Fusion Update: Signs of Life from the National Ignition Facility

The National Ignition Facility, or NIF, is a huge, 192 beam laser system, located at Lawrence Livermore National Laboratory in California.  It was designed, as the name implies, to achieve thermonuclear ignition in the laboratory.  “Ignition” is generally accepted to mean getting a greater energy output from fusion than the laser input energy.  Unlike magnetic confinement fusion, the approach currently being pursued at the International Thermonuclear Experimental Reactor, or ITER, now under construction in France, the goal of the NIF is to achieve ignition via inertial confinement fusion, or ICF, in which the fuel material is compressed and heated to the extreme conditions at which fusion occurs so quickly that it is held in place by its own inertia.

The NIF has been operational for over a year now, and a two year campaign is underway with the goal of achieving ignition by the end of this fiscal year.  Recently, there has been a somewhat ominous silence from the facility, manifesting itself as a lack of publications in the major journals favored by fusion scientists.  That doesn’t usually happen when there is anything interesting to report.  Finally, however, some papers have turned up in the journal Physics of Plasmas, containing reports of significant progress.

To grasp the importance of the papers, it is necessary to understand what is supposed to occur within the NIF  target chamber for fusion to occur.  Of course, just as in magnetic fusion, the goal is to bring a mixture of deuterium and tritium, two heavy isotopes of hydrogen, to the extreme conditions at which fusion takes place.  In the ICF approach, this hydrogen “fuel” is contained in a tiny, BB-sized target.  However, the lasers are not aimed directly at the fuel “capsule.”  Instead, the capsule is suspended in the middle of a tiny cylinder made of a heavy metal like gold or uranium.  The lasers are fired through holes on each end of the cylinder, striking the interior walls, where their energy is converted to x-rays.  It is these x-rays that must actually bring the target to fusion conditions.

It was recognized many years ago that one couldn’t achieve fusion ignition by simply heating up the target.  That would require a laser driver orders of magnitude bigger than the NIF.  Instead, it is first necessary to compress, or implode, the fuel material to extremely high density.  Obviously, it is harder to “squeeze” hot material than cold material to the necessary high densities, so the fuel must be kept as “cold” as possible during the implosion process.  However, cold fuel won’t ignite, begging the question of how to heat it up once the necessary high densities have been achieved.

It turns out that the answer is shocks.  When the laser generated x-rays hit the target surface, they do so with such force that it begins to implode faster than the speed of sound.  Everyone knows that when a plane breaks the sound barrier, it, too, generates a shock, which can be heard as a sonic boom.  The same thing happens in ICF fusion targets.  When such a shock converges at the center of the target, the result is a small “hot spot” in the center of the fuel.  If the temperature in the hot spot were high enough, fusion would occur.  Each fusion reaction would release a high energy helium nucleus, or alpha particle, and a neutron.  The alpha particles would be slammed to a stop in the surrounding cold fuel material, heating it, in turn, to fusion conditions.  This would result in a fusion “burn wave” that would propagate out through the rest of the fuel, completing the fusion process.

The problem is that one shock isn’t enough to create such a “hot spot.”  Four of them are required, all precisely timed by the carefully tailored NIF laser pulse to converge at the center of the target at exactly the same time.  This is where real finesse is needed in laser fusion.  The implosion must be extremely symmetric, or the shocks will not converge properly.  The timing must be exact, and the laser pulse must deliver just the right amount of energy.

One problem in the work to date has been an inability to achieve high enough implosion velocities for the above scenario to work as planned.  One of the Physics of Plasmas papers reports that, by increasing the laser energy and replacing some of the gold originally used in the wall of the cylinder, or “hohlraum,” in which the fuel capsule is mounted with depleted uranium, velocities of 99% of those required for ignition have been achieved.  In view of the recent announcement that a shot on the NIF had exceeded its design energy of 1.8 megajoules, it appears the required velocity is within reach.  Another of the Physics of Plasmas papers dealt with the degree to which implosion asymmetries were causing harmful mixing of the surrounding cold fuel material into the imploded core of the target.  It, too, provided grounds for optimism.

In the end, I suspect the success or failure of the NIF will depend on whether the complex sequence of four shocks can really be made to work as advertised.  That will depend on the accuracy of the physics algorithms in the computer codes that have been used to model the experiments.  Time and again, earlier and less sophisticated codes have been wrong because they didn’t accurately account for all the relevant physics.  There is no guarantee that critical phenomena have not been left out of the current versions as well.  We may soon find out, if the critical series of experiments planned to achieve ignition before the end of the fiscal year are carried out as planned.

One can but hope they will succeed, if only because some of our finest scientists have dedicated their careers to the quest to achieve the elusive goal of controlled fusion.  Even if they do, fusion based on the NIF approach is unlikely to become a viable source of energy, at least in the foreseeable future.  Laser fusion may prove scientifically feasible, but getting useful energy out of it will be an engineering nightmare, dangerous because of the need to rely on highly volatile and radioactive tritium, and much too expensive to compete with potential alternatives.  I know many of the faithful in the scientific community will beg to differ with me, but, trust me, laser fusion energy aint’ gonna happen.

On the other hand, if ignition is achieved, the NIF will be invaluable to the country, not as a source of energy, but for the reason it was funded in the first place – to insure that our nation has an unmatched suite of experimental facilities to study the physics of nuclear weapons in a era free of nuclear testing.  As long as we have unique access to facilities like the NIF, which can approach the extreme physical conditions within exploding nukes, we will have a significant leg up on the competition as long as the test ban remains in place.  For that, if for no other reason, we should keep our fingers crossed that the NIF team can finally clear the last technical hurdles and reach the goal they have been working towards for so long.

Fusion ignition process,courtesy of Lawrence Livermore National Laboratory

Space Colonization and Stephen Hawking

Stephen Hawking is in the news again as an advocate for space colonization.  He raised the issue in a recent interview with the Canadian Press, and will apparently include it as a theme of his new TV series, Brave New World with Stephen Hawking, which debuts on Discovery World HD on Saturday.  There are a number of interesting aspects to the story this time around.  One that most people won’t even notice is Hawking’s reference to human nature.  Here’s what he had to say.

Our population and our use of the finite resources of planet Earth are growing exponentially, along with our technical ability to change the environment for good or ill. But our genetic code still carries the selfish and aggressive instincts that were of survival advantage in the past. It will be difficult enough to avoid disaster in the next hundred years, let alone the next thousand or million.

The fact that Hawking can matter-of-factly assert something like that about innate behavior in humans as if it were a matter of common knowledge speaks volumes about the amazing transformation in public consciousness that’s taken place in just the last 10 or 15 years.  If he’d said something like that about “selfish and aggressive instincts” 50 years ago, the entire community of experts in the behavioral sciences would have dismissed him as an ignoramus at best, and a fascist and right wing nut case at worst.  It’s astounding, really.  I’ve watched this whole story unfold in my lifetime.  It’s just as stunning as the paradigm shift from an earth-centric to a heliocentric solar system, only this time around, Copernicus and Galileo are unpersons, swept under the rug by an academic and professional community too ashamed of their own past collective imbecility to mention their names.  Look in any textbook on Sociology, Anthropology, or Evolutionary Psychology, and you’ll see what the sounds of silence look like in black and white.  Aside from a few obscure references, the whole thing is treated as if it never happened.  Be grateful, dear reader.  At last we can say the obvious without being shouted down by the “experts.”  There is such a thing as human nature.

Now look at the comments after the story in the Winnipeg Free Press I linked above.  Here are some of them.

“Our only chance of long-term survival is not to remain lurking on planet Earth, but to spread out into space.”  If that is the case, perhaps we don’t deserve to survive. If we bring destruction to our planet, would it not be in the greater interest to destroy the virus, or simply let it expire, instead of spreading its virulence throughout the galaxy?

And who would decide who gets to go? Also, “Our only chance of long-term survival is not to remain lurking on planet Earth, but to spread out into space.” What a stupid thing to say: if we can’t survive ‘lurking’ on planet Earth then who’s to say humans wouldn’t ruin things off of planet Earth?

I will not go through any of this as I will be dead by then and gone to a better place as all those who remain and go through whatever happenings in the Future,will also do!

I’ve written a lot about morality on this blog.  These comments speak to the reasons why getting it right about morality, why understanding its real nature, and why it exists, are important.  All of them are morally loaded.  As is the case with virtually all morally loaded comments, their authors couldn’t give you a coherent explanation of why they have those opinions.  They just feel that way.  I don’t doubt that they’re entirely sincere about what they say.  The genetic programming that manifests itself as human moral behavior evolved many millennia ago in creatures who couldn’t conceive of themselves as members of a worldwide species, or imagine travel into space.  What these comments demonstrate is something that’s really been obvious for a long time.  In the environment that now exists, vastly different as it is from the one in which our moral predispositions evolved, they can manifest themselves in ways that are, by any reasonable definition of the word, pathological.  In other words, they can manifest themselves in ways that no longer promote our survival, but rather the opposite.

As can be seen from the first comment, for example, thanks to our expanded consciousness of the world we live in, we can conceive of such an entity as “all mankind.”  Our moral programming predisposes us to categorize our fellow creatures into ingroups and outgroups.  In this case, “all mankind” has become an outgroup or, as the commenter puts it, a “virus.”  The demise, not only of the individual commenter, but of all mankind, has become a positive Good.  More or less the same thing can be said about the second comment.  This commenter apparently believes that it would be better for humans to become extinct than to “mess things up.”  For whom?

As for the third commenter, survival in this world is unimportant to him because he believes in eternal survival in a future imaginary world under the proprietership of an imaginary supernatural being.  It is unlikely that this attitude is more conducive to our real genetic survival than those of the first two commenters.  I submit that if these commenters had an accurate knowledge of the real nature of human morality in the first place, and were free of delusions about supernatural beings in the second, the tone of their comments would be rather different.

And what of my opinion on the matter?  In my opinion, morality is the manifestation of genetically programmed traits that evolved because they happened to promote our survival.  No doubt because I understand morality in this way, I have a subjective emotional tendency to perceive the Good as my own genetic survival, the survival of my species, and the survival of life as it has evolved on earth, not necessarily in that order.  Objectively, my version of the Good is no more legitimate or objectively valid that those of the three commenters.  In some sense, you might say it’s just a whim.  I do, however, think that my subjective feelings on the matter are reasonable.  I want to pursue as a “purpose” that which the evolution of morality happened to promote; survival.  It seems to me that an evolved, conscious biological entity that doesn’t want to survive is dysfunctional – it is sick.  I would find the realization that I am sick and dysfunctional distasteful.  Therefore, I choose to survive.  In fact, I am quite passionate about it.  I believe that, if others finally grasp the truth about what morality really is, they are likely to share my point of view.  If we agree, then we can help each other.  That is why I write about it.

By all means, then, let us colonize space, and not just our solar system, but the stars.  We can start now.  We lack sources of energy capable of carrying humans to even the nearest stars, but we can send life, even if only single-celled life.  Let us begin.

Belgium Joins the Nuclear de-Renaissance

The move away from nuclear power in Europe is becoming a stampede.  According to Reuters, the Belgians are now on the bandwagon, with plans for shutting down the country’s last reactors in 2025.  The news comes as no surprise, as the anti-nukers in Belgium have had the upper hand for some time.  However, the agreement reached by the country’s political parties has been made ”conditional” on whether the energy deficit can be made up by renewable sources.  Since Belgium currently gets about 55 percent of its power from nuclear, the chances of that appear slim.  It’ s more likely that baseload power deficits will be made up with coal and gas plants that emit tons of carbon and, in the case of coal, represent a greater radioactive hazard than nuclear because of the uranium and thorium they spew into the atmosphere.  No matter.  Since Fukushima global warming hysteria is passé and anti-nuclear hysteria is back in fashion again for the professional saviors of the world.

It will be interesting to see how all this turns out in the long run.  In the short term it will certainly be a boon to China and India.  They will continue to expand their nuclear capacity and their lead in advanced nuclear technology, with a windfall of cheaper fuel thanks to Western anti-nuclear activism.  By the time the Europeans come back to the real world and finally realize that renewables aren’t going to cover all their energy needs, they will likely be forced to fall back on increasingly expensive and heavily polluting fossil fuels.  Germany is already building significant new coal-fired capacity.

Of course, we may be dealt a wild card if one of the longshot schemes for taming fusion on the cheap actually works.  The odds look long at the moment, though.  We’re hearing nothing but a stoney silence from the National Ignition Facility, which bodes ill for what seems to be the world’s last best hope to perfect inertial confinement fusion.  Things don’t look much better at ITER, the flagship facility for magnetic fusion, the other mainstream approach.  There are no plans to even fuel the facility before 2028.

Of Ingroups, Outgroups, and Global Climate Change

As I pointed out in my last post, “The outgroup have ye always with you.” Of all the very good reasons for mankind to give up the cobbling together of new moral systems once and for all, it’s probably the best. It’s more likely you’ll find a unicorn browsing in your back yard than one of the pathologically pious among us suffused with the milk of human kindness. One typically finds them in their “ground state,” frothing at the the mouth with virtuous indignation over the latest sins of their preferred outgroup.

So it is with Eugene Robinson, one of their number who happens to pen an occasional column in the Washington Post. He recently delivered himself of some observations concerning the phenomenon of global warming. As anyone who hasn’t been asleep for the last decade will be aware, no branch of the sciences has been more afflicted of late by the attentions of the professionally righteous than climatology. Robinson gives us a good example of how the neat separation of climate scientists into good guys and bad guys works in practice.

Hero of his piece is one Richard Muller, a physicist at the University of California at Berkeley who, we learn, once dismissed “climate alarmism” as “shoddy science.” Not to worry. Though once lost, he is now found, and though once blind, he now sees. It turns out the scales fell from his eyes after he “launched his own comprehensive study (referred to as the Berkeley Earth Surface Temperature, or BEST, study, ed.) to set the record straight,” and discovered that, lo and behold, “Global warming is real.” Well, perhaps it is and perhaps it isn’t. I happen to believe that the arguments as to why it should be real are plausible enough, but that’s beside the point as far as this post is concerned.

What is to the point is Robinson’s reaction to all this. For him, Muller’s study isn’t just another batch of data points relating to a very complex scientific issue. For him, global warming is an absolute and incontrovertable certainty, because it represents the “good.” Muller’s study is, therefore, not just a scientific study, but a victory in the eternal battle of good versus evil. In Robinson’s own words,

For the clueless or cynical diehards who deny global warming, it’s getting awfully cold out there.

Rick Perry, Herman Cain, Michele Bachmann and the rest of the neo-Luddites who are turning the GOP into the anti-science party should pay attention.

But Muller’s plain-spoken admonition that “you should not be a skeptic, at least not any longer,” has reduced many deniers to incoherent grumbling or stunned silence.

and so on. As it happens, not all of the “skeptics” have been reduced to incoherent grumbling or stunned silence. Take, for example, Judith Curry, a distinguished climate researcher and Chair of the Department of Earth and Atmospheric Sciences at Georgia Tech. She was actually a member of Muller’s team, and so is presumably familiar with the copious data Robinson was so enthused about. However, in an interview for the Daily Mail, Curry accuses Muller of “trying to mislead the public by hiding the fact that BEST’s research shows global warming has stopped.” She also says that, “Prof. Muller’s claim that he has proven global warming sceptics wrong was also a ‘huge mistake’, with no scientific basis,” and goes so far as to compare the affair to “Climategate.” This is strong stuff, but Prof. Curry has the goods. She notes that, in carefully sifting through, as Robinson informs us, “1.6 billion records,” Muller somehow failed to mention that, according to BEST’s own data, “there has been no significant increase in world temperatures since the end of the 90′s.” The following two graphs from the website of the Global Warming Policy Foundation summarize that data:

Source: Global Warming Policy Foundation

It would seem that the good Prof. Muller, who had much to say about the first graph, complete with “hockey stick,” somehow forgot to mention the data in the second. In fact, as Prof. Curry put it, “…in the wake of the unexpected global warming standstill, many climate scientists who had previously rejected sceptics’ arguments were now taking them much more seriously.”

The Daily Mail article contains much else in the way of less than pleased reactions by a number of other climatologists at what was apparently a premature release of the BEST data before the peer review process was complete. Of course, all this fits very ill with the lurid picture of good triumphing over evil painted for us by Mr. Robinson. Predictably, while he was apparently observant enough to turn up any number of “grumbling and stunned” warming deniers, when it came to Prof. Curry and her equally chagrined colleagues, he didn’t notice a thing.

It should come as no surprise. Mr. Curry is merely acting as one might expect of a member of a species endowed with certain innate behavioral characteristics. Some of those traits give rise to what is commonly referred to as moral behavior, and none of us are free of their emotional grip. That’s why Hollywood still makes movies about good guys and bad guys. It is our subjective nature to perceive sublime good, but the yin of sublime good cannot exist without the yang of despicable evil. Every ingroup implies an outgroup. There is little we can do to change our nature, and we would probably be unwise to try given our current intellectual endowments. We can, however, while accepting it for what it is, seek to find ways of channeling its expression in ways less destructive than we have experienced in the past. At the very least we need to understand it and develop an awareness of how it affects our behavior. The results of failing to do so in the past have been destructive enough, and have certainly made a hash of the science of climatology. The results of failing to do so in the future are unlikely to be any more encouraging.

The Great Heisenberg Uncertainty

Few of the great scientific principles have been more abused than that of the famous German physicist, Werner Heisenberg.  Known as the Heisenberg Uncertainty Principle, it states that no pair of certain physical quantities, such as position and momentum, can both be known at the same time with a precision greater than a certain very small number.  It was one of the great discoveries in quantum mechanics in the 1920′s, a decade studded with such discoveries that resulted in the development of modern quantum theory.  Among other things, the modern theory states in mathematical terms the implications of the wave nature of both matter and energy.  That mathematics can be used to derive Heisenberg’s famous principle. 

Unfortunately, because many things in life are uncertain, the principle has been abundantly misapplied to a whole range of uncertainties to which it has no relevance whatsoever, just as the Theory of Relativity has been misapplied to a whole host of things that happen to be relative to each other in one way or another.  Some of the misapplications and misconceptions are more subtle than others.  I recently ran across an interesting one in a book entitled Swarm Intelligence, by James Kennedy and Russell Eberhart, the former a social psychologist and the latter an expert in evolutionary computation.  The book argues that “intelligent human cognition derives from the interactions of individuals in a social world and that the sociocognitive view can be effectively applied to computationally intelligent systems.”  I actually bought it to try programming a few of the computational examples contained therein, but found that it was a much a statement of ideology as of computational theory, larded with all the usual illusions to all the usual suspects among the philosophers who are currently fashionable in works of that genre.   Among other things there is a discussion on page 11 of whether such a thing as “true randomness” exists, or whether, on the contrary, in the words of the authors, “The basis of observed randomness is our incomplete knowledge of the world.  A seemingly random set of events may have a perfectly good explanation; that is, it may be perfectly compressible.” 

As you may have gathered, all this eventually relates to the question of free will, and whether the universe is truly random or “stochastic” at some level, or, on the contrary, purely deterministic.  I will not presume to answer that fascinating question here.  However, the authors appear to be of the opinion that the latter is the case.  What caught my eye was one of the arguments they used to support that point of view.  Allow me to quote them at length:

For most of the 20th century it was thought that “true” randomness existed at the subatomic level. Results from double-slit experiments and numerous thought experiments had convinced quantum physicists that subatomic entities such as photons should be conceptualized both as particles and waves. In their wave form, such objects were thought to occupy a state that was truly stochastic, a probability distribution, and their position and momentum were not fixed until they were observed. In one of the classic scientific debates of 20th-century physics, Niels Bohr argued that a particles’s state was truly, unkowably random, while Einstein argued vigorously that this must be impossible: “God does not play dice.” Until very recently, Bohr was considered the winner of the dispute, and quantum events were considered to be perhaps the only example of true stochasticity in the universe. But in 1998, physicists Duerr, Nonn, and Rempe disproved Bohr’s theorizing, which had been based on Heisenberg’s uncertainty principle. The real source of quantum “randomness” is now believed to be the interactions or “entanglements” of particles, whose behavior is in fact deterministic.”

In fact, the paper referred to, entitled “Origin of quantum-mechanical complementarity probed by a ‘which-way’ experiment in an atom interferometer,” is an elegant piece of work, but in no way, shape or form does it demonstrate that the “real source of quantum randomness is the interactions of “entanglements” of particles, whose behavior is in fact deterministic.”  It can be found in its entirety here. The math and scientific notation are a little dense, but if you simply trust the authors of the paper on those matters, and just look at the discussion and conclusions at the end, you should be able to see without too much difficulty that it in no way has the significance that Kennedy and Eberhart assign to it.  They seem to think that it somehow represents a refutation of the Heisenberg principle.  In fact, the authors of the paper explicitly state the contrary. 

Their paper is one of the many that have sought to shed light on the famous experiment in which interference patterns are formed by particles passing through a double slit, even when single particles are passed through one at a time, defeating any attempt to explain the phenomenon based on classical (non-quantum) physics.  The question they attempt to answer is not whether the Heisenberg principle is itself valid or not, but merely whether the principle must be invoked to explain the fact that “measuring” which one of the slits each particle passes through causes the loss of the interference pattern, or, on the contrary, some other mechanism can enforce the change.  It turns out that, in fact, the Heisenberg principle is not necessary.  Which of the ”slits” (in this case the experiment is done with standing light waves rather than physical slits) each particle passes through can be measured by much more subtle means that have orders of magnitude less effect on particle momentum than would be necessary to justify invoking it.  In other words, what the authors are really saying is, not that the Heisenberg principle is wrong, or has been superceded by some new “deterministic” theory, but merely that it is not true that it must be invoked to explain “complementarity,” or the ability of quantum mechanical entities to behave as either particles or waves.

All this is very intriguing.  One wonders to what extent this meme that the experiment in question “proves” that we live in a deterministic universe is making the rounds among people who don’t actually understand its implications one way or the other.  It would hardly be the first time that authors have been cited as authorities for ideas that never appeared in their work.  To what extent do the authors of the paper realize they’ve become “famous” in this way?

And what of the great questions of free will, and whether we live in a deterministic or stochastic universe?  The world is full of people who are cocksure they know the answer.  They just don’t agree on what it is.  Alas, I fear we are not at the point at which we can really say one way or the other.  Before that can happen, it will be necessary for us to figure out the fundamental nature of all this stuff around us, and why it all exists to begin with.  We are yet far from having that knowledge, a fact that makes life that much more exciting.  There are still great new worlds for us to discover out there.

Werner Heisenberg

What is “Real Science?”

In our ideology drenched times, it’s the same thing as “good science:”  anything that happens to agree with your ideological narrative. 

Powerline just served up a typical example relating to that über-politicized topic, global warming. According to the “good scientists” at Powerline, global warming theories are all wrong because they are currently experiencing snow and cold weather in Great Britain. Quoting from the article:

It’s fun to ridicule the warmists because they are so often wrong, but their errors are in fact significant: a scientific theory that implies predictions that turn out to be wrong, is false. A principal feature of climate hysteria is its proponents’ unwillingness to be judged by the standards that govern real science.

I know of not a single reputable climate scientist who would claim their theories “imply the prediction” that localized incidences of cold weather on the planet will no longer occur. In view of the solid evidence that, overall, the planet has, indeed, been warming over the past decade, I would like to know on what evidence Powerline is basing the claim that “warmists” are “so often wrong.” It’s rather cold in the DC area today, too. Does that also “disprove” global warming?

It’s not hard to find the same phenomenon on the other side of the ideological spectrum. There we often hear the claim that theories that significant global warming will occur over, say, the next century have been “proved.” This is “good science” in the same sense as Powerline’s claims about the cold weather in Britain. In the first place, the computational models on which such claims are based are just that; models. Even the best computational models are approximations.  Computational models of climate are far from the best.  Ideally, they would need to account for billions of degrees of freedom just to model the atmosphere alone, not to mention the coupling of the atmosphere with the oceans, etc.  No computer on earth, either now or in the foreseeable future, is capable of solving such a problem without severe simplifying assumptions.  The mathematical error bars on those assumptions have never been rigorously proved.  Throw in the fact that the data is noisy and often corrupt or nonexistent, and the best models are themselves probabilistic and not deterministic, and the claim that they “prove” anything is absurd.

“Proved” is much too strong a term, but I would buy the claim that significant long term global warming is probable.  Given the fact that this is the only planet we have to live on at the moment, it doesn’t make a lot of sense to me that we should be rocking the boat.  I doubt that “science” will offer any solutions, though.  The hardening of ideological dogmas on both sides won’t allow it.  Whatever decisions are finally made, they are far more likely to be based on politics than science.

More Thorium Silliness

Thorium is a promising candidate as a future source of energy.  I just wonder what it is about the stuff that inspires so many people to write nonsense about it.  It doesn’t take a Ph.D. in physics to spot the mistakes.  Most of them should be obvious to anyone who’s taken the trouble to read a high school science book.  Another piece of misinformation has just turned up at the website of Popular Mechanics, dubiously titled The Truth about Thorium and Nuclear Power.

The byline claims that, “Thorium has nearly 200 times the energy content of uranium,” a statement I will assume reflects the ignorance of the writer rather than any outright attempt to deceive. She cites physicist Carlo Rubbia as the source, but if he ever said anything of the sort, he was making some very “special” assumptions about the energy conversion process that she didn’t quite understand. I assume it must have had something to do with his insanely dangerous subcritical reactor scheme, in which case the necessary assumptions to get a factor of 200 would have necessarily been very “special” indeed. Thorium cannot sustain the nuclear chain reaction needed to produce energy on its own. It must first be transmuted to an isotope of uranium with the atomic weight of 233 (U233) by absorbing a neutron. Strictly speaking, then, the above statement is nonsense, because the “energy content” of thorium actually comes from a form of uranium, U233, which can sustain a chain reaction on its own. However, let’s be charitable and compare natural thorium and natural uranium as both come out of the ground when mined. 

As I’ve already pointed out, thorium cannot be directly used in a nuclear reactor on its own.  Natural uranium actually can.  It consists mostly of an isotope of uranium with an atomic weight of 238 (U238), but also a bit over 0.7% of a lighter isotope with an atomic weight of 235 (U235).  U238, like thorium, is unable to support a nuclear chain reaction on its own, but U235, like U233, can.  Technically speaking, what that means is that, when the nucleus of an atom of U233 or U235 absorbs a neutron, enough energy is released to cause the nucleus to split, or fission.  When U238 or natural thorium (Th232) absorbs a neutron, energy is also released, but not enough to cause fission.  Instead, they become U239 and Th233, which eventually decay to produce U233 and plutonium 239 (Pu239) respectively. 

Let’s try to compare apples and apples, and assume that enough neutrons are around to convert all the Th232 to U233, and all the U238 to Pu239.  In that case we are left with a lump of pure U233 derived from the natural thorium and a mixture of about 99.3% Pu239 and 0.7% U235 from the natural uranium.  In the first case, the fission of each atom of U233 will release, on average, 200.1 million electron volts (MeV) of energy that can potentially be converted to heat in a nuclear reactor.  In the second, each atom of U235 will release, on average, 202.5 Mev, and each atom of Pu239 211.5 Mev of energy.  In other words, the potential energy release from natural thorium is actually about equal to that of natural uranium. 

Unfortunately, the “factor of 200″ isn’t the only glaring mistake in the paper.  The author repeats the familiar yarn about how uranium was chosen over thorium for power production because it produced plutonium needed for nuclear weapons as a byproduct.  In fact, uranium would have been the obvious choice even if weapons production had not been a factor.  As pointed out earlier, natural uranium can sustain a chain reaction in a reactor on its own, and thorium can’t.  Natural uranium can be enriched in U235 to make more efficient and smaller reactors.  Thorium can’t be ”enriched” in that way at all.  Thorium breeders produce U232, a highly radioactive and dangerous isotope, which can’t be conveniently separated from U233, complicating the thorium fuel cycle.  Finally, the plutonium that comes out of nuclear reactors designed for power production, known as “reactor grade” plutonium, contains significant quantities of heavier isotopes of plutonium in addition to Pu239, making it unsuitable for weapons production.

Apparently the author gleaned some further disinformation for  Seth Grae, CEO of Lightbridge, a Virginia-based company promoting thorium power.  He supposedly told her that U233 produced in thorium breeders “fissions almost instantaneously.”  In fact, the probability that it will fission is entirely comparable to that of U235 or Pu239, and it will not fission any more “instantaneously” than other isotopes.  Why Grae felt compelled to feed her this fable is beyond me, as “instantaneous” fission isn’t necessary to prevent diversion of U233 as a weapons material.  Unlike plutonium, it can be “denatured” by mixing it with U238, from which it cannot be chemically separated.

It’s a mystery to me why so much nonsense is persistently associated with discussions of thorium, a potential source of energy that has a lot going for it.  It has several very significant advantages over the alternative uranium/plutonium breeder technology, such as not producing significant quantities of plutonium and other heavy actinides, less danger that materials produced in the fuel cycle will be diverted for weapons purposes if the technology is done right, and the ability to operate in a more easily controlled “thermal” neutron environment.  I can only suggest that people who write popular science articles about nuclear energy take the time to educate themselves about the subject.  Tried and true old textbooks like Introduction to Nuclear Engineering and Introduction to Nuclear Reactor Theory by John Lamarsh have been around for years, don’t require an advanced math background, and should be readable by any intelligent person with a high school education.

“Avatar” in Real Life: The BBC’s Uranium Fear Mongering

I give the movie Avatar two thumbs up. It was spectacular in 3-D, and had an entertaining plot featuring noble good guys (native Na’vi, stewards of the environment dedicated to serving the life spirit of their home, the moon Pandora) and evil bad guys (minions of a greedy corporation bent on interstellar vandalism in the search for the precious mineral, unobtainium.) As fiction, it’s great, but if this article about uranium mining in Arizona is any indication, one of the BBC’s reporters saw the movie one too many times. It’s more a reflection of the prevailing ideological narrative at the “objective” BBC than of the real world.

The article, entitled “’Uranium Rush’ Prompts Grand Canyon Fears,” with the signature BBC quotation marks around “Uranium Rush,” is about the possible resumption of uranium mining in Arizona. It would have been more appropriate to put the quotation marks around “Grand Canyon.” According to the article, which appears beneath a lovely picture of the canyon itself,

The Grand Canyon region in the US state of Arizona holds one of the nation’s largest concentrations of high grade uranium, the fuel for nuclear power.

In fact, there is no imminent threat that mining for uranium or any other mineral will occur within the Grand Canyon watershed, because, as the BBC article fails to mention, the entire area was removed from mineral entry by the Arizona Wilderness Act of 1984.  In fact, over 55.6% of the total area of the State of Arizona is already withdrawn from mineral exploration and mining.
The article continues,

The US government is currently weighing the costs and benefits of mining, with Arizona Congressman Raul Grijalva proposing a ban on mining near the Grand Canyon.

Again, the Beeb is playing fast and loose with the truth. The key word here is “near.” At issue is mining in the Arizona strip near the northern border of the state. The “evil corporation” is the Denison Mines Corporation of Canada, operator of the Arizona 1 mine about 45 miles southwest of the city of Fredonia. You can see exactly what is meant by “near” by starting at this satellite view of the mine location and zooming out until you see the canyon to the south. The “Na’vi” are the Native Americans in the region. According to the article,

…Native American populations living near uranium mines fear exploration could contaminate their drinking water.

Unsurprisingly, the article fails to mention any credible basis for this fear. In fact, as noted in this report, the uranium deposits in the area are in breccia pipes a few hundred feet below the surface and generally about 1,000 feet above the local aquifer. The deposits and the aquifer are separated by the impermeable Supai formation. Hence there is little chance of the water being contaminated. There is little danger of runoff, because the region is in a desert, and the mining property is contained in a lined pond.

The article continues,

On a recent trip into the mine, none of the miners wore masks, and their hands and face were caked with uranium ore. “It washes off,” miner Cody Behuden, 28, told the BBC while licking his ore-caked lips.
Vice-president of US operations Harold Roberts said the miners were under no danger from ingesting uranium.

The implication here, of course, is that there really is a danger from ingesting uranium, and the “evil corporation” doesn’t care. In fact, there is credible evidence that uranium miners can suffer a high incidence of lung cancer from inhaling radon gas. There is very little that demonstrates a correlation between “ingesting” the ore and cancer or any other illness. I am certainly willing to believe that conditions in the mine are dangerous if any credible evidence to that effect is forthcoming. If the BBC has something more convincing than innuendo to make the case, let’s see it. The article continues,

Dr Lee Grier, a biologist at University of California at Riverside, said exposure to uranium can be harmful, and the Navajo Native American reservation nearby is still is grappling with contamination from previous uranium mining and milling done by other companies. Those companies now no longer exist.
“The danger with long term exposure is that people breathe it, ingest it or it seeps through the skin,” he said. “These particles start bombarding tissues and cause wild uncontrolled cell growth like cancer.”

In fact, the local Indians are under no danger of contamination, because the ore will be removed and taken out of state to be milled. However, let’s assume the “evil corporation” ignores our environmental laws and allows some uranium to escape into the environment in Utah where the milling operations will actually take place. What would the radioactive hazard be compared to the alternative? In the US, the alternative is coal, and the radioactive hazard of burning it, without even taking the risk of global warming and cancer causing particulates into account, is vastly greater than the risk of mining uranium. Every year a typical coal plant releases several tons of uranium and thorium, which are natural contaminants of coal, into the atmosphere in the form of particulates, highly dangerous because they are breathed in, coming directly into contact with sensitive lung tissue. Special scrubbers can be used to remove some of this, but in that case the captured ash will be radioactive, just like the uranium mill tailings, and will represent a comparable hazard. Are we to prefer solar or wind energy? They come with their own environmental hazards, such as heavy metal contamination and destruction of the fragile desert environments that would be ideal locations for them. They also don’t work if the sun isn’t shining or the wind isn’t blowing. How are we to make up the slack when they are off line?

The article continues:

The waste from the milling process is 80% more radioactive than yellow cake and has a half-life of 4.7 billion years. Thousands of tonnes of waste are buried in containers lined with 60mm (2.4in) of plastic.

Here, the author simply has no clue what she is talking about. 80% more radioactive than yellow cake? But isn’t yellow cake a uranium compound, and isn’t the ore radioactive to begin with because of the presence of a fraction of one percent of uranium? Yellow cake is more than half pure uranium by weight, and most of the uranium will have been extracted from the waste. How, then, could it conceivably be 80% more radioactive than yellow cake? Presumably by 4.7 billion years she means the half life of uranium 238, which is actually somewhat less than that, but if she’s talking about uranium, how could it be 80% more radioactive than uranium? The sentence is incomprehensible as it stands.

Of course, there is always a “theoretical risk” of anything one could name, and, sure enough,

“Theoretically uranium could get into the water supply,” said Andrea Alpine, senior adviser on the USGS uranium project.

It’s not only “theoretical,” but a fact that natural uranium gets into our food and water regardless, and we each ingest a microgram or two of the stuff every day. What the article fails to describe is a credible explanation of how significant amounts of uranium over and above this natural average would contaminate anyone’s water supply from the Denison mine, and what the risk of such a thing happening really is. The article continues,

When uranium comes into contact with oxygen it becomes soluble in water, which increases the chance of contamination. Radioactive dust can also be blown away by the wind or washed away by rain. This is what Carletta Tilousi of the Havasupai Indian tribe fears most. The Havasupai live on the bottom of the Grand Canyon and derive water from the rim.

What the author means by this is anybody’s guess. Uranium mined in Arizona usually comes in the form of U3O8, an oxide of uranium which has a very low solubility in water, and does not become more soluble on exposure to air. Possibly she’s talking about leaching operations, in which uranium compounds can be made more soluble by introducing oxygen into the leaching liquid. It really makes very little difference. Anti-nuclear ideologues often emphasize the solubility of uranium if it’s a question of telling scary stories about ground water contamination, but can make it insoluble with a wave of their magic wands if they prefer scary stories that require it to stay in place, as in contamination of small geographic locations or organs in the body. Once again, of course, the mine is not in the Grand Canyon watershed. We are not enlightened about why the Havasupai should, nevertheless, be afraid of water washing over the rim.

The article concludes with a perfect “Avatar” ending,

“Mining companies are pursuing uranium for their own profit,” she said. “But the only benefit that we are going to get is a source of contamination. We are concerned about the future of our children, that’s why we fight this.”

Apparently the Beeb is no longer worried that the future of our children is threatened by the emission of greenhouse gases that happen not to come from nuclear plants. I will await with interest their explanation of why they have become global warming deniers.

Stephen Hawking’s Issues with God

According to Reuters, theoretical physicist Stephen Hawking has deigned to inform the rest of us that it’s OK to be an infidel because, according to the most up-to-date physics models of the universe, God isn’t necessary:

In “The Grand Design,” co-authored with U.S. physicist Leonard Mlodinow, Hawking says a new series of theories made a creator of the universe redundant, according to the Times newspaper which published extracts on Thursday.

“Because there is a law such as gravity, the universe can and will create itself from nothing. Spontaneous creation is the reason there is something rather than nothing, why the universe exists, why we exist,” Hawking writes.

Hawking’s latest won’t be released until tomorrow, and I hesitate to commence panning him until I’ve read it, but this story smacks of a well-managed publicity stunt. In the first place, it’s a virtual carbon copy of the great urban myth about the exchange between the great French mathematician, Laplace, and Napoleon (hattip Wiki):

Laplace went in state to Napoleon to accept a copy of his work, and the following account of the interview is well authenticated, and so characteristic of all the parties concerned that I quote it in full. Someone had told Napoleon that the book contained no mention of the name of God; Napoleon, who was fond of putting embarrassing questions, received it with the remark, ‘M. Laplace, they tell me you have written this large book on the system of the universe, and have never even mentioned its Creator.’ Laplace, who, though the most supple of politicians, was as stiff as a martyr on every point of his philosophy, drew himself up and answered bluntly, ‘Je n’avais pas besoin de cette hypothèse-là.’ (“I had no need of that hypothesis.”) Napoleon, greatly amused, told this reply to Lagrange, who exclaimed, ‘Ah! c’est une belle hypothèse; ça explique beaucoup de choses.’ (“Ah, it is a fine hypothesis; it explains many things.”)

Well, it’s not really that well authenticated, but it still captures the substance of Laplace’s thought on the subject accurately enough.  In the second place, if that’s really all Hawking’s got, he was beaten to the punch by the brilliant Frenchman Jean Meslier in his Testament by more than 250 years:

Is it not more natural and more intelligible to deduce all which exists, from the bosom of matter, whose existence is demonstrated by all our senses, whose effects we feel at every moment, which we see act, move, communicate, motion, and constantly bring living things into existence, than to attribute the formation of things to an unknown force, to a spiritual being, who cannot draw from his ground that which he has not himself, and who, by the spiritual essence claimed for him, is incapable of making anything, and putting anything in motion.

Indeed, all of the best arguments of the likes of Dawkins, Hitchens, and Harris, appear in Meslier’s work, along with much else besides.  As an infidel myself, I fail to see what, if anything, Hawking is contributing to the discussion, assuming he’s being quoted accurately.  After all, how do physical laws prove anything?  Laws can have no disembodied existence of their own, floating around in nothingness.  If they don’t apply to any real thing, then they cease to exist themselves.  If they do apply to something real, it still begs the question, why do the real thing(s) exist to begin with?  We’re still left to wonder, “How did all this stuff get here?”

Earthlike Worlds…

The Kepler Mission has now identified more than 700 suspected new planets, some of them earthlike, in interstellar space.  As Insty would say, “faster please.” We should be searching for life forms on earth that are most likely to survive on these worlds and working on the technology to get them there as quickly as possible. At first these will be limited to single celled or simple multi-celled species that are small enough to accelerate to the speeds necessary for interstellar travel. While we’re doing that, we can work on the nano-technology required to self-assemble human nurseries on alien worlds capable of nurturing single human cells through birth to adulthood. The energy cost of sending fully developed human beings is prohibitive, and probably impossible at the moment. However, the technology required to send single living cells is within our grasp.

Every other challenge we face and all the great political, religious, and ideological issues that have captured our imaginations and whipped us into self-destructive frenzies since the dawn of human existence pale in significance compared to the ultimate challenge of carrying life into interstellar space.  Unless we meet the challenge, all our pompous babbling about morality and ethics will be as meaningless as the life of a soap bubble.  There can be nothing more immoral than failing to survive.