... even if N = 4 in a non-double-blind placebo-controlled experiment isn't exactly science. But a lovely anecdote, and one that matches my own personal experience (from long ago) in many ways. I hope people are actually reading TFA -- but wait, this is/. so that's a silly thought.
I gotta say, are we talking about the same Parthenon? The one built at the top of a hill overlooking Athens as pretty nearly the sole structure on the hilltop?
As you can see, it is pretty much on top of a mesa. So I'm not sure where your "slight dip in the terrain" could possibly be.
I only point this out not because your argument is implausible in general, but your specific example is one of my favorite places on Earth and although I've only been fortunate enough to visit it in person twice in my lifetime (so far) I remember the walk up from Athens proper quite well, including stopping in some of the many small taverns that are along the trek for octopus and retsina.
That was really lovely, and thank you for posting it.
You assert that one problem with detection is the difficulty of accelerating entire neutrino detectors to GeV energy scales. I'm not sure that I agree. Muons, as we know, decay into electrons and two kinds of neutrino/antineutrino. Electrons moving at GeV scales have more than enough energy to be transformed into muons in the inverse reaction -- if they happen to hit an electron antineutrino -- or more properly, they have a chance to be transformed into a W- boson which can then decay into several things -- lepton/neutrino pairs or quark pairs, one of which produces muons
Muons are easy to detect. Electrons with "suddenly" shifted energy are also easy to detect (another possible outcome). Finally, quark-antiquark "jets" are easy to detect.
At the densities of thermal neutrinos asserted, it seems reasonably probable (without, admittedly, doing the computation) that GeV scale electrons will encounter free neutrinos and undergo the inverse reaction and produce muons along a freely moving beam track and indeed that places like SLAC and the Duke FEL would be producing a small but detectable flux of muons all along the straight legs of their beams that would then either exit sideways (where they could be detected lots of ways) or continue along the collision frame of reference and be moderately separable at the next bending magnet. Yes, there would likely be some auxiliary production near the actual beam from electron collisions with beam pipe metal outside of the beam envelope, but one would expect to be able to put a vacuum pipe along the frame of reference of the collision a kilometer long or thereabouts PAST a a bending magnet (at the right angle) at the end of a long straight leg and run it into a detector, which would then detect all/mostly muons produced by neutrino scattering. Or so it seems.
...contradictory, inconclusive, and (as even Dr. Sanjay Gupta of CNN finally came to realize and stated in public when he changed his stance on pot) the result of decades of research funded for the sole purpose of finding something wrong with pot. If 96% or more of all research grants are titled "Investigating Marijuana as a risk factor of bipolar disorder and schizophrenia", and the only way to have a grant renewed is to find some positive (that is, negative) effect, it is hardly surprising that 96% of all research results turn up something negative about pot. What is really interesting is that in spite of subjecting it to a microscope far more demanding than we have ever applied to any other substance under similar circumstances, so very little has been double-blind confirmed as a "risk" to pot smokers. It "interferes with" (but certainly does not "prevent") the formation of short term memory -- for the duration of the time you are high, with no long-term effects. It is indeed used as self-medication for lots of different kinds of dysphoria, and can by preventing or ameliorating dysphoria keep people from making beneficial life changes. Sometimes one does need to take action instead of endure when life sucks. Other times, its gonna suck regardless of what you do, and then sure, pot can help make it suck less.
The other really interesting thing about pot is the number of myths straight out of the War on Drugs are still being perpetuated by people who heard some pithy thing about it twenty or thirty years ago and never thought to doubt the veracity of their government or question its interest in the whole matter.
The government itself is pretty schizophrenic on the issue. There are several places one can get to (compilations of) original papers on pot, and (allowing for the confirmation bias that is rampant in medical science these days, especially when reporting anecdotal "evidence" rather than double blind, placebo controlled studies) it really is pretty benign compared to ever so many other things that are quite legal. The same cop who arrests you, the judge who sits on your case, and the lawyer who gets you off can easily be functional alcoholics. I'm guessing alcohol and bipolar disorder or schizophrenia don't mix real well either -- but that is never mentioned or discussed, for some reason...
When I was much (decades) younger (and still smoked) I wrote code all of the time when high. In fact, it was one of life's pleasures -- the concentration focus was fantastic. And yes, the code was very complex, was thousands of lines long (when finished) and ran perfectly when I was done as far as I was ever able to tell.
With that said, not everybody could do what I did and work effectively high. But I knew a fair number who could and did, and of course I knew a few who were useless when high. Of course, I knew a fair number or people who were useless coders stone cold straight. This isn't terribly surprising -- the world is full of functional alcoholics too. Pot is different from alcohol, though, in so many ways. Alcohol eventually puts you into a stupor, then kills you. Pot at worst puts you to sleep and has no known fatal dose. It is considerably safer than aspirin or caffeine -- the former you can easily overdose on or it can kill you outright with e.g. Reyes' Syndrome. Caffeine is lethal at doses somewhere between 2 and 20 grams (depending on your metabolism and weight) -- not easy to ingest in coffee, easy to ingest if you put a couple of spoonfuls of legal, over the counter caffeine powder onto your morning post toasties. Cigarettes, don't get me started -- a single cigarette can kill a small child if accidentally ingested, and nicotine makes a dandy insecticide even when highly diluted.
In addition to being amazingly safe compared to almost anything humans consume outside of brocolli, pot is basically a non-prescription (openly illegal in many states) antidepressant. Lots of people who smoke (or drink, for that matter) are self-medicating or compensating for the fact that their lives suck for reasons utterly beyond their control. Is it a good medicine compared to SSRIs or other prescription medicines? I don't know. I do know that drug companies don't want you to have the choice. I do know from bitter experience that the law enforcement industry from police through the lawyers and the courts make a living from pot. I know that the biggest single risk for pot smokers isn't anything associated with pot itself -- it is being arrested, charged, jailed, forced to pay thousands of dollars for bail, forced to pay thousands more for lawyers, forced to pay fines and court costs, forced to endure probation, forced to pay for "rehabilitation". It is being fired, not being hired, not getting into college not because of your grades or intelligence (both of which can be just fine) but because of your "police record". And the penalties scale up enormously for the poor and stupid who often smoke weed because life as a janitor or store greeter or one of the dudes who has to put on a costume and wave at passing cars to get them to file their taxes or patronize a failing store sucks, but weed makes the menial and mindless jobs you can get a bit more tolerable without ruining your liver.
If pot has a flaw as a recreational substance, it is that it can, by making a shitty situation tolerable, act as an ambition suck. Hamlet on pot:
To be, or not to be: that is the question: Whether 'tis nobler in the mind to suffer The slings and arrows of outrageous fortune, Or to take arms against a sea of troubles, And by opposing end them? Or just get high And suffer no more; and by suffer to say we end The head-ache of the thousand natural schlocks That life is heir to, 'tis a consummation Devoutly to be wish'd. So don't bogart that joint, My friend, pass it on over to me...
Sometimes, though, it really is better to take arms against the sea of troubles and by opposing end them. Pot can make it a bit too easy to suffer the slings and arrows and end up trapped in a life that consists of little else. Or not. Or it can do so for a while, and then people grow up. Ultimately, it ain't nobody's business but your own, and it certainly isn't a positive predictor of failure -- or success. Like anything, for some people (especially some of the me
Well, to be honest, they've asked for funding to do the obvious experiment to test it. It's not particularly clever, only expensive. And, as has been pointed out repeatedly above, they haven't "discovered" this, it is part of the standard lexicon of QED and has been for maybe 60-70 years.
A clever way of testing it would be to use e.g. a free electron laser like the one we already have at Duke and shoot the laser beam into a "wiggler" -- a region of alternating crossed fields -- well downstream of the circulating ring. No need for two lasers, no need for massive new expense. In the frame of the photons, the region of alternating crossed EM fields looks like a photon heading the other way. You can make the wiggler field strength quite large and put a bending magnet just past it with detectors and look for positron-electron coincidences. This would actually have lots of advantages. Cheap. It uses existing hardware instead of building (much) new stuff. The pairs produced would not be in the rest frame of the lab (but in the "virtual" rest frame of the collision) and would only have to travel a short distance before encountering a field that could separate them before they annihilate. And when one was done, one could take the whole thing apart and go back to using the FEL for its many other purposes and say: Gee, guess quantum theory works after all and go about one's business. Unless of course, there are surprises, which seems to be to be class A unlikely but which is barely, barely possible and hence worth perhaps a MODEST expense to verify it.
Re: IBM Memo 92148 (Anonymous Coward/Slashdot) Can you make condoms with it?
Hmm, intriguing idea. Almost certainly, but out of which polymer? A rigid "Titan" condom could certainly cover more than one situation (and the idea had considerable appeal when we ran it over the flagpole among our senior execs to see who saluted it and who turned away blushing) but the boys here in R&D said there might be trouble fitting it into a wallet. However, the marketing boys said that we wouldn't even have to change the name -- Titan Condoms (made by IBM!) would sell like hot cakes even if one did have to keep them standing on a shelf or nightstand next to the bed. Besides, if they don't sell to the general population, a bit of retooling and they'll make gangbusters self-propelled grenade casings (especially in the larger sizes) -- although legal says that calling them "Titan missiles" might infringe some trademark or other.
R&D was, however, quite excited at the prospect of a brush-on "Hydro" condom -- one would never need to take it off. We had a number of volunteers for a pilot project, and it turns out that in fact, one might never be able to take it off. Apparently "Hydro" is also being considered as a nearly indestructible super glue because of all of its dangling, um, "bonds" but this was being investigated by another team. There were, unfortunately, a few drawbacks pointed out by those party-poopers over in legal and their paid shills from the medical profession, so the idea was tabled for the time being, which basically means that we're still going ahead with the project but looking for just the right test population -- males on dialysis or willing to undergo a critical surgical alteration of the liquid waste elimination pathway, for example. However, we're a lot more interested in large federal or state contracts; this is (for example) an intriguing idea for our prison systems, if we can get it past Engineering.
Keep up the good work, AC, and we are gratified that you are making this valuable suggestion anonymously, as it saves us from the tedious process of running you down and making you sign release forms or having you assassinated so that we can cleanly patent the idea as our own. Now you'll have to excuse me -- I have to go empty my cloaca.
And 1) is both true empirically (climate models are failing to accurately predict climate) and openly acknowledged to be true by, among others, the IPCC. Openly in AR3, relegated to selected paragraphs deep in the document in AR5, but there nonetheless.
2) is still an open question -- or rather, there are definitely feedback that mute the severity, but it is also claimed that there are positive feedbacks and it is not yet clear which one wins. CO_2 alone would produce between 1 and 1.5 C of warming by 600 ppm (some 0.5 of which we have already realized). Hansen believed (and probably still believes) that water vapor feedback would at least double, more likely triple it to between 3 and 5 C. Empirical evidence has gradually forced nearly all of the climate science community to cut back their "best estimates" (based on a statistically meaningless mean of the predictions of the broken climate models, see 1) above) of total climate sensitivity to roughly 2.7 C in AR5 and it is currently in free fall in the literature, increasingly constrained by the lack of tropospheric warming, "the hiatus" (as it is named and discussed in AR5) and Bayes theorem. Currently the argument is whether or not it will end up as high as 2.3C, with papers appearing arguing that it will end up being in more or less neutral net feedback territory -- 1 to 1.5 C -- and others covering the range of 1.7 to 2.3 C. Since basically this is a scientific crap shoot and has been from the 1980s on (partly because we are still learning about clouds, partly because the "physics" that the models supposedly are based on begins by averaging phenomena in a nonlinear Navier-Stokes equation from its Kolmogorov scale of around 1 mm to the cell size of around 100 km -- with adjustable parameters galore -- as if it does not matter) so you pays your money, you places your bet. Net negative feedback hasn't even been ruled out by the data, and the longer the hiatus continues the more likely it is that the feedback is indeed net negative.
4-6) are what they are. Sea level rise is almost invariably given as the primary cause of catastrophic damage, yet it has also proven to be the one place where there is absolutely no sign of catastrophe. SLR rates have changed little for 140 years. It is also remarkably difficult to predict the rates at which land ice will melt, given the problems with 1) and 2) -- Hansen (as the primary author of the entire claim for future catastrophe) goes on TED Talks and with a straight face says that he expects 5 meters of SLR. Any other sane climate scientist I've talked to is now talking about anywhere from 30 cm to as much as a meter. The data itself suggests that we'd be unlucky to make as much as 30 cm by 2100. Public media are full of egregious claims of ongoing disaster (melting Himalayan glaciers, increasing tornado or hurricane damage) often and sadly backed by public figures in the scientific community that should no better as there is no evidence of any of the above). This quite correctly reduces the credibility of the other claims of these individuals -- if one went back and looked at the predictions that Hansen in particular has made in fully public view ex officio as head of GISS and how badly they've failed, it would be difficult to see how he has any credibility left. Beyond that, many -- although not all -- of the claims for damage due to "climate change" (something that happens all of the time naturally and hence is impossible to attribute or refute) are marginal results that are not statistically significant. And estimates for the damage resulting or likely to result from climate change often fail to take into account benefits accruing from climate change or the simple fact that nature has already accommodated the change given the smear of temperatures and climate ranges available between the equator and the poles.
All of this greatly complicates the discussion of costs and benefits. Not everything about global warming is bad. Indeed, the global warming that has been ongoing
Was there an actual point in there? Is your optimism going to produce a battery capable of storing 20 GW-hours of energy or high temperature high current superconductivity capable of transmitting electrical energy 5000 miles (both cost-effectively)?
If you want to look at more than a couple of decades, you can look at the entirety of figure 9.8a in the IPCC's AR5 for the still appallingly short term, or the thermal record of the Holocene for a somewhat longer term view. Allowing for high-frequency vs low-frequency (proxy derived) information, the temperature is rising at an entirely non-alarming rate from a) the Little Ice Age, which was the lowest temperature in almost the entire Holocene (hence its name); b) the Dalton Minimum. Both of these were serious bouts of extreme cold as far as the Earth's "mean" interglacial climate is concerned, and it is both reasonable and fortunate that the Earth rebounded from them. If you look at the more recent data (e.g. 9.8a) you will note that the models of CMIP5 do a literally terrible job not only over the recent past but over the entire span of HADCRUT4 outside of the reference period. If you look at a fourier transform of the model predictions when their forcing is turned off -- I believe that there is one you can find in AR4 but I can't recall the specific page/section -- you will note that it is flat as a pancake for times greater than around 100 months. That is the basis of modeller's belief that the 20th century's warming stretch was due to CO_2 and not natural causes -- their models produce NO unforced warming in the long term as they do not permit the significant aggregation of natural fluctuations.
Of course nature has all kinds of unforced variation at timescales longer than a decade as a glance a the long term climate record clearly reveals.
While we are on timescales of a decade, note well that very nearly all of the warming of the last 70 years occurred in a single stretch of roughly 15 years from 1983 to 1998. Temperatures were very, very nearly flat before this, actually descending from a high point in the mid-40's to the mid-70's, rising a tiny bit back roughly to par with the 40's by the early 80's, and then went up in the late 80's and early 90's capped with a sudden bump due to the 1998 super-ENSO event. Since then, temperatures have once again been nearly flat. Why is it that this one 15 year stretch is proof of AGW to you, but the rest of the 20th century (including the unforced increase in temperature from 1910 to 1945, almost equal in magnitude to the late-20th century bump) doesn't count?
Finally, why do you feel compelled to force the world to "transform", at enormous expense and the consequent perpetuation of human misery and death, to try to eke out renewable energy when the technologies that might make it work one day are still pitifully immature? Do you not understand that by making energy more expensive, you are directly increasing and perpetuating world poverty not for Al Gore or any of the comparatively wealthy people in the US, but in the third world where tens of millions of people die every year from poverty that can be directly linked to energy poverty?
Finally, you can wonder all you like about how well I understand statistics. The answer is properly "better than 99.99% of the people on the planet" -- at least 4 nines, probably 5 -- but the one relevant thing you might want to study to catch up on is encapsulated in a lovely little monograph entitled "How to Lie With Statistics" -- a well-known classic in the field, written for a lay person.
When you read it, then go back to read AR5, sections 9.2.2 and 9.2.3. To translate for you: "We haven't any justification for forming a MultiModel Ensemble mean and using it as if it is an axiomatically justified statistic. In fact, we have excellent reasons not to, and if we do we cannot possibly say what the result means or how it might predict the actual climate. But we're going to do so anyway."
Ha, very good sir! I'm assuming that he was using -- as we all do, in casual conversation, unless we are conversing with a mathematician about black sheep in Scotland -- his own personal, gravitationally oriented sense of up and down. In his personal reference frame the sun will indeed rise, and if it doesn't he can always do a sommersault.
Your warped Nietzsche quote, BTW, also has me gasping in admiration. Even your fondness for Penguins is admirable.
You mean extrapolating from known behavior in the past sort of like what we do using -- Physics? Chemistry? Biology? Anything else in the entire compendium of human knowledge about the real world (as opposed to empty exercises in self-referential logic like pure mathematics)?
Or are you trying to imply that Hume's problem with extrapolating the past has finally got an analytical/logical solution as opposed to an axiomatic/statistical solution a la Jaynes?
I'm only asking because as soon as you remove empirical science from our system of knowledge -- which is all fundamentally extrapolation from past observations (that's the "empirical" bit) -- what is left as a non-joke prediction is being psychic. Which is, curiously enough, a bit of a joke.
(And yes, the examples given were deliberately obvious, but the point of the obvious is well taken -- we cannot be certain that the sun will rise tomorrow on the mere basis of either a compendium of observations that it has done so in many, many past tomorrows or even on the basis of observationally deduced laws concerning gravitation, the shape, location, and probable trajectory of the Earth relative to the Sun, the probable continuity of the processes that drive the sun, the probably true empirically based law that the angular momentum of the Earth will be conserved and that rotation will eventually "make the sun rise" yet again, because all conclusions about the future are ultimately based on the extrapolation of observed -- not really "known" -- behavior in the past, and as Hume noted, we cannot prove using any sort of pure reason that the future will be like the past, and the best proof of scientific induction that we have so far is the Cox-Jaynes axioms and probability theory as the logic of science.)
Incredibly well stated, sir. Sadly, nobody who reads proclamations of The Government as if they are gospel truth seems aware of the fact that we are currently extending the all time record interval without a category 3 hurricane making landfall in the US, that like it or not SLR is being measured at the terrifying rate of between 2.5 and 3.5 mm/year, within noise of its 140 year rate (and if anything, is currently actually decelerating, although statistically neither any observed "acceleration" nor "deceleration" is meaningful when compared to the historical record). Tornadoes are way down and have been for several years. We just had a record-setting cold year in the US (with daily cold records outnumber warm records maybe 2 to 1) with a record-setting cold winter. The current projection for midsummer sea ice is pretty close to normal. The antarctic has quietly been setting sea ice records for two or three years running without anyone paying the slightest attention (except maybe when boatloads of tourists travelling there to "document sea ice loss" get trapped for weeks in the ice, the boats that come to rescue them get trapped in the ice, and it takes large amounts of money and risk to rescue them).
But aside from all of that, the assertion that we could deliver all of the world's current energy requirements at all, with almost unlimited investment, without carbon is almost without foundation. Almost because if we invested sufficiently heavily in nuclear power and successfully developed e.g. LFTR (Thorium) as an alternative nuclear power resource, it is barely possible that with enormous investment and the building of hundreds if not thousands of plants and the extensive mining of e.g. Monazite sand we could make it. Assuming, of course, somebody were willing to foot the bill for the third world and the rapidly developing nations like India and China.
As for solar, I love it to death, and as time passes and technology develops it might eventually be a prime-time player. In the meantime, it is expensive compared to carbon, useless above a certain latitude, and useless at night. We do not have any mature, cost-effective technology for storing energy from solar to deliver at night, and we are in all probability at least decades away from having one. Wind power is even more problematic -- you can't even be guaranteed of having power during the day, and it has to be stored/buffered on a minute by minute basis as the wind is highly intermittent nearly everywhere. Long range delivery of electricity is also still not feasible, so we cannot generate electricity in Arizona and ship it to Maine, not without a truly monumental investment in e.g. ultra-high voltage trans-continental transmission lines or the development of new technologies. In the meantime, both of these power sources are completely inadequate as standalone energy resources without substantial backing from fuel-burning resources -- either carbon or nuclear. Even things like electric cars, touted as being better than gasoline, suffer from serious energy density storage problems and have pitiful ranges (as well as numerous other issues). Biofuels do better -- I can actually believe that we might manage to break even or win a bit on biofuels within the next decade, especially if new genetically engineered organisms and improved technologies there help out. But not even biofuels are prepared AFAIK to take on the full burden of generating not only automotive power but general electrical demand, and there are major questions about how scalable they will end up being even produced on an industrial scale.
So precisely how could we eliminate the use of fossil fuels, or carbon based fuels, worldwide, without any negative impact on life style? I track the technologies that are out there pretty closely, and am a physicist (and thereby "probably not an idiot") and I cannot see any possible way we could manage it with a HUGE negative impact as the required technologies simply don't exist yet (and some of the one
Not exactly lost, just thermalized. The mean free path of photons was simply short relative to cosmic distances, and gravity hadn't yet pulled enough hydrogen down into a gravitational well to ignite it, the distribution of matter was still fairly uniform except where it was gravitationally coalescing.
Once the stars lit up, radiation pressure quickly enough swept their immediate vicinity clear and created "shockwaves" of moving stellar wind that nucleated lots more gravitational structure as it propagated. You can see this process continue today in star-forming regions of our own galaxy.
But the light produced by the recombination era -- which was not all that short, or all that violent -- is what eventually became the CMB, "frozen out" once the universe's density dropped to where the mean free path of a photon reached "infinity".
...and one could go on and on. Line by line, Genesis is pretty much nonsense, and isn't even particularly good poetry in places where it is poetic. Heaven and Earth first. Darkness on the face of the deep, where from the next sentence it is clear that the "deep" is the waters, that is, the ocean. Then light, which divides light from darkness, with light called day and dark night. Note well that there is still no sun, but there is day and night. Then he creates a "firmament" -- that would be a solid bowl -- to divide "the waters above from the waters below" and called it heaven. Then he causes the waters under the big bowl to collect so that dry land appears, leaving behind seas. Still no sun, but light and darkness, day and night. Then he covers the earth with grass and fruit trees. Only then, on day four does he actually get around to creating the stars -- and what is their purpose? To fill an enormous visible Universe with hundreds of billions of galaxies containing hundreds of billions of stars each? Oh, no, for signs and for seasons. God created the stars so he could use them as portents and so that we could tell when to plant. Afterwards, he finally gets around to creating two "lights", one greater and one lesser, the Sun and the Moon, to give light to the night and day. That is, Genesis doesn't even grasp that the Moon isn't a light at all, it is a passive reflector of sunlight, a big ball of rock, as opposed to the Sun, which is a star just like those lights that mark out the seasons. Then he created whales and birds and fish -- after land-based vegetation that managed without a sun, and only then did he create land animals ending with humans.
So let's see, we've got a flat earth, a solid bowl of heaven hung with a tiny handful of stars to mark out the seasons, a completely wrong and absurd order of appearance of the living species and pretty much all of the matter in the Universe, and there isn't a hint of the possibility that the Earth itself isn't even a pimple on the backside of the Universe, it isn't even a single cell on a pimple on the backside of the Universe, it is a single atom in a single cell on the backside of the Universe (to scale).
Then there is Genesis 2, which tells a completely distinct and different account of creation, where Adam was created before the animals and had to name them, one at a time (good luck with that, even today) as God created them and then had to beg for God to create a woman only after it became clear that all of the animals had females but he didn't. Note well that naming a species a second it still would have taken years to name even a reasonable fraction of them; not exactly the sort of thing that could possibly be finished in a day.
Then there is Genesis 3, with the completely absurd story of God creating a tree with magical fruit that gives you knowledge of good and evil, telling the original couple not to eat any of the fruit, which they proceeded to do anyway because -- duh -- they didn't have a knowledge of good or evil so they had no way of knowing that what they were doing was wrong (where clearly, by the way, it wasn't), and then punishing them for doing what He had preordained from the beginning of time etc that they would do just so that God wouldn't die of boredom.
It isn't, in fact, the case that Genesis is anything like a good metaphor for the scientific account of the big bang through the present, which in any event is not a creation as we have no evidence of "creation" ever happening anywhere in the sense that the Bible uses the term, ex nihilo. In fact, we have these lovely conservation laws that pretty much say "creation never happens", mostly because we never see it happening no matter where and how hard we look.
Hinduism does much better, but even the Vedic creation myths and stories, treated as metaphor or not, are not a terribly good account of the scientific history.
Finally, last time I read about (and taught) astronomy, the
No real argument, but next we're going to be referencing "The Tragedy of the Commons" and "The Tyranny of Democracy" and related works. Human society works because we all make certain trade-offs of our personal freedom against our security. If we were rational, we would actually do a cost-benefit analysis of our legal system to determine whether it makes more sense to eliminate (for example) intellectual property laws, making it perfectly legal to copy any work or produce anything we know how to produce, or maintain any variant of the existing IP laws. Sadly, we're not. But a lot of the drug laws -- pot in particular -- are low hanging fruit. There is really no question that it costs far more to keep pot illegal than it ever could cost society legal.
I can attest -- Lawdy, Lawdy -- that the drug prohibition laws are far more expensive than any possible effect of the drugs themselves. Marijuana, for example, is in no way as bad for your health as being arrested for possessing marijuana. Its direct cost to a user -- once all of the artificial price increase associated with it being illegal is removed -- is orders of magnitude less costly than the complex mix of legal expenses to the user and the state, the cost of enforcing the law, and of course the cost of punishing (usually incarcerating) the user if they are caught with anything less than a tiny amount of the substance. The cost of drug laws worldwide is credibly estimated to be in the hundreds of billions of dollars -- say half a trillion. One could feed the hungry and bring about World Peace if one diverted all of this insanely spent money to other purposes and just let drug users use drugs, with fairly benign restrictions on what they can do while they are doing so.
Even the really bad, scary, truly dangerous drugs are in some sense self-limiting in proportion to their danger. Heroin is mighty bad, and extremely addicting. Like tobacco, only not quite as addicting. But if heroin were inexpensive and legal, instead of being horrendously expensive and illegal, an entire shadow government and underworld would be instantly starved for money and would wither and die, and heroin addicts would be no worse off trying to work and manage their lives with a daily fix of cheap heroin than they would be with a daily fix of expensive methadone. They'd have about the same chance of getting tired of it and deciding to kick the addiction, or maybe even a greater one if we spent a tiny bit of the money we wouldn't be spending in the war on heroin on free addiction treatment programs and public education.
People who end up fond of much worse combos -- PCP plus cocaine plus heroin -- well, I'm sure that it is really bad for them, but for better or worse that sort of thing will very likely kill them quickly, and even that is comparatively cheap compared to the lifetime costs of arresting them, putting them into prison for decades where they contract HIV and come out real criminals with a whole lot of anger and a expensive chronic diseases to manage while still not being over whatever it was that cause them to be a hard core addict in the first place.
Drug cartels, my friend, exist because drugs are illegal. Legalize pretty much everything, and "cartels" vanish overnight. We've already been through this once -- Prohibition was the best thing that ever happened to organized crime in the US, at least until drug prohibition came along with an even higher profit margin. Lose the prohibition, empty the prisons of all drug offenders who don't have an associated violent crime tagged on, and watch crime rates, murder rates, the number of police in our police state, the number of lawyers (drug laws being a huge boon to lawyers, of course) and courts, all plummet. There isn't any real money in drugs without the prohibition -- anybody can grow pot in their back yard, cocaine would cost a few dollars a pound if it weren't for drug laws, heroin ditto. And most people would still avoid both of these, because both of them are pretty dangerous and addiction or life problems associated with them would be expensive and embarrassing, just as they are now for smokers and alcoholics.
And I was wrong when I said that I have no vices. I definitely want to buy kitty porn. Would you believe that I've never seen cats doing it? Kitty porn must be rare and hard to get.
I didn't realize that governments regulated it so strictly, though. For the rest of my life, I'll never be able to drive past the Tom Cat Club (a local, err, "massage" parlor that has been around on the US-70 corridor for fifty years or so) without going into hysterics. Purveyors of kitty porn, pictures of hot pussies. Arrgh.
Granting the illegal bit, illegal does not equate to "causing harm to someone". Would that it did -- that would be so very rational. However, there are plenty of things one might want to spend money on that are illegal but harm no one but arguably yourself. Drugs is one obvious example, but in many parts of the world buying pornography or sexual toys/aids is illegal, all the way up to being a capital crime. In China or much of the Moslem world, an enormous number of things are illegal that don't harm anyone or anything but the nominal reputation of Islam or Mohammed or Allah, or that represent freedom for repressed majorities like women. We're not really talking only about the relatively permissive US or Western Europe, in other words.
Of course people will use this to do some things that are directly intended to harm others in non-victimless-crime ways: Steal/pirate and resell IP of various sorts, fence stolen goods, arrange for a hit on your alimony-hungry ex-wife (maybe, dunno if that is a "commodity" it can handle), engage in human trafficking, sell arms. But some people will use it to buy freedom from oppressive governments that have made a whole lot of things that harm no one illegal because they violate some statement made in a piece of pure scriptural crack if you squint your eyes just right when you read it. Because there is rarely any percentage in prosecuting crimes of this sort once one cannot detect them or stop them for long enough for violations to become commonplace, it might even motivate social change.
To me personally, the tool is not going to be terribly useful. I'm heterosexual and married, my primary vices are at least quasi-legal and tolerated where I live, and I consider buying stolen goods of most varieties to be unethical. It isn't clear that I'd resort to it if I lived in e.g. a Moslem country and had a thing for porn -- no matter how nominally secure, the penalties are pretty horrendous. But I'm guessing that there are those who will value it who aren't planning to use it to hurt others.
Yeah, yeah. What you said. If DM/DE is an elephant in the room, it's an elephant that we know only in the sense of the blind men trying to describe the elephant by feel -- one says it is long and pliable, like a snake, another says that it is flat and massive, like a house, a third says that it is floppy and flat, like a large tree-leaf. We cannot yet see the whole elephant, and part of what we CAN see may turn out to be only the shadow of the elephant cast on the walls of Plato's Cave in some projection, nothing like the actual multidimensional elephant. Our knowledge of physics (so far) helps define a few of the projective dimensions or the parts of the elephant we can feel out, but it, too, is incomplete, being part of an even bigger elephant known in various projections by the blind...
Well said, sir. Repeatedly, even. Although (as a physicist also) I do have to say that DM/DE are a) one of several possible explanations or models that we have -- so far -- and while it has emerged as one of the most consistent that doesn't make it either unique or right. We may not have even hypothesized the right model yet (given the indirect nature of the data, that would hardly even be surprising, if true). b) One of the problems with having a huge amount of mass-energy out there, effectively decoupled to electromagnetic forces, in addition to making said mass-energy literally invisible is that one can imagine entire "universes" of field theories underneath the very loose constraint of the observational data. Does DM couple to e.g. the nuclear force? Are the quanta of DM stable? Is DM not really "dark", but merely very, very weakly interacting, e.g. massive neutrinos? IIRC it is possible to explain the cosmological data by giving three flavors of neutrinos a mass-energy order of an eV. And then we have to ask -- what if there are more than three flavors, and DM is a "leftover" neutrino from a super-heavy lepton that hasn't existed since the big bang so that the neutrinos have nowhere to go? DE is even more difficult to cope with -- are we talking about the massless quantum of a fifth force altogether, or is it somehow tied to the four fields we already know about?
Given that we have yet to fully reconcile gravitation and relativity in a consistent quantum theory and that we lack a TOE (meaning there is still room enough to drive -- err, "elephants" through the gaps:-) we are, as you say, working with descriptive phenomenology -- classical theories of gravitation, or relativistic theories of curved spacetime, quantum models of nuclear (strong and weak) and electromagnetic interactions that works (so far) pretty well in specific contexts. But we don't even know if DM interacts strongly enough with sufficiently dense "known" matter -- matter e.g. in the heart of suns -- to be able to slow down in transit and accumulate. We don't know if DM remains stable and decoupled at energy densities like those accessible inside the cores of stars, or for that matter inside e.g. neutron stars. We don't know if DM interacts with other DM to be able to provide the "friction" needed to cause gravitational collapse of DM. All we know is that when we examine galaxies, the profile of orbital velocities observed is consistent with their being more matter in the galaxy than we can see, distributed in a very unusual way.
Personally, I think it is all very interesting (although definitely not my field), but don't take any of the many assertions about DM or DE too seriously yet. Both are the ultimate "invisible fairy theory" -- literally invisible -- where the fairy is known only indirectly by means of the "the fairy must have done it" argument. This is right up there at the edge of religious thinking, because as long as the fairies remain invisible, it remains almost impossible to falsify any assertion about what the fairies do or do not cause in the observational data. I'd mumble about Ptolomeic epicycles vs gravitation, or the many gods of the many gaps over human history, but in the end, until somebody puts salt on the tail of a darkon or manages to build a TOE that includes DM/DE consistently, explains all observations, and has a prayer of being verified/falsified by more than crude phenomenological agreement it is all in the same category as supersymmetry, string theory, etc -- pretty stories, but which one (if any) of the myriad of possible models within the general approach is true?
Damn skippy. Hence the baseline external pressure limits the maximum height the siphon can operate over according to the rule P_0 = \rho g H_max, because the lowest pressure one can encounter in any fluid is zero and the pressure decreases in the constant cross-sectional area tube with height from the baseline of P_0 at the upper fluid's surface. At one atmosphere, one cannot go over a barrier of more than 10 meters. At a tenth of an atmosphere, one cannot go over a barrier of more than 1 meter (with water, ignoring viscosity and the tendency of water to boil into a vacuum at room temperature so that instead of vacuum we have a low partial pressure of water vapor in the gap).
Oh, wait -- that's exactly what they demonstrated. What a surprise. Bernoulli's formula, conservation of flow. Do we really need a 21st century publication confirming physics known, confirmed repeatedly, and taught in any halfway decent INTRODUCTORY physics textbook since the 17th century? How and why, exactly, is this idea getting press coverage? This is the second place I've seen this article reposted, and it isn't really worth the original publication anywhere but the AJP, which exists to publish precisely this sort of article for physics TEACHERS, not as "proof" of anything that isn't already well known.
...when it is a textbook problem in fluid mechanics at the introductory level? Bernoulli's equation, conservation of flow, physical conditions, end of story (within the minor tweaks introduced by viscosity and Poisieulle's formula).
Oh, wait, because somebody did the umpty-zillionth practical experiment of running a siphon and managed to publish the results.
Yeah. Sure. That makes sense.
Or, perhaps it makes no sense at all. It might make sense as a science fair project, though, for some bright high school student.
Peak acceleration (given in multiples of g) is relevant. Humans can survive impacts involving accelerations up to around 100g -- much over that and there is "no" survival (I think the peak estimate for a documented survival is around 105 g) and to survive that very much depends on how it is experienced -- uniformly good, non-locally over your body bad. Under that, a few people survive, usually damaged, with damage that reduces on average until you reach forces spread out enough and slowly acting enough that they can bring you to rest with accelerations on the order of 10g (100 m/sec^2) that most people can survive without more than bruising if the forces that produce them are spread out enough on the body. This is order of the forces/accelerations involved in surviving a car crash with seat belt and air bag and collapsible front end of a car.
These are based on both experiences/circumstances of survivors, plus analysis of the physics. There are actually lists and well-documented accounts of survivors:
(plus many others). As the first of these two links suggests, water is marginally better than concrete, and frothy, air-bubble-filled water is better than flat, calm water. Landing behind a large, heavy object (falling directly into the splash) helps enormously.
Actually, I looked into it further and it turns out that the encapsulating agent is alpha cyclodextrin. This basically a ring of 6 dextrose molecules, hydrophilic on the outside and hydrophobic on the inside. It is extremely stable and to the extent that it breaks up at all, breaks into dextrose and dextrins. Basically, it is an indigestible complex sugar that the body completely ignores. Not only that, but it is a food-safe source of fiber. Not only that, but as a food supplement, that hydrophobic center loves to grab triglycerides and trans fats and forms a complex of fats bound to the ring that can bind 9 times the weight of the ACD in fats and flush them out of the body. There is double blind placebo controlled data that it has a number of health benefits -- 6 grams a day neutralizes over 500 calories of fat a day, lowers triglycerides, lowers cholesterol, drops insulin levels, prevents weight gain, all at statistically significant levels in spite of the comparatively small N of the studies done so far.
I was impressed enough with what I learned that I'm considering adding an ACD supplement to the beer I make. There are reasons to think that it will alter the flavor profile, but quite possibly in positive ways (there is a German research paper onto this very subject, but it is paywalled). The interesting thing is that if the alterations are acceptable, one could end up with a beer that absorbed (say) half of the fat from the buffalo wings you eat along with the beer so that your body never absorbs it. It could also mean that the powdered alcohol beverages already on sale in e.g. The Netherlands could be more valuable as a dietary supplement fat eliminator than they are as a 3% alcohol fruit punch in a packet sold mostly to young people.
In a truly paranoid world, it might explain why the FDA put it on hold here. Imagine the chaos if somebody started marketing a "Margarita in a pouch" where 2-3 of them a day completely blocked weight gain and cured metabolic syndrome and effectively treated type II diabetes! Drug companies would go nuts -- nobody can really patent a complex sugar that has been known and studied for decades and that is really pretty easy to make. I can't QUITE get it to be automatically created during the mashing process of making my own beer -- it requires certain specific bacteria and/or the direct addition of a particular enzyme that takes the dextrins that are produced in the mash and wraps some fraction of them into rings -- but somebody could easily decide to mass produce the enzyme and sell it ready to add as a supplement to a wort, or one can do what I'm doing -- buying a jar of ACD directly, crush the tablets, and add them to the wort. That's too expensive for the long run, but hey, beer that is really, really good for you is a dream worth pursuing, is it not?
I think it is a mix of all of the above. Terrorists are rare (not quite non-existent) and are obviously incompetent and unimaginative. At most airports, one could fill an entire full-sized bus with explosives as long as it was labelled "Hertz" on the side, drive it right up to a place in front of the main terminal, and detonate it as a suicide bomber on any of the busy travel days of the year. If one wore the right uniform, one could probably get out, walk around to the off-side of the bus, jump into a getaway car, and get several hundred meters away before remote detonating with a phone call to a cell-phone detonator and actually escape in the resulting panic and confusion. One could do this at sports arenas, shopping malls, on large bridges. A full size bus would hold easily 5 to 10 tons of homemade explosive, and a really smart terrorist could amplify a smaller amount with aerosolized gasoline dispersed immediately before the detonation via compressed air and gasoline in tanks (the military has a similar super-bomb that has a devastating effect).
Then yes, small airplanes are trivial -- for a smart, well-funded non-suicidal terrorist -- to convert into GPS guided cruise missiles, and the idea of the kamakazi -- a suicidal human guided cruise missile -- is now seventy years old, not even a new concept. Indeed, it's a good thing there aren't too many truly sociopathic people and that true sociopaths and religious or political zealots (is there a difference?) are often pretty stupid, unimaginative and so on.
And yeah, they probably are opposed by occult counterterrorist forces that reduce the frequency of "smart" attacks like 9/11. So there might have been any number of additional attacks that were foiled. It isn't completely trivial to assemble the ingredients for large quantities of homemade explosives, and making explosives at home is a good way to end up aerosolized yourself. To do a good job of making something with a lot of power that is stable enough to transport and detonate on demand rather than when you sneeze, one has to use pure ingredients, strong chemistry-fu, precise temperature regulation and so on or one ends up making nitrate-based "stable" explosive stuff with all sorts of side compounds that detonate if you look at them funny. The feds keep careful tabs on high quality nitrates (fertilizer, nitric acid) that are often a primary ingredient. So even a lot of deranged psychopaths might have difficulty assembling the ingredients for making a bomb like that used in Oklahoma City and combining them and transporting them without killing themselves, their families (if any) and a number of their neighbors.
But still, in the end we are remarkably dependent on the general goodwill and sanity of our co-humans. Lots of people working together to make a stable, secure, moderately contented world are never guaranteed to succeed, but all it takes is one suicidally deranged and stupid sociopath to murder tens to hundreds of people or do millions in property damage; smart sociopaths can bump that pretty easily by orders of magnitude. Fortunately they are rare, and opposed by smart anti-sociopaths who at least sometimes succeed.
Slashdot Mirror
... even if N = 4 in a non-double-blind placebo-controlled experiment isn't exactly science. But a lovely anecdote, and one that matches my own personal experience (from long ago) in many ways. I hope people are actually reading TFA -- but wait, this is /. so that's a silly thought.
I gotta say, are we talking about the same Parthenon? The one built at the top of a hill overlooking Athens as pretty nearly the sole structure on the hilltop?
It doesn't precisely show the elevations, but:
https://maps.google.com/maps?o...
is one view, or perhaps this will do better:
http://www.greatbuildings.com/...
As you can see, it is pretty much on top of a mesa. So I'm not sure where your "slight dip in the terrain" could possibly be.
I only point this out not because your argument is implausible in general, but your specific example is one of my favorite places on Earth and although I've only been fortunate enough to visit it in person twice in my lifetime (so far) I remember the walk up from Athens proper quite well, including stopping in some of the many small taverns that are along the trek for octopus and retsina.
rgb
That was really lovely, and thank you for posting it.
You assert that one problem with detection is the difficulty of accelerating entire neutrino detectors to GeV energy scales. I'm not sure that I agree. Muons, as we know, decay into electrons and two kinds of neutrino/antineutrino. Electrons moving at GeV scales have more than enough energy to be transformed into muons in the inverse reaction -- if they happen to hit an electron antineutrino -- or more properly, they have a chance to be transformed into a W- boson which can then decay into several things -- lepton/neutrino pairs or quark pairs, one of which produces muons
Muons are easy to detect. Electrons with "suddenly" shifted energy are also easy to detect (another possible outcome). Finally, quark-antiquark "jets" are easy to detect.
At the densities of thermal neutrinos asserted, it seems reasonably probable (without, admittedly, doing the computation) that GeV scale electrons will encounter free neutrinos and undergo the inverse reaction and produce muons along a freely moving beam track and indeed that places like SLAC and the Duke FEL would be producing a small but detectable flux of muons all along the straight legs of their beams that would then either exit sideways (where they could be detected lots of ways) or continue along the collision frame of reference and be moderately separable at the next bending magnet. Yes, there would likely be some auxiliary production near the actual beam from electron collisions with beam pipe metal outside of the beam envelope, but one would expect to be able to put a vacuum pipe along the frame of reference of the collision a kilometer long or thereabouts PAST a a bending magnet (at the right angle) at the end of a long straight leg and run it into a detector, which would then detect all/mostly muons produced by neutrino scattering. Or so it seems.
Is this wrong?
rgb
...contradictory, inconclusive, and (as even Dr. Sanjay Gupta of CNN finally came to realize and stated in public when he changed his stance on pot) the result of decades of research funded for the sole purpose of finding something wrong with pot. If 96% or more of all research grants are titled "Investigating Marijuana as a risk factor of bipolar disorder and schizophrenia", and the only way to have a grant renewed is to find some positive (that is, negative) effect, it is hardly surprising that 96% of all research results turn up something negative about pot. What is really interesting is that in spite of subjecting it to a microscope far more demanding than we have ever applied to any other substance under similar circumstances, so very little has been double-blind confirmed as a "risk" to pot smokers. It "interferes with" (but certainly does not "prevent") the formation of short term memory -- for the duration of the time you are high, with no long-term effects. It is indeed used as self-medication for lots of different kinds of dysphoria, and can by preventing or ameliorating dysphoria keep people from making beneficial life changes. Sometimes one does need to take action instead of endure when life sucks. Other times, its gonna suck regardless of what you do, and then sure, pot can help make it suck less.
The other really interesting thing about pot is the number of myths straight out of the War on Drugs are still being perpetuated by people who heard some pithy thing about it twenty or thirty years ago and never thought to doubt the veracity of their government or question its interest in the whole matter.
http://www.drfranklucido.com/p...
http://medicalmarijuana.procon...
The government itself is pretty schizophrenic on the issue. There are several places one can get to (compilations of) original papers on pot, and (allowing for the confirmation bias that is rampant in medical science these days, especially when reporting anecdotal "evidence" rather than double blind, placebo controlled studies) it really is pretty benign compared to ever so many other things that are quite legal. The same cop who arrests you, the judge who sits on your case, and the lawyer who gets you off can easily be functional alcoholics. I'm guessing alcohol and bipolar disorder or schizophrenia don't mix real well either -- but that is never mentioned or discussed, for some reason...
When I was much (decades) younger (and still smoked) I wrote code all of the time when high. In fact, it was one of life's pleasures -- the concentration focus was fantastic. And yes, the code was very complex, was thousands of lines long (when finished) and ran perfectly when I was done as far as I was ever able to tell.
With that said, not everybody could do what I did and work effectively high. But I knew a fair number who could and did, and of course I knew a few who were useless when high. Of course, I knew a fair number or people who were useless coders stone cold straight. This isn't terribly surprising -- the world is full of functional alcoholics too. Pot is different from alcohol, though, in so many ways. Alcohol eventually puts you into a stupor, then kills you. Pot at worst puts you to sleep and has no known fatal dose. It is considerably safer than aspirin or caffeine -- the former you can easily overdose on or it can kill you outright with e.g. Reyes' Syndrome. Caffeine is lethal at doses somewhere between 2 and 20 grams (depending on your metabolism and weight) -- not easy to ingest in coffee, easy to ingest if you put a couple of spoonfuls of legal, over the counter caffeine powder onto your morning post toasties. Cigarettes, don't get me started -- a single cigarette can kill a small child if accidentally ingested, and nicotine makes a dandy insecticide even when highly diluted.
In addition to being amazingly safe compared to almost anything humans consume outside of brocolli, pot is basically a non-prescription (openly illegal in many states) antidepressant. Lots of people who smoke (or drink, for that matter) are self-medicating or compensating for the fact that their lives suck for reasons utterly beyond their control. Is it a good medicine compared to SSRIs or other prescription medicines? I don't know. I do know that drug companies don't want you to have the choice. I do know from bitter experience that the law enforcement industry from police through the lawyers and the courts make a living from pot. I know that the biggest single risk for pot smokers isn't anything associated with pot itself -- it is being arrested, charged, jailed, forced to pay thousands of dollars for bail, forced to pay thousands more for lawyers, forced to pay fines and court costs, forced to endure probation, forced to pay for "rehabilitation". It is being fired, not being hired, not getting into college not because of your grades or intelligence (both of which can be just fine) but because of your "police record". And the penalties scale up enormously for the poor and stupid who often smoke weed because life as a janitor or store greeter or one of the dudes who has to put on a costume and wave at passing cars to get them to file their taxes or patronize a failing store sucks, but weed makes the menial and mindless jobs you can get a bit more tolerable without ruining your liver.
If pot has a flaw as a recreational substance, it is that it can, by making a shitty situation tolerable, act as an ambition suck. Hamlet on pot:
To be, or not to be: that is the question:
Whether 'tis nobler in the mind to suffer
The slings and arrows of outrageous fortune,
Or to take arms against a sea of troubles,
And by opposing end them? Or just get high
And suffer no more; and by suffer to say we end
The head-ache of the thousand natural schlocks
That life is heir to, 'tis a consummation
Devoutly to be wish'd. So don't bogart that joint,
My friend, pass it on over to me...
Sometimes, though, it really is better to take arms against the sea of troubles and by opposing end them. Pot can make it a bit too easy to suffer the slings and arrows and end up trapped in a life that consists of little else. Or not. Or it can do so for a while, and then people grow up. Ultimately, it ain't nobody's business but your own, and it certainly isn't a positive predictor of failure -- or success. Like anything, for some people (especially some of the me
Well, to be honest, they've asked for funding to do the obvious experiment to test it. It's not particularly clever, only expensive. And, as has been pointed out repeatedly above, they haven't "discovered" this, it is part of the standard lexicon of QED and has been for maybe 60-70 years.
A clever way of testing it would be to use e.g. a free electron laser like the one we already have at Duke and shoot the laser beam into a "wiggler" -- a region of alternating crossed fields -- well downstream of the circulating ring. No need for two lasers, no need for massive new expense. In the frame of the photons, the region of alternating crossed EM fields looks like a photon heading the other way. You can make the wiggler field strength quite large and put a bending magnet just past it with detectors and look for positron-electron coincidences. This would actually have lots of advantages. Cheap. It uses existing hardware instead of building (much) new stuff. The pairs produced would not be in the rest frame of the lab (but in the "virtual" rest frame of the collision) and would only have to travel a short distance before encountering a field that could separate them before they annihilate. And when one was done, one could take the whole thing apart and go back to using the FEL for its many other purposes and say: Gee, guess quantum theory works after all and go about one's business. Unless of course, there are surprises, which seems to be to be class A unlikely but which is barely, barely possible and hence worth perhaps a MODEST expense to verify it.
rgb
Re: IBM Memo 92148 (Anonymous Coward/Slashdot) Can you make condoms with it?
Hmm, intriguing idea. Almost certainly, but out of which polymer? A rigid "Titan" condom could certainly cover more than one situation (and the idea had considerable appeal when we ran it over the flagpole among our senior execs to see who saluted it and who turned away blushing) but the boys here in R&D said there might be trouble fitting it into a wallet. However, the marketing boys said that we wouldn't even have to change the name -- Titan Condoms (made by IBM!) would sell like hot cakes even if one did have to keep them standing on a shelf or nightstand next to the bed. Besides, if they don't sell to the general population, a bit of retooling and they'll make gangbusters self-propelled grenade casings (especially in the larger sizes) -- although legal says that calling them "Titan missiles" might infringe some trademark or other.
R&D was, however, quite excited at the prospect of a brush-on "Hydro" condom -- one would never need to take it off. We had a number of volunteers for a pilot project, and it turns out that in fact, one might never be able to take it off. Apparently "Hydro" is also being considered as a nearly indestructible super glue because of all of its dangling, um, "bonds" but this was being investigated by another team. There were, unfortunately, a few drawbacks pointed out by those party-poopers over in legal and their paid shills from the medical profession, so the idea was tabled for the time being, which basically means that we're still going ahead with the project but looking for just the right test population -- males on dialysis or willing to undergo a critical surgical alteration of the liquid waste elimination pathway, for example. However, we're a lot more interested in large federal or state contracts; this is (for example) an intriguing idea for our prison systems, if we can get it past Engineering.
Keep up the good work, AC, and we are gratified that you are making this valuable suggestion anonymously, as it saves us from the tedious process of running you down and making you sign release forms or having you assassinated so that we can cleanly patent the idea as our own. Now you'll have to excuse me -- I have to go empty my cloaca.
Irving Bentabit
IBM (R&D)
And 1) is both true empirically (climate models are failing to accurately predict climate) and openly acknowledged to be true by, among others, the IPCC. Openly in AR3, relegated to selected paragraphs deep in the document in AR5, but there nonetheless.
2) is still an open question -- or rather, there are definitely feedback that mute the severity, but it is also claimed that there are positive feedbacks and it is not yet clear which one wins. CO_2 alone would produce between 1 and 1.5 C of warming by 600 ppm (some 0.5 of which we have already realized). Hansen believed (and probably still believes) that water vapor feedback would at least double, more likely triple it to between 3 and 5 C. Empirical evidence has gradually forced nearly all of the climate science community to cut back their "best estimates" (based on a statistically meaningless mean of the predictions of the broken climate models, see 1) above) of total climate sensitivity to roughly 2.7 C in AR5 and it is currently in free fall in the literature, increasingly constrained by the lack of tropospheric warming, "the hiatus" (as it is named and discussed in AR5) and Bayes theorem. Currently the argument is whether or not it will end up as high as 2.3C, with papers appearing arguing that it will end up being in more or less neutral net feedback territory -- 1 to 1.5 C -- and others covering the range of 1.7 to 2.3 C. Since basically this is a scientific crap shoot and has been from the 1980s on (partly because we are still learning about clouds, partly because the "physics" that the models supposedly are based on begins by averaging phenomena in a nonlinear Navier-Stokes equation from its Kolmogorov scale of around 1 mm to the cell size of around 100 km -- with adjustable parameters galore -- as if it does not matter) so you pays your money, you places your bet. Net negative feedback hasn't even been ruled out by the data, and the longer the hiatus continues the more likely it is that the feedback is indeed net negative.
4-6) are what they are. Sea level rise is almost invariably given as the primary cause of catastrophic damage, yet it has also proven to be the one place where there is absolutely no sign of catastrophe. SLR rates have changed little for 140 years. It is also remarkably difficult to predict the rates at which land ice will melt, given the problems with 1) and 2) -- Hansen (as the primary author of the entire claim for future catastrophe) goes on TED Talks and with a straight face says that he expects 5 meters of SLR. Any other sane climate scientist I've talked to is now talking about anywhere from 30 cm to as much as a meter. The data itself suggests that we'd be unlucky to make as much as 30 cm by 2100. Public media are full of egregious claims of ongoing disaster (melting Himalayan glaciers, increasing tornado or hurricane damage) often and sadly backed by public figures in the scientific community that should no better as there is no evidence of any of the above). This quite correctly reduces the credibility of the other claims of these individuals -- if one went back and looked at the predictions that Hansen in particular has made in fully public view ex officio as head of GISS and how badly they've failed, it would be difficult to see how he has any credibility left. Beyond that, many -- although not all -- of the claims for damage due to "climate change" (something that happens all of the time naturally and hence is impossible to attribute or refute) are marginal results that are not statistically significant. And estimates for the damage resulting or likely to result from climate change often fail to take into account benefits accruing from climate change or the simple fact that nature has already accommodated the change given the smear of temperatures and climate ranges available between the equator and the poles.
All of this greatly complicates the discussion of costs and benefits. Not everything about global warming is bad. Indeed, the global warming that has been ongoing
Was there an actual point in there? Is your optimism going to produce a battery capable of storing 20 GW-hours of energy or high temperature high current superconductivity capable of transmitting electrical energy 5000 miles (both cost-effectively)?
If you want to look at more than a couple of decades, you can look at the entirety of figure 9.8a in the IPCC's AR5 for the still appallingly short term, or the thermal record of the Holocene for a somewhat longer term view. Allowing for high-frequency vs low-frequency (proxy derived) information, the temperature is rising at an entirely non-alarming rate from a) the Little Ice Age, which was the lowest temperature in almost the entire Holocene (hence its name); b) the Dalton Minimum. Both of these were serious bouts of extreme cold as far as the Earth's "mean" interglacial climate is concerned, and it is both reasonable and fortunate that the Earth rebounded from them. If you look at the more recent data (e.g. 9.8a) you will note that the models of CMIP5 do a literally terrible job not only over the recent past but over the entire span of HADCRUT4 outside of the reference period. If you look at a fourier transform of the model predictions when their forcing is turned off -- I believe that there is one you can find in AR4 but I can't recall the specific page/section -- you will note that it is flat as a pancake for times greater than around 100 months. That is the basis of modeller's belief that the 20th century's warming stretch was due to CO_2 and not natural causes -- their models produce NO unforced warming in the long term as they do not permit the significant aggregation of natural fluctuations.
Of course nature has all kinds of unforced variation at timescales longer than a decade as a glance a the long term climate record clearly reveals.
While we are on timescales of a decade, note well that very nearly all of the warming of the last 70 years occurred in a single stretch of roughly 15 years from 1983 to 1998. Temperatures were very, very nearly flat before this, actually descending from a high point in the mid-40's to the mid-70's, rising a tiny bit back roughly to par with the 40's by the early 80's, and then went up in the late 80's and early 90's capped with a sudden bump due to the 1998 super-ENSO event. Since then, temperatures have once again been nearly flat. Why is it that this one 15 year stretch is proof of AGW to you, but the rest of the 20th century (including the unforced increase in temperature from 1910 to 1945, almost equal in magnitude to the late-20th century bump) doesn't count?
Finally, why do you feel compelled to force the world to "transform", at enormous expense and the consequent perpetuation of human misery and death, to try to eke out renewable energy when the technologies that might make it work one day are still pitifully immature? Do you not understand that by making energy more expensive, you are directly increasing and perpetuating world poverty not for Al Gore or any of the comparatively wealthy people in the US, but in the third world where tens of millions of people die every year from poverty that can be directly linked to energy poverty?
Finally, you can wonder all you like about how well I understand statistics. The answer is properly "better than 99.99% of the people on the planet" -- at least 4 nines, probably 5 -- but the one relevant thing you might want to study to catch up on is encapsulated in a lovely little monograph entitled "How to Lie With Statistics" -- a well-known classic in the field, written for a lay person.
When you read it, then go back to read AR5, sections 9.2.2 and 9.2.3. To translate for you: "We haven't any justification for forming a MultiModel Ensemble mean and using it as if it is an axiomatically justified statistic. In fact, we have excellent reasons not to, and if we do we cannot possibly say what the result means or how it might predict the actual climate. But we're going to do so anyway."
And boy, do they! Confidence assertion eve
Ha, very good sir! I'm assuming that he was using -- as we all do, in casual conversation, unless we are conversing with a mathematician about black sheep in Scotland -- his own personal, gravitationally oriented sense of up and down. In his personal reference frame the sun will indeed rise, and if it doesn't he can always do a sommersault.
Your warped Nietzsche quote, BTW, also has me gasping in admiration. Even your fondness for Penguins is admirable.
Well done!
You mean extrapolating from known behavior in the past sort of like what we do using -- Physics? Chemistry? Biology? Anything else in the entire compendium of human knowledge about the real world (as opposed to empty exercises in self-referential logic like pure mathematics)?
Or are you trying to imply that Hume's problem with extrapolating the past has finally got an analytical/logical solution as opposed to an axiomatic/statistical solution a la Jaynes?
I'm only asking because as soon as you remove empirical science from our system of knowledge -- which is all fundamentally extrapolation from past observations (that's the "empirical" bit) -- what is left as a non-joke prediction is being psychic. Which is, curiously enough, a bit of a joke.
(And yes, the examples given were deliberately obvious, but the point of the obvious is well taken -- we cannot be certain that the sun will rise tomorrow on the mere basis of either a compendium of observations that it has done so in many, many past tomorrows or even on the basis of observationally deduced laws concerning gravitation, the shape, location, and probable trajectory of the Earth relative to the Sun, the probable continuity of the processes that drive the sun, the probably true empirically based law that the angular momentum of the Earth will be conserved and that rotation will eventually "make the sun rise" yet again, because all conclusions about the future are ultimately based on the extrapolation of observed -- not really "known" -- behavior in the past, and as Hume noted, we cannot prove using any sort of pure reason that the future will be like the past, and the best proof of scientific induction that we have so far is the Cox-Jaynes axioms and probability theory as the logic of science.)
rgb
Incredibly well stated, sir. Sadly, nobody who reads proclamations of The Government as if they are gospel truth seems aware of the fact that we are currently extending the all time record interval without a category 3 hurricane making landfall in the US, that like it or not SLR is being measured at the terrifying rate of between 2.5 and 3.5 mm/year, within noise of its 140 year rate (and if anything, is currently actually decelerating, although statistically neither any observed "acceleration" nor "deceleration" is meaningful when compared to the historical record). Tornadoes are way down and have been for several years. We just had a record-setting cold year in the US (with daily cold records outnumber warm records maybe 2 to 1) with a record-setting cold winter. The current projection for midsummer sea ice is pretty close to normal. The antarctic has quietly been setting sea ice records for two or three years running without anyone paying the slightest attention (except maybe when boatloads of tourists travelling there to "document sea ice loss" get trapped for weeks in the ice, the boats that come to rescue them get trapped in the ice, and it takes large amounts of money and risk to rescue them).
But aside from all of that, the assertion that we could deliver all of the world's current energy requirements at all, with almost unlimited investment, without carbon is almost without foundation. Almost because if we invested sufficiently heavily in nuclear power and successfully developed e.g. LFTR (Thorium) as an alternative nuclear power resource, it is barely possible that with enormous investment and the building of hundreds if not thousands of plants and the extensive mining of e.g. Monazite sand we could make it. Assuming, of course, somebody were willing to foot the bill for the third world and the rapidly developing nations like India and China.
As for solar, I love it to death, and as time passes and technology develops it might eventually be a prime-time player. In the meantime, it is expensive compared to carbon, useless above a certain latitude, and useless at night. We do not have any mature, cost-effective technology for storing energy from solar to deliver at night, and we are in all probability at least decades away from having one. Wind power is even more problematic -- you can't even be guaranteed of having power during the day, and it has to be stored/buffered on a minute by minute basis as the wind is highly intermittent nearly everywhere. Long range delivery of electricity is also still not feasible, so we cannot generate electricity in Arizona and ship it to Maine, not without a truly monumental investment in e.g. ultra-high voltage trans-continental transmission lines or the development of new technologies. In the meantime, both of these power sources are completely inadequate as standalone energy resources without substantial backing from fuel-burning resources -- either carbon or nuclear. Even things like electric cars, touted as being better than gasoline, suffer from serious energy density storage problems and have pitiful ranges (as well as numerous other issues). Biofuels do better -- I can actually believe that we might manage to break even or win a bit on biofuels within the next decade, especially if new genetically engineered organisms and improved technologies there help out. But not even biofuels are prepared AFAIK to take on the full burden of generating not only automotive power but general electrical demand, and there are major questions about how scalable they will end up being even produced on an industrial scale.
So precisely how could we eliminate the use of fossil fuels, or carbon based fuels, worldwide, without any negative impact on life style? I track the technologies that are out there pretty closely, and am a physicist (and thereby "probably not an idiot") and I cannot see any possible way we could manage it with a HUGE negative impact as the required technologies simply don't exist yet (and some of the one
he universe was opaque and this light is lost.
Not exactly lost, just thermalized. The mean free path of photons was simply short relative to cosmic distances, and gravity hadn't yet pulled enough hydrogen down into a gravitational well to ignite it, the distribution of matter was still fairly uniform except where it was gravitationally coalescing.
Once the stars lit up, radiation pressure quickly enough swept their immediate vicinity clear and created "shockwaves" of moving stellar wind that nucleated lots more gravitational structure as it propagated. You can see this process continue today in star-forming regions of our own galaxy.
But the light produced by the recombination era -- which was not all that short, or all that violent -- is what eventually became the CMB, "frozen out" once the universe's density dropped to where the mean free path of a photon reached "infinity".
rgb
...and one could go on and on. Line by line, Genesis is pretty much nonsense, and isn't even particularly good poetry in places where it is poetic. Heaven and Earth first. Darkness on the face of the deep, where from the next sentence it is clear that the "deep" is the waters, that is, the ocean. Then light, which divides light from darkness, with light called day and dark night. Note well that there is still no sun, but there is day and night. Then he creates a "firmament" -- that would be a solid bowl -- to divide "the waters above from the waters below" and called it heaven. Then he causes the waters under the big bowl to collect so that dry land appears, leaving behind seas. Still no sun, but light and darkness, day and night. Then he covers the earth with grass and fruit trees. Only then, on day four does he actually get around to creating the stars -- and what is their purpose? To fill an enormous visible Universe with hundreds of billions of galaxies containing hundreds of billions of stars each? Oh, no, for signs and for seasons. God created the stars so he could use them as portents and so that we could tell when to plant. Afterwards, he finally gets around to creating two "lights", one greater and one lesser, the Sun and the Moon, to give light to the night and day. That is, Genesis doesn't even grasp that the Moon isn't a light at all, it is a passive reflector of sunlight, a big ball of rock, as opposed to the Sun, which is a star just like those lights that mark out the seasons. Then he created whales and birds and fish -- after land-based vegetation that managed without a sun, and only then did he create land animals ending with humans.
So let's see, we've got a flat earth, a solid bowl of heaven hung with a tiny handful of stars to mark out the seasons, a completely wrong and absurd order of appearance of the living species and pretty much all of the matter in the Universe, and there isn't a hint of the possibility that the Earth itself isn't even a pimple on the backside of the Universe, it isn't even a single cell on a pimple on the backside of the Universe, it is a single atom in a single cell on the backside of the Universe (to scale).
Then there is Genesis 2, which tells a completely distinct and different account of creation, where Adam was created before the animals and had to name them, one at a time (good luck with that, even today) as God created them and then had to beg for God to create a woman only after it became clear that all of the animals had females but he didn't. Note well that naming a species a second it still would have taken years to name even a reasonable fraction of them; not exactly the sort of thing that could possibly be finished in a day.
Then there is Genesis 3, with the completely absurd story of God creating a tree with magical fruit that gives you knowledge of good and evil, telling the original couple not to eat any of the fruit, which they proceeded to do anyway because -- duh -- they didn't have a knowledge of good or evil so they had no way of knowing that what they were doing was wrong (where clearly, by the way, it wasn't), and then punishing them for doing what He had preordained from the beginning of time etc that they would do just so that God wouldn't die of boredom.
It isn't, in fact, the case that Genesis is anything like a good metaphor for the scientific account of the big bang through the present, which in any event is not a creation as we have no evidence of "creation" ever happening anywhere in the sense that the Bible uses the term, ex nihilo. In fact, we have these lovely conservation laws that pretty much say "creation never happens", mostly because we never see it happening no matter where and how hard we look.
Hinduism does much better, but even the Vedic creation myths and stories, treated as metaphor or not, are not a terribly good account of the scientific history.
Finally, last time I read about (and taught) astronomy, the
No real argument, but next we're going to be referencing "The Tragedy of the Commons" and "The Tyranny of Democracy" and related works. Human society works because we all make certain trade-offs of our personal freedom against our security. If we were rational, we would actually do a cost-benefit analysis of our legal system to determine whether it makes more sense to eliminate (for example) intellectual property laws, making it perfectly legal to copy any work or produce anything we know how to produce, or maintain any variant of the existing IP laws. Sadly, we're not. But a lot of the drug laws -- pot in particular -- are low hanging fruit. There is really no question that it costs far more to keep pot illegal than it ever could cost society legal.
rgb
I can attest -- Lawdy, Lawdy -- that the drug prohibition laws are far more expensive than any possible effect of the drugs themselves. Marijuana, for example, is in no way as bad for your health as being arrested for possessing marijuana. Its direct cost to a user -- once all of the artificial price increase associated with it being illegal is removed -- is orders of magnitude less costly than the complex mix of legal expenses to the user and the state, the cost of enforcing the law, and of course the cost of punishing (usually incarcerating) the user if they are caught with anything less than a tiny amount of the substance. The cost of drug laws worldwide is credibly estimated to be in the hundreds of billions of dollars -- say half a trillion. One could feed the hungry and bring about World Peace if one diverted all of this insanely spent money to other purposes and just let drug users use drugs, with fairly benign restrictions on what they can do while they are doing so.
Even the really bad, scary, truly dangerous drugs are in some sense self-limiting in proportion to their danger. Heroin is mighty bad, and extremely addicting. Like tobacco, only not quite as addicting. But if heroin were inexpensive and legal, instead of being horrendously expensive and illegal, an entire shadow government and underworld would be instantly starved for money and would wither and die, and heroin addicts would be no worse off trying to work and manage their lives with a daily fix of cheap heroin than they would be with a daily fix of expensive methadone. They'd have about the same chance of getting tired of it and deciding to kick the addiction, or maybe even a greater one if we spent a tiny bit of the money we wouldn't be spending in the war on heroin on free addiction treatment programs and public education.
People who end up fond of much worse combos -- PCP plus cocaine plus heroin -- well, I'm sure that it is really bad for them, but for better or worse that sort of thing will very likely kill them quickly, and even that is comparatively cheap compared to the lifetime costs of arresting them, putting them into prison for decades where they contract HIV and come out real criminals with a whole lot of anger and a expensive chronic diseases to manage while still not being over whatever it was that cause them to be a hard core addict in the first place.
Drug cartels, my friend, exist because drugs are illegal. Legalize pretty much everything, and "cartels" vanish overnight. We've already been through this once -- Prohibition was the best thing that ever happened to organized crime in the US, at least until drug prohibition came along with an even higher profit margin. Lose the prohibition, empty the prisons of all drug offenders who don't have an associated violent crime tagged on, and watch crime rates, murder rates, the number of police in our police state, the number of lawyers (drug laws being a huge boon to lawyers, of course) and courts, all plummet. There isn't any real money in drugs without the prohibition -- anybody can grow pot in their back yard, cocaine would cost a few dollars a pound if it weren't for drug laws, heroin ditto. And most people would still avoid both of these, because both of them are pretty dangerous and addiction or life problems associated with them would be expensive and embarrassing, just as they are now for smokers and alcoholics.
rgb
And I was wrong when I said that I have no vices. I definitely want to buy kitty porn. Would you believe that I've never seen cats doing it? Kitty porn must be rare and hard to get.
I didn't realize that governments regulated it so strictly, though. For the rest of my life, I'll never be able to drive past the Tom Cat Club (a local, err, "massage" parlor that has been around on the US-70 corridor for fifty years or so) without going into hysterics. Purveyors of kitty porn, pictures of hot pussies. Arrgh.
Damn, coffee all over the keyboard again.
Granting the illegal bit, illegal does not equate to "causing harm to someone". Would that it did -- that would be so very rational. However, there are plenty of things one might want to spend money on that are illegal but harm no one but arguably yourself. Drugs is one obvious example, but in many parts of the world buying pornography or sexual toys/aids is illegal, all the way up to being a capital crime. In China or much of the Moslem world, an enormous number of things are illegal that don't harm anyone or anything but the nominal reputation of Islam or Mohammed or Allah, or that represent freedom for repressed majorities like women. We're not really talking only about the relatively permissive US or Western Europe, in other words.
Of course people will use this to do some things that are directly intended to harm others in non-victimless-crime ways: Steal/pirate and resell IP of various sorts, fence stolen goods, arrange for a hit on your alimony-hungry ex-wife (maybe, dunno if that is a "commodity" it can handle), engage in human trafficking, sell arms. But some people will use it to buy freedom from oppressive governments that have made a whole lot of things that harm no one illegal because they violate some statement made in a piece of pure scriptural crack if you squint your eyes just right when you read it. Because there is rarely any percentage in prosecuting crimes of this sort once one cannot detect them or stop them for long enough for violations to become commonplace, it might even motivate social change.
To me personally, the tool is not going to be terribly useful. I'm heterosexual and married, my primary vices are at least quasi-legal and tolerated where I live, and I consider buying stolen goods of most varieties to be unethical. It isn't clear that I'd resort to it if I lived in e.g. a Moslem country and had a thing for porn -- no matter how nominally secure, the penalties are pretty horrendous. But I'm guessing that there are those who will value it who aren't planning to use it to hurt others.
rgb
Yeah, yeah. What you said. If DM/DE is an elephant in the room, it's an elephant that we know only in the sense of the blind men trying to describe the elephant by feel -- one says it is long and pliable, like a snake, another says that it is flat and massive, like a house, a third says that it is floppy and flat, like a large tree-leaf. We cannot yet see the whole elephant, and part of what we CAN see may turn out to be only the shadow of the elephant cast on the walls of Plato's Cave in some projection, nothing like the actual multidimensional elephant. Our knowledge of physics (so far) helps define a few of the projective dimensions or the parts of the elephant we can feel out, but it, too, is incomplete, being part of an even bigger elephant known in various projections by the blind...
rgb
Well said, sir. Repeatedly, even. Although (as a physicist also) I do have to say that DM/DE are a) one of several possible explanations or models that we have -- so far -- and while it has emerged as one of the most consistent that doesn't make it either unique or right. We may not have even hypothesized the right model yet (given the indirect nature of the data, that would hardly even be surprising, if true). b) One of the problems with having a huge amount of mass-energy out there, effectively decoupled to electromagnetic forces, in addition to making said mass-energy literally invisible is that one can imagine entire "universes" of field theories underneath the very loose constraint of the observational data. Does DM couple to e.g. the nuclear force? Are the quanta of DM stable? Is DM not really "dark", but merely very, very weakly interacting, e.g. massive neutrinos? IIRC it is possible to explain the cosmological data by giving three flavors of neutrinos a mass-energy order of an eV. And then we have to ask -- what if there are more than three flavors, and DM is a "leftover" neutrino from a super-heavy lepton that hasn't existed since the big bang so that the neutrinos have nowhere to go? DE is even more difficult to cope with -- are we talking about the massless quantum of a fifth force altogether, or is it somehow tied to the four fields we already know about?
Given that we have yet to fully reconcile gravitation and relativity in a consistent quantum theory and that we lack a TOE (meaning there is still room enough to drive -- err, "elephants" through the gaps:-) we are, as you say, working with descriptive phenomenology -- classical theories of gravitation, or relativistic theories of curved spacetime, quantum models of nuclear (strong and weak) and electromagnetic interactions that works (so far) pretty well in specific contexts. But we don't even know if DM interacts strongly enough with sufficiently dense "known" matter -- matter e.g. in the heart of suns -- to be able to slow down in transit and accumulate. We don't know if DM remains stable and decoupled at energy densities like those accessible inside the cores of stars, or for that matter inside e.g. neutron stars. We don't know if DM interacts with other DM to be able to provide the "friction" needed to cause gravitational collapse of DM. All we know is that when we examine galaxies, the profile of orbital velocities observed is consistent with their being more matter in the galaxy than we can see, distributed in a very unusual way.
Personally, I think it is all very interesting (although definitely not my field), but don't take any of the many assertions about DM or DE too seriously yet. Both are the ultimate "invisible fairy theory" -- literally invisible -- where the fairy is known only indirectly by means of the "the fairy must have done it" argument. This is right up there at the edge of religious thinking, because as long as the fairies remain invisible, it remains almost impossible to falsify any assertion about what the fairies do or do not cause in the observational data. I'd mumble about Ptolomeic epicycles vs gravitation, or the many gods of the many gaps over human history, but in the end, until somebody puts salt on the tail of a darkon or manages to build a TOE that includes DM/DE consistently, explains all observations, and has a prayer of being verified/falsified by more than crude phenomenological agreement it is all in the same category as supersymmetry, string theory, etc -- pretty stories, but which one (if any) of the myriad of possible models within the general approach is true?
rgb
Damn skippy. Hence the baseline external pressure limits the maximum height the siphon can operate over according to the rule P_0 = \rho g H_max, because the lowest pressure one can encounter in any fluid is zero and the pressure decreases in the constant cross-sectional area tube with height from the baseline of P_0 at the upper fluid's surface. At one atmosphere, one cannot go over a barrier of more than 10 meters. At a tenth of an atmosphere, one cannot go over a barrier of more than 1 meter (with water, ignoring viscosity and the tendency of water to boil into a vacuum at room temperature so that instead of vacuum we have a low partial pressure of water vapor in the gap).
Oh, wait -- that's exactly what they demonstrated. What a surprise. Bernoulli's formula, conservation of flow. Do we really need a 21st century publication confirming physics known, confirmed repeatedly, and taught in any halfway decent INTRODUCTORY physics textbook since the 17th century? How and why, exactly, is this idea getting press coverage? This is the second place I've seen this article reposted, and it isn't really worth the original publication anywhere but the AJP, which exists to publish precisely this sort of article for physics TEACHERS, not as "proof" of anything that isn't already well known.
rgb
...when it is a textbook problem in fluid mechanics at the introductory level? Bernoulli's equation, conservation of flow, physical conditions, end of story (within the minor tweaks introduced by viscosity and Poisieulle's formula).
Oh, wait, because somebody did the umpty-zillionth practical experiment of running a siphon and managed to publish the results.
Yeah. Sure. That makes sense.
Or, perhaps it makes no sense at all. It might make sense as a science fair project, though, for some bright high school student.
rgb
Peak acceleration (given in multiples of g) is relevant. Humans can survive impacts involving accelerations up to around 100g -- much over that and there is "no" survival (I think the peak estimate for a documented survival is around 105 g) and to survive that very much depends on how it is experienced -- uniformly good, non-locally over your body bad. Under that, a few people survive, usually damaged, with damage that reduces on average until you reach forces spread out enough and slowly acting enough that they can bring you to rest with accelerations on the order of 10g (100 m/sec^2) that most people can survive without more than bruising if the forces that produce them are spread out enough on the body. This is order of the forces/accelerations involved in surviving a car crash with seat belt and air bag and collapsible front end of a car.
There are actually howtos on the subject:
http://www.wikihow.com/Survive...
These are based on both experiences/circumstances of survivors, plus analysis of the physics. There are actually lists and well-documented accounts of survivors:
http://www.oddee.com/item_9696...
(plus many others). As the first of these two links suggests, water is marginally better than concrete, and frothy, air-bubble-filled water is better than flat, calm water. Landing behind a large, heavy object (falling directly into the splash) helps enormously.
rgb
Actually, I looked into it further and it turns out that the encapsulating agent is alpha cyclodextrin. This basically a ring of 6 dextrose molecules, hydrophilic on the outside and hydrophobic on the inside. It is extremely stable and to the extent that it breaks up at all, breaks into dextrose and dextrins. Basically, it is an indigestible complex sugar that the body completely ignores. Not only that, but it is a food-safe source of fiber. Not only that, but as a food supplement, that hydrophobic center loves to grab triglycerides and trans fats and forms a complex of fats bound to the ring that can bind 9 times the weight of the ACD in fats and flush them out of the body. There is double blind placebo controlled data that it has a number of health benefits -- 6 grams a day neutralizes over 500 calories of fat a day, lowers triglycerides, lowers cholesterol, drops insulin levels, prevents weight gain, all at statistically significant levels in spite of the comparatively small N of the studies done so far.
I was impressed enough with what I learned that I'm considering adding an ACD supplement to the beer I make. There are reasons to think that it will alter the flavor profile, but quite possibly in positive ways (there is a German research paper onto this very subject, but it is paywalled). The interesting thing is that if the alterations are acceptable, one could end up with a beer that absorbed (say) half of the fat from the buffalo wings you eat along with the beer so that your body never absorbs it. It could also mean that the powdered alcohol beverages already on sale in e.g. The Netherlands could be more valuable as a dietary supplement fat eliminator than they are as a 3% alcohol fruit punch in a packet sold mostly to young people.
In a truly paranoid world, it might explain why the FDA put it on hold here. Imagine the chaos if somebody started marketing a "Margarita in a pouch" where 2-3 of them a day completely blocked weight gain and cured metabolic syndrome and effectively treated type II diabetes! Drug companies would go nuts -- nobody can really patent a complex sugar that has been known and studied for decades and that is really pretty easy to make. I can't QUITE get it to be automatically created during the mashing process of making my own beer -- it requires certain specific bacteria and/or the direct addition of a particular enzyme that takes the dextrins that are produced in the mash and wraps some fraction of them into rings -- but somebody could easily decide to mass produce the enzyme and sell it ready to add as a supplement to a wort, or one can do what I'm doing -- buying a jar of ACD directly, crush the tablets, and add them to the wort. That's too expensive for the long run, but hey, beer that is really, really good for you is a dream worth pursuing, is it not?
rgb
I think it is a mix of all of the above. Terrorists are rare (not quite non-existent) and are obviously incompetent and unimaginative. At most airports, one could fill an entire full-sized bus with explosives as long as it was labelled "Hertz" on the side, drive it right up to a place in front of the main terminal, and detonate it as a suicide bomber on any of the busy travel days of the year. If one wore the right uniform, one could probably get out, walk around to the off-side of the bus, jump into a getaway car, and get several hundred meters away before remote detonating with a phone call to a cell-phone detonator and actually escape in the resulting panic and confusion. One could do this at sports arenas, shopping malls, on large bridges. A full size bus would hold easily 5 to 10 tons of homemade explosive, and a really smart terrorist could amplify a smaller amount with aerosolized gasoline dispersed immediately before the detonation via compressed air and gasoline in tanks (the military has a similar super-bomb that has a devastating effect).
Then yes, small airplanes are trivial -- for a smart, well-funded non-suicidal terrorist -- to convert into GPS guided cruise missiles, and the idea of the kamakazi -- a suicidal human guided cruise missile -- is now seventy years old, not even a new concept. Indeed, it's a good thing there aren't too many truly sociopathic people and that true sociopaths and religious or political zealots (is there a difference?) are often pretty stupid, unimaginative and so on.
And yeah, they probably are opposed by occult counterterrorist forces that reduce the frequency of "smart" attacks like 9/11. So there might have been any number of additional attacks that were foiled. It isn't completely trivial to assemble the ingredients for large quantities of homemade explosives, and making explosives at home is a good way to end up aerosolized yourself. To do a good job of making something with a lot of power that is stable enough to transport and detonate on demand rather than when you sneeze, one has to use pure ingredients, strong chemistry-fu, precise temperature regulation and so on or one ends up making nitrate-based "stable" explosive stuff with all sorts of side compounds that detonate if you look at them funny. The feds keep careful tabs on high quality nitrates (fertilizer, nitric acid) that are often a primary ingredient. So even a lot of deranged psychopaths might have difficulty assembling the ingredients for making a bomb like that used in Oklahoma City and combining them and transporting them without killing themselves, their families (if any) and a number of their neighbors.
But still, in the end we are remarkably dependent on the general goodwill and sanity of our co-humans. Lots of people working together to make a stable, secure, moderately contented world are never guaranteed to succeed, but all it takes is one suicidally deranged and stupid sociopath to murder tens to hundreds of people or do millions in property damage; smart sociopaths can bump that pretty easily by orders of magnitude. Fortunately they are rare, and opposed by smart anti-sociopaths who at least sometimes succeed.
rgb