
Bob Clark
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Not viable like the rest of your ideas. Pressure containers are in tension
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On Dec 8, 3:17pm, snipped-for-privacy@yahoo.com wrote:

Diamond has more than 100 times higher strength in tension than high strength aluminum alloys.
Bob Clark
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wrote:

Diamond has more than 100 times higher strength in tension than high strength aluminum alloys.
=============================================Oh whoopee! Let's build sheet-of-paper-thick diamond pressure vessels and watch them shatter on the launch pad when a metal would stretch. Never mind the cost, feel the money. You are a complete dork, Clark, with no absolutely zero experience in engineering, material science and last but not least, economics.
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If you look at the description of the method to make this large size synthetic diamond it is well within the capabilities of most university physics labs. Within a year you're going to see universities across the country and around the world making golf ball sized diamonds. Within 5 years you'll see diamond being used in contruction materials. Diamond is *relatively* brittle, but even brittle structures like glass can have important uses for improving strength. For instance glass fibers, fiberglass, have been used in light weight car bodies, boat hulls, tennis rackets, etc. because it is lightweight yet still high in tensile strength. And concrete of course is quite brittle yet is extremely important in construction. The quantity used in materials science to measure brittleness is "fracture toughness". The table on this page shows the brittleness of concrete is worse than some types of ceramics and in fact is comparable to some forms of glass:
Fracture toughness. "Fracture toughness is a quantitative way of expressing a material's resistance to brittle fracture when a crack is present. If a material has a large value of fracture toughness it will probably undergo ductile fracture. Brittle fracture is very characteristic of materials with a low fracture toughness value." http://en.wikipedia.org/wiki/Fracture_toughness
And carbon fiber of course has become extremely important as a strengthening material in aerospace. It is what has for instance made possible Scaled Composite's commercial suborbital launch system. Well, carbon fiber is more brittle than diamond! This report shows the fracture toughness of carbon fiber is in the range of 1 to 2 (which is worse than that of ceramics):
DIRECT MEASUREMENT ON FRACTURE TOUGHNESS OF CARBON FIBER. http://extra.ivf.se/eccm13_programme/abstracts/812.pdf
However, this web page by the team that developed the new large scale diamond synthesis method states natural diamond has fracture toughness in the range of 8 to 12 depending on type:
Chemical Vapor Deposition (CVD) Lab. http://cdac.gl.ciw.edu/index.php?option=com_content&task=view&id=99&Itemid=40
But what is extremely important here is that not only does the new method increase the hardness of the synthetic diamond over that of natural diamond, but it increases the fracture toughness as well. Indeed in their patent application they say their new method creates diamond of fracture toughness of 30:
(WO/2007/018555) ULTRATOUGH CVD SINGLE CRYSTAL DIAMOND AND THREE DIMENSIONAL GROWTH THEREOF. http://www.wipo.int/pctdb/en/wo.jsp?IA=US2005032199&DISPLAY=DESC
Note that this is better than the fracture toughness of standard aluminum and close to that of aluminum alloys such as those used in the aerospace industry! See the table again on the "Fracture toughness" page.
There is little doubt that diamond will be used in both the construction and aerospace industries, and soon.
Bob Clark
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wrote:

If you look at the description of the method to make this large size synthetic diamond it is well within the capabilities of most university physics labs. Within a year you're going to see universities across the country and around the world making golf ball sized diamonds. Within 5 years you'll see diamond being used in contruction materials. Diamond is *relatively* brittle, but even brittle structures like glass can have important uses for improving strength. For instance glass fibers, fiberglass, have been used in light weight car bodies, boat hulls, tennis rackets, etc. because it is lightweight yet still high in tensile strength. And concrete of course is quite brittle yet is extremely important in construction. The quantity used in materials science to measure brittleness is "fracture toughness". The table on this page shows the brittleness of concrete is worse than some types of ceramics and in fact is comparable to some forms of glass:
Fracture toughness. "Fracture toughness is a quantitative way of expressing a material's resistance to brittle fracture when a crack is present. If a material has a large value of fracture toughness it will probably undergo ductile fracture. Brittle fracture is very characteristic of materials with a low fracture toughness value." http://en.wikipedia.org/wiki/Fracture_toughness
And carbon fiber of course has become extremely important as a strengthening material in aerospace. It is what has for instance made possible Scaled Composite's commercial suborbital launch system. Well, carbon fiber is more brittle than diamond! This report shows the fracture toughness of carbon fiber is in the range of 1 to 2 (which is worse than that of ceramics):
DIRECT MEASUREMENT ON FRACTURE TOUGHNESS OF CARBON FIBER. http://extra.ivf.se/eccm13_programme/abstracts/812.pdf
However, this web page by the team that developed the new large scale diamond synthesis method states natural diamond has fracture toughness in the range of 8 to 12 depending on type:
Chemical Vapor Deposition (CVD) Lab. http://cdac.gl.ciw.edu/index.php?option=com_content&task=view&id &Itemid@
But what is extremely important here is that not only does the new method increase the hardness of the synthetic diamond over that of natural diamond, but it increases the fracture toughness as well. Indeed in their patent application they say their new method creates diamond of fracture toughness of 30:
(WO/2007/018555) ULTRATOUGH CVD SINGLE CRYSTAL DIAMOND AND THREE DIMENSIONAL GROWTH THEREOF. http://www.wipo.int/pctdb/en/wo.jsp?IA=US2005032199&DISPLAY SC
Note that this is better than the fracture toughness of standard aluminum and close to that of aluminum alloys such as those used in the aerospace industry! See the table again on the "Fracture toughness" page.
There is little doubt that diamond will be used in both the construction and aerospace industries, and soon.
Bob Clark
======================================== "Using a dedicated 5kW MPCVD system at Carnegie, we extended our previous work to fabricate perfect single crystals of diamond of unprecedented thickness and at unmatched growth rates of 50-150 ?m/h "
So 1 meter will take 1,000,000/100 = 10,000 hours = 416 days (and 5,000 Megawatts?).
You are a complete dork, Clark, with no absolutely zero experience in engineering, material science and last but not least, economics.
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fact not evident in your quote, above, since the Greek letter Mu does not translate into ASCII. --MJ}***

***{Yes, if we take 100 micrometers/hr as a representative growth rate, then the time required to grow a crystal 1 meter long is 10,000 hours, or about 417 days.

***{No. Megawatts are a measure of the rate of energy production/consumption--to wit: the number of millions of Joules/sec. (A Watt is 1 J/sec.) To obtain the actual amount of energy used, you multiply the average rate of usage times the elapsed time. In the present case the energy consumed will be (5)(10,000) = 50,000 kilowatt-hrs (50 megawatt-hrs). At a cost of roughly $0.11/kWh, that comes to $5,500. (See http://www.eia.doe.gov/cneaf/electricity/epm/table5_6_a.html for a table of U.S. electric rates.) --MJ}***

***{Only idiots are impressed when you initiate ad hominem attacks, Androcles. All you accomplish by such behavior is to undermine your credibility in the minds of reasonable people. The question is why, after all these years, have you still not managed to figure that out? Were you dropped on your head as a child, or what? --MJ}***
***************************************************************** If I seem to be ignoring you, consider the possibility that you are in my killfile. --MJ
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After a web search I found there are microwave generators used in fusion research that can put out continuous beams of microwaves in the 1-2 megawatt range. There are also microwave pulse generators that put out pulses at a peak power of hundreds of megawatts. However, you need the continuous wave (CW) generators for our purpose. Using one of these, you could cut the production time to a day or two for a meter size diamond since the production rate scales approximately linearly with microwave power with CVD diamond production methods:
CVD Diamond - a new Technology for the Future. "One of the great challenges facing researchers in CVD diamond technology is to increase the growth rates to economically viable rates, (hundreds of m/h), or even mm/hr) without compromising film quality. Progress is being made using microwave deposition reactors, since the deposition rate has been found to scale approximately linearly with applied microwave power. Currently, the typical power rating for a microwave reactor is ~5 kW, but the next generation of such reactors have power ratings up to 50-80 kW. This gives a much more realistic deposition rate for the diamond, but for a much greater cost, of course." http://www.ddk.com/PDFs/CVDNewTechnology.pdf
Or you could use a few hundred of the kilowatt scale microwaves. How much does a 1,000 watt microwave go for nowadays? A hundred dollars?
"Hey, Ace I need you to front me 50 large." "50 large?? What for?" "I know this guy see. A real nerdy science type. He claims for 50 grand he can deliver a diamond the size of a basketball ..."
Bob Clark
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wrote:

After a web search I found there are microwave generators used in fusion research that can put out continuous beams of microwaves in the 1-2 megawatt range. There are also microwave pulse generators that put out pulses at a peak power of hundreds of megawatts. However, you need the continuous wave (CW) generators for our purpose. Using one of these, you could cut the production time to a day or two for a meter size diamond since the production rate scales approximately linearly with microwave power with CVD diamond production methods:
CVD Diamond - a new Technology for the Future. "One of the great challenges facing researchers in CVD diamond technology is to increase the growth rates to economically viable rates, (hundreds of m/h), or even mm/hr) without compromising film quality. Progress is being made using microwave deposition reactors, since the deposition rate has been found to scale approximately linearly with applied microwave power. Currently, the typical power rating for a microwave reactor is ~5 kW, but the next generation of such reactors have power ratings up to 50-80 kW. This gives a much more realistic deposition rate for the diamond, but for a much greater cost, of course." http://www.ddk.com/PDFs/CVDNewTechnology.pdf
Or you could use a few hundred of the kilowatt scale microwaves. How much does a 1,000 watt microwave go for nowadays? A hundred dollars?
You are a complete dork, Clark, with no absolutely zero experience in engineering, material science and last but not least, economics. But you are a dreamer. I can buy an 800 watt microwave oven for less that 20 and I have one in my shed that is 7 years old, but dirty. I'll give it to you, just come and collect it. For FREE. Make diamonds with it, I give it to you for nothing. Please take it away and be rich!
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Sharing such knowledge is obviously not permitted on Usenet.
Perhaps keeping public funded research in the dark is best for everyone.
~ BG
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Perhaps braille astronomy of inert eye-candy will suddenly advance to visual observationology via optical or even better pixel data via radar imaging.
Who knows, possibly well discover that terrestrial laws of physics could even function while on our physically dark Selene/moon, or god forbid, Venus.
How about our using the Earth-moon L1 Clarke Station, Boeing OASIS or my LSE-CM/ISS?
~ BG
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