It's a bit like while it is impossible to predict which days will get rain in Bergen, Norway this november, it's pretty easy to predict the average temperature, the annual rainfall and how many days it'll rain.
Yes it makes a difference. It's surprising to me that this needs to be pointed out.
When the question is what christians believe, then it is, indeed, relevant what christians believe. This should come as a surprise to nobody. Thus, an argument that christians commonly believe the world to be like 4000 years old, can indeed be supported by evidence such as polls showing that a large percentage of american christians do indeed believe this.
When the question is how many states the US has, then it is irrelevant what some people believe.
There's a differnece between saying: "Many americans believe there are 49 or less US states" (a demonstrably TRUE statement) and saying: "There are 49 or less US states" (an equally demonstrable FALSE statement).
To answer your other question; no this does not make those American dumb (though some of them are doubtlessly dumb, the fact that they don't know how many states there are does not demonstrate this), but it does indeed demonstrate that they are uneducated, atleast in geography.
This is true, and well-known. It's so because though say quicksort is O(n*log(n)), and bubble sort is O(n^2), that's the average "number of steps" needed to sort a large collection. It doesn't take account for the fact that one "step" with bubblesort is smaller and thus quicker.
I surprised my not-terribly-brigth professor in algorithms-101 by claiming I'd improve on his quicksort by incorporating bubblesort.
He found the idea ridiculous, and said so, but I persisted, saying that by incorporating bubblesort, I'd make the algorithm run faster for any size data-set.
What I did was run quicksort with a cutoff value of around 20, and to bubble-sort if the set to be sorted is smaller than that.
This means a small set will be only bubble-sorted, a large set will be quick-sorted until the recursive calls work on collections smaller than 20, at which point those get bubble-sorted.
Fairly standard technique. Ran something like twice as fast as the standard quicksort. Astonishing everyone who thougth that the Big-Oh notation is the be-all and end-all of performance.
Not really. MS-DOS doesn't really have a "kernel" in the traditional sense.
MS-DOS is basically an interrupt handler, plus a selection of programs such as command.com and dir.exe.
Handling interupts is pretty much *all* the OS does. If you read any "OS-construction-101" textbook, you will find that DOSs response to like 90% of the problems presented in there is: "We don't deal with that."
MS-DOS does not protect the memory-areas of one program from another.
It also does not handle allocation of any other resources to programs.
It neither knows about, nor cares about multitasking.
It has no concept of "user" or "process", all it knows about what's going on outside dos is that it's got a saved pointer to the adress it should return control to when done servicing the interrupt.
No part of it is asynchronous. Ask for something, and you've got no choise but to wait until it's done.
From the point of view of quite a few programs, MS-DOS is a filesystem-driver. A few programs even do *that* on their own, rather than relying on DOS. They typically use what seems to DOS to be one large file, but which does in reality contain a complete filesystem, somewhat like Linux loopback-mounting of an image, but with the difference that the program itself interprets the filesystem with no help from the OS.
...The bicycle is the perfect transducer to match man's metabolic energy to the impedance of locomotion. Equipped with this tool, man outstrips the efficiency of not only all machines but all other animals as well.
It's not terribly impressive that a person on wheels outstrip animals that have to walk, fly or swim, atleast on a even, smooth surface such as a road.
As for the other claim, that man on a bicycle outstrips all machines, it's bullshit.
A electric engine converts electric energy into mechanical work with an efficiency well into the 90%s. The human body is nowhere in the ballpark. I doubt it can even reach 25% in converting chemical energy (i.e. food) into mechanical energy.
Thus, a machine consisting of a battery and a electric engine hooked up to the wheels will easily beat any cyclist in efficiency.
People are incredibly naive. I think that the demise of the traditional market has a lot to do with this.
Today people are used to shopping at supermarkets where $12.95 really means $12.95 and you're unlikely to get it even a single cent cheaper vy trying to haggle.
Thus, many people fails to consider the real power they as customers have when making larger purchases.
Spiegel here in Germany made a simple test earlier this year to see how much of a difference even minimal haggling make.
They walked into a few dozen auto-dealers saying one of the two following:
I would like to buy a car. It'll be paid cash in full, can you make me an offer ?
I'm looking for a new car, so I was visiting a few dealers looking for offers. I've had a few offers already, but I was wondering if you'd be able to make me a better one. What would you ask for a ?
Result ?
By hinting that you're comparing, and that the dealer will have to make you an actually competitive offer to have any chanse of getting a sale, the average offer in the dealers where they used tactic 2 was around 10% better than the average offer gotten with request 1.
That's a lot of money saved for saying a single sentence out loud.
If you want to produce a given amount of power constantly, with no need for sudden peaks 5 times as high as the average energy-need, then the efficient motor is *not* going to be a huge heavy-diesels 300rpm motor.
It's going to be a small turbine-motor whirling at maybe 12-15000 rpm, and running at something like 80% of it's max capacity.
This is even *more* true in applications where size and weigth of the motor plays a role, such as in a car.
You are rigth that ships-engines are typically large, slow and heavy. There are other reasons for that though;
Gearboxes for so much power are extremely expensive, and need much maintenance. Lower rpm lets you run a much simpler gearbox.
It also decreases needed maintenance. Ship-engines often run continously for literally *years*, major service is very expensive, because you need to stop the entire ship, atleast if you ain't got two motors on the ship. (which I think should be required by law on large ships, but which isn't, because two engines cost more than one...)
It makes it easier to burn heavier oils, which can be had for cheap. This is also a bad idea really, the typical ship-engine produces *much* more pollution pro Kwh than even a normal car-engine.
On a large, loaded ship, the engine is a tiny fraction of the total weigth, doubling the weigth of the engine to make it 10% sturdier is almost certainly a plus. In a car that would not at all be true.
I'm aware that Americans typically like to have even more wastefully powerful cars than do most Europeans, not only bigger, but also more ps-pro-ton than we tend to have over here.
It sure as hell ain't because you need the power though, because it's fairly easy to argue that both the two European countries I have close ties to "need" more power than do the average American.
Germany because there's literally no speed-limit on the autobahn and cruising at 180km/h is considered perfecly normal by many. Norway because it's got more mountains, and thus more up-and-down and windy-roads than just about anywhere. (75% of the country or so is at 1000m or more)
To people buying 3 ton SUVs with 250hp engines in order to transport 1.17 (average ridership in US cars according to C.I.A) persons at a speed of 40 mph to the shop/work and back, there's fairly obvious things that can be done to save fuel without needing to go to extremes like hybrids.
Sure. A car with simple the same small-size engine that is in the typical hybrid, but without the extra weigth and complexity of the hybrid will be both a lot cheaper, and get a little more mileage than the hybrid.
It will however have a lot poorer performance.
The essential benefit of hybrids is that you can have a car that use (almost as) little fuel as a very weak car, while still having performance under acceleration and other short power-needs similar to a much stronger car.
The best you can hope for with a hybrid is a car that accelerates as if it'd got 120ps, but drinks fuel as if it's got only half that. (doesn't mean it'll drink half the fuel though !)
If you simply want to save money, or save the environment, or both, simply buy a small, ligthweigth and weak car. Not only will it drink little fuel, it'll also have required a lot less energy and raw-materials to produce it.
The electrical assist means that your engine can be improbably weak, but I don't know if that necessarily translates to a more efficient engine.
It does. A fairly typical family-car has 120ps and a 1.6 litre engine. Even though, 90% of the time it uses only a fraction of that power, the power is "needed" because people expect acceleration and ability to climb short hills without loosing speed.
With an electric assist that can give an additional push, powered from batteries for short periods, a weaker engine can be used. And here's the thing: a weaker engine is more economical.
Under circumstances where you need 35ps (for example 100km/h on flat highway) a 50ps engine is going to consume less fuel than a engine capable of 120ps, but currently near-idling at 40ps.
This is so for various reasons, partly that it requires energy to pump all that air in and out, and partly that there's a lot more mass to move in a bigger motor, which tends to lead to more internal friction-losses.
On the flipside a hybrid will tend to be heavier, because it essentially has two engines (though smaller) and two energy-storages.
Still, hybrids *do* get more mileage than conventional autos with comparable performance. Just not as much extra as the EPA-estimates will have you believe.
It's worse than that. Much worse. It's not even a security trade-off (where some convenience and privacy is sacrificed to gain a little security), it can quite convincingly be argued that systems such as these make security *worse*. Consider the following, insanely optimistic assumptions:
Everyone will travel under their real identity.
There will exist no fake-but-valid-looking biometric identity-cards.
Noone will be able to obtain real cards under an assumed name.
The BigBrother database manages, by collecting various info on people will be able to group people in three classes: terrorist, suspect and innocent.
"terrorists" are denied air-travel, "suspects" are subjected to a more thorough search.
False negatives for "terrorist" will be only 25%, only 1% of all "innocents" will falsely be labeled suspect or terrorist.
Now, every single one of those assumptions are very optimistic, I have no faith at all that a system could possibly work this well. Still, even with a system like the above, gaming the system to virtually guarantee success is trivial:
The staff manning checkpoints has a finite capacity to check/search people.
So, if one group of people ("suspects" are checked more, this *must* mean that others ("innocents") are checked less than today.
So here's what you do:
Send the vrious members of your terror-cell on a fligth-trip involving 4-5 fligths. Have a real and good explanation for the trip, carry nothing illegal whatsoever, and behave exemplary.
75% of the terrorists will be on the "terrorist" or "suspect" list. They'll notice this, because though you can't demand to know if you're listed or not, it's not hard to notice if you get denied boarding or not, nor if you get searched on every boarding or not.
For the real attack, a month later, you use people from the 25% who you now know to be on the "innocent" list.
Since the system can only work by checking "suspects" more and "innocents" less, you have now improved your chasnes of success in comparison with a system without classification of passengers into groups.
You could argue that this still cuts the number of available terrorrists usable for a plane-terror-mission by a factor of 4, but that's not very impressive. Especially not since most organisations capable of planning and carrying out a large attack have enough people available that being forced to choose between 1/4 of them is no large issue.
Furthermore, even this is optmitistic, because even with "secret" algorithms and "secret" data-collection for the "BigBrother" database, it'd still be more than possible to reverse-engineer atleast some of the criteria from the database simply from the publicly available information about what happens when various people try to fly.
Oh, and the 1% false positives will still cause a few million people to be hassled or denied air-travel alltogether, for no open reason. With no mechanism of appeal available, indeed even without the rigth to demand a answer to simple questions like "why can I not travel?" or "who decided that I can not travel?" or "what can I do to again be allowed travel?"
It does not change the fact that when certain countries pollute much more than what is sustainable, it degrades a shared resource.
I see your point about population-changes though, it is true that it is probably not a good idea to encourage poor countries to have as large a population as possible.
What do you think ? When an island-nation in the pacific which pollutes very little still disappears under the waves because other, far richer nations pollute enormously much more, are they then "unproductive rent-seekers" when they consider it fair that those responsible for the damage also cough up to cover it ? That's a fairly common principle in law...
You knew (or had very very strong indications) that acting in a certain way would a) give yourself increased profits and b) cause damage to the property of others. You do it anyway, collect the profits, and see the damage happen. Is it fair that the hurt ones claim *anything* from you ?
Assume that our atmosphere has a finite capacity for absorbing various pollutants, such as for example CO2.
Now, I don't know how you see it, but to me it seems sensible that the atmosphere of our planet belongs equally to all people of the planet.
Thus, I don't see it as fair, or logical, that an American gets to "spend" 10 times as much of this, our shared, finite resource, as someone born in a poorer country.
A more fair way of doing it would be, for example:
Decide what the acceptable levels of global CO2-release is. (that's probably the hardest part, since noone knows for sure it'd have to be a "best guess")
Divide this amount equally between all countries according to population. (ok, I'm willing to consider the possibility that there should be sligth changes to this basic idea, for example somewhat higher quotas to people in colder climates to compensate for needed heating.)
Make the quotas freely tradeable on an open market.
This system would have numerous benefits:
It wouldn't force Americans (or anyone else, you're not unique in polluting a lot) to live in poverty.
If an American factory can produce $1000 in value if allowed to pollute 10 tonnes extra CO2, while a chinese powerplant produces only $100 in value for the same pollution, then it'd be better for the chinese to sell that quota to USA for for example $200.
It'd be more *fair* there's no ethical reasons, other than essentially "because we're the bosses" why we western people have the rigth to claim the large majority of the atmospheres potential for absorbing pollution as "ours".
You are offcourse rigth that much of the industry in China is very inefficient, in the sense that it produces a lot of pollution for every dollar-worth of product. Improving this would have benefits both for China and the rest of the world.
On the other hand, there is something that stinks a little when you over and over and over get to hear people from USA state that the "real" problem is the inefficient industries in China, while at the same time having the highest CO2-pro-capita of the entire world, 9 times that of China, for example.
What he probably means is that though the average American release 9 times as much CO2 as the average Chinese, that's ok, because they're 20 times as rich, so they're "entitled".
The arrogance of that statement you can evaluate yourself.
Most people resolve it by defining "know" as something like "Feel sufficiently sure that I'm willing to act as if it is proven true."
We don't have any *proof* in the mathemathical sense that stones fall when let loose in gravity. I, and most people, are still going to *act* as if we do.
Your examples falter a bit. The thing is, science cannot even be proved to show the most probable outcome. For example, assume a scientist, faced with my unbelievably-lucky dice-trowing. The only reasonable hypothesis when faced with a dice that 1000 times after eachothers land on 6 is to hypothesise that this dice always land on 6. Yet that ain't the most likely outcome at all, the chanses against are astronomical.
Also, even if you touch a warm oven, and get hurt, this in no way *prooves* that the same thing is going to happen next time.
I don't really see the problem. Most scientists, if pressed hard enough, will admit that what they produce isn't nessecarily true. But they'll probably also point out that while not nessecarily true, it's the best we've got, and best we're going to get.
Science doesn't produce "This is true." kinda things. It produces: "This hypothesis fits for all experiments we could manage to think of, we're not aware of any single one where it doesn't fit." kinda things. If you want to label those things "knowledge" or not is largely semantic and not really of consequence.
I never argued with that. Obviously any restriction whatsoever limits keyspace. For example, if everyone has 8-char passwords, then requiring atleast one non-alpha reduces the keyspace (and thus the required searching) by around 0.4%.
The thing which you don't understand, or pretend you don't understand is that absent this restriction *much* more than 0.4% of the users would choose passwords in this small subset of the keyspace.
If 0.4% of all passwords are all-alpha, but 40% of all actually used passwords as choosen freely by users are all-alpha, then searching the all-alpha keyspace is 100 times as likely to net you a working password as searching any random part of the keyspace.
Nope. Sorry. That calculation is correct if I had required that the *last* position MUST be a non-alpha. Then I would indeed have 101 keys to choose from in all positions, except the last, where I'd only have 49.
To simplify your example a bit, let's say the user chooses between a total of 100 characters, half of which are non-alphas.
*if* the user choose only alphas for the first 7 characters, then he is indeed forced to choose between only half the characters in the last position, halving this part of the keyspace.
However, in most cases (99.2% of the cases) there is already atleast one non-alpha in the first 7, and thus there's no reduction at all.
So, this example works out to about 0.8% chanse of halfing the choise on the last position, a total reduction in keyspace of 0.4%.
If you don't believe my maths, try it yourself with a smaller example:
Assume that you are to choose a random 4-digit number, but that the evil admin has required that atleast one of the digits be 5-9 (i.e not all lows).
By your logic this should also lead to a halving of keyspace, but in actual fact there is only a 6.25% keyspace-decrease. You can check this yourself with this simple script:
seq 0 9999 | grep '5|6|7|8|9' | wc-l
It'll tell you 9375. So, of the total keyspace of 10000, you've excluded 625, or 6.25%
In the practical, you are correct. Thinking philosophically though, the poster previous to you has a point.
He says we "believe", you say we "know". Both of you are rigth, you only define the words differently.
From a philosophical perspective, even if you drop a stone a million times, and it falls, with acceleration close to that of gravity, every single time, this is not absolute proof that the stone will always do so.
It's a bit like, if I toss a dice, and say I'll manage to get a 6er 5 times in a row. If I manage it, you'll consider you "know" that something is foul (say louded dice). But offcourse it's *possible* that I simply had luck. (the chanse to pull of the trick is about 1:8000) Even if I tossed 6 a hundred times after oneanother, you have no *proof* that what you're seeing is not random chanse. I could be lucky. Yes, the chanses against are 1:10^77, but that doesn't make it impossible, only very unlikely.
The problem with the parent posters position is that with this definition of "know" there is, and can be no knowledge, with possible exception for mathemathics.
This ignores the very real difference between the belief "There is a God who considers it ok to eat meat, and drink milk, but gets angry/sad/whatever if I mix the two", for which there is essentially no evidence whatsoever, and the 'belief' ligth in vacum moves at around 300.000 km/s for which there are literally thousands of experiments that say: "yes, it seems to be so", and not a *single* one we've been able to device (despite trying hard!) that says: "Ooops, not in this case..."
The Lysol-pages are brilliant ! Exactly the sort of thing you'd expect to read -- around 1960 -- when germs where new and "dangerous" and people generally had no clue.
"The perfect solution to keep your home germ-free". Discounting the absurdity of the claim, why would anyone want to ?
Or such gems as: Some experts agree that colds may be caught by touching contaminated surfaces. If that ain't glowing recommendation, then I don't know. SOME experts agree that cold MAY be caught... (no discussion if, assuming it was possible, living in a sterile home would leave your kid well-prepared to handle the real world where germs are everywhere.)
Is the "must kill evil GERMS" disease really running rampant in Americas housewives even today ? Hello ! It's the year 2004 people...
But 5 byte-and-under passwords aren't 1.9% of (say) a 8-byte password keyspace. If users use a small set of characters (64) then it's 0.00038 % of the keyspace. If they use a better (i.e. larger) set of characters, then it's even less.
I agree that rules that restrict the keyspace *more* than they force users to increase entropy are pointless or even harmful. "Must start with a capital" is obviously in this category. "Must include some sign that is not a letter" is probably not, because, again, the rule excludes maybe 0.0005% of all passwords, but forces 10-30% of users, the ones which otherwise would choose "all alphas" to select a better password.
You're rigth, in principle, practically however, you are wrong.
It is true, for example that excluding 5-and-under passwords reduces the keyspace. But that is still a win if that part of the keyspace was overpopulated.
Put differently, if everyone has passwords 8 characters or less, choosen from a set of 64 characters (I realise there's more, but some are much more used than others, so the effective strength of a password choosen by a user is seldom more than 6bit/char)
There's 2^(5*6) = 2^30 passwords that are exactly 5 characters long.
There's 1.015 * 2^30 passwords that are 5 or less characters wrong.
There are about 2**(8*6) = 2**48 passwords in total.
So, by excluding the shorter ones, you've excluded 0.00038% of your keyspace.
If users choose passwords randomly, then one in 262000 users would choose a password with 5 or less characters, and for an attacker, searching this keyspace would be no more fruitful than searching any other random part of the keyspace.
Problem is, users do NOT typically choose passwords anywhere close to randomly. A more typical scenario is that 10% of all the users choose passwords 5 characters or less.
In that case, searching the 5-or-less part of the keyspace is 26000 times more likely to net you a working password than choosing a random part of the keyspace to search.
In practice, you can brute-force the 30-bit 5-and-under keyspace in minutes, and you'll have passwords for 10% of the user-accounts, allthough you only searched less than one thousandth of one percent of the keyspace.
THAT is why requiring users to have passwords over a minimum length does not, as you claim, harm security. (instead it helps quite a bit)
Everyones roots are various nature-religions. Beliefs evolve and change just as any other aspect of culture. They start out from those things that matter to people, and which everyone can see, but not understand, and evolve from there.
It's no accident, for example, that the "sungod", the "moongodess", various gods for weather and bad or good hunting/harvest whatever developed multiple times independently.
It's also no accident that as more and more of the things we observe can be explained rationally, the importance of religion fades. Essentially, religion is that which some people clutch to to explain what we cannot (yet anyway) explain rationally.
Today, most people are satisfied that the sun is a large clump of hydrogen undergoing fusion. We know that ligthining is caused by electrical discharge, we can tell that the harvest is bad on that land not due to a curse, but due to a lack of say nitrogen-compounds and so on.
Stonehenge, and similar astronomical sites are important, because they give us an idea how much the ancients knew about the movements of the various stars, sun and moon. And it marks a first step from mystism to rationality.
The constitution of EU, ain't got much to do with this, but if it's any comfort to you, it's very likely to not mention any religions spesifically at all. If for no other reason than that the various religious nutcases could never agree on what to write.
Uhm. In any existing state you're forced to pay for stuff other people decided that the nation needs, regardless of what you think about it.
Even people who never voted for Bush will have to pay for the War on Terror. People who think posession of minor quantities of cannabis should be legal still have to pay for the jails and courts which today deal with it. And so on.
Show me a single country that is "free" with this definition of yours.
Considering how the density of pollution increases as you get closer to major cities, real life seems to disagree with that theory.
Not really. If you go from rural Texas to downtown NYC, the pollution does indeed increase a lot. But the thing is, the density of people increase even more.
To illustrate, using purely fictional numbers.
Assume you have 10000 people, living on 100km^2, a rural setting, lots of space low pollution.
If you made a town for those people, it'd occupy maybe 10km^2, if you made something with the density of the core of a bigger town they'd occupy 1km^2 at most.
And the thing is, even though the pollution in the centre of that town would be much higher than on a random spot in the earlier rural setting, the *total* pollution would still be smaller. It's logical really, there's much less need for transport when everyone lives on 1km^2, you could get around only by walking.
Other resources would also be saved. It takes an order of magnitude less energy to heat (or AC) an apartment-building instead of 100 individual houses. You need less resources to offer electricity, water, sewage-service, internet, postal-service or basically anything to 10K people living on 1km^2 than you do to offer the same to the same people living spread-out over 100km^2
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A bit simplified, climate is average weather.
It's a bit like while it is impossible to predict which days will get rain in Bergen, Norway this november, it's pretty easy to predict the average temperature, the annual rainfall and how many days it'll rain.
When the question is what christians believe, then it is, indeed, relevant what christians believe. This should come as a surprise to nobody. Thus, an argument that christians commonly believe the world to be like 4000 years old, can indeed be supported by evidence such as polls showing that a large percentage of american christians do indeed believe this.
When the question is how many states the US has, then it is irrelevant what some people believe.
There's a differnece between saying: "Many americans believe there are 49 or less US states" (a demonstrably TRUE statement) and saying: "There are 49 or less US states" (an equally demonstrable FALSE statement).
To answer your other question; no this does not make those American dumb (though some of them are doubtlessly dumb, the fact that they don't know how many states there are does not demonstrate this), but it does indeed demonstrate that they are uneducated, atleast in geography.
I surprised my not-terribly-brigth professor in algorithms-101 by claiming I'd improve on his quicksort by incorporating bubblesort.
He found the idea ridiculous, and said so, but I persisted, saying that by incorporating bubblesort, I'd make the algorithm run faster for any size data-set.
What I did was run quicksort with a cutoff value of around 20, and to bubble-sort if the set to be sorted is smaller than that.
This means a small set will be only bubble-sorted, a large set will be quick-sorted until the recursive calls work on collections smaller than 20, at which point those get bubble-sorted.
Fairly standard technique. Ran something like twice as fast as the standard quicksort. Astonishing everyone who thougth that the Big-Oh notation is the be-all and end-all of performance.
MS-DOS is basically an interrupt handler, plus a selection of programs such as command.com and dir.exe.
Handling interupts is pretty much *all* the OS does. If you read any "OS-construction-101" textbook, you will find that DOSs response to like 90% of the problems presented in there is: "We don't deal with that."
From the point of view of quite a few programs, MS-DOS is a filesystem-driver. A few programs even do *that* on their own, rather than relying on DOS. They typically use what seems to DOS to be one large file, but which does in reality contain a complete filesystem, somewhat like Linux loopback-mounting of an image, but with the difference that the program itself interprets the filesystem with no help from the OS.
It's not terribly impressive that a person on wheels outstrip animals that have to walk, fly or swim, atleast on a even, smooth surface such as a road.
As for the other claim, that man on a bicycle outstrips all machines, it's bullshit.
A electric engine converts electric energy into mechanical work with an efficiency well into the 90%s. The human body is nowhere in the ballpark. I doubt it can even reach 25% in converting chemical energy (i.e. food) into mechanical energy.
Thus, a machine consisting of a battery and a electric engine hooked up to the wheels will easily beat any cyclist in efficiency.
Today people are used to shopping at supermarkets where $12.95 really means $12.95 and you're unlikely to get it even a single cent cheaper vy trying to haggle.
Thus, many people fails to consider the real power they as customers have when making larger purchases.
Spiegel here in Germany made a simple test earlier this year to see how much of a difference even minimal haggling make.
They walked into a few dozen auto-dealers saying one of the two following:
- I would like to buy a car. It'll be paid cash in full, can you make me an offer ?
- I'm looking for a new car, so I was visiting a few dealers looking for offers. I've had a few offers already, but I was wondering if you'd be able to make me a better one. What would you ask for a ?
Result ?By hinting that you're comparing, and that the dealer will have to make you an actually competitive offer to have any chanse of getting a sale, the average offer in the dealers where they used tactic 2 was around 10% better than the average offer gotten with request 1.
That's a lot of money saved for saying a single sentence out loud.
Still, tons of people fail to do even this.
If you want to produce a given amount of power constantly, with no need for sudden peaks 5 times as high as the average energy-need, then the efficient motor is *not* going to be a huge heavy-diesels 300rpm motor.
It's going to be a small turbine-motor whirling at maybe 12-15000 rpm, and running at something like 80% of it's max capacity.
This is even *more* true in applications where size and weigth of the motor plays a role, such as in a car. You are rigth that ships-engines are typically large, slow and heavy. There are other reasons for that though;
It sure as hell ain't because you need the power though, because it's fairly easy to argue that both the two European countries I have close ties to "need" more power than do the average American.
Germany because there's literally no speed-limit on the autobahn and cruising at 180km/h is considered perfecly normal by many. Norway because it's got more mountains, and thus more up-and-down and windy-roads than just about anywhere. (75% of the country or so is at 1000m or more)
To people buying 3 ton SUVs with 250hp engines in order to transport 1.17 (average ridership in US cars according to C.I.A) persons at a speed of 40 mph to the shop/work and back, there's fairly obvious things that can be done to save fuel without needing to go to extremes like hybrids.
It will however have a lot poorer performance.
The essential benefit of hybrids is that you can have a car that use (almost as) little fuel as a very weak car, while still having performance under acceleration and other short power-needs similar to a much stronger car.
The best you can hope for with a hybrid is a car that accelerates as if it'd got 120ps, but drinks fuel as if it's got only half that. (doesn't mean it'll drink half the fuel though !)
If you simply want to save money, or save the environment, or both, simply buy a small, ligthweigth and weak car. Not only will it drink little fuel, it'll also have required a lot less energy and raw-materials to produce it.
It does. A fairly typical family-car has 120ps and a 1.6 litre engine. Even though, 90% of the time it uses only a fraction of that power, the power is "needed" because people expect acceleration and ability to climb short hills without loosing speed.
With an electric assist that can give an additional push, powered from batteries for short periods, a weaker engine can be used. And here's the thing: a weaker engine is more economical.
Under circumstances where you need 35ps (for example 100km/h on flat highway) a 50ps engine is going to consume less fuel than a engine capable of 120ps, but currently near-idling at 40ps.
This is so for various reasons, partly that it requires energy to pump all that air in and out, and partly that there's a lot more mass to move in a bigger motor, which tends to lead to more internal friction-losses.
On the flipside a hybrid will tend to be heavier, because it essentially has two engines (though smaller) and two energy-storages.
Still, hybrids *do* get more mileage than conventional autos with comparable performance. Just not as much extra as the EPA-estimates will have you believe.
- Everyone will travel under their real identity.
- There will exist no fake-but-valid-looking biometric identity-cards.
- Noone will be able to obtain real cards under an assumed name.
- The BigBrother database manages, by collecting various info on people will be able to group people in three classes: terrorist, suspect and innocent.
- "terrorists" are denied air-travel, "suspects" are subjected to a more thorough search.
- False negatives for "terrorist" will be only 25%, only 1% of all "innocents" will falsely be labeled suspect or terrorist.
Now, every single one of those assumptions are very optimistic, I have no faith at all that a system could possibly work this well. Still, even with a system like the above, gaming the system to virtually guarantee success is trivial:- The staff manning checkpoints has a finite capacity to check/search people.
- So, if one group of people ("suspects" are checked more, this *must* mean that others ("innocents") are checked less than today.
So here's what you do:- Send the vrious members of your terror-cell on a fligth-trip involving 4-5 fligths. Have a real and good explanation for the trip, carry nothing illegal whatsoever, and behave exemplary.
- 75% of the terrorists will be on the "terrorist" or "suspect" list. They'll notice this, because though you can't demand to know if you're listed or not, it's not hard to notice if you get denied boarding or not, nor if you get searched on every boarding or not.
- For the real attack, a month later, you use people from the 25% who you now know to be on the "innocent" list.
Since the system can only work by checking "suspects" more and "innocents" less, you have now improved your chasnes of success in comparison with a system without classification of passengers into groups.You could argue that this still cuts the number of available terrorrists usable for a plane-terror-mission by a factor of 4, but that's not very impressive. Especially not since most organisations capable of planning and carrying out a large attack have enough people available that being forced to choose between 1/4 of them is no large issue.
Furthermore, even this is optmitistic, because even with "secret" algorithms and "secret" data-collection for the "BigBrother" database, it'd still be more than possible to reverse-engineer atleast some of the criteria from the database simply from the publicly available information about what happens when various people try to fly.
Oh, and the 1% false positives will still cause a few million people to be hassled or denied air-travel alltogether, for no open reason. With no mechanism of appeal available, indeed even without the rigth to demand a answer to simple questions like "why can I not travel?" or "who decided that I can not travel?" or "what can I do to again be allowed travel?"
It does not change the fact that when certain countries pollute much more than what is sustainable, it degrades a shared resource.
I see your point about population-changes though, it is true that it is probably not a good idea to encourage poor countries to have as large a population as possible.
What do you think ? When an island-nation in the pacific which pollutes very little still disappears under the waves because other, far richer nations pollute enormously much more, are they then "unproductive rent-seekers" when they consider it fair that those responsible for the damage also cough up to cover it ? That's a fairly common principle in law...
You knew (or had very very strong indications) that acting in a certain way would a) give yourself increased profits and b) cause damage to the property of others. You do it anyway, collect the profits, and see the damage happen. Is it fair that the hurt ones claim *anything* from you ?
Assume that our atmosphere has a finite capacity for absorbing various pollutants, such as for example CO2.
Now, I don't know how you see it, but to me it seems sensible that the atmosphere of our planet belongs equally to all people of the planet.
Thus, I don't see it as fair, or logical, that an American gets to "spend" 10 times as much of this, our shared, finite resource, as someone born in a poorer country.
A more fair way of doing it would be, for example:
- Decide what the acceptable levels of global CO2-release is. (that's probably the hardest part, since noone knows for sure it'd have to be a "best guess")
- Divide this amount equally between all countries according to population. (ok, I'm willing to consider the possibility that there should be sligth changes to this basic idea, for example somewhat higher quotas to people in colder climates to compensate for needed heating.)
- Make the quotas freely tradeable on an open market.
This system would have numerous benefits:You are offcourse rigth that much of the industry in China is very inefficient, in the sense that it produces a lot of pollution for every dollar-worth of product. Improving this would have benefits both for China and the rest of the world.
On the other hand, there is something that stinks a little when you over and over and over get to hear people from USA state that the "real" problem is the inefficient industries in China, while at the same time having the highest CO2-pro-capita of the entire world, 9 times that of China, for example.
The arrogance of that statement you can evaluate yourself.
Most people resolve it by defining "know" as something like "Feel sufficiently sure that I'm willing to act as if it is proven true."
We don't have any *proof* in the mathemathical sense that stones fall when let loose in gravity. I, and most people, are still going to *act* as if we do.
Your examples falter a bit. The thing is, science cannot even be proved to show the most probable outcome. For example, assume a scientist, faced with my unbelievably-lucky dice-trowing. The only reasonable hypothesis when faced with a dice that 1000 times after eachothers land on 6 is to hypothesise that this dice always land on 6. Yet that ain't the most likely outcome at all, the chanses against are astronomical.
Also, even if you touch a warm oven, and get hurt, this in no way *prooves* that the same thing is going to happen next time.
I don't really see the problem. Most scientists, if pressed hard enough, will admit that what they produce isn't nessecarily true. But they'll probably also point out that while not nessecarily true, it's the best we've got, and best we're going to get.
Science doesn't produce "This is true." kinda things. It produces: "This hypothesis fits for all experiments we could manage to think of, we're not aware of any single one where it doesn't fit." kinda things. If you want to label those things "knowledge" or not is largely semantic and not really of consequence.
The thing which you don't understand, or pretend you don't understand is that absent this restriction *much* more than 0.4% of the users would choose passwords in this small subset of the keyspace.
If 0.4% of all passwords are all-alpha, but 40% of all actually used passwords as choosen freely by users are all-alpha, then searching the all-alpha keyspace is 100 times as likely to net you a working password as searching any random part of the keyspace.
To simplify your example a bit, let's say the user chooses between a total of 100 characters, half of which are non-alphas.
*if* the user choose only alphas for the first 7 characters, then he is indeed forced to choose between only half the characters in the last position, halving this part of the keyspace.
However, in most cases (99.2% of the cases) there is already atleast one non-alpha in the first 7, and thus there's no reduction at all.
So, this example works out to about 0.8% chanse of halfing the choise on the last position, a total reduction in keyspace of 0.4%.
If you don't believe my maths, try it yourself with a smaller example:
Assume that you are to choose a random 4-digit number, but that the evil admin has required that atleast one of the digits be 5-9 (i.e not all lows).
By your logic this should also lead to a halving of keyspace, but in actual fact there is only a 6.25% keyspace-decrease. You can check this yourself with this simple script:
seq 0 9999 | grep '5|6|7|8|9' | wc-l
It'll tell you 9375. So, of the total keyspace of 10000, you've excluded 625, or 6.25%
He says we "believe", you say we "know". Both of you are rigth, you only define the words differently.
From a philosophical perspective, even if you drop a stone a million times, and it falls, with acceleration close to that of gravity, every single time, this is not absolute proof that the stone will always do so.
It's a bit like, if I toss a dice, and say I'll manage to get a 6er 5 times in a row. If I manage it, you'll consider you "know" that something is foul (say louded dice). But offcourse it's *possible* that I simply had luck. (the chanse to pull of the trick is about 1:8000) Even if I tossed 6 a hundred times after oneanother, you have no *proof* that what you're seeing is not random chanse. I could be lucky. Yes, the chanses against are 1:10^77, but that doesn't make it impossible, only very unlikely.
The problem with the parent posters position is that with this definition of "know" there is, and can be no knowledge, with possible exception for mathemathics.
This ignores the very real difference between the belief "There is a God who considers it ok to eat meat, and drink milk, but gets angry/sad/whatever if I mix the two", for which there is essentially no evidence whatsoever, and the 'belief' ligth in vacum moves at around 300.000 km/s for which there are literally thousands of experiments that say: "yes, it seems to be so", and not a *single* one we've been able to device (despite trying hard!) that says: "Ooops, not in this case..."
"The perfect solution to keep your home germ-free". Discounting the absurdity of the claim, why would anyone want to ?
Or such gems as: Some experts agree that colds may be caught by touching contaminated surfaces. If that ain't glowing recommendation, then I don't know. SOME experts agree that cold MAY be caught... (no discussion if, assuming it was possible, living in a sterile home would leave your kid well-prepared to handle the real world where germs are everywhere.)
Is the "must kill evil GERMS" disease really running rampant in Americas housewives even today ? Hello ! It's the year 2004 people ...
I agree that rules that restrict the keyspace *more* than they force users to increase entropy are pointless or even harmful. "Must start with a capital" is obviously in this category. "Must include some sign that is not a letter" is probably not, because, again, the rule excludes maybe 0.0005% of all passwords, but forces 10-30% of users, the ones which otherwise would choose "all alphas" to select a better password.
It is true, for example that excluding 5-and-under passwords reduces the keyspace. But that is still a win if that part of the keyspace was overpopulated.
Put differently, if everyone has passwords 8 characters or less, choosen from a set of 64 characters (I realise there's more, but some are much more used than others, so the effective strength of a password choosen by a user is seldom more than 6bit/char)
- There's 2^(5*6) = 2^30 passwords that are exactly 5 characters long.
- There's 1.015 * 2^30 passwords that are 5 or less characters wrong.
- There are about 2**(8*6) = 2**48 passwords in total.
- So, by excluding the shorter ones, you've excluded 0.00038% of your keyspace.
If users choose passwords randomly, then one in 262000 users would choose a password with 5 or less characters, and for an attacker, searching this keyspace would be no more fruitful than searching any other random part of the keyspace.Problem is, users do NOT typically choose passwords anywhere close to randomly. A more typical scenario is that 10% of all the users choose passwords 5 characters or less.
In that case, searching the 5-or-less part of the keyspace is 26000 times more likely to net you a working password than choosing a random part of the keyspace to search.
In practice, you can brute-force the 30-bit 5-and-under keyspace in minutes, and you'll have passwords for 10% of the user-accounts, allthough you only searched less than one thousandth of one percent of the keyspace.
THAT is why requiring users to have passwords over a minimum length does not, as you claim, harm security. (instead it helps quite a bit)
It's no accident, for example, that the "sungod", the "moongodess", various gods for weather and bad or good hunting/harvest whatever developed multiple times independently.
It's also no accident that as more and more of the things we observe can be explained rationally, the importance of religion fades. Essentially, religion is that which some people clutch to to explain what we cannot (yet anyway) explain rationally.
Today, most people are satisfied that the sun is a large clump of hydrogen undergoing fusion. We know that ligthining is caused by electrical discharge, we can tell that the harvest is bad on that land not due to a curse, but due to a lack of say nitrogen-compounds and so on.
Stonehenge, and similar astronomical sites are important, because they give us an idea how much the ancients knew about the movements of the various stars, sun and moon. And it marks a first step from mystism to rationality.
The constitution of EU, ain't got much to do with this, but if it's any comfort to you, it's very likely to not mention any religions spesifically at all. If for no other reason than that the various religious nutcases could never agree on what to write.
Even people who never voted for Bush will have to pay for the War on Terror. People who think posession of minor quantities of cannabis should be legal still have to pay for the jails and courts which today deal with it. And so on.
Show me a single country that is "free" with this definition of yours.
Not really. If you go from rural Texas to downtown NYC, the pollution does indeed increase a lot. But the thing is, the density of people increase even more.
To illustrate, using purely fictional numbers.
Assume you have 10000 people, living on 100km^2, a rural setting, lots of space low pollution. If you made a town for those people, it'd occupy maybe 10km^2, if you made something with the density of the core of a bigger town they'd occupy 1km^2 at most.
And the thing is, even though the pollution in the centre of that town would be much higher than on a random spot in the earlier rural setting, the *total* pollution would still be smaller. It's logical really, there's much less need for transport when everyone lives on 1km^2, you could get around only by walking.
Other resources would also be saved. It takes an order of magnitude less energy to heat (or AC) an apartment-building instead of 100 individual houses. You need less resources to offer electricity, water, sewage-service, internet, postal-service or basically anything to 10K people living on 1km^2 than you do to offer the same to the same people living spread-out over 100km^2