Quantum Computing

8 views
Skip to first unread message

John Clark

unread,
Jun 23, 2022, 12:23:12 PMJun 23
to 'Brent Meeker' via Everything List
In yesterday's issue of the journal Nature there is a report that in my opinion is one of the most significant advances in the field of quantum computing. Scientists not only used a scanning tunneling microscope to make a functional quantum processor that is composed of 10 quantum dots placed with sub-nanometer precision by a scanning tunneling microscope, they tested it by modeling how electrons move along a polyacetylene molecule, a task conventional supercomputers would have great difficulty with even for a molecule as simple as polyacetylene. A penicillin molecule only has 41 atoms but a classical computer would need to have 10^86 transistors to make a quantum mechanical model of it. There are only 10^80 atoms in the observable universe. A quantum computer would only need 286 logical qubits to do the same thing; yes those 286 would need to be high-quality qubits but thanks to quantum error correction they don't have to be perfect.


John K Clark    See what's on my new list at  Extropolis

spudb...@aol.com

unread,
Jun 24, 2022, 8:12:16 PMJun 24
to johnk...@gmail.com, everyth...@googlegroups.com
John, isn't it a wiser thing to consider impact over capability? Maybe this is my hang up, but if your QC's solves medical problems or energy problems, rather than the Gee Whiz of mere computational prowess. Yeah, prowess should lead to the things I cited. But then in the 1950's the immensity of nuclear fission over carbon burning should have led to an Atomic Age, but it didn't.  


--
You received this message because you are subscribed to the Google Groups "Everything List" group.
To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/CAJPayv2s%3DOPN_xagX_Jkh7iWpb6azEWfJTxfvduo7sbKqacqRA%40mail.gmail.com.

John Clark

unread,
Jun 25, 2022, 7:20:50 AMJun 25
to spudb...@aol.com, everyth...@googlegroups.com
On Fri, Jun 24, 2022 at 8:12 PM <spudb...@aol.com> wrote:

> John, isn't it a wiser thing to consider impact over capability?

One thing at a time. Before you can have any impact you've got to have a capacity. And if large-scale quantum computers are practical, and it's getting to look like they are, then somebody somewhere is certain to make one. The best historical analogy is with nuclear energy, we've known since 1905 that matter contained a huge amount of energy but there didn't seem to be any practical way to get at it; that suddenly changed in 1938 when Uranium fission was discovered, after that the technological path one needed to travel to release a large amount of that energy very quickly was obvious. It was also very expensive, but it was only a matter of time before somebody somewhere did so. And just 7 years later somebody did. The moral is that if something very powerful can be made then like it or not it will be made.


> then in the 1950's the immensity of nuclear fission over carbon burning should have led to an Atomic Age, but it didn't.  

Nuclear didn't beat out fossil fuels its true but you could still say we live in an Atomic Age because it still had an enormous impact on society.  Considering the rate that wars were happening in the first half of the 20th century, if nuclear weapons were impossible or impractical to make I imagine we'd be in the middle of World War 5 or 6 about now; they wouldn't be nuclear wars but 20 million people died in the first world war and 50 million died in the second.
John K Clark    See what's on my new list at  Extropolis
nwb


 

spudb...@aol.com

unread,
Jun 28, 2022, 8:40:14 PMJun 28
to johnk...@gmail.com, everyth...@googlegroups.com
All true JC, yet a world powered by atomic energy seems to await commercial fusion which out of my world view is a thing, despite recent progress, is a decades off. Nukes may have reduced the great war cycles, but Putin has restarted it again. Even with nukes. All it takes is a different set of values and culture and there we go. Comrade Xi seems of a similar mind set. For energy and prosperity it becomes a matter of getting along until that golden day arrives.

The societal impact of QC is sketchy to me, as it needs to be conformed to human impacts if it is to be better than conventional? It may hit this secretly with code cracking which for all I know may already be here? In that case all foreign policy would need to become visceral, in the sense that one knows everyone's intent, and thus adjusts accordingly. 

Not my idea of the 21st century, but then who asked my opinion?

American Serf, Spud100 (olde sod!)


-----Original Message-----
From: John Clark <johnk...@gmail.com>

John Clark

unread,
Jun 29, 2022, 10:17:20 AMJun 29
to spudb...@aol.com, everyth...@googlegroups.com
On Tue, Jun 28, 2022 at 8:40 PM <spudb...@aol.com> wrote:

> All true JC, yet a world powered by atomic energy seems to await commercial fusion which out of my world view is a thing, despite recent progress, is a decades off.

A Liquid Fluoride Thorium Reactor (LFTR) would greatly reduce or eliminate entirely the problems associated with conventional fission reactors; they need some additional research and development before they become practical but vastly less than what would be required for a fusion reactor.
 
> Nukes may have reduced the great war cycles, but Putin has restarted it again. Even with nukes. All it takes is a different set of values and culture and there we go. Comrade Xi seems of a similar mind set.

Stalin and Mao Zedong had nuclear weapons and both were monsters, but neither of them ever used one in anger, the fact is the only human being who ever did was Harry Truman, and that was nearly 80 years ago. So I think the human race has a pretty good chance of surviving Putin and Xi.

> The societal impact of QC is sketchy to me, as it needs to be conformed to human impacts if it is to be better than conventional?

Quantum Computers are well known for their code breaking abilities but that's not all they can do, in the June 9 2022 issue of the journal Science researchers report they have found a quantum learning algorithm that achieves an exponential speed increase over the that of any known conventional algorithm both in predicting how a quantum system, for example an atom or a molecule, changes over time, and also in its ability to extract useful information from noisy input data. It perhaps should be noted that a brain frozen to liquid nitrogen temperatures is bound to contain a lot of noisy data regardless of how carefully it was frozen. This is the abstract of the article:

"Quantum technology promises to revolutionize how we learn about the physical world. An experiment that processes quantum data with a quantum computer could have substantial advantages over conventional experiments in which quantum states are measured and outcomes are processed with a classical computer. We proved that quantum machines could learn from exponentially fewer experiments than the number required by conventional experiments. This exponential advantage is shown for predicting properties of physical systems, performing quantum principal component analysis, and learning about physical dynamics. Furthermore, the quantum resources needed for achieving an exponential advantage are quite modest in some cases. Conducting experiments with 40 superconducting qubits and 1300 quantum gates, we demonstrated that a substantial quantum advantage is possible with today’s quantum processors."



John K Clark    See what's on my new list at  Extropolis
mbc

Brent Meeker

unread,
Jun 29, 2022, 3:30:55 PMJun 29
to everyth...@googlegroups.com


On 6/29/2022 7:16 AM, John Clark wrote:
On Tue, Jun 28, 2022 at 8:40 PM <spudb...@aol.com> wrote:

> All true JC, yet a world powered by atomic energy seems to await commercial fusion which out of my world view is a thing, despite recent progress, is a decades off.

A Liquid Fluoride Thorium Reactor (LFTR) would greatly reduce or eliminate entirely the problems associated with conventional fission reactors; they need some additional research and development before they become practical but vastly less than what would be required for a fusion reactor.

I understand Indian is building a prototype LFTR.  A molten salt reactor is "walk away safe".  Thorium also has the advantage that there is enough already enough for millennia of power as a by product of mining rare earths for magnets.


 
> Nukes may have reduced the great war cycles, but Putin has restarted it again. Even with nukes. All it takes is a different set of values and culture and there we go. Comrade Xi seems of a similar mind set.

Stalin and Mao Zedong had nuclear weapons and both were monsters, but neither of them ever used one in anger, the fact is the only human being who ever did was Harry Truman, and that was nearly 80 years ago. So I think the human race has a pretty good chance of surviving Putin and Xi.

> The societal impact of QC is sketchy to me, as it needs to be conformed to human impacts if it is to be better than conventional?

Quantum Computers are well known for their code breaking abilities but that's not all they can do, in the June 9 2022 issue of the journal Science researchers report they have found a quantum learning algorithm that achieves an exponential speed increase over the that of any known conventional algorithm both in predicting how a quantum system, for example an atom or a molecule, changes over time, and also in its ability to extract useful information from noisy input data. It perhaps should be noted that a brain frozen to liquid nitrogen temperatures is bound to contain a lot of noisy data regardless of how carefully it was frozen. This is the abstract of the article:

"Quantum technology promises to revolutionize how we learn about the physical world. An experiment that processes quantum data with a quantum computer could have substantial advantages over conventional experiments in which quantum states are measured and outcomes are processed with a classical computer. We proved that quantum machines could learn from exponentially fewer experiments than the number required by conventional experiments. This exponential advantage is shown for predicting properties of physical systems, performing quantum principal component analysis, and learning about physical dynamics. Furthermore, the quantum resources needed for achieving an exponential advantage are quite modest in some cases. Conducting experiments with 40 superconducting qubits and 1300 quantum gates, we demonstrated that a substantial quantum advantage is possible with today’s quantum processors."



You didn't even mention what most scientist see as the big application for QC, modeling and predicting the interaction of big biological molecules, e.g. protein folding.  One of the big motivators for QC way Feynman's talk, "There's Always Room at the Bottom".

Brent

spudb...@aol.com

unread,
Jun 29, 2022, 7:07:58 PMJun 29
to johnk...@gmail.com, everyth...@googlegroups.com
Much thanks, JC.


-----Original Message-----
From: John Clark <johnk...@gmail.com>
To: spudb...@aol.com
Cc: everyth...@googlegroups.com <everyth...@googlegroups.com>
Sent: Wed, Jun 29, 2022 10:16 am
Subject: Re: Quantum Computing

spudb...@aol.com

unread,
Jun 29, 2022, 8:50:48 PMJun 29
to meeke...@gmail.com, everyth...@googlegroups.com
Walk away safe. Are you two  convinced that we have done enough research via chemical engineering? This'd be for corrosion of pipes, and as all us science nerds know sodium itself can ignite in air and explode when exposed to water, which is one reason I like it. But the sodium fluoride is nonflammable. I am still betting on solar and wind as cheaper and faster. I am thinking that getting this boy (LFTR) to market will take the Chinese and Gates 20 years longer to get it all to work correctly. Hence, even though I am a foul Trumpkin, I support the quick and the modular, with batteries and, or, micro-hydroelectric. It is something that dudes with a pickup truck can install and maintain, distributed nationwide & worldwide. 

Environmentally Safe!
Spud100

--
You received this message because you are subscribed to the Google Groups "Everything List" group.
To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com.

Brent Meeker

unread,
Jun 29, 2022, 9:34:48 PMJun 29
to spudb...@aol.com, everyth...@googlegroups.com
A LFTR has already been run for years.  A prototype was built at Oak Ridge in the '50s as a research reactor prototype for the Air Force proposal to have nuclear powered version of the B-36 that would stay airborne almost continuously so as to be immune to a Soviet first strike.  But the project was dropped without ever being turned into a power source.  Part of the problem was that only enough shielding could be carried to protect the crew, but the radiation also damages structure.

Brent

spudb...@aol.com

unread,
Jun 29, 2022, 10:09:50 PMJun 29
to meeke...@gmail.com, everyth...@googlegroups.com
So would we use uranium 235 or do Thorium 232-->U233 as a fuel cycle and would it be safe enough so the public wouldn't object (protest, riots, etc)? I'd am more interested (if doable) with Lead-Bismuth moderated reactors, or Helium using TRISO fuel-

I am hoping your LFTR does the job for pragmatic reasons alone,  but wonder if the sticker shock of development cost may push MSR's to the 22nd century? 

Brent Meeker

unread,
Jun 30, 2022, 12:42:50 AMJun 30
to spudb...@aol.com, everyth...@googlegroups.com


On 6/29/2022 7:09 PM, spudb...@aol.com wrote:
So would we use uranium 235 or do Thorium 232-->U233 as a fuel cycle

Notice that it not only gets energy from "burning" thorium which is four times as abundant as U238, it also breeds U238 to plutonium.  It does this with thermal neutrons rather than fast neutrons required in a uranium-plutonium cycle.


and would it be safe enough so the public wouldn't object (protest, riots, etc)?

The public has no grasp of safety

And that's just fatalities due to accidents.  Thousands more deaths are estimated to come from fossil fuel air pollution.


I'd am more interested (if doable) with Lead-Bismuth moderated reactors, or Helium using TRISO fuel-

Well, then figure out if it's doable and what it costs.

Brent

John Clark

unread,
Jun 30, 2022, 8:21:51 AMJun 30
to 'Brent Meeker' via Everything List, meeke...@gmail.com
On Wed, Jun 29, 2022 at 10:09 PM spudboy100 via Everything List <everyth...@googlegroups.com> wrote:


> do Thorium 232-->U233 as a fuel cycle and would it be safe enough

Yes. All Uranium breeders produce massive amounts of Plutonium which is a bad thing if you're worried about people making bombs. Thorium reactors produce an insignificant amount of Plutonium, they do produce Uranium-233 and theoretically you could make a bomb out of that, but it would be contaminated with Uranium-232 which would take a billion dollar isotope separation plant to decontaminate. Uranium-232 is a powerful gamma ray emitter which would make it suicidal to work with unless extraordinary precautions were taken, and even then the unexploded bomb would be so radioactive it would give away its location if you tried to hide it, and the gamma rays would destroy its electronic firing circuits, and degrade its chemical explosives. But as long as the U-232 and U-233 remain inside the LFTR they are safe because it will quickly burn them up, in fact that's what powers the reactor. 

As far as I know a U-233 bomb was attempted only twice, in 1955 the USA set off a Plutonium/U233 composite bomb, it was expected to produce 33 kilotons but only managed 22; the only pure U-233 bomb I know of was set off in 1998 by India, but it was a fizzle, a complete flop, it produced a minuscule explosion of only equivalent to 200 tons of TNT due to pre-detonation. For these reasons even after nearly 80 years no nation currently has U233 bombs in their arsenal because if you want to kill people on a mass scale Uranium-235 and Plutonium-239 are far more practical than Uranium-233.

A Thorium reactor only produces about 1% as much radioactive waste as a conventional reactor, and the stuff it does make is not as nasty, after about 5 years 87% of it would be safe and the remaining 13% in 300 years; a conventional reactor would take 100,000 years.  The fundamental reason for this is because the starting material of a LFTR is Thorium 232, lower down on the periodic table than Uranium 238 so much less nasty transuranium stuff is produced.  A LFTR  reactor has an inherent safety feature, the fuel is in liquid form (Thorium dissolved in un-corrosive molten Fluoride salts) so if for whatever reason things get too hot the liquid expands and so the fuel gets less dense and the reaction slows down. There is yet another fail safe device. At the bottom of the reactor is something called a "freeze plug", fans blow on it to freeze it solid, if things get too hot the plug melts and the liquid drains out (by gravity, mechanical pumps are not needed) into a neutron absorbing holding tank and the reaction stops; also, if all electronic controls die due to a loss of electrical power the fans will stop the plug will melt and the reaction will stop, so it's walk away safe.

Although the liquid Fluoride salt is very hot it is not under pressure so that makes the plumbing of the thing much easier, and even if you did get a leak it would not be the utter disaster it would be in a conventional reactor; that's also why the containment building in common light water reactors need to be so much larger than the reactor itself and why the walls of it needs to be so thick. With Thorium nothing is under pressure and there is no danger of a disastrous phase change, like ultra hot pressurized water turning into steam, so the super expensive containment building can be made much more compact. And because LFTR reactors work at much higher temperatures than conventional reactors you have much higher thermodynamic efficiency; in fact they are so hot the waste heat could be used to desalinate sea water or generate hydrogen fuel from water.
 
> so the public wouldn't object (protest, riots, etc)?

Of course environmentalists will protest! Environmentalists are not serious people so they will protest ANY large scale energy project. Natural gas kills fewer people than oil because of pollution and oil kills fewer people than coal, but that distinction makes no difference to environmentalists, they are equal opportunity protesters. Environmentalists never saw an energy source that was actually built that they didn't hate, although they might like some provided they stay strictly on the drawing board. Solar cells in the desert harm super rare desert species, wind power turbines are ugly and disrupt natural wind patterns and kill little birdies, geothermal causes earthquakes, and nuclear power is the power that must not be named, this despite the fact nuclear has by far the best safety record of any energy source. Environmentalists will not be satisfied unless something is 100% safe, 99.99999% simply will not do, and it must have precisely zero impact on the environment. And that's just not realistic.

Never before in the history of life on this planet has 8 billion large animals of the same species existed, in order to keep that many individuals alive (much less happy) some disruption in the environment is inevitable, but some do not recognize this fact. When you get down to practicalities the only advice environmentalists can give us is to freeze to death in the dark. And that's why I say environmentalists are not serious people.
 
> I'd am more interested (if doable) with Lead-Bismuth moderated reactors,

That's a type of fast breeder reactor that turns common non-fissile Uranium 238 into fissile Plutonium 239 that can be easily used to make bombs. Maybe it has some potential but the only ones who ever used this type of reactor was the Soviet Union in their submarines, and the results were not pretty.  All crew members of submarines that used this type of reactor received life-shortening amounts of radiation, and the submarine K-64 was so accident prone that even before its reactor completely melted down and killed 22 members of its crew the ship was given the nickname "The Widowmaker". They even made a Hollywood movie about it. 

John K Clark    See what's on my new list at  Extropolis
qq9




Brent Meeker

unread,
Jun 30, 2022, 5:48:06 PMJun 30
to John Clark, 'Brent Meeker' via Everything List


On 6/30/2022 5:21 AM, John Clark wrote:

A Thorium reactor only produces about 1% as much radioactive waste as a conventional reactor, and the stuff it does make is not as nasty, after about 5 years 87% of it would be safe and the remaining 13% in 300 years; a conventional reactor would take 100,000 years.  The fundamental reason for this is because the starting material of a LFTR is Thorium 232, lower down on the periodic table than Uranium 238 so much less nasty transuranium stuff is produced. 


A perhaps more fundamental reason is that uranium reactor rods have to be removed when the U235 component drops to about 60% of it's initial value, from 3.5% to 2.2%.  
In the original conception of nuclear power these removed fuel rods were to be re-refined to produce new fuel rods and this recursive process would "burn" almost all the uranium.  Put the "fundamentals" of economics intervened.  It turned out to be a lot more expensive to re-refine those rods than to simply enrich more natural uranium.  That's why there's a waste problem with light-water reactors.  It's also a problem with LFTRs.

That box labelled "Uranium separator" also contains a lot of other fission products that need to be removed and not returned to the Th232.  They can be separated chemically and most have short half-lives so long-term storage isn't a problem.  But at industrial scale it's not something that has been engineered yet.

Brent

spudb...@aol.com

unread,
Jun 30, 2022, 8:12:49 PMJun 30
to meeke...@gmail.com, everyth...@googlegroups.com
The closest thing we have to safety are not smr's but baby reactors that are air cooled and mounted on flatbed trucks.

These would all be factory built and the world would need 1000's. Yet in a flood or even a hijacking, these heat pipe reactors would pose little threat. I believe these use not fuel pellets but Triso silicon carbide microspheres as fuel. 

Sent: Thu, Jun 30, 2022 12:42 am
Subject: Re: Quantum Computing

spudb...@aol.com

unread,
Jun 30, 2022, 8:21:12 PMJun 30
to johnk...@gmail.com, everyth...@googlegroups.com, meeke...@gmail.com
That's the thing JC, its not always rationality, or compelled rationality that rules us. Energy policy is performed outside of logic, or even greed, but ideology. Will an era of energy shortages compel the Greens to yield to reason (assuming its as safe as postulated and affordable?) and the leadership going along? I am thinking not. Also, if we were smarter would we have not already poured money into R&D for MSR reactors decades ago. No, I am not referring to the Canadian produced CANDU reactors that ran using Th232-U233 and used heavy water as a moderator. 


-----Original Message-----
From: John Clark <johnk...@gmail.com>
To: 'Brent Meeker' via Everything List <everyth...@googlegroups.com>
Cc: meeke...@gmail.com <meeke...@gmail.com>
Sent: Thu, Jun 30, 2022 8:21 am
Subject: Re: Quantum Computing

--
You received this message because you are subscribed to the Google Groups "Everything List" group.
To unsubscribe from this group and stop receiving emails from it, send an email to everything-li...@googlegroups.com.
To view this discussion on the web visit

John Clark

unread,
Jul 1, 2022, 7:27:52 AMJul 1
to spudb...@aol.com, everyth...@googlegroups.com, meeke...@gmail.com
On Thu, Jun 30, 2022 at 8:21 PM <spudb...@aol.com> wrote:

> That's the thing JC, its not always rationality, or compelled rationality that rules us. Energy policy is performed outside of logic, or even greed, but ideology.

Sadly that is true.
 
> Will an era of energy shortages compel the Greens to yield to reason

That's unlikely because, as you say, ideology is extremely resistant to reason. No Ideologie has been formed through the use of logic so logic can't be used to change an ideologue's mind , to do that you'd need some sort of dramatic road to Damascus incident that had nothing to do with reason.

> if we were smarter would we have not already poured money into R&D for MSR reactors decades ago

 
Yes, the Molten-Salt Reactor at Oak Ridge was remarkably advanced considering it was built in the early 1960s, and it was very successful achieving all its design goals and more. It's only disadvantage, or at least it seemed like a disadvantage of the time, was that it produced virtually no Plutonium that could be used in bombs, and that was considered to be a wonderful side benefit of the light water Uranium reactors we use in most reactors today.  CANDU reactors are the exception to that, but the Oak Ridge reactor used liquid fuel which is inherently safer than solid fuel, CANDU still uses solid fuel.

John K Clark    See what's on my new list at  Extropolis
boa

spudb...@aol.com

unread,
Jul 1, 2022, 7:17:55 PMJul 1
to johnk...@gmail.com, everyth...@googlegroups.com, meeke...@gmail.com
This is why I shifted to solar and wind till somebody comes out with a success with MSR's or Fusion, maybe deep rock geothermal? My view is small, modular, and everywhere. Confirmed by this study last year. 

The low hanging fruit might get the species through C21.

-----Original Message-----
From: John Clark <johnk...@gmail.com>
To: spudb...@aol.com
Cc: everyth...@googlegroups.com <everyth...@googlegroups.com>; meeke...@gmail.com <meeke...@gmail.com>
Sent: Fri, Jul 1, 2022 7:27 am
Subject: Re: Quantum Computing

Reply all
Reply to author
Forward
0 new messages