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

Would that be a crazy diamond with a weight given in carats, or a crazy diamond with a weight given in SI kilograms?

I'm just sayin'...

Actually, terminal SPEED is the result of drag forces that scale like bv^2 opposing motion. The horizontal velocity component v_0 decays to zero like, lessee, v_x(t) = mv_0/(b v_0 t + m), just as the vertical component approaches the value where drag force balances gravitation like a hyperbolic tangent with a similar characteristic time. The real question is how long one is in the air relative to the drag and mass, that is, if dimensionless b v_0 t/m >> 1. A small person wearing a big puffy jacket (small m, large b) might do much better than a big guy wearing a tight wetsuit. With a v_0 on the order of hundreds of meters per second and greater than terminal speed, one of the times it is actually better to fall from a larger height rather than a smaller one to allow initial speed to decay to terminal speed.

There are a number of cases on record of people falling out of moving airplanes (presumably travelling at speeds order of 300 to 800 kph, well above terminal speed) who survived, usually by falling into deep snow, soft plowed fields, just the right patch of springy trees. A VERY few weren't even terribly injured. And you are dead right -- water, an incompressible fluid, is literally "as hard as concrete" when struck at high speed. Because it isn't compressible, the collision has to literally move the quite massive water out of the way. People who jump from bridges don't always or even generally drown -- they break bones, rupture their body cavity, suffer massive internal brain trauma. There is an amusing, not-quite-tongue-in-cheek section in the Worst Case Scenario Survival Guide on surviving a fall out of a plane several kilometers high over water. Falling bluff (maximize b), turning vertical at the last moment, enter feet first and streamlined and keep those butt-cheeks clenched as we don't want to explode our intestines via a power enema.

With luck one breaks ones legs, pops a few disks, remains conscious, floats back to the surface in time to breathe, and can then stay afloat with broken legs and internal injuries until somebody pulls you out of the water and gets you to medical care. I'm sure one "can" learn to enter the water perfectly enough to do better than this -- cliff divers manage it at a significant fraction of terminal speed -- but it's one of those experiences most of us would be better off avoiding...:-)

Hey, I'm turning water into ale even as I sit here. Not that hard. A bit of barley, some hops, some yeast. I'd turn water into wine too but NC wine simply sucks, at least so far. Wrong climate, wrong soil, and who wants to turn water in the form of imported extract into wine?

The difference between this ancient process of turning water into beer, ale, wine and adding a powder to water that releases alcohol is that one might actually want to drink the results of the former process and one might even find the resulting beverages (consumed in moderation) healthful, brimming with b-vitamins and bioflavanoids/pigments and antioxidants. OTOH, since alcohol per se does not have a "powderable" form at room temperature, the powder involved can at best break down into alcohol and leftovers when put in contact with water. And I'll just bet that those leftovers are organic and/or inorganic molecules, oxidants, and quite probably carcinogenic. Finally, I'd bet a fair bit that even cheap vodka would be less toxic, less expensive, and less likely to cause cancer as an additive used to achieve any given concentration if all you want is to turn a water-based beverage into a cocktail.

rgb

Why? The only issue is the belt convexity. If the new pulley would pull the belt away from the intermediate pulley if it ran on the outside one can simply switch it to the inside. It cannot be pulled away on both sides. The point is that the run of the belt can be made topologically equivalent to a line drawn between all of the pulley centers in the configuration generated by a distance-ordered recursion from any starting point. All one has to prove is that for a trivial set of local geometries, one can always find a side of the pulley that maintains tension upon addition. The diameter of the pulley ends up being functionally irrelevant.

Perhaps I'm not being sufficiently clear. Take a configuration of N points/pulleys presumed to be spanned by a belt that was systematically structured by starting on the pulley closest to the center of the bounding circle. Add one pulley outside or on the bounding circle of the configuration (one can always reorder the problem to ensure that the N+1 pulley is outside or on this bounding circle). Pick the two (most distant from the center, if there are more than two) pulleys that bracket the new pulley inside rays drawn from the center of the circle through the pulley center. One can always loop in the new pulley in between the two thus selected, and one always does so without adding a loop that "occludes" a future distance-ordered addition. The insistence of maintaining rank order and radially ordered convexity as one proceeds suffices to ensure that one can always add a pulley to a suitably developed set of N pulleys.

Or, maybe I'm missing something, but when I draw sequences of points in this way there aren't really a lot of cases to consider on the addition. The convexity requirement eliminates, I think, your assertion of "distant points" for the nearest neighbors. They cannot be more distant than the diameter of the bounding N circle, and the construction ensures that one does not build a loop that twists around in some snaky way across angles. By posing the solution in this way, I simply avoid having to consider going back to do nonlocal rearrangements of some arbitrary looping selected from the (probably quite large) set of loopings that would work for any set of N pulleys. One really only needs to consider the two bracketing pulleys and the two next neighbors of those pulleys with the comfortable constraint that the next nearest neighbor has a belt that run at an angle of pi or less relative to the exterior of the radius of a/the bracketing pulley in question. Four permutations of possible side swap to consider, done, induction proven.