It should be common sense to never build a device that cannot be tuned off (or 3 months to turn off).
All fission reactors are hard to turn off, and fairly tricky to turn back on again once off. This isn't due to bad engineering: the underlying nuclear physics makes it that way.
"A Russian publication, Chernobyl, concludes that 985,000 excess deaths occurred between 1986 and 2004 as a result of radioactive contamination."
The number of excess deaths from Chernobyl is controversial, and the nearly-a-million number you cite is the absolute top of the range, based on a theoretical model that is known to be false--cancer demographics simply do not support a no-threshold dose-response model, nor does the fact that we use the quality factor to correct for multi-hit damage from heavy particles.
The linear dose-response model is used to set safety guideline precisely because it is enormously conservative, and the belief has been that the cost of such conservative limits is small. To use linear dose-response to estimate actual deaths, however, is irresponsible to the point of being anti-scientific. It requires that things we know to be false--the implied variation of cancer rates with altitude and other natural background changes--to be true.
The safety issue from nuclear power is non-trivial, and the cost issue is enormous, but this is a case where people who are probably on the right side of the issue in the long term are damaging their own cause by over-estimating the consequences and hurting their own cause, except amongst their anti-scientific fellow-travelers. The problem is they are saying "Chernobyl killed a million people so we must have no nukes!" which is setting themselves up for the (insane) reply, "No, it only killed 5000 people so nukes are OK."
They would be far better off saying, "Chernobyl killed 5000 people, and that is 5000 too many."
What he wrote was that his straight and vanilla sex life was not just unsickening but "the way it was meant to be", which implies a very strong normative element in addition to his visceral response. As it happens, his visceral response is one I happen to share, but I'm not an idiot or three years old, so I don't infer normative value from hind-brain emotions.
Spiders creep me out too, in pretty much exactly the same way, and I don't pretend there's anything wrong with them because of that: if anything, there's something wrong with me, although it's pretty trivial as I'm not about to let such feelings influence my stand on public policy, which is based on the conscious recognition that homosexuals have as much right to do what they like with their own bodies as the rest of us.
Trying to pick a bad guy in the region is pretty easy. It's pretty much all bad. I've seen no one that doesn't have blood on their hands.
My attitude toward the Palestinian/Israel thing is to believe everything both sides say. It comes far closer to the truth than listening to one side or the other, and it throws partisans for a loop when you say, "Yeah, I believe all of that. Now let's talk about Israeli war crimes" or "Totally true, every bit, but you've left out all the stuff about state-sponsored Palestinian terrorists blowing up school children."
The thing is, both bunches of vicious idiots believe that the other side's actions are an automatic justification for their own atrocities, and they really can't wrap their heads around the idea that that might not be the case.
The prevailing theory for some time now (guessing a decade, maybe two?) is that the very early Earth was hit by by a sizeable object, at an angle and speed that didn't outright shatter the Earth but blew enough of the combined masses away from each other to form the Earth and Moon as we more or less know them today.
The theory goes back to the '70's and is pretty well supported by computational models of the impact. It is difficult to get a moon as large as ours to form in any other way, particularly given the lack of water in surface rocks on the Moon.
Reading the comments here it is clear that many people are badly misunderstanding the story, including misjudging the scale of the impact. Although it is good to know that the arrogance of the ignorant is sufficiently alive and well here to ensure that when one or two people agree that it "just makes sense" that something happened, it surely did.
The present result shows that unlike surface rocks on the Moon, which are essentially anhydrous, rocks deep underground have a comparable amount of "water" in their structure as rocks on Earth. By "water" people mean "water molecules that are chemically bound to mineral molecules", not "drops of free liquid or unbound molecules in the rock matrix".
When rock is heated, water, which is a weakly bound molecular group in most minerals, gets driven off. Impact models suggest that the lunar material post-impact was pretty much all heated to the point of being liquid, which would have driven off all the water. Surface geology was consistent with that. The current findings are not.
It is my understanding that the lunar-formation impact has to occur after the Earth was already wet, so hydrous geology in the lunar mantle implies the impact hypothesis needs to be revisited.
One of the major benefits of the impact hypothesis is that it explains the high angular momentum of the Earth-Moon system, which competing theories cannot. Given that, I expect the preference will be for modifications to the impact initial conditions, perhaps in the form of a more grazing collision, and even potentially a collision that resulted from the capture of a co-orbiting body. This would be a bit baroque, but really, looking at the data, if Earth and Theia were formed in orbit around each other and then Theia's orbit decayed due to late impacts it might explain most of the problems.
It makes no sense to me. You have by far the strongest military in the world.
I think you just answered your own question. As someone else here pointed out: a lot of people's jobs in the US depend on the size of the security-industrial complex. Having the strongest military in the world gives you a powerful incentive to keep people afraid so they will be willing to keep funding the most powerful military in the world, thereby transferring enormous amounts of wealth from average Americans to shareholders in American security-industrial corporations.
. So begins the formalisation of thoughtcrime - through state promotion of doublethink.
Fortunately Orwell's fantasy was a fantasy. He imagined a society that was dominated by doublethink and yet still able to function to the extent that there weren't mass famines and complete social collapse. He assumed--for perfectly valid artistic purposes--that the kind of psychological gymnastics required to live in such a society came at zero cost. If you read "Burmese Days" you'll see he knew better than to think such a thing was remotely plausible in the real world.
Purveyors of various utopias and distopias routinely sneak in the premise that some particular form of human activity has zero cost. Imperialist societies discount the costs of war. Statist societies discount the cost of social control. Corporatist societies discount the cost of corruption. Socialist societies discount the cost of resource misallocation.
Liberal democrats and social democrats believe what they do precisely because they refuse to discount the costs of the systems they advocate. Liberal democrats are more worried about the costs of statism, social democrats more about the costs of gangsterism, but both are fairly realistic about costs overall.
So while I'm worried about the rise of Imperial America, I know that it will be self-limiting, as the repressive Organs of the State grow to stifle innovation and dissent at home for the sake of maintaining the stability of your empire abroad. This paper is just saying out loud what imperialists have always done, and in it doesn't represent a triumph of state control. It represents an admission that the American Empire is doomed to fail under the weight of its own domestic repression, which will grow over the next few decades until the cost of maintaining it completely overwhelms you.
When this happens, apologists will say, "No one could have predicted this!"
For global warming, it means taking two different planet Earths...
Err, no. What you are describing is some kind of rationalist/skeptic myth of science, not science as it has been done for the past three hundred years. Not the science that has explained the motion of the wandering stars and the tides, built flying machines and novel power plants, taken us to the Moon and back.
Universal gravitation does not meet your criteria. "Sorry, Mr Newton. You have to take two masses, one with inertia, one without, and compare their gravitational attraction. Otherwise you aren't testing your hypothesis that resistance to motion and the force of attraction are strictly proportional, as your theory requires."
All of astrophysics, most of geology and geophysics and vast tracts of biology are not science according to you. It is remarkably difficult to get a star, a planet or a species into the average sized laboratory, given university budgets these days.
Science is the discipline of testing ideas--and their rigorously (often mathematically) worked out logical consequences--by systematic observation and controlled experiment.
Climate science is definitely science, albeit of a highly politicized kind, and has less rigor than one might ideally want, which is a necessary consequence of letting people who are not computational or experimental physicists work on problems of computational and experimental physics.
The only kind of people who equate knowledge with certainty are extreme rationalists and the uneducated (or unreflective) people who have never thought about how they use the word.
In my view as an empiricist, knowledge is possible without certainty, and indeed the vast majority of things we know are not certain. I know where I parked my car, and would go so far as to say I know where my car is right now. I know my name. I know what colour of socks I'm wearing. I know THAT I'm wearing socks. All of these things could quite conceivably be wrong.
These are perfectly ordinary uses of the word "know", and I mean "know" this way pretty much whenever I use it, including when discussing the early universe, properties of neutrons, and so on, because our methods of knowing about those things are no different from our methods of knowing about our socks.
Empirical observation and Bayesian reasoning are universal in their application, and they are the only way of creating knowledge. That they do not produce certainty is something that extreme rationalists find upsetting, but that just means it sucks to be them.
Certainty has no practical value over any reasonably high degree of plausibility, and people who value certainty over correct Bayesian inference--which merely produces knowledge--are at risk of hanging on to unjustified conclusions for the sake of the pragmatically useless feeling of certainty they have about them. So I would argue that the elevation of certainty as the goal of science is operationally useless at best, and positively dangerous at worst. Science produces knowledge, not certainty.
I find it unnerving that people/scientists claim to know things when they only think they know them
I find it amusing that on the one hand you claim not to to know anything about physics (and clearly you don't, nor science in general) and then try to bolster your skeptical position based on claims that come directly from modern physics.
Skepticism is not a self-consistent position: to motivate it skeptics have to claim that they know things, and that their knowledge of those things (from sensory illusions to radical meaning variance to the simple complexity of the universe) justifies their skepticism.
Any astrophysicists (or at least postgrads) here to say how important or true this achievement really is?
It's fairly significant. They have confirmed that some fraction of the missing baryonic matter (the ordinary stuff we are made of, like Galactic Dark Matter, not the exotic new-particle stuff) is in the filaments that exist on very large scales in the universe. If they had failed to find it the result would have been more interesting, but even so they've done a good bit of science by testing the idea that the missing baryonic matter is in these filaments by actually going and looking for it rather than taking it on faith that it must be there.
We know there is missing baryonic matter because we know what the baryonic density in the universe is from the primordial helium/hydrogen ratio. Free neutrons only live about fifteen minutes, so as the Big Bang cooled and neutrons and protons condensed out of the primordial quark-gluon plasma there was a relatively short interval in which helium could form. We know the size of the universe at that time from the temperature, and we know the density because the denser it was the more neutrons would have been captured onto protons to form heavier isotopes, so by figuring out the primordial density of deuterium, helium and lithium we can put pretty strong constraints on the total baryonic mass of the universe.
This is the thing that kills me about Penrose, who is a mathematician: his claims fly in the face of everything we know about quantum theory. They amount to, "Quantum phenomena are a mystery, consciousness is a mystery, erg consciousness must be a quantum phenomenon."
I take the opposite course (I am an experimental physicist who has applied QM to the real world quite a lot, and also worked in genetics and microbiology): Quantum phenomena are a mystery to beings with consciousness like ours. Far from explaining consciousness, quantum phenomena raise a huge question: why is our consciousness restricted to an awareness of a strictly classical world? Or as Max Born famously put it in response to Bohr's dictum: "Why must I treat the measurement apparatus as classical? What will happen to me if I don't!?"
Decoherence theories do not answer this question because they take for granted that we are only able to gain an awareness of quantum phenomena by observing the classical effects of interference. That is, the accept that the measurement apparatus must be treated classically and have no account of why we are not and cannot be aware of incoherent superpositions as such.
So I think Penrose has this issue exactly backward, and the really interesting questions are: "Why is there a classical world at all, and why is it the only world we can be conscious of?"
This stuff is hard to think about, and getting the classical models out of your head before it explodes is a worthy goal (although were that to happen I guess it would be like cranial popcorn for your zombie neighbours, assuming you have any...)
The problem with thinking about electrons as "things" with "properties" is that they aren't. The whole point of quantum physics is that the "things" it deals with don't share the ontological constraints that are required for genuine thingness. An ordinary thing like a rock is always under observation in the relevant sense, regardless of what any conscious observer is doing. As such it can't be in two places at once (it is local) and it can't behave in contradictory ways under incompatible experimental conditions because no two experimental conditions are genuinely incompatible, for a rock.
For an electron, this is not the case. Electrons for the most part cannot be observed, and when they are observed their interaction with the experimental apparatus makes some measurements entirely incompatible with others. As such, any model we have in our heads of "what an electron is doing when no one is able to look at it" is wrong: we literally cannot conceive of such a situation. Doing so would require us to violate the law of non-contradiction, because that's what electrons do.
We we can think about is how electrons behave in various well-defined situations. In those situations they do reveal something like "properties", but those "properties" mean "they behave like X under exactly situation Y", and don't generalize well to other situations.
The closest classical analogy in the present case might be to think of an electron as a very squishy ball, like an unbreakable soap-bubble. Under normal circumstances it's very hard to tell what the shape of the ball is because the least force acting on it distorts it. What these guys have done is make a precision measurement that says in the absence of any external forces the soap-bubble-electron has a shape that is, to a very high degree of precision, a sphere. You can then think of the wave-like properties as being wobbles in the surface of the soap-bubble as it moves, or something like that (any analogy of this kind is going to be at best woefully inexact and at worst misleading and wrong, so be cautious!)
There is a related measurement that looks at deviations from point-like-ness. Electrons have a "characteristic scale", the Compton wavelength, that is vaguely analogous to the relaxed radius of the soap-bubble-electron. But it turns out if you squeeze the soap-bubble by running another soap-bubble into it, instead of distorting the two bubbles shrink during the collision while remaining perfectly spherical, then bounce back to there original radius after it. This means that while the electron when left alone has a "radius" associated with it, when it scatters off another charged particle is appears "point-like" in the sense that the structure function never deviates from unity.
Again: these are analogies between apples and penguins, so use them with care.
Proportional to what? The number of votes a private organization got? Why should private organizations be privileged? Why should Parliament or Congress or whatever represent the interests of private organizations rather than voters?
People, not Parties, are what should be represented in Parliament.
Proportional representation schemes just take for granted that political parties ought to have precedence over people, which is the problem with most modern democracies, not the solution.
PR is an attempt by parties to capitalize on the flaws of a check-mark voting system. Any voting system that allows voters to rank candidates is vastly better than PR because it provides electoral officials with more information, and minimizes rather than maximizes the role of private organizations in the representational system.
1% of the population controls more than 50% of the wealth
Nonsense!
400 divided by 300 million is a little over 0.01%, not the ridiculously large 1% you suggest.
I'm pretty sure we're going to have to rethink the whole "eat the rich" plan: there are no longer enough of them to feed more than a couple of poor families for a few years...
Why are we dumbing things down to cater to the bottom of the pool? What the hell is wrong with society, It's encouraging people to be illiterate and undecuated?
Humans are convenience-seeking. The whole process of technology development is driven by convenience-seeking. Hardly anyone knows how to use a manual spark advance on a car anymore, or a manual choke and even a manual transmission. Why learn those skills when we can get the machine to take care of them automatically?
You probably don't know how to crack-start a car, do you? There's a special trick to it to avoid breaking your wrist in the event of a backfire (which was sufficiently common that the resulting break pattern actually had the medical name of "chauffeur's fracture").
You use technology every single day that is the direct result of the process of "dumbing down" that you're decrying. We all do. The problem is, as geeks, we like to see the bones of the system exposed. We like the freedom to tinker and create and fix. We inevitably lose all that as the very process that motivated the creators of the technology continues to refine it.
This is true on all levels, both within a technological area and across time when looking at different technologies that solve the same problem. Cars are vastly easier to operate than horses. Power boats are vastly easier to operate than sail boats or canoes or kayaks. The most complex smart phone is vastly easier to operate than a telegraph. Guns are easier to use than bows or swords. I'm sure various types of stone tool in use 10,000 years ago were more convenient in some sense than their predecessors from 100,000 years ago.
So far from decrying this tendency toward convenience-seeking, we should embrace it and accept it, and always be looking to keep ahead of the curve of boring, convenient technology. The Web itself grew this way: however awkward early browsers were to use they gave more convenient access to information than books and periodicals.
What's the advantage of this over one in a mine that justifies the cost
Primary cosmic rays are much simpler animals than secondary cosmic rays. Primary cosmic rays are almost 100% protons, which almost never reach the surface of the Earth because they interact with the atmosphere and create cosmic ray "showers" that are rich and complex, full of muons and gamma rays and prolific in neutron production as well. Even fairly deep underground dealing with these backgrounds is a complicated process.
Having only primary cosmic rays to deal with makes life somewhat easier. There may also be dark matter signals that are too low energy to penetrate the Earth's atmosphere--that is, weak signals in the low-energy cosmic ray background due to dark matter collisions or decays integrated over a very large volume.
The ideal place to do this kind of work is on the Moon: because it has no atmosphere, pions produced by cosmic ray protons will come to a halt before they decay, so there are only low-energy muons produced. Thus, a couple of metres of rock on the Moon will give you shielding as good as a much thicker layer on Earth.
they are dangerous and they need to be built properly, I.E. NOT WITH A PROFIT MOTIVE
What a strange thing to say. I fly in aircraft built with a profit motive now and then, and haven't noticed that the motive of the builders particularly affects the dangers involved. Subsidized, state-run airlines like Aeroflot have no particular advantage over commercial airlines.
Why do you think the motive of the builders matters? The people who built Chernobyl were not motivated by profit. Nor were the people who built Windscale.
Bad engineering is a product of human beings, and it isn't like we live in a world where you can divide people into "good people" and "bad people" based on their motives, particularly when the major choices are profit on the one hand and power on the other. I can't offhand think of any major engineering work that wasn't primarily driven by one or the other of those motives, and I note that the profit motive sometimes produces wonderful things. The power motive does too, if you're into that kind of thing, although perhaps less frequently, and with more manufactured famines and genocides along the way.
All you're doing is saying that concentrated dangers are more worthy of avoidance than distributed dangers simply because they're concentrated.
Not at all. I'm saying that coal plants fail in ways that are cheaper than nuclear plant failures. This is trivially true. I don't know of any case in the past fifty years where a coal plant failure has led to a complete loss of capital investment of the kind that routinely happens in relatively trivial nuclear plant disasters. If Fukushima were a coal plant it would be back in operation today, not written-off.
This has nothing to do with danger, which is fairly trivial in both cases, albeit greater for a coal plant due to chronic release of radioactives, heavy metals and other pollutants. It has to do with cost, which is why I said, "The cost is the big problem."
Now, you can argue that coal is unfairly subsidized and whatnot, although nuclear has its own subsidies as well, notably the whole liability cap thing. But you can't argue that nuclear doesn't write itself off pretty easily compared to coal.
Yeah, the thermal feedback and the lack of containment (necessary to allow the fuel to be replaced while operating) is a huge draw-back.
The confusion between "pressure vessel" and "containment" is one of the most frustrating thing about this whole discussion, although it does have the useful side-effect of marking the ignorant.
Reactors like the CANDU, which run on natural uranium and can be refueled while running don't have a pressure vessel of the kind a conventional PWR or BWR does. Dunno what the RMBK (Chernobyl) design has but the CANDU uses "calandria" tubes that contain the fuel rods. The refueling machine works on one tube at a time.
However, the reactor containment has nothing to do with the pressure vessel. All well-designed power reactors have containments, which do not in any way interfere with refueling.
OK, so I've never really understood 'dark matter', but if there's a bunch of stuff floating about that's not stars and only shows up through things like gravitational micro-lensing... might this cover some of the mass that is dark matter?
Maybe, for galactic dark matter, which is completely unrelated in every respect to dark matter on larger scales, although ignorant people typically use the general term "dark matter" to refer to all types of dark matter indiscriminately, creating enormous confusion in the process.
Galactic dark matter (GDM) is hypothesized as an explanation for the flat rotation curves of spiral galaxies. Based on the visible matter (stars) in a galaxy we can get an estimate of the mass inside a given radius. At sufficiently high radii we see the amount of visible matter dropping off, and expect that the few stars at even larger radii will start to behave like planets orbiting a distant mass with a 1/r**2 fall off in gravitational strength. But we don't see that. Instead more distant stars move as if the amount of matter inside their orbits around the galactic center contained ever more mass as they get further and further away. We can't see any visible matter to account for this, ergo, "dark matter".
One possible candidate for GDM are so-called "MACroscopic Halo Objects" (MACHOS, to contrast them with Weakly Interacting Massive Particles, or WIMPS. Physicists really need to get out more.)
An impediment to the MACHO hypothesis has been that the Initial Mass Function, which describes the probability of an object of mass M condensing out of a primordial cloud of gas and/or dust, was believed to drop off rather steeply at low masses. This observation suggests that it is at least a little higher than previously estimated, although I don't know if that is anywhere near high enough to account for a significant portion of GDM--my sense is not, but it's been a few years since I've paid much attention to this question.
At larger scales we also see anomalous motion of galaxies and galactic clusters relative to the amount of visible matter, and at the very largest scale there is much less visible mass than required to keep the universe in the state of almost-but-not-quite-closed that we see. If these phenomena are caused by an excess of matter at larger scales we know that it is non-baryonic (not made of protons and neutrons) because we have a very good estimate of the density of protons and neutrons in the universe based on primordial nucleosynthesis: the denser the early universe was in protons and neutrons, the more helium would have been created, and given we know the early universe was about 23% helium (there are complex self-consistency checks on this number based on other atomic species) we know there are not enough protons and neutrons to account for the large-scale dark matter (LSDM).
Therefore, we know that LSDM is completely unrelated in every respect to GDM: the problems they solve have different constraints and one requires exotic new physics while the other is relatively mundane. It is deeply unfortunate that people are so incompetent in their use of abstractions that they are chronically unable to distinguish between these two unrelated problems.
I guess it's because we all love tatas but the prostate just isn't very sexy
Nope, it's because we think "Men last!" is a noble sentiment, although it's usually expressed in a more obfuscated but logically equivalent manner.
Men die of all causes at younger ages than women. Men are the majority victims in all forms of violent crime except (possibly) rape, where male victims are about 10% of the total, although under-reporting is such a huge problem no one really knows (or much cares) what the real number is. Men--especially young men--commit suicide up to five times as frequently as women. If a person dies on the job, the odds are over 90% they are male. And so on.
Tell anyone this and they will immediately start making stuff up, mostly in the vein of "Men are complicit in their own poor health, high rates of crime victimization and on-the-job fatalities." Because, you see, males are autonomous, powerful, independent individuals who are completely and totally responsible for their own behaviour and under no social influence of any kind whatsoever, whereas women are helpless little things who are never to blame for their own actions and must be carefully treasured and protected by society. That's the implicit message, anyway, however vile and nonsensical it may be in its characterization of both sexes.
Yep, we can't trust our government or companies to do anything competently. For our own safety, we should clearly ban:
Nuclear plants are unique amongst these things in that their failure modes are:
1) rapid 2) complex 3) expensive
The speed comes from the energy density of the core, which is many orders of magnitude higher than for any other power source. A typical nuclear plant contains something like the equivalent of 100,000 boxcars of coal in its fuel rods, and while only a tiny fraction of that can be released over a reasonably short interval, only a tiny fraction has to be released over a relatively short interval to ruin the core.
Reactor kinetics are complicated and the cooling and control systems more-so. Complexity is a bigger issue in second and third generation designs--one could even say that the whole point of fourth generation designs is to engineer out as much complexity as possible. However, there is always going to be a fairly high level of complexity for anything beyond the "nuclear battery" type reactors (which to my mind are probably viable sources of energy in the long term.) The high energy density and consequent rapid pace of events during failure mean that the humans involved in the process are going to frequently make bad choices.
The cost is the big problem: a failure in a coal plant results in some nasty chemicals released into the environment, maybe some people burned in a steam explosion or the like. But it is very hard to create a coal plant disaster that writes off the capital investment or exposes the operator to the kind of widespread liability that nuclear disasters do.
So anyone who is not innumerate realizes that the risk-cost/benefit trade-off for nuclear power is very different from most other technologies. The benefits are significant, but a long, long way from "power too cheap to meter", which was the original promise of nuclear power. The costs are having an event like Windscale or Chernobyl or Fukushima every decade or two. For numerate people, the trade-offs involved are not a slam-dunk on either side.
By way, as a noob and an AC, the link isn't in html - maybe some moderator will fix it.
You REALLY must be new here.../. mods have one job: to create misleading and false headlines and ensure that summaries are less accurate when they are posted than when they are submitted. In this case, they have for some reason replaced "pressure vessel" with "containment vessel", presumably to make it clear to absolutely everyone that they know nothing about the technology of nuclear power.
That's an excellent link, though, and the data indicate that the scenario described in the article is pretty unlikely--the water level is clearly stable until significantly after the tsunami. No amount of fiddling with the calibration on the gauge is going to affect that: the curve is flat, then starts to fall an hour or so after the tsunami.
Slashdot Mirror
It should be common sense to never build a device that cannot be tuned off (or 3 months to turn off).
All fission reactors are hard to turn off, and fairly tricky to turn back on again once off. This isn't due to bad engineering: the underlying nuclear physics makes it that way.
"A Russian publication, Chernobyl, concludes that 985,000 excess deaths occurred between 1986 and 2004 as a result of radioactive contamination."
The number of excess deaths from Chernobyl is controversial, and the nearly-a-million number you cite is the absolute top of the range, based on a theoretical model that is known to be false--cancer demographics simply do not support a no-threshold dose-response model, nor does the fact that we use the quality factor to correct for multi-hit damage from heavy particles.
The linear dose-response model is used to set safety guideline precisely because it is enormously conservative, and the belief has been that the cost of such conservative limits is small. To use linear dose-response to estimate actual deaths, however, is irresponsible to the point of being anti-scientific. It requires that things we know to be false--the implied variation of cancer rates with altitude and other natural background changes--to be true.
The safety issue from nuclear power is non-trivial, and the cost issue is enormous, but this is a case where people who are probably on the right side of the issue in the long term are damaging their own cause by over-estimating the consequences and hurting their own cause, except amongst their anti-scientific fellow-travelers. The problem is they are saying "Chernobyl killed a million people so we must have no nukes!" which is setting themselves up for the (insane) reply, "No, it only killed 5000 people so nukes are OK."
They would be far better off saying, "Chernobyl killed 5000 people, and that is 5000 too many."
While that fact is interesting and unexpected,
How on Earth is this unexpected? People have been pointing this out since the '70's!
So read what he wrote again
What he wrote was that his straight and vanilla sex life was not just unsickening but "the way it was meant to be", which implies a very strong normative element in addition to his visceral response. As it happens, his visceral response is one I happen to share, but I'm not an idiot or three years old, so I don't infer normative value from hind-brain emotions.
Spiders creep me out too, in pretty much exactly the same way, and I don't pretend there's anything wrong with them because of that: if anything, there's something wrong with me, although it's pretty trivial as I'm not about to let such feelings influence my stand on public policy, which is based on the conscious recognition that homosexuals have as much right to do what they like with their own bodies as the rest of us.
Trying to pick a bad guy in the region is pretty easy. It's pretty much all bad. I've seen no one that doesn't have blood on their hands.
My attitude toward the Palestinian/Israel thing is to believe everything both sides say. It comes far closer to the truth than listening to one side or the other, and it throws partisans for a loop when you say, "Yeah, I believe all of that. Now let's talk about Israeli war crimes" or "Totally true, every bit, but you've left out all the stuff about state-sponsored Palestinian terrorists blowing up school children."
The thing is, both bunches of vicious idiots believe that the other side's actions are an automatic justification for their own atrocities, and they really can't wrap their heads around the idea that that might not be the case.
The prevailing theory for some time now (guessing a decade, maybe two?) is that the very early Earth was hit by by a sizeable object, at an angle and speed that didn't outright shatter the Earth but blew enough of the combined masses away from each other to form the Earth and Moon as we more or less know them today.
The theory goes back to the '70's and is pretty well supported by computational models of the impact. It is difficult to get a moon as large as ours to form in any other way, particularly given the lack of water in surface rocks on the Moon.
Reading the comments here it is clear that many people are badly misunderstanding the story, including misjudging the scale of the impact. Although it is good to know that the arrogance of the ignorant is sufficiently alive and well here to ensure that when one or two people agree that it "just makes sense" that something happened, it surely did.
The present result shows that unlike surface rocks on the Moon, which are essentially anhydrous, rocks deep underground have a comparable amount of "water" in their structure as rocks on Earth. By "water" people mean "water molecules that are chemically bound to mineral molecules", not "drops of free liquid or unbound molecules in the rock matrix".
When rock is heated, water, which is a weakly bound molecular group in most minerals, gets driven off. Impact models suggest that the lunar material post-impact was pretty much all heated to the point of being liquid, which would have driven off all the water. Surface geology was consistent with that. The current findings are not.
It is my understanding that the lunar-formation impact has to occur after the Earth was already wet, so hydrous geology in the lunar mantle implies the impact hypothesis needs to be revisited.
One of the major benefits of the impact hypothesis is that it explains the high angular momentum of the Earth-Moon system, which competing theories cannot. Given that, I expect the preference will be for modifications to the impact initial conditions, perhaps in the form of a more grazing collision, and even potentially a collision that resulted from the capture of a co-orbiting body. This would be a bit baroque, but really, looking at the data, if Earth and Theia were formed in orbit around each other and then Theia's orbit decayed due to late impacts it might explain most of the problems.
It makes no sense to me. You have by far the strongest military in the world.
I think you just answered your own question. As someone else here pointed out: a lot of people's jobs in the US depend on the size of the security-industrial complex. Having the strongest military in the world gives you a powerful incentive to keep people afraid so they will be willing to keep funding the most powerful military in the world, thereby transferring enormous amounts of wealth from average Americans to shareholders in American security-industrial corporations.
. So begins the formalisation of thoughtcrime - through state promotion of doublethink.
Fortunately Orwell's fantasy was a fantasy. He imagined a society that was dominated by doublethink and yet still able to function to the extent that there weren't mass famines and complete social collapse. He assumed--for perfectly valid artistic purposes--that the kind of psychological gymnastics required to live in such a society came at zero cost. If you read "Burmese Days" you'll see he knew better than to think such a thing was remotely plausible in the real world.
Purveyors of various utopias and distopias routinely sneak in the premise that some particular form of human activity has zero cost. Imperialist societies discount the costs of war. Statist societies discount the cost of social control. Corporatist societies discount the cost of corruption. Socialist societies discount the cost of resource misallocation.
Liberal democrats and social democrats believe what they do precisely because they refuse to discount the costs of the systems they advocate. Liberal democrats are more worried about the costs of statism, social democrats more about the costs of gangsterism, but both are fairly realistic about costs overall.
So while I'm worried about the rise of Imperial America, I know that it will be self-limiting, as the repressive Organs of the State grow to stifle innovation and dissent at home for the sake of maintaining the stability of your empire abroad. This paper is just saying out loud what imperialists have always done, and in it doesn't represent a triumph of state control. It represents an admission that the American Empire is doomed to fail under the weight of its own domestic repression, which will grow over the next few decades until the cost of maintaining it completely overwhelms you.
When this happens, apologists will say, "No one could have predicted this!"
For global warming, it means taking two different planet Earths...
Err, no. What you are describing is some kind of rationalist/skeptic myth of science, not science as it has been done for the past three hundred years. Not the science that has explained the motion of the wandering stars and the tides, built flying machines and novel power plants, taken us to the Moon and back.
Universal gravitation does not meet your criteria. "Sorry, Mr Newton. You have to take two masses, one with inertia, one without, and compare their gravitational attraction. Otherwise you aren't testing your hypothesis that resistance to motion and the force of attraction are strictly proportional, as your theory requires."
All of astrophysics, most of geology and geophysics and vast tracts of biology are not science according to you. It is remarkably difficult to get a star, a planet or a species into the average sized laboratory, given university budgets these days.
Science is the discipline of testing ideas--and their rigorously (often mathematically) worked out logical consequences--by systematic observation and controlled experiment.
Climate science is definitely science, albeit of a highly politicized kind, and has less rigor than one might ideally want, which is a necessary consequence of letting people who are not computational or experimental physicists work on problems of computational and experimental physics.
To myself, "know" implies certainty
The only kind of people who equate knowledge with certainty are extreme rationalists and the uneducated (or unreflective) people who have never thought about how they use the word.
In my view as an empiricist, knowledge is possible without certainty, and indeed the vast majority of things we know are not certain. I know where I parked my car, and would go so far as to say I know where my car is right now. I know my name. I know what colour of socks I'm wearing. I know THAT I'm wearing socks. All of these things could quite conceivably be wrong.
These are perfectly ordinary uses of the word "know", and I mean "know" this way pretty much whenever I use it, including when discussing the early universe, properties of neutrons, and so on, because our methods of knowing about those things are no different from our methods of knowing about our socks.
Empirical observation and Bayesian reasoning are universal in their application, and they are the only way of creating knowledge. That they do not produce certainty is something that extreme rationalists find upsetting, but that just means it sucks to be them.
Certainty has no practical value over any reasonably high degree of plausibility, and people who value certainty over correct Bayesian inference--which merely produces knowledge--are at risk of hanging on to unjustified conclusions for the sake of the pragmatically useless feeling of certainty they have about them. So I would argue that the elevation of certainty as the goal of science is operationally useless at best, and positively dangerous at worst. Science produces knowledge, not certainty.
I find it unnerving that people/scientists claim to know things when they only think they know them
I find it amusing that on the one hand you claim not to to know anything about physics (and clearly you don't, nor science in general) and then try to bolster your skeptical position based on claims that come directly from modern physics.
Skepticism is not a self-consistent position: to motivate it skeptics have to claim that they know things, and that their knowledge of those things (from sensory illusions to radical meaning variance to the simple complexity of the universe) justifies their skepticism.
Any astrophysicists (or at least postgrads) here to say how important or true this achievement really is?
It's fairly significant. They have confirmed that some fraction of the missing baryonic matter (the ordinary stuff we are made of, like Galactic Dark Matter, not the exotic new-particle stuff) is in the filaments that exist on very large scales in the universe. If they had failed to find it the result would have been more interesting, but even so they've done a good bit of science by testing the idea that the missing baryonic matter is in these filaments by actually going and looking for it rather than taking it on faith that it must be there.
We know there is missing baryonic matter because we know what the baryonic density in the universe is from the primordial helium/hydrogen ratio. Free neutrons only live about fifteen minutes, so as the Big Bang cooled and neutrons and protons condensed out of the primordial quark-gluon plasma there was a relatively short interval in which helium could form. We know the size of the universe at that time from the temperature, and we know the density because the denser it was the more neutrons would have been captured onto protons to form heavier isotopes, so by figuring out the primordial density of deuterium, helium and lithium we can put pretty strong constraints on the total baryonic mass of the universe.
Or biology, or neuroscience, or...
...or quantum mechanics.
This is the thing that kills me about Penrose, who is a mathematician: his claims fly in the face of everything we know about quantum theory. They amount to, "Quantum phenomena are a mystery, consciousness is a mystery, erg consciousness must be a quantum phenomenon."
I take the opposite course (I am an experimental physicist who has applied QM to the real world quite a lot, and also worked in genetics and microbiology): Quantum phenomena are a mystery to beings with consciousness like ours. Far from explaining consciousness, quantum phenomena raise a huge question: why is our consciousness restricted to an awareness of a strictly classical world? Or as Max Born famously put it in response to Bohr's dictum: "Why must I treat the measurement apparatus as classical? What will happen to me if I don't!?"
Decoherence theories do not answer this question because they take for granted that we are only able to gain an awareness of quantum phenomena by observing the classical effects of interference. That is, the accept that the measurement apparatus must be treated classically and have no account of why we are not and cannot be aware of incoherent superpositions as such.
So I think Penrose has this issue exactly backward, and the really interesting questions are: "Why is there a classical world at all, and why is it the only world we can be conscious of?"
So.... it's a sphere when it is a particle?
Nope.
This stuff is hard to think about, and getting the classical models out of your head before it explodes is a worthy goal (although were that to happen I guess it would be like cranial popcorn for your zombie neighbours, assuming you have any...)
The problem with thinking about electrons as "things" with "properties" is that they aren't. The whole point of quantum physics is that the "things" it deals with don't share the ontological constraints that are required for genuine thingness. An ordinary thing like a rock is always under observation in the relevant sense, regardless of what any conscious observer is doing. As such it can't be in two places at once (it is local) and it can't behave in contradictory ways under incompatible experimental conditions because no two experimental conditions are genuinely incompatible, for a rock.
For an electron, this is not the case. Electrons for the most part cannot be observed, and when they are observed their interaction with the experimental apparatus makes some measurements entirely incompatible with others. As such, any model we have in our heads of "what an electron is doing when no one is able to look at it" is wrong: we literally cannot conceive of such a situation. Doing so would require us to violate the law of non-contradiction, because that's what electrons do.
We we can think about is how electrons behave in various well-defined situations. In those situations they do reveal something like "properties", but those "properties" mean "they behave like X under exactly situation Y", and don't generalize well to other situations.
The closest classical analogy in the present case might be to think of an electron as a very squishy ball, like an unbreakable soap-bubble. Under normal circumstances it's very hard to tell what the shape of the ball is because the least force acting on it distorts it. What these guys have done is make a precision measurement that says in the absence of any external forces the soap-bubble-electron has a shape that is, to a very high degree of precision, a sphere. You can then think of the wave-like properties as being wobbles in the surface of the soap-bubble as it moves, or something like that (any analogy of this kind is going to be at best woefully inexact and at worst misleading and wrong, so be cautious!)
There is a related measurement that looks at deviations from point-like-ness. Electrons have a "characteristic scale", the Compton wavelength, that is vaguely analogous to the relaxed radius of the soap-bubble-electron. But it turns out if you squeeze the soap-bubble by running another soap-bubble into it, instead of distorting the two bubbles shrink during the collision while remaining perfectly spherical, then bounce back to there original radius after it. This means that while the electron when left alone has a "radius" associated with it, when it scatters off another charged particle is appears "point-like" in the sense that the structure function never deviates from unity.
Again: these are analogies between apples and penguins, so use them with care.
proportional representation
Proportional to what? The number of votes a private organization got? Why should private organizations be privileged? Why should Parliament or Congress or whatever represent the interests of private organizations rather than voters?
People, not Parties, are what should be represented in Parliament.
Proportional representation schemes just take for granted that political parties ought to have precedence over people, which is the problem with most modern democracies, not the solution.
PR is an attempt by parties to capitalize on the flaws of a check-mark voting system. Any voting system that allows voters to rank candidates is vastly better than PR because it provides electoral officials with more information, and minimizes rather than maximizes the role of private organizations in the representational system.
1% of the population controls more than 50% of the wealth
Nonsense!
400 divided by 300 million is a little over 0.01%, not the ridiculously large 1% you suggest.
I'm pretty sure we're going to have to rethink the whole "eat the rich" plan: there are no longer enough of them to feed more than a couple of poor families for a few years...
Why are we dumbing things down to cater to the bottom of the pool? What the hell is wrong with society, It's encouraging people to be illiterate and undecuated?
Humans are convenience-seeking. The whole process of technology development is driven by convenience-seeking. Hardly anyone knows how to use a manual spark advance on a car anymore, or a manual choke and even a manual transmission. Why learn those skills when we can get the machine to take care of them automatically?
You probably don't know how to crack-start a car, do you? There's a special trick to it to avoid breaking your wrist in the event of a backfire (which was sufficiently common that the resulting break pattern actually had the medical name of "chauffeur's fracture").
You use technology every single day that is the direct result of the process of "dumbing down" that you're decrying. We all do. The problem is, as geeks, we like to see the bones of the system exposed. We like the freedom to tinker and create and fix. We inevitably lose all that as the very process that motivated the creators of the technology continues to refine it.
This is true on all levels, both within a technological area and across time when looking at different technologies that solve the same problem. Cars are vastly easier to operate than horses. Power boats are vastly easier to operate than sail boats or canoes or kayaks. The most complex smart phone is vastly easier to operate than a telegraph. Guns are easier to use than bows or swords. I'm sure various types of stone tool in use 10,000 years ago were more convenient in some sense than their predecessors from 100,000 years ago.
So far from decrying this tendency toward convenience-seeking, we should embrace it and accept it, and always be looking to keep ahead of the curve of boring, convenient technology. The Web itself grew this way: however awkward early browsers were to use they gave more convenient access to information than books and periodicals.
What's the advantage of this over one in a mine that justifies the cost
Primary cosmic rays are much simpler animals than secondary cosmic rays. Primary cosmic rays are almost 100% protons, which almost never reach the surface of the Earth because they interact with the atmosphere and create cosmic ray "showers" that are rich and complex, full of muons and gamma rays and prolific in neutron production as well. Even fairly deep underground dealing with these backgrounds is a complicated process.
Having only primary cosmic rays to deal with makes life somewhat easier. There may also be dark matter signals that are too low energy to penetrate the Earth's atmosphere--that is, weak signals in the low-energy cosmic ray background due to dark matter collisions or decays integrated over a very large volume.
The ideal place to do this kind of work is on the Moon: because it has no atmosphere, pions produced by cosmic ray protons will come to a halt before they decay, so there are only low-energy muons produced. Thus, a couple of metres of rock on the Moon will give you shielding as good as a much thicker layer on Earth.
they are dangerous and they need to be built properly, I.E. NOT WITH A PROFIT MOTIVE
What a strange thing to say. I fly in aircraft built with a profit motive now and then, and haven't noticed that the motive of the builders particularly affects the dangers involved. Subsidized, state-run airlines like Aeroflot have no particular advantage over commercial airlines.
Why do you think the motive of the builders matters? The people who built Chernobyl were not motivated by profit. Nor were the people who built Windscale.
Bad engineering is a product of human beings, and it isn't like we live in a world where you can divide people into "good people" and "bad people" based on their motives, particularly when the major choices are profit on the one hand and power on the other. I can't offhand think of any major engineering work that wasn't primarily driven by one or the other of those motives, and I note that the profit motive sometimes produces wonderful things. The power motive does too, if you're into that kind of thing, although perhaps less frequently, and with more manufactured famines and genocides along the way.
All you're doing is saying that concentrated dangers are more worthy of avoidance than distributed dangers simply because they're concentrated.
Not at all. I'm saying that coal plants fail in ways that are cheaper than nuclear plant failures. This is trivially true. I don't know of any case in the past fifty years where a coal plant failure has led to a complete loss of capital investment of the kind that routinely happens in relatively trivial nuclear plant disasters. If Fukushima were a coal plant it would be back in operation today, not written-off.
This has nothing to do with danger, which is fairly trivial in both cases, albeit greater for a coal plant due to chronic release of radioactives, heavy metals and other pollutants. It has to do with cost, which is why I said, "The cost is the big problem."
Now, you can argue that coal is unfairly subsidized and whatnot, although nuclear has its own subsidies as well, notably the whole liability cap thing. But you can't argue that nuclear doesn't write itself off pretty easily compared to coal.
Yeah, the thermal feedback and the lack of containment (necessary to allow the fuel to be replaced while operating) is a huge draw-back.
The confusion between "pressure vessel" and "containment" is one of the most frustrating thing about this whole discussion, although it does have the useful side-effect of marking the ignorant.
Reactors like the CANDU, which run on natural uranium and can be refueled while running don't have a pressure vessel of the kind a conventional PWR or BWR does. Dunno what the RMBK (Chernobyl) design has but the CANDU uses "calandria" tubes that contain the fuel rods. The refueling machine works on one tube at a time.
However, the reactor containment has nothing to do with the pressure vessel. All well-designed power reactors have containments, which do not in any way interfere with refueling.
OK, so I've never really understood 'dark matter', but if there's a bunch of stuff floating about that's not stars and only shows up through things like gravitational micro-lensing ... might this cover some of the mass that is dark matter?
Maybe, for galactic dark matter, which is completely unrelated in every respect to dark matter on larger scales, although ignorant people typically use the general term "dark matter" to refer to all types of dark matter indiscriminately, creating enormous confusion in the process.
Galactic dark matter (GDM) is hypothesized as an explanation for the flat rotation curves of spiral galaxies. Based on the visible matter (stars) in a galaxy we can get an estimate of the mass inside a given radius. At sufficiently high radii we see the amount of visible matter dropping off, and expect that the few stars at even larger radii will start to behave like planets orbiting a distant mass with a 1/r**2 fall off in gravitational strength. But we don't see that. Instead more distant stars move as if the amount of matter inside their orbits around the galactic center contained ever more mass as they get further and further away. We can't see any visible matter to account for this, ergo, "dark matter".
One possible candidate for GDM are so-called "MACroscopic Halo Objects" (MACHOS, to contrast them with Weakly Interacting Massive Particles, or WIMPS. Physicists really need to get out more.)
An impediment to the MACHO hypothesis has been that the Initial Mass Function, which describes the probability of an object of mass M condensing out of a primordial cloud of gas and/or dust, was believed to drop off rather steeply at low masses. This observation suggests that it is at least a little higher than previously estimated, although I don't know if that is anywhere near high enough to account for a significant portion of GDM--my sense is not, but it's been a few years since I've paid much attention to this question.
At larger scales we also see anomalous motion of galaxies and galactic clusters relative to the amount of visible matter, and at the very largest scale there is much less visible mass than required to keep the universe in the state of almost-but-not-quite-closed that we see. If these phenomena are caused by an excess of matter at larger scales we know that it is non-baryonic (not made of protons and neutrons) because we have a very good estimate of the density of protons and neutrons in the universe based on primordial nucleosynthesis: the denser the early universe was in protons and neutrons, the more helium would have been created, and given we know the early universe was about 23% helium (there are complex self-consistency checks on this number based on other atomic species) we know there are not enough protons and neutrons to account for the large-scale dark matter (LSDM).
Therefore, we know that LSDM is completely unrelated in every respect to GDM: the problems they solve have different constraints and one requires exotic new physics while the other is relatively mundane. It is deeply unfortunate that people are so incompetent in their use of abstractions that they are chronically unable to distinguish between these two unrelated problems.
I guess it's because we all love tatas but the prostate just isn't very sexy
Nope, it's because we think "Men last!" is a noble sentiment, although it's usually expressed in a more obfuscated but logically equivalent manner.
Men die of all causes at younger ages than women. Men are the majority victims in all forms of violent crime except (possibly) rape, where male victims are about 10% of the total, although under-reporting is such a huge problem no one really knows (or much cares) what the real number is. Men--especially young men--commit suicide up to five times as frequently as women. If a person dies on the job, the odds are over 90% they are male. And so on.
Tell anyone this and they will immediately start making stuff up, mostly in the vein of "Men are complicit in their own poor health, high rates of crime victimization and on-the-job fatalities." Because, you see, males are autonomous, powerful, independent individuals who are completely and totally responsible for their own behaviour and under no social influence of any kind whatsoever, whereas women are helpless little things who are never to blame for their own actions and must be carefully treasured and protected by society. That's the implicit message, anyway, however vile and nonsensical it may be in its characterization of both sexes.
Yep, we can't trust our government or companies to do anything competently. For our own safety, we should clearly ban:
Nuclear plants are unique amongst these things in that their failure modes are:
1) rapid
2) complex
3) expensive
The speed comes from the energy density of the core, which is many orders of magnitude higher than for any other power source. A typical nuclear plant contains something like the equivalent of 100,000 boxcars of coal in its fuel rods, and while only a tiny fraction of that can be released over a reasonably short interval, only a tiny fraction has to be released over a relatively short interval to ruin the core.
Reactor kinetics are complicated and the cooling and control systems more-so. Complexity is a bigger issue in second and third generation designs--one could even say that the whole point of fourth generation designs is to engineer out as much complexity as possible. However, there is always going to be a fairly high level of complexity for anything beyond the "nuclear battery" type reactors (which to my mind are probably viable sources of energy in the long term.) The high energy density and consequent rapid pace of events during failure mean that the humans involved in the process are going to frequently make bad choices.
The cost is the big problem: a failure in a coal plant results in some nasty chemicals released into the environment, maybe some people burned in a steam explosion or the like. But it is very hard to create a coal plant disaster that writes off the capital investment or exposes the operator to the kind of widespread liability that nuclear disasters do.
So anyone who is not innumerate realizes that the risk-cost/benefit trade-off for nuclear power is very different from most other technologies. The benefits are significant, but a long, long way from "power too cheap to meter", which was the original promise of nuclear power. The costs are having an event like Windscale or Chernobyl or Fukushima every decade or two. For numerate people, the trade-offs involved are not a slam-dunk on either side.
By way, as a noob and an AC, the link isn't in html - maybe some moderator will fix it.
You REALLY must be new here... /. mods have one job: to create misleading and false headlines and ensure that summaries are less accurate when they are posted than when they are submitted. In this case, they have for some reason replaced "pressure vessel" with "containment vessel", presumably to make it clear to absolutely everyone that they know nothing about the technology of nuclear power.
That's an excellent link, though, and the data indicate that the scenario described in the article is pretty unlikely--the water level is clearly stable until significantly after the tsunami. No amount of fiddling with the calibration on the gauge is going to affect that: the curve is flat, then starts to fall an hour or so after the tsunami.