The Point of the Banach-Tarski Theorem – not just a curiosity - <AUTHOR> http://www.solipsys.co.uk/new/ThePointOfTheBanachTarskiTheorem.html?HN_20150607 <comment><USER2> Accepting or rejecting the axiom of choice as "natural" is a red herring based on the idea that mathematics express external truths about the world. Mathematics describe rules of reasoning which _preserve_ truths about the world.

For instance, if I am trying to count my goats, the concept of natural integer allows me to count two groups, sum the results, and still have an accurate understanding of the number of goats I have.

As it turns out, the theory of natural integers allows one to define arbitrarily large numbers, even though I cannot possibly have more than, say, 1000 goats. Yet, a theory that deals only with numbers less than 1000 might be more cumbersome to work with. Try to define addition there and see for yourself.

The theory of natural numbers is useful because it provides a simple formal way to accurately count the number of goats (and possibly other things). It doesn't matter that it allows us to conceive of an absurd number of goats, like 1,000,000. It does the job, and as long you use it in the real world on real data you won't get absurd results.

\---

The same goes for the axiom of choice. Whether or not you accept it isn't going to make a practical difference once it comes to measuring the volume of helium needed to fill your balloon.

Think of it as upcasting and downcasting. You're dealing with a finite problem which is hard to solve. So you upcast it to a more general theory, solve it, and then downcast it back to the original setting.

There are as many ways to upcast as there are ways to pick independent axioms, so pick whichever make the problem easiest to solve, and don't worry about the "truth" of these propositions.

<comment><USER3> Another perspective is that mathematics is not intended to describe the real world, and so what makes a mathematical assumption "natural" is how elegant or inelegant its consequences are. There is a long list of strange things that would be true if you assume the axiom of choice is false [1], and I'm pretty sure nobody who has ever considered the pros and cons of AoC has cared about the amount of helium in their balloon. Esp. considering that it's not possible to construct nonmeasurable sets in the physical world (since you would need to do operations at a scale infinitely smaller than the Planck constant, for one!).

[1]: [http://mathoverflow.net/questions/129036/counterintuitive- co...](http://mathoverflow.net/questions/129036/counterintuitive-consequences- of-the-axiom-of-determinacy)

<comment><USER4> The reason those things are strange is that uncountable sets have absolutely no bearing on computable objects (== enduring in math and science) but everyone mistakenly applies their countable intuition to uncountable set theory.

<comment><USER5> If one uses classical logic there are even many countable, even finite sets which are beyond computable distinction. The set of computable functions on say natural numbers is a countable set, but even distinguishing when two such are equal cannot be effectively done.

The solution is either to distinguish between countable and enumerable and decidable, or to use intuitionistic logic.

</comment></comment></comment></comment><comment><USER6> The author of Irregular Webcomic walks through a Banach-Tarski decomposition and it turns out not to require any really heavy-duty math. You should understand it if you know what rational and irrational numbers are:

[http://www.irregularwebcomic.net/2339.html](http://www.irregularwebcomic.net/2339.html)

<comment><USER7> "I have discovered a truly remarkable proof of the Banach-Tarski theorem which this margin is too small to contain - oh wait, this is a webcomic, of course there's room!"

</comment></comment><comment><USER5> I just want to mention that there is a much deeper discussion to be had about the axiom of choice than the apparent impossibility of Banach Tarski, and it has to do with equality.

In mathematics is is common to change the equality between sets (form quotient sets). For example, the set of real numbers are infinite sequences of rational numbers (fractions) which approximate the value. But the equality which we place on this set is not the equality of sequences, which is too strict. We put a new equality on these real numbers which identify two of them iff they come arbitrarily close to each other.

The axiom of choice (AC) says that if for a ∈ A there is b ∈ B satisfying some requirement, then there is a function A → B selecting these elements. The axiom of choice is only problematic if we require that choice function it produces respects some quotient equality we placed on A and B. The confusion arise because ZF Set Theory cannot express the weaker notion of a function which does not express the quotient equality. Other foundations, such as Martin-Löf Type Theory, can express this difference and you get AC without the paradoxes.

<comment><USER8> What's the _disadvantage_ of those other foundations that makes them unsuitable for universal use?

<comment><USER9> They're certainly not unsuitable, but they have a tendency to take observation/realization/grasping/proving as an instantaneous process. In most people's regular understanding of logic, however, this is false. There is a process by which new data and new conclusions from that data are drawn and made available to you.

So ultimately, if those things matter for either UX of mathematics or for actual mathematical content is a large question, but it's fairly clear that if you need to capture something closer to the actual dynamics of knowledge/learning/understanding then you are sunk when you base your foundations in set theory.

</comment></comment></comment><comment><USER10> There is no evidence that the real world has anything to do with a continuum, real numbers, or R^3. When we look closely at things, we always find combinatorial structures of discrete entities (smooth matter -> atoms -> protons -> quarks). For example, electrical charge is discrete, not continuous, and the unit appears to be 1/3 the charge on the electron (as carried by quarks).

The balance of evidence is that our universe is spatially compact, with time bounded in the past (Big Bang), so it is possible that there are no infinities at the cosmological scale either. The evidence for the temporal future has recently changed from closed (Big Crunch) to open (infinite expansion).

There are various theories about how space and time emerge from discrete quantum mechanical structures. For example, a simple derivation in Loop Quantum Gravity gives a discrete spectrum for area. At the moment, we don't know which theory is correct, but it is likely there is a smallest finite unit of area (and volume).

Another reason for rejecting real numbers in physics, is that each value contains an infinite amount of information. The Holographic Principle is interesting because it rejects the notion of an infinite amount of information in a finite space. In fact, it goes a lot further, and says the total information within a 3D volume does not scale as the volume (!), but as the 2D surface area. Essentially there is one bit per Planck Area, so 10^66 bits/m^2.

It is easy to imagine, but not to describe or prove, a combination of these theories that implies everything is finite, discrete and combinatorial, without an infinity or a real number in sight.

<comment><AUTHOR> But that's not really the point.

        All models are wrong,
        some models are useful.

Using the reals as a model makes the math a _lot_ easier than trying to do everything in discrete structures, especially since we don't actually know the scales that these discrete structures might be at. We don't know what the smallest unit of space is, and it's still not clear that there is one. As a result we use the reals as a model, and it does incredibly well.

So in a sense you are helping support the main point of the original article. The fact that the reals are an approximation to what you claim reality might be should be acknowledged, and then we should explore the limits and limitations of that models. The Banach-Tarski theorem does exactly that, showing us at least one place there the model apparently fails, and should certainly be treated with care.

</comment></comment><comment><USER11> >So if we have a bounded set (and I've not given a technical definition of what that means) then we'd like the measure of that to exist

Why in the world should this be true? I'd much sooner try to weaken this requirement than the additivity requirement or the axiom of choice. For example, I imagine restricting measures to (unions of countably many disjoint) (path-)connected subspaces of the ambient topology would solve the problem just as handily, without making any compromises on how well the math models our intuitive notion of measure. On that note, I suspect that to really have a _meaningful_ notion of measure, one really needs to have at least a topology, if not an outright metric space.

Can anyone more versed in this area comment on this?

<comment><AUTHOR> People I talk to about this are often very unhappy about countable additivity, and are often unhappy about infinite in general. I suspect that the reason they think they want a measure to be defined on every set is because they don't know just how weird sets can be, and are relying on their intuition. Everything can be weighed, everything can be dunked in water to test its volume, so why should something _not_ have a "volume"?

You clearly have a different intuition born of your background and training. You're talking about

      > "... unions of countably many disjoint
      > (path-)connected subspaces of the ambient
      > topology ..."

You already have an unusual intuition.

And you're right - it's "obviously" better to restrict the sets we play with rather than limiting ourselves to finite collections, but that "obvious" comes from years, perhaps decades, of playing with these ideas.

And with regards having a topology or a metric, consider that perhaps a measure can be coerced into providing a metric ...

<comment><USER12> > Everything can be weighed, everything can be dunked in water to test its > volume, so why should something not have a "volume"?

But it seems pretty obvious to me that you can't measure the volume of something (accurately) if it has features smaller than a water molecule.

Don't know about an equivalent example for weighing things.

But it stands to reason that, whatever you (think you) want to measure shouldn't have meaningful features smaller than the accuracy of the thing you're measuring _with_.

That's why we made electron microscopes, because photons were too big.

</comment></comment></comment><comment><USER13> > _If that 's true, then there can be no measure satisfying the requirements > even when weakened from countable additivity to finite additivity._

I think this is an important/interesting point and should be highlighted more in the article. The "magic trick" is not hidden in the fact that you are using infinitely many pieces. The "magic trick" is that the pieces have very odd shapes.

<comment><AUTHOR> OK, I've made a change to highlight that, and it's processing and uploading now. Let me know what you think.

</comment></comment><comment><USER14> I am very much not a mathematician. I took physics at university, but that was 20 years ago. The mathematics here is beyond me.

So, I realise I'm probably confusing theoretical mathematics with a practical science. But, still. If this was a real, true result, couldn't someone simply take a sphere of, say, gold, and recut it to be two spheres of gold? Then keep doing it until they're richer than Croesus?

Or, to be more serious, what value are results like this if they are obviously false in the real world?

Also, if they plainly don't apply to the real world, isn't that a really good sign that the mathematics is actually incorrect?

Or, have I completely misunderstood the article?

<comment><USER15> You would need to cut the spheres in very strange pieces and since spheres of gold are made of atoms you can't do that in the real world.

<comment><USER14> Why not, assuming you make the spheres big enough? Let's say not gold, but a moon. I mean, let's do a thought experiment with superhuman tech and a big enough sphere that atoms are small enough to make the slices right.

I guess I just don't understand why this doesn't violate conservation of mass.

<comment><AUTHOR> Because you really, really can't make the slices small enough.

And your point about violating the conservation of mass is the whole point of the article. When we try to come up with a mathematical model of what "volume" means there are certain properties we want it to have. One of them is that any arbitrary collection of point - not atoms, but mathematical points - can have a volume associated with it. The Banach-Tarski theorem shows that such a requirement is impossible.

You're not alone if you think this is all nonsense - so did Feynman. However, many clever people not only believe that this is relevant, but also useful and insightful. The article is trying to give a sense of why that's the case.

I want to write a sister article to this to help people like you come to understand what's going on, but I'm having trouble finding people who are willing to engage with me on it. They usually just find that it offends their sense of reality and reject it all. I think that's a shame, because unless people like me can come to understand what others find so objectionable we can never learn how to help people understand why this is interesting, useful, adn relevant.

<comment><USER14> I think the problem is there's mathematics on one hand and my experience of the real world on the other. I either didn't do any set theory, or I've forgotten it. So it looks just like squiggles on the page to me when I try to understand the maths.

So, all I'm left with is trying to relate what the words might mean in real- world terms. And coming up confused.

I don't think it's your fault. I just lack the grounding to see both sides of the picture.

One thought, though. I'm not trying to reject it because it offends my sense of reality. I'm trying to use my sense of reality (which is the only tool I have) to understand it.

For example, if someone came up to me at work and said, "I've just worked out how to cut a sphere up into bits and reassemble it as two spheres the same size," I'd say, "ok, then, show me."

If all they could do is make marks on paper I couldn't understand I'd think they'd got the paper wrong, not reality. Which is the dissonance here. I guess, speaking personally, if you want someone like me to understand it you'd need to really, really explain the maths (as if to a simpleton!), or explain what's happening in real-world terms and why it wouldn't work yet is still valid.

Does that help?

<comment><AUTHOR> But what we're saying here is this.

We use sets to model the real world. They do remarkably well, and the math we've developed to work on them includes calculus to make bridges that stay up, fluid dynamics that make aeroplanes fly, and discrete math that helps us understand routing, scheduling, and all sorts of stuff.

We use the real line to model distances. In the real world we are limited as to the accuracy we can use, but modelling those limitations is nasty. It's easier to assume that things are continuous. In its turn, we make choices that make working with these models easier, and they turn out to be amazingly useful.

But then we start poking the dusty corners. The choices we make in the development of the theory have consequences, and math is about exploring both the choices, and their consequences.

So we can choose that between every two numbers there's another number. We can choose that there's a number whose square is 2. We can choose that the sum of the reciprocals of squares : 1+1/4+1/9+1/16+1/25+1/36+ ... : is a real number.

And we can choose that there is no smallest positive number. That has a consequence. If you believe that there is no smallest positive number, then 0.99999... has to equal 1. You can't have one without the other.

So we can talk about "the length of a line." Then we can talk about the "length" of a set of points on a line. Then we start to find that these simplistic models, these obvious and natural choices, even though they are amazingly useful have some unexpected consequences.

Does that help you to understand the context?

I'd be really interested in developing an agreed dialog about this. Will you send me an email?

<comment><USER14> > I'd be really interested in developing an agreed dialog about this. Will you > send me an email?

I've sent you an email, as requested.

From the sound of it, though, the answer to my puzzlement, is that it doesn't apply to this universe. In which case, I don't think it's a problem at all. I'm quite happy to imagine mathematicians doing work on geometries that don't map to the real world, for example.

Mostly, then, is this just a question of presentation? I mean, if you said "this does not apply to the real world, but to some fictitious mathematical assumption that assumes things can be divided up infinitely," I don't think anyone would have an issue with it. It sounds like it's a problem to most people because it's presented as if it's a real-world result.

Or, at least, that seems to be the impression I get, given the other comments.

What I mean is, is there's a question of misdirection here? I.e. the theorem is presented as this non-intuitive thing that can't possibly be the case in the real world, then when someone asks what would happen if you tried it in the real world, the answer is "it's assuming some things that aren't true for the real world." Because if that's the case, I'm not sure I see the paradox. Assuming a weird set of ideas, I would expect you can come up with weird answers.

Here's a question, though, because something is nagging at me. And I'm going to assume this is a universe of infinite points and no atoms (as I understand it, at least).

Let's say we have a sphere of volume 4/3 pi r^3 = 100

Now you do your cuts, but don't reassemble yet. The sphere is still the original sphere, with all the shapes it has been cut into still in virtually their original spaces.

The total volume still has to be 100, right? I mean they all still fit into the original space.

So now, you immerse it in water, in a bathtub ready to overflow, and start manipulating the pieces.

At what point does the water level rise?

<comment><USER4> You at exactly right. The "paradox" is that people naively assume that the Real ("Real" = math theory, "real" = CS turing-computable and physics "real universe") numbers are a smooth continuum, but if you follow the actual definition, you discover that it is too powerful -- the Real numbers could construct physically impossible objects, which proves that real numbera aren't real. In reality, we must confine ourselves to countable sets, which has ugly asymmetries: we must distinguish a set of "nameable" numbers as more "real" than the others, but we can choose _any_ small-enough subset of Real numbers we want, we can choose every single Real number we practically encounter, but we can't choose _all_ of them at the same time.

<comment><USER16> I'm not sure in what sense you mean real numbers could "construct" anything, but you can make physically impossible shapes out of rational numbers too, so their cardinality has nothing to do with that.

</comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER17> Banach-Tarski is absurd because matter in reality is made out of particles. If you take this into account in your definitions you can't do absurd stuff like Banach-Tarski.

As such it offers an insight into what can happen if your mathematical model fails at representing the reality.

<comment><USER18> Strictly speaking, math it self isn't intended to reflect reality. It's just logical system together with some initial axioms. But it does happen to model reality very well, given the right interpretations.

<comment><USER4> But uncountable sets do NOT model reality well.

<comment><USER19> Oh but they do. When taking measurements in a scientific setting, it usually gives the most accurate and simple model to assume that your measurement is an approximation of a certain _real_ number, and understand more accurate measurements as better estimates of this real number. Using rational numbers or other countable sets in this position usually leads to undesirable biases and or circuity in the model. When you need a "continuum", the real numbers have the best properties for the job.

</comment></comment></comment></comment><comment><USER20> Excellent article, but my first reaction was "Goodness, that's an awfully punny title". It still gives me fuzzies, but I can't tell if it's intentional or not.

</comment><comment><USER21> If one solid ball can be partitioned into two solid balls of equal radius, then can't each of THOSE be partitioned into four solid balls of equal radius, and so on ad infinitum?

<comment><USER4> Yes. Except that the ball can't really "be paritioned". That's a mathematical illusion. There is an isomorphism of structures, but there is no _computable algorithm_ that can perform the partition operation.

</comment></comment><comment><USER22> Maybe it helps to circularize the problem a bit? Or at least, if not help, not make it worse? And then mix in some quadratic equations?

[http://en.wikipedia.org/wiki/Non- measurable_set#Consistent_d...](http://en.wikipedia.org/wiki/Non- measurable_set#Consistent_definitions_of_measure_and_probability)

If B-T is true, then you've got to select 1 of 4 known cheat codes to allow the definition of volume of "normal real world things" at least the way non- math people like to measure volumes. The least icky is the option that demands sets with non-measurable volumes exist, weird as that sounds. Then again, how weird is it really, given that no one freaks out about an infinite number of irrational numbers existing in between all possible fractions. Pi, after all, is no fraction, but its handy to keep around anyway. If you assume B-T is true and in choose-your-own-adventure fashion select that non-measurable sets exist, then, it turns out that having non-measurable sets make B-T "obvious- ish" or at least less obscure sounding, it all kind of works out in a circular manner.

Why in the name of Occams Razor would you want a pair of weird ideas instead of dust bin both and stick to grade school geometry? Well the axiom of choice wedges in sideways between B-T and the non-measurable sets above, kind of like two balls wedge into the space one ball takes up above (making kind of a joke or tongue in cheek). Its not just two weirdo ideas that work together but a couple of them. And the axiom of choice is just so useful in so many ways (see its wikipedia page) I'd have to think for a second about chucking out the axiom of choice. I think it would be ickier than keeping it around. Life is so much easier if you keep all three hanging around, and all their hangers on.

A really good analogy would be some real world quadratic equations for a land survey (well, made up example) only have one solution in the reals although everyone knows there's two mathematical solutions to any quadratic even if you don't like negative sq roots, and thats OK, and you kinda have to look sideways at the solutions involving negative square roots. Its not that real world geometry problems are full of negative square roots in practice or it means anything in the context of land survey problems, but its kind of a place holder in math.

Kind of a "conservation of weirdness" physics theory where they cancel out over a large enough collection of theorems or a collection of weird ideas is in sum less weird than any individual idea. So if you'd like this and that, and its really interesting and handy and seems to work quite well, sometimes you're going to have to not look overly closely at weird point sets that literally do not have a defined volume, at least not as you'd define volumes, and then screwing around with those volumeless objects can result in super weird stuff like two balls for the price of one. Which is OK in the physical world because we don't have abstract spheres that can have anything happen to them, we have vaguely round piles of atoms with really complicated rules about what you can do to that pile of atoms.

It all vaguely resembles the manufacture of sausage where you'll probably be happier if you don't look to closely at things that shouldn't exist, yet, its a tasty breakfast sausage if you don't think too hard about where any individual part came from. This is a highly heretical view, we're only supposed to think about math as some beautiful, pure, and virtuous thing, which I'm convinced is sociologically some repressed Victorian views about virgin brides or some nonsense so I don't feel too bad about being a heretic.

<comment><USER12> > Pi, after all, is no fraction, but its handy to keep around anyway.

You actually only need a surprisingly small amount of decimals of pi to calculate the circumference of the visible universe (just about the largest circle you can possibly have) to the accuracy of a single proton (just about the smallest scale you can realistically want to measure).

I think it was about 50 decimals or so.

Take _that_ , crazy hundreds-of-decimals-of-pi memorizing people! ;-)

</comment></comment><comment><USER23> I don't believe in the axiom of choice.

<comment><USER4> You don't believe it is true? That's silly, there is no good reason to believe it true or false, except in the sense that you think one of Chess or Go is the more fun game of the two.

Or you don't believe it is a meaningful to try to choose an answer? That's ZF, the home to the portion of set theory that has anything useful to say about the physical Universe.

<comment><USER12> So because Go _is_ (objectively) more fun than Chess, that means Banach-Tarski is bollocks!</comment></comment></comment>


Dollar's Decline Speeds Up, With Risks for U.S - <AUTHOR> http://online.wsj.com/article/SB10001424052748703907004576279321350926848.html?mod=googlenews_wsj

<comment><USER2> Here's a Google redirect if anyone else can't read the article as linked:

[http://www.google.com/url?q=http://online.wsj.com/article/SB...](http://www.google.com/url?q=http://online.wsj.com/article/SB10001424052748703907004576279321350926848.html?mod=googlenews_wsj)

</comment><comment><USER3> I think it very likely that most of the US government is cheering a devalued dollar; weak dollar = significantly increased exports, and jobs. America really, really needs both of those right now.

What's clear in the last few years is that nobody is going to shoot missiles or send troops over currency devaluation; this is a relatively simple way to boost your own country's economic strength.

Since we're more decentralized than say, China, those who'd like devaluation can't just mandate it, but I'd be stunned if a weak dollar is seen as a bad thing by the current Administration.

<comment><USER3> p.s. The article imagines China dumping their $3T in US dollars; that would be a real surprise; it would cause more strain on the RMB-USD rates, and boost US exports.

</comment></comment><comment><USER4> I'm not surprised. I took advantage of the exchange rate to move a bunch of my Australian dollars across to US dollars last week. But I was earning about 6% on my savings account in Australia, and I'm only earning 0.1% in my savings account in the US.

Obviously there's a huge element of pricing the interest rate discrepancy into the exchange rate, so one should expect the exchange rate to return to something more normal once the US economy starts growing again and interest rates become more reasonable.

(Actually in related news, can anyone think of a good place to invest fifty thousand US dollars right now?)

<comment><USER5> (Jokingly) I can think of a few upcoming companies that could turn that around for you in a few years. ;) (Seriously: And I'd love to pitch mine, if you're interested.)

</comment></comment><comment><USER6> Been going on for a while -

[http://www.ritholtz.com/blog/2011/04/dollars-biggest- decline...](http://www.ritholtz.com/blog/2011/04/dollars-biggest- decline-2001-08/)

during the crisis the dollar strangely stopped declining partly due to a 'flight to quality', a lot of other countries were in even worse shape.

When you need to sell a lot of debt to foreign investors, they need to think the currency is at a level where it won't decline too much in the future, and if they don't think that, the dollar goes down or interest rates go up.

</comment><comment><USER5> The USD has been trending more strongly in relation to the NOK. ([http://www.google.com/search?sourceid=chrome&ie=UTF-8...](http://www.google.com/search?sourceid=chrome&ie=UTF-8&q=1+usd+in+nok)) Probably an irrelevant currency for most, but the Kroner has been extremely strong and independent (IMO). Can anyone explain how this trend relates to the above article?

<comment><USER6> Norway has oil and a huge sovereign wealth fund, compared to certain countries that import lots of oil and have lots of debt.

See page 5 where they are listed as the least risky sovereign debt in the world (USA still #5, although the people who suggest not raising the debt ceiling are trying to change that)

[http://blog.stocktwits.com/sponsored-post-cma-global- soverei...](http://blog.stocktwits.com/sponsored-post-cma-global-sovereign- credit-risk-report-for-q4-2010/)

<comment><USER5> But even with such independence, the only way to reconcile this article with my observation is to say that the NOK is weakening even faster than the USD. I don't see/understand how that's the case.

<comment><USER6> Not sure I follow the math, since beginning of December NOK is up 14% against the USD, about 3% against the EUR

<http://www.google.com/finance?q=CURRENCY%3ANOKUSD></comment></comment></comment></comment>


Do we really need project managers? - <AUTHOR> http://corporategeek.info/why-do-we-need-project-managers-positive-justification

<comment><USER2> I am managing projects in an Open-Hardware community. My personal observation says - yes. The chief reason being, a large number of ideas. The good ones tend to get lost, or ignored. My role is to constantly review the new ideas, at the same time to make sure that the old on-going projects are not stalled. I also make sure that the repetition of effort does not happen.</comment>


Using a hosts file to make the internet not suck as much - <AUTHOR> http://someonewhocares.org/hosts/

<comment><USER2> No offense to the author or OP, but I think most people on HN know that you can use your hosts file for adblocking. It's not something I like to do because it's not very flexible, especially if some sites block ad-blocking users.

<comment><USER3> Agreed. If ABP starts sucking, someone will make a not horrible version which lets you turn it on and off. I'm not editing a hosts file each time a streaming video doesn't work.

<comment><USER4> [http://www.abelhadigital.com/hostsman](http://www.abelhadigital.com/hostsman)

A decent hosts file manager.

<comment><USER5> Apparently someonewhocares does not work with it.

</comment></comment></comment></comment><comment><USER6> One thing I have noticed about all of the 'edit your hosts' posts seem to ignore/forget is ABP also collapses/removes/hides the element housing the ad as well as not showing the add.

I have used it for so long that I forget ads might even be on sites/pages I visit, as I am not presented with a bunch of holes in sites.</comment>


Australian government considers blocking porn and gambling sites - <AUTHOR> http://www.theage.com.au/articles/2008/10/27/1224955916155.html

<comment><USER2> A quick note for readers who aren't familiar with the ins and outs of Australian politics: the two senators named here as supporting these measures (Xenophon and Fielding) aren't part of any major party, and certainly not part of the "Government" as we usually use the term.

The way that senators are elected in Australia allows for people to occasionally get elected with a tiny percentage of the actual vote, usually by having a nice-sounding party name like "Family First" or "No Pokies" (the latter of which refers to poker machines in bars, which are a bit of an annoyance). Unfortunately the way the balance of power in the Senate usually works out, the government has to rely on the support of the minor parties in order to pass legislation.

The headline is thus somewhat inaccurate -- I would never defend what the Australian government is trying to do to the internet, but the _actual_ government isn't considering these measures on its own initiative, although they may be considering adding them in order to appease the minor parties.

I'm very depressed that both my home country (Australia) and my adopted country (the USA) are both seem to be taking steps away from liberty and towards statism simultaneously.</comment>


I hacked something. Now what? - <AUTHOR> http://www.acloudtree.com/i-hacked-something-now-what/

<comment><USER2> If you live in the U.S, publishing information on how you cracked software is likely to violate the DMCA.

<http://www.law.cornell.edu/uscode/text/17/1201>

"(2) No person shall manufacture, import, offer to the public, provide, or otherwise traffic in any technology, product, service, device, component, or part thereof, that— (A) is primarily designed or produced for the purpose of circumventing a technological measure that effectively controls access to a work protected under this title;"

\-- 17 USC § 1201 - Circumvention of copyright protection systems

<comment><AUTHOR> Good point. I think last night I was just high on accomplishment. It has been proposed that I obfuscate my research some how though I then question the value of it.

I guess this is why pseudonyms are popular.</comment></comment>


Ask HN: Any recommended resources to learn online community building? - <AUTHOR> <comment><USER2> Oh, these could help:

[http://www.managingcommunities.com/](http://www.managingcommunities.com/)

[https://www.feverbee.com/richs-blog/](https://www.feverbee.com/richs-blog/)

I'd also recommend The Admin Zone as a forum, since it's basically dedicated to community building and forum software:

[https://theadminzone.com/](https://theadminzone.com/)

Another site to look out for is Forum Promotion, though mainly once your site has been launched and needs more help:

[https://forumpromotion.net/forum/home/](https://forumpromotion.net/forum/home/)

</comment><comment><USER3> Here's a complete free guide: [http://www.communitybuildingguide.com/](http://www.communitybuildingguide.com/)

<comment><AUTHOR> Thank you</comment></comment>


The Missing Alias Manager - <AUTHOR> http://ytbryan.github.io/aka/

<comment><AUTHOR> Hi folks, last year, I made this ruby script with thor to manage my terminal shortcuts.

The script makes it easier to grow my aliases and improve my terminal workflow. I'm posting this here to see how I can improve it further.

Any feedback will be appreciated!</comment>


Ha4: Concurrent ML and HOPAC - <AUTHOR> http://t0yv0.blogspot.com/2014/03/concurrent-ml-and-hopac.html <comment> xyz-x I've started writing code in Hopac after reading the red Reppy book and the awesome [https://github.com/Hopac/Hopac/blob/master/Docs/Programming....](https://github.com/Hopac/Hopac/blob/master/Docs/Programming.md) -guide. It's really neat.

</comment><comment><USER2> Wasn't aware of Hopac before, just done some digging around online, these benchmarks look fairly impressive:

[http://vaskir.blogspot.co.uk/2015/01/fibanacci-hopac-vs- asyn...](http://vaskir.blogspot.co.uk/2015/01/fibanacci-hopac-vs- async.html?m=1)

Are there any downsides to using Hopac over one of the other .NET concurrency libraries?

<comment> xyz-x It's a different programming model that you'll have to learn. It will take you a week or two to become proficient. It's not mainstream but instead based on a time-tested abstraction. The docs are top notch when you include the book, but they are not spread out over multiple sources. It's doing cooperative multi- threading, so if you have software that doesn't want to cooperate you may experience problems with fairness. It's [pull-based/cold/sync/rendezvous based], not [push-based/hot|cold/sync/scheduler-oriented] (rx), not [pull- based/cold/async/non-deterministic] (F# async), not [pull-based/hot/async/non- deterministic] (TPL) so you'll have to start thinking about what concurrency and parallelism means for you.

<comment><USER3> I agree with that. Played a little bit with Hopac (after also using anything from TPL, F# async, Rx, ...), and I think it's quite awesome. However it takes some time to get into it, and the monadic expressions and all those operations really take some time to learn and are not as easy to understand as e.g. Go's inbuilt concurrency primitives. For that reason I don't think Hopac will become mainstream. However it's very powerful, probably more powerful than any often the other things. And the performance is also excellent.

Some other ultra-short comparisons to the other concurrency approaches:

\- The rendezvous model with bounded channels is IMHO the best communication model for resource passing between different "actors", as you can avoid situations were you pass a resource but nobody listens for it any more.

\- Hopac (like Go) provides selective communication, which is very helpful for implementing some kind of stuff as explained in the Hopac documentation (and avoiding weird "try two things and cancel the second one later workarounds").

\- Hopac is a lot faster then F# async according to my benchmarks. C# async/await with good TaskScheduler implementation can however reach a similar performance level.

\- Rx has probably the most event combinators. I think it's nice for event processing in some scenarios, e.g. UI events.

\- The pull based approaches of TPL, F# async and Hopac provide more explicit flow control (and thereby backpressure) as the push based approach of Rx. I personally wouldn't use Rx anymore for anything where flow control is important. But this is only my taste, the newer Rx versions also provide some backpressured stream support.

</comment></comment></comment><comment><USER4> Wooh. That [HOPAC API]([http://hopac.github.io/Hopac/Hopac.html](http://hopac.github.io/Hopac/Hopac.html)) is ginormous! How can anyone seriously code with that?

<comment><USER5> What's with the awful font and seriously slacker half attempt at alignment? I basically can't read anything on that page.

<comment><USER6> Thanks! I removed the bold attribute from links so things should align better now on some browsers.

<comment><USER5> 1\. That helps a lot!

2\. The alignment still leaves a lot to be desired. There's stuff that is clearly intended to align that doesn't, and it's more distracting than if it didn't attempt to align at all.

3\. I apologize for the insulting way my previous comment was written. I try not to do that; I must have been grumpy, but it's no excuse.

<comment><USER6> No problem.

There were still some bolded elements, so I switched to a different color scheme and further removed bold elements.

Looking through the doc I can't spot any cases where alignment would be unintentionally wrong. I think the next thing to do to improve readability would be to add some spacing around groups of definitions. This way different alignments used in side-by-side groups should cause less visual interference. I suspect that the visual interference from side-by-side groups is what makes the alignment look distracting.

</comment></comment></comment></comment></comment><comment><USER7> > would "help fight actor/reactive nonesense" and was asked to elaborate

So, basically fighting actors with channels and synchronous selective operators, right? This is not how it works, because bounded nondeterminism is precisely what actor model was trying to get away from.

<comment> xyz-x I had to read up a bit on (un-)bounded non-determinism there. It would seem actors give you even looser safety properties in that it has unbounded non- determinism and you can't really sure about anything about your programming model in the default case.

<comment><USER7> That was the point, you can't have something reliable and performant in a real world if you use a bounded model for it [world].

<comment> xyz-x I'm actually don't agree at all to this. Is e.g. the MillWheel software, or Kafka, or Storm/Spark inherently unreliable and non-performant because they feature strong consistency and bounds on their operations? I don't think so.</comment></comment></comment></comment>


Ancient shell shows days were half-hour shorter 70M years ago - <AUTHOR> https://news.agu.org/press-release/ancient-shell-shows-days-were-half-hour-shorter-70-million-years-ago/ <comment><USER2> > The length of a year has been constant over Earth's history, because Earth's > orbit around the Sun does not change.

That is decidedly not true. At the very least the eccentricity of the Earth's orbit around the Sun is known to change[0]: "The major component of these variations occurs with a period of 413,000 years (eccentricity variation of ±0.012)".

Moreover, I seem to recall reading that over the 4.5 billion year scale the distance of various planets to the Sun has varied as well, though I don't have a reference for that right now.

[0] [https://en.wikipedia.org/wiki/Milankovitch_cycles](https://en.wikipedia.org/wiki/Milankovitch_cycles)

<comment><USER3> From your link:

> The orbital period (the length of a sidereal year) is also invariant, > because according to Kepler's third law, it is determined by the semi-major > axis.

Which makes sense, because the semi-major axis depends on the energy of the orbit, and there's not really much that would be altering that in the short timeframe of a Milankovitch cycle.

<comment><USER4> It should be mostly invariant, but tugs and changes from other bodies in the system (Jupiter and Saturn particularly) can change the energy of the orbit. It's one of things that makes n-Body solutions to orbital mechanics nearly impossible to make. I doubt it's change too significantly for something as massive as earth though, but the collision with the mars sized body that created the moon early on in Earth's history definitely would have been able to change the orbital energy.

</comment></comment></comment><comment><USER5> I disagree with assumption that year length has stayed constant the past 70 million years. The Earth experiences tidal friction from the Sun just like the Moon and Earth affect each other. I am guessing the year lengthening effect slower than month & day lengthening because Suns tidal force is a third of Moons.

In addition Earth year may have changed during the Great Solar System Reconfiguration Event when Jupiter and the other gaseous planets hypothesized to have migrated outwards from orbits closed to the Sun. This may have happened 3.8 billion years ago causing increase of craters on the terrestrial planets at that time.

[https://www.nasa.gov/topics/solarsystem/features/young- jupit...](https://www.nasa.gov/topics/solarsystem/features/young-jupiter.html)

<comment><USER6> The energy required to change the length of the year is very large. Solar tides could transfer some energy from the Earth's rotation to the Earth's revolution, but even tapping all that energy (leaving the Earth tidally locked to the Sun) would not change the year length very much,

<comment><USER7> _> Solar tides could transfer some energy from the Earth's rotation to the Earth's revolution_

No, they can't. See my other response just upthread.

<comment><USER6> I have responded to that response and pointed out it cannot be correct.

<comment><USER7> See my response in that other subthread.

<comment><USER6> It was a cloud of obfuscation where you never admitted your statement was wrong and violates conservation of angular momentum.

</comment></comment></comment></comment></comment></comment><comment><USER8> I can see how counting the rings can tell you that there were 372 rotations per revolution vs today's 365 rotations per revolution. What I don't get is how you correlate that to shorter days. Wasn't the Earth's revolution on a different period back then too?

If you assume the revolution period was same back then as it is now... sure, half an hour difference I get it. Or are we assuming that the rotation is changing faster than the revolution?

<comment><USER9> There is no force comparable to lunar tidal forces affecting the period of revolution. The Earth's slower rotation is coupled to the Moon's recession. The closest thing we've got with our orbit is resonance with Jupiter, and that's an awfully long way away.

<comment><USER10> > There is no force comparable to lunar tidal forces affecting the period of > revolution.

But there are... The earth orbiting causes tiny tides on the sun. They might only be a few millimeters, but they're non-zero. Over time, tidal drag will tend to make years longer.

Anyone have the time and skill to do a ballpark guess the magnitude of this effect?

<comment><USER11> Wouldn't tidal drag make years shorter? Longer years means a more distant, high energy orbit.

<comment><USER12> The sidereal year is what we're talking about here, the time it takes the earth to orbit the sun and come back to the same position. What's changing isn't that, it's the sidereal day.

Earth spins slower > Moon Speeds Up Less Rotations per Orbit > More Hours per Day

Number of days is changing because the day is going from 23.X hours to 24.X hours due to the Earth rotating slower. Hence, same length year if you measure it in absolute time, just less days in relative time.

<comment><USER11> Assuming that revolution means sidereal year, this discussion thread is speculating about how minute the changes in the sidereal year would be, and in what direction they would have been. I don't think there's confusion about the fact that the orders of magnitude larger change as discussed in the article is in the sidereal day, except perhaps for GGGGP's comment that started the thread.

>>>>> Wasn't the Earth's revolution on a different period back then too?

>>>> There is no force comparable to lunar tidal forces affecting the period of revolution

>>> But there are... The earth orbiting causes tiny tides on the sun [...] Over time, tidal drag will tend to make years longer.

>> Wouldn't tidal drag make years shorter?

> What's changing isn't that, it's the sidereal day.

</comment></comment></comment></comment></comment></comment><comment><USER13> Falsehoods programmers believe about time: "3\. Years have 365 days." Dinosaurs had 372 days per year!

[https://infiniteundo.com/post/25326999628/falsehoods- program...](https://infiniteundo.com/post/25326999628/falsehoods-programmers- believe-about-time)

<comment><USER14> If you can find a dinosaur calendar it will be implemented.

</comment></comment><comment><USER15> _The new method focused a laser on small bits of shell, making holes 10 micrometers in diameter, or about as wide as a red blood cell. Trace elements in these tiny samples reveal information about the temperature and chemistry of the water at the time the shell formed. The analysis provided accurate measurements of the width and number of daily growth rings as well as seasonal patterns. The researchers used seasonal variations in the fossilized shell to identify years.

The new study found the composition of the shell changed more over the course of a day than over seasons, or with the cycles of ocean tides. The fine-scale resolution of the daily layers shows the shell grew much faster during the day than at night_

</comment><comment><USER16> Mathematically challenged person here. Does this means that after 3.3B years, Earth will lose its rotation completely?

<comment><USER17> I think you have it backwards. Days are getting longer. So assuming tidal lock with Sun in the future which means 1 year = 1 day (1 revolution per year). So how long until 1 day becomes 365 days long. Assuming the 30min per 70M years is linear, this would take 1.2 Trillion years.

Somebody double check this please. ;) Also, the Sun will only last for another 4B years.

<comment><USER3> Earth's tidal locking is more a result of the Moon than interactions with the Sun, and it's not really linear.

</comment></comment></comment><comment><USER18> 31*12=372

So we would have had a nice regular calendar back then.

<comment><USER19> 28*13(+1)=365 (or +2 on leap years)

<comment><USER20> 1 second = 9192631770 unperturbed ground-state hyperfine transitions of cesium-133 atom (preferably outside of solar system gravitation well)

Calendars are silly. "Neat" ones even more so.

<comment><USER21> Nah, humans are just missing about a twelfth of a finger.

</comment></comment></comment></comment><comment><USER22> If the Earth was spinning faster would that mean that dinosaurs weighed less back then?

I know their mass would be the same but wouldn't a faster spinning earth counter gravity similar to how satellites maintain a stable orbit?

<comment><USER23> Centripetal acceleration at the equator is R ω^2 = (radius of the earth) * (2 * pi / 24 hours)^2 = 0.0337 m/s^2 .

Acceleration due to gravity is 9.8 m/s^2, so you weigh 0.3% less in Singapore than at the North Pole. (There are other factors, like the Earth's bulge, which I won't consider.)

This small enough that people don't notice it. (Presumably dinosaurs wouldn't either.) Plus, most people don't live on the equator, and there's a cos(latitude)^2 factor which reduces the centripetal acceleration. At 45 degree latitude the acceleration is 1/2 that of the equator.

Speed up the Earth's rotation to 23.5 hours and it's 0.0352 m/s^2.

The difference is 0.0015 m/s^2 , which is quite small compared to the normal force of gravity.

Thus, it isn't really important for most things.

<comment><USER22> Thanks for the response, and for doing the math. After reading your response it I agree that it wouldn't have much more effect than an increase in elevation. I thought it might explain how the dinosaurs were able to grow so big without collapsing under their own weight(which probably can be explained too)

<comment><USER23> [https://www.thoughtco.com/why-were-dinosaurs-so- big-1092128](https://www.thoughtco.com/why-were-dinosaurs-so-big-1092128) suggests the reasons aren't well known for why some dinosaurs got so large.

<comment><USER24> Interestingly, that article doesn't mention the theory that I think is most promising – that there was potentially a higher concentration of oxygen in the air when the dinosaurs were around, making it easier to get enough oxygen even if you were much larger in size.

<comment><USER25> I thought that was an accepted fact. It's been a while since I read about dinosaurs : )

</comment></comment></comment></comment></comment></comment><comment><USER26> 4,500,000,000 divided by 70,000,000 equals 62.

If the Earth slowed 30 minutes 62 times, uh, the days would be less than zero.

Any reason why the slowing of the day would be more dramatic these last 70 million years?

<comment><USER27> Assuming a constant force of friction the slowing of Earth's rotation would be linear ~ t and the lengthening of our days would be the inverse ~ 1/t so we cannot simply divide 4,500,000,000 by 70,000,000 to estimate the original length of a day.

Still, extrapolating back to Earth's early years would yield a rather short day. Sources from Wikipedia [1] [2] estimate a 5 hour day after the Theia Impact that created the Moon.

[1]: [https://en.wikipedia.org/wiki/Earth's_rotation#Origin](https://en.wikipedia.org/wiki/Earth's_rotation#Origin)

[2]: [https://www.annualreviews.org/doi/10.1146/annurev.ea.15.0501...](https://www.annualreviews.org/doi/10.1146/annurev.ea.15.050187.001415)

</comment></comment><comment><USER28> > Earth turned faster at the end of the time of the dinosaurs than it does > today, rotating 372 times a year, compared to the current 365, according to > a new study of fossil mollusk shells from the late Cretaceous. This means a > day lasted only 23 and a half hours, according to the new study in AGU's > journal Paleoceanography and Paleoclimatology.

I'm curious, how do they decide that the earth spun faster on it's axis rather than the earth taking longer to orbit the sun?

<comment><USER29> I'd like to know too how they can confidently state that Earth's orbit does not change. Would it mean we'd spiral into the sun or out of orbit if it did?

<comment><USER30> From Newtonian mechanics, the orbit can only change by applying a force from somewhere, and a big move would require a lot of energy. And there's no evidence of such an event in the geologic pas; if it was triggered by an impact, it would be far larger than the one which killed the dinosaurs.

<comment><USER31> There's a reasonably thorough discussion of this topic, from an...interesting...perspective, in this essay: _" How to Destroy the Earth"_ [https://qntm.org/destroy](https://qntm.org/destroy)

</comment></comment></comment></comment><comment><USER32> 'Earth turned faster at the end of the time of the dinosaurs than it does today, rotating 372 times a year, compared to the current 365, according to a new study of fossil mollusk shells from the late Cretaceous'.

I can't begin to imagine the forces that made this happen!

<comment><USER33> It's the lunar tide.

[https://bowie.gsfc.nasa.gov/ggfc/tides/intro.html](https://bowie.gsfc.nasa.gov/ggfc/tides/intro.html)

<comment><USER34> Didn't we already know this, for quite a long time? I feel like I learned about this 20 years ago and I'm confused as to why it's news today.

<comment><USER35> Yes we did. This is a press-release (It's right in the URL). Unfortunately AGU has gone down hill recently in its attempt to engage a wider audience and now you are getting the click bait "Ancient shell shows days were half-hour shorter 70 million years ago" instead of a more sober one about what the study is really about. The journal paper's title is "Subdaily‐Scale Chemical Variability in a Torreites Sanchezi Rudist Shell: Implications for Rudist Paleobiology and the Cretaceous Day‐Night Cycle". So maybe at title for the scientifically interested general public could be, "70 million year old Rudist shells improve length of day estimates during the late Cretaceous"

<comment><USER32> My comment was more a romantic one about the forces in play rather than a literal question. I'm also in awe of our solstice declination moments.

<comment><USER33> Oops! My bad!

</comment></comment></comment></comment></comment></comment><comment><USER36> Are they referring to bash or zsh?

<comment><USER37> If they're ancient shells, surely it must refer to at least the original Bourne shell, not these Johnny-come-lately replacements.

</comment></comment><comment><USER38> This is probably explained by tidal breaking, which requires things like leap seconds.

[https://en.wikipedia.org/wiki/Tidal_acceleration](https://en.wikipedia.org/wiki/Tidal_acceleration)

<comment><USER39> So at 2.3 ms/century * 70 million years - so 1610000ms = 1610s = ~27 minutes

<comment><USER38> Tidal breaking is also a deceleration/acceleration rather than a velocity, which means the rate of change grows as the speed changes. This is because the moon's gravity is uniformly pulling on Earth and stretching the day in proportion to the uniform gravitational force on the rotational velocity. While the moon's gravitational force will remain constant over time, and thus the pull on Earth's rotation, and the proportion of gravitational force to Earth's rotational velocity will also remain unchanged over time Earths rotational velocity is changing as a result, which is a compounding effect.

That means leap seconds will need to be inserted at ever increasing frequency over time until the Earth becomes tidally locked. Tidally locked means the Earth stops rotation so that the same side always faces the sun.

</comment></comment></comment><comment><USER40> This makes me wonder if life expectancy in terms of years would be proportionally shorter if our days were say 48hrs instead of 24. Would slowing the earth's rotation have the side effect of extending our lifespan?

</comment><comment><USER41> So is it because the earths' density is moving away from it's center? Like when you're spinning and you tighten up?

<comment><USER35> Nope. It because of angular momentum transfer between the Earth and the Moon due to tides. The Moon moves farther away and the Earth slows rotation.

</comment></comment><comment><USER42> I've always known I should have been born some 420-490 millions years in the future¹. Now it's science fact!

[1]: _A good day for me is more like 27-28 hours, on average. Don 't ask. Yes, I'll donate my hypothalamus to science._

</comment><comment><USER6> It's amazing what they can discover looking at 1970s sh sources.

</comment><comment><USER43> > _Ancient shell shows days were half-hour shorter 70M years ago._

Nope! That was just a typo bug in date.c:

      int seconds = days * 84600;

See the transposed digits? That makes it exactly 1800 seconds shorter than 86400, or half an hour.

<comment> 867-5309 the shell is not aware of date.c

</comment></comment><comment><USER44> After the first half of the sentence I thought that somebody had found an old shell connection that hadn't been closed in 40 years.

<comment><USER45> Yep, and now I wonder which could be the oldest open shell connection in the world, maybe some plant or industrial process?

</comment></comment><comment><USER46> Took me half a second to realize it's not a *nix shell...

</comment><comment><USER47> No wonder this work day feels so damn long!

<comment><USER48> In another 70M years my body clock will be just about right.

</comment></comment><comment><USER49> It was ... a different epoch

<comment><USER50> Still the same eon, though.

Life is _old_. The time between stegosaurus's day and T. rex's is longer that between T. rex's and today.

</comment></comment><comment><USER51> Called it.

</comment><comment><USER52> Somehow I was thinking of the shell in v6 written in pdp-11 assembler.

</comment><comment><USER53> Did the clocks built by dinosaurs include leap seconds?

</comment><comment><USER54> Don't humans operate best on a 23 hour schedule? I wonder if that is an evolutionary hold over from shorter days.

<comment><USER3> It's estimated that human circadian rhythms are just over 24 hours.

</comment></comment><comment><USER55> At first glance I thought this was referring to a Bourne or Korn shell.

<comment><USER56> Fsh would be the only one extant back then.

</comment></comment><comment><USER57> I've got a programmer joke for you:

AncientShell#> echo day.length</comment>


Another Interest $35 Linux ARM SBC - <AUTHOR> http://linuxgizmos.com/35-dollar-quad-core-hacker-sbc-offers-rpi-like-expansion/

<comment><USER2> [https://news.ycombinator.com/item?id=8748658](https://news.ycombinator.com/item?id=8748658)

</comment><comment><AUTHOR> I was looking at other systems that were in the RPi/Beaglebone category and this one popped up. I don't recall seeing it mentioned here before. I've just ordered one to see how it compares to the Pi.</comment>


Show HN: Devblogs.co – a feed of engineering blogs from top tech companies - <AUTHOR> https://devblogs.co <comment><USER2> cool idea, but do you have a list of what is included?

<comment><AUTHOR> Thanks! We will add a filter by companies and topics in the nearest future.

<comment><USER2> awesome, i bookmarked it and will keep an eye out, love the idea!

can you also add company blogs that have a dev subsection?

<comment><AUTHOR> Hey! FYI, we've just released the filters feature. Now you can filter blogs by companies.

<comment><USER2> awesome, thank you!</comment></comment></comment></comment></comment>


The Whistled Language of Northern Turkey - <AUTHOR> http://www.newyorker.com/tech/elements/the-whistled-language-of-northern-turkey <comment><USER2> It seems obvious, even to those unfamiliar with phonetics, how tonal languages are transformed into whistled languages by whistling the underlying tone contours.

However, even languages with no phonemic tonality are able to be whistled because we distinguish vowels almost entirely by the volume of the harmonic frequencies produced by changing the shape of the resonating chamber of the mouth. Musicians often call this "color" or "timbre". Jaw aperture roughly corresponds to the volume of the first formant produced, and how the tongue is raised or retracted within the mouth roughly corresponds to the second formant produced.

Even the surrounding consonants leave their mark on the surrounding vowels. For instance, sounds produced with the lips, (like English "b"/"p"), tend to lower the formants of the surrounding vowels. Consonants produced with the back of the tongue against the soft palate (c.f. English "k"/"g") tend to "pinch" the second and third formants of the preceding vowel closer together. Collapsing and merging consonant clusters while bringing the tonal variation into the fundamental pitch is one of the most common theories of tonogenesis, or how tonality evolves in languages.

Whistled languages based on non-tonal languages tend to whistle the patterns of the second formant, which captures subtle information about what the vowel and surrounding consonants would have been in the underlying spoken language.

</comment><comment><AUTHOR> Three reasons I love this:

1.) It's Aristotelian mimesis made manifest AND practical. It does diverge from his linguistic ideas about syllable construction, etc., but that's fine because it's not about him.

2.) It's about communicating, clearly, across huge distances chock-full of interference. If you watch the video at the end of the article, the two guys are probably a quarter mile apart and having a perfect conversation: in my experience, not possible with just the human voice. I have a hard enough time talking to someone across the table in a noisy restaurant - and I've (at least socially) attributed that to the fact that my voice resonates at about the same frequency as background chatter. I either have to seriously amp up my volume, or raise the pitch of my voice, neither of which are comfortable for extended periods.

3.) It's weird and it's beautiful and it's man-made. It's like realizing the power of Lisp macros when you've only ever written JavaScript, or learning FP when you've only ever worked with OOP. It breaks down ideas of what a "proper" language is, and reconstructs them in a way that conveys an entirely different ideological purpose.

I love it.

<comment><USER3> Since Turkish is a highly agglutinative language, copulas are rendered as suffixes, albeit with a few exceptions See: [https://en.wikipedia.org/wiki/Turkish_copula](https://en.wikipedia.org/wiki/Turkish_copula) and [https://en.wikibooks.org/wiki/Turkish/Present_Tense](https://en.wikibooks.org/wiki/Turkish/Present_Tense)

@shiplet I know turkish, but I was still amazed that I mostly understood what they whistled after reading your post (not sure why). I heard out some customizations to spoken turkish that I think are there to allow for a better distinction between similar sounding words. But I suspect that these are domain specific and have to be learned in order to fully speak and understand the whistled language.

Whistle-speaking in english is much harder, because you don't have enough syllables. One can't easily concatenate "meaning" to a word like in Turkish. That's why whistled-english words would sounds too similar and not harmonic enough to be distinguished.

For example try to say this loud: "I won't go to the school today." Now speak it in your mind, but with syllables. And now try to whistle that sentence (as if you were speaking, but without actually speaking). There are only single- syllable words and these sound all too similar when whistled.

</comment></comment><comment><USER4> See [https://en.wikipedia.org/wiki/Whistled_language](https://en.wikipedia.org/wiki/Whistled_language) for more instances of this phenomenon and a good discussion. My understanding is that whistled languages often arise on top of tonal languages where tones carry a lot of information. The Turkish example is interesting since Turkish is not a tonal language but they still figured out how to do it.

<comment><AUTHOR> The tonal aspect makes a lot of sense, and in the case of Turks applying it to a non-tonal language, I'd love to learn how they did it. Maybe it'd be possible to apply to English?

</comment></comment><comment><USER5> It sounds similar to Chinese.

<comment><USER6> As a native Turkish speaker: It actually sounds.. Turkish... They replaced clear words with their corresponding tones. I think with a little training, a native speaker can understand what he hear. It feels like listening a karaoke version of a well known song.

<comment><USER7> In James Gleick's The Information, the first chapter is about a West African culture, turning phonemes, stressed and unstressed, into drumbeats, for conveyance over longer distances than one could shout, and needing to compensate for the information-loss of sound into drum pulse by using longer and longer "phrases".</comment></comment></comment>


We DMCA-ed our own game because it got hijacked by publisher - <AUTHOR> https://www.reddit.com/r/gamedev/comments/ai80zd/we_dmcaed_our_own_game_last_week_because_it_got/ <comment><AUTHOR> Here's the game in question: [https://store.steampowered.com/app/505740/Eximius_Seize_the_...](https://store.steampowered.com/app/505740/Eximius_Seize_the_Frontline/)

And the announcement on Steam: [https://steamcommunity.com/games/505740/announcements/detail...](https://steamcommunity.com/games/505740/announcements/detail/1699446873491336874)

</comment><comment><USER2> Hey y'all. (At least in USA) ask for a provision awarding attorneys fees and costs to prevailing party in the event of a dispute over major contracts.

Disputes happen less frequently, go faster, settle more often, and are easier to fund if necessary.

Suspect parties that won't sign it (or at least discuss their reasons).

</comment><comment><USER3> Steam/Valve has a great PR opportunity here. They could pay out all the money to the indie developer and then use their legal might to sue the publisher to recover the stolen funds.

<comment><USER4> That would come perilously close to tortious interference. They would have no standing to do so, any more than withholding your funds because you didn't pay your rent.

<comment><USER3> Their standing would come from the fact that they had to refund the indie developer and therefore are now in need of funds to cover that expense incurred because of the publishers actions.

<comment><USER4> Any competent attorney (and realize that not for one moment do I have any sympathy for the publisher, who sounds like a complete garbage person) would turn around and say "You had no obligation to do so, and your desire to do so for PR purposes or otherwise in no way creates an obligation for me to reimburse you".

And legally, they'd be entirely right.

</comment></comment></comment></comment><comment><USER5> I'm super confused on what a publisher does in this case. seems all they did was release on steam? Can't any dev do the same? What was the purpose of the publisher? (Did I miss something?)

<comment><USER6> Usually the publisher acts like a movie producer, in theory, they get all the marketing and distribution setup and usually also help either raise or provide initial funding for the venture. In this case it seems like they didn't do much at all.

</comment></comment><comment><USER7> This seems like the wrong tool for the job.

They seem to have good reasons for doing what they did. So I don't fault them, but this should be a contract dispute/fraud.

<comment><USER8> Isn't it the contract which gives the publisher rights to publish the game? If the publisher hasn't executed their side of the contract, wouldn't that mean that they don't have rights to the game? DMCA sounds like an appropriate tool, then.

From what I understand, the way a breached contract gets handled varies a lot from jurisdiction to jurisdiction, and I'm no expert.

<comment><USER7> The publisher is UK based, as far as I'm aware contract law is somewhat similar in the US.

The DMCA isn't against the publisher as I understand, its against the sites actually selling the game.

<comment><USER8> > The DMCA isn't against the publisher as I understand, its against the sites > actually selling the game.

Well, yes, that's how DMCA takedown notices work. If Lex Luthor posts my video on YouTube, I don't send the DMCA takedown notice to Lex Luthor, I send the DMCA takedown notice to YouTube. Lex Luthor has no responsibility to accept DMCA takedown notices, and there's no way to send them to him.

The sequence is (1) publisher breaches contract (2) developer voids contract in response (3) publisher no longer has right to distribute game (4) DMCA takedown notice. This makes sense to me, but again, I'm not a legal expert and I'm willing to entertain arguments. I feel like the only thing in question here is whether the contract was voided properly, and whether it could be voided in the first place.

<comment><USER7> My point is, is that the publisher isn't involved in the prices at all, which as they are the wrong doer suggests to me that this is indeed the wrong tool.

Its like Superman going after Lex Luther's office supplier, rather than destroying his underground lair.

<comment><USER8> I think you may misunderstand what a DMCA takedown notice is, or how they are used.

You send DMCA takedown notices to _innocent parties,_ that's how they work, that's how they're designed to work, that's the only way they work at all. If you want to send something to a guilty party then you send a lawsuit instead.

You can't send a DMCA takedown notice to Lex Luthor's office supplier, because the office supplier doesn't claim DMCA safe harbor. YouTube does, Steam does, so you can send DMCA takedown notices to Steam and YouTube. You can't send DMCA takedown notices to Lex Luthor, his office supplier, or the publisher at fault here.

In effect, the DMCA takedown notice is just a way of telling YouTube, "Lex Luthor does not have the rights to this video." This is not _going after YouTube_ in any meaningful way. This is exactly what the DMCA is designed to do... prevent YouTube or Steam from being targets of lawsuits. Because Steam accepts DMCA takedown notices, they are protected from certain lawsuits for copyright infringment. DMCA takedown is a process where you tell Steam about third-party copyright infringement, and they remove the content and this clears Steam of liability.

When Lex Luthor posts my video on YouTube, I can do two things: I can send a DMCA to YouTube and I can sue Lex Luthor. Suing Lex Luthor is expensive, so I start with the DMCA takedown notice to YouTube.

<comment><USER7> Ok then its like Superman sending DMCA takedown notices to Youtube over Lex Luther's unauthorised use of Superman's S. Rather than destroying the space laser that's about to destroy the earth. :P

<comment><USER8> No, Superman's S would be covered by trademark. Sending DMCA takedown notices in response to trademark violations may expose you to liability under DMCA section 512(f).

It seems like you have an objection to the DMCA, but the story about space lasers is a bit hard to understand. I'm not sure what your complaint is. The reason I chose "Lex Luthor" is because choosing a name makes it easier to understand hypothetical scenarios (instead of using them/they everywhere, or "the infringing party"), and because he took forty cakes, and that's as many as four tens.

<comment><USER7> My point is that you should be going after the actual problem, rather then messing round with the periphery. The DMCA is designed to combat a diffuse mass of people that you can't really target directly. The publisher like the gigantic space laser is one large target. Target it directly.

To torture another metaphor, this may only be one starfighter against a star destroyer, in that case, if you don't have an ion canon, kamikazing the shield generators is an option, but not your first choice.

Don't ask me what the DMCA is in that metaphor :P

<comment><USER9> in the DMCA case, you cease their profit-making pipelines, so that when you go for the actual problem, the defenders have less reason to defend (and thus, less incentive to throw more money into the defense). Theres a big difference in defending something that brings in 100k/yr, versus something that's been DMCA'd everywhere relevant, and can't be sold (is there any reason left to continue defending, unless you expect to win & get sales rights back?)

For any weaker party, targetting the problem itself is too expensive to start with, especially if the defendant is the only one currently making money off the product (the accuser only has external funds to work with, no matter how valuable the product is/was, while the defender has both product value and external funds; DMCA can remove one of those revenue streams)

</comment></comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER10> Well, the right step outside of legal battle would be updating the game to say that the publisher doesn't pay up.</comment>


Berlin-Munich high-speed train services carry 2M passengers in first six months - <AUTHOR> https://www.railjournal.com/index.php/high-speed/berlin-munich-hs-services-carry-2-million-passengers-in-first-six-moths.html <comment><USER4> They had a "High Speed" line before, but it was on old tracks, and they had to use tilting trains. I took it a few times when I lived in Berlin. It was somewhat slower than driving. Still, the ICE is an excellent train. It's very punctual (Germans will complain when it's five minutes late), it's smooth, it's clean, the seats are comfortable, you can get a seat with a table if you want, there are power outlets, and if you get hungry, you can go get a snack, a beer, or a full dinner. It's just just a civilized, pleasant way to travel. The Internet, either through the DB system, or my normal 3G/4G tethering was a bit spotty, but I was nearly as productive on the train as I would have been at the office. At six hours Berlin-Munich, it was much nicer, less stressful, and more productive en-route than an airplane, but somewhat slower. At four hours, the train is a no-brainer.

Air travel is the king of hidden time fees. They say that it's an hour from Berlin to Munich, but you have to show up at the airport an hour before the flight, it takes 15 minutes to get off the plane and get out to the curb, even if you didn't check a bag, it takes 40 minutes to get to the airport, and another 40 minutes to get from the airport to the city center. By the time you add it all up, 4 hours is how long it takes on the plane, and most of that is annoying stressful walking from one place to another, waiting in one line after another, cooped up in a tiny seat, and for maybe 30 minutes of the whole 4 hours, you can use your laptop and do something useful.

<comment><USER5> Myself living in Berlin I'd still take the flight (and I did usually).

First of all, it's nearly legendary how unreliable the trains can be here during winters and hot summers. Second, flying is actually cheaper (I rarely fly with a big luggage).

Finally, it takes me 15 minutes to get to Tegel airport. All the security and boarding procedures are highly optimised there. I usually leave my flat around an hour to the boarding time.

Then the flight to Munich is an hour or less. In the end (with the train to the city center) it takes less than 4 hours.

On the other hand I wouldn't mind taking a long distance overnight international train provided I had a bed there.

<comment><USER6> The CO2 emissions of trains are significantly lower, though.

You might want to reconsider if slightly more convenience is worth ~80-90% higher emissions.

<comment> cup-of-tea The government should be enforcing this. Nobody should be expected to make a personal sacrifice to do the right thing.

<comment><USER7> If only we had a uniform, slowly ramping global $100/ton carbon tax. From the models I've seen it would fairly abruptly correct all of these "two methods are vastly different in carbon emissions but otherwise fairly comparable" situations.

<comment><USER8> The carbon tax should be tied to the price of extracting a ton of carbon from the atmosphere.

<comment><USER9> In Norway there's taxation on drinks containers that is set high enough that it's cheaper to participate in a return scheme. The audited return/recycling/reuse rates are then used to provide a discount against the per-unit tax.

I've always liked this scheme, because assuming you set the tax high enough for society to - as a fallback - take action to rectify the problem (e.g. hiring more people to clean up in this case), with a punitive margin on top, the tax provides a financial incentive to innovate to drive down the cost of acting responsibly.

There is a collective return service you can participate in, but if you find a better alternative you're free to use it as long as you can demonstrate what your return rate is. Or you can pay the tax and leave it to the government, but your margins will be worse than the competitions, as the return scheme is cheaper.

The general mechanism feels like it'd be adaptable to a lot of situations where you want to make sure it gets rectified, but also don't want to trust the government to dictate specific solutions - in this case it doesn't matter if e.g. the fallback solution is severely cost-ineffective; the more costly the fallback is, the stronger the financial incentive to find a better solution is.

</comment></comment></comment></comment></comment></comment></comment><comment><USER10> As a frequent Berlin-Munich traveller, it's such a joy to now be able to make this route in less than 4 hours directly from and to the city center.

Last month I had to instead take a flight (direct ~1h) but it ended up being more stressful and pretty much taking the same time since you have to add the time it takes to get to the airport and go through security.

Not to mention that the trains are quite comfortable and there's lot of room to walk or even sit down at the on board bistro for a beer or some food.

</comment><comment><USER11> > DB will introduce the nre ICE 4 train on the route, which allow bicycles to > be taken for the first time and with 830 seats provide 10% more capacity > than the previous model.

These ICE4 are the worst ICEs in terms of comfort. They've been reducing the distance between rows over the years, and it is now only 85cm. It used to be 102cm in the ICE1 -- that was cool. ICE2 had 97cm, ICE3 had 92cm, which was still comfortable for me. Now, 85cm is too short to sit comfortably if you are a tall person. The previous models all had good seats and enough space. But the ICE4 is awful. The seats are also too upright and the backrest can only be tilted when pulling the seat to the front, which is impossible for taller people because the legs will have no space. Without this, the seats are so upright they almost push you over. Naps are impossible due to this. And where some lordose support should be, there is a hole. I really hate the ICE4s, I always end up with a sore back.

But sure, there is 10% more capacity thank you very much.

<comment><USER12> ICE4 also has a maximum speed of "only" 250 km/h. Deutsche Bahn has apparently given up on higher speeds.

By the way, even ICE1 trains are less comfortable than they used to be because the rubber rings in the wheels were removed for safety reasons.

<comment><USER13> Yes, most German routes are not built for higher speeds, so it made sense to optimize new trains for cost and reliability instead of speed.

But Berlin—Munich has a Vmax of 300 km/h, so it would only make sense to put more ICE 3 on that route. I doubt the ICE 4 info is correct.

</comment></comment></comment><comment><USER14> I took this connection for the first time this week and I was really impressed. I even took a picture of the screen once it showed that we crossed 300km/h. They used the latest ICE model, wifi was really reliable and they now even offer onboard entertainment. You can watch tv shows, movies, get access to audiobooks etc. on your phone, tablet or laptop (even though the selection is still quite limited). The train is one of my favorite places to get work done. I always try to get a seat in the cabin where phone calls are not allowed.

</comment><comment><USER15> With Sydney house prices 12.9 times the median yearly household income [1] second only to Hong Kong (SF is 9.1, Hong Kong is 19.4, San Jose is 10.3 and Vancouver is 12.6) would value capture make a similar high speed project work in Australia? Is the cost in the infrastructure or the rolling stock?

Something like Newcastle <-> Sydney <-> Wollongong?

[1]: [http://www.abc.net.au/news/2018-01-22/australian-housing- una...](http://www.abc.net.au/news/2018-01-22/australian-housing- unaffordability-experts-disagree-on-extent/9349796)

<comment><USER16> Even though the rolling stock is technically more advanced and loaded with sensors (sometimes resulting is degraded service aka. lower speed for security reasons) the main cost definitely lies in infrastructure. You basically need to rebuild the whole track for highspeed trains. And with Australia being a litigious nation it will also take a while to acquire and execute the land rights.

<comment><USER17> The line north of Sydney towards Grosford would have to be completely rebuilt to support fast service.

</comment></comment></comment><comment><USER18> During Oktoberfest... 2012, we stayed during the week in Munich and then planned on leaving for Berlin before the weekend.

I recall the cost of 2 train tickets being comparable to gas and 1 day 1-way rental for an entry level Mercedes (E class perhaps?).

Autobahn or train... it wasn't a hard choice.

Edit: As Canadians, we took the car rental. We couldn't turn down an experience of no-speed limits, even if driving is work.

<comment><USER19> Yes. Regular ticket prices for trains are horrible expensive in Germany. You can pay a yearly fee (called Bahncard) to get 25% (62€) or 50% (255€) off. There is also a flatrate for everything called Bahncard 100 (4.270€)

You can also book early. Often you get a ticket for 20-60€ but these are limited. At least they made an UI for this: [https://ps.bahn.de/preissuche/preissuche/psc_start.post?dbka...](https://ps.bahn.de/preissuche/preissuche/psc_start.post?dbkanal_007=L01_S01_D001_KIN0014_sparpreisfinder- content-button_LZ03#stay)

If you don't use ICE/IC you can get a daily flatrate for 44€ for whole Germany or for 20-25€ for one (or multiple) federal states.

Now we often have empty trains and busses are on the Autobahn...

<comment><USER20> Why are the prices so high?

<comment><USER19> It's difficult. They privatized everything in the early 90ies and even attempted to go to the stock exchange - this resulted in cuts and bad long- term decisions - now most of the Deutsche Bahn is public owned but a private company. They probably want to make some profit where it's possible. They need to invest a lot of money in the coming years because their infrastructure is crumbling and running on attrition.

Here are the prices vs. inflation: [https://media0.faz.net/ppmedia/aktuell/wirtschaft/1643856533...](https://media0.faz.net/ppmedia/aktuell/wirtschaft/1643856533/1.2598616/default/die- preise-der-deutschen-bahn.jpg)

However the price for a certain track depends on a lot of things and this new high-speed track has lot's of buisness customers that avoid a flight this way - so it's priced higher.

It's a complicated system with lot's of subsidies, subcontractors and so on. There is a price to pay for using the track to a different company that runs the train...

Another problem is that freight train traffic is even more expensive and they simply forgot to invest in the system for 30 years - now the Autobahn is clogged with trucks...

<comment><USER21> >"They privatized everything in the early 90ies and even attempted to go to the stock exchange - this resulted in cuts and bad long-term decisions - <USER2> most of the Deutsche Bahn is public owned but a private company"

Can you say how it is "public owned" if it is not a publicly traded stock? It sound like their bid to list it on the stock exchange failed?

<comment><USER19> I'm sorry not a native speaker - I mean the GmbH is owned by the state of Germany.

<comment><USER22> It's an AG (a stock company), not a GmbH (a limited company). But yeah, all the stocks are still owned by the federal government, and therefore all profits get credited into the federal budget.

<comment><USER21> This is interesting. I am curious what is the upside to a stock company if all the shares are owned by the same entity(the government)? Are there some classes of the DB stack that are allowed to be publicly traded then?

<comment><USER19> The original plan was to somehow make the whole thing profitable and publicy trade a large partion of shares - so they bought a lot of companies and hoped that they can refinance the train operations. Turn's out it's not so easy...it was just typical management failure, neoliberal politics and pipedreams - <USER3> they stopped it in 2005 - Hartmut Mehdorn the CEO at the time is now infamous for basically destroying everything he touches.

It's still not a government entity so they don't need to be that transparent and have more leeway to keep wages down.

<comment><USER21> Very interesting, thanks for the detailed information. I will need to read up more on this. It sounds like a good case study. Cheers.

</comment></comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER23> What the article forgets to mention: The train ride takes 3 hours 55 minutes.

<comment><USER24> Also, three times per day. You'd have to plan as you would with air travel so that you were at the station to catch these specific trains even if you weren't price sensitive enough to book a seat in advance. Three per day isn't enough for it to make sense to just show up and catch the next one.

<comment><USER25> The faster ones that only need 4h are indeed going only three times a day but there is a connection every hour that takes 4.5h (on workdays from 6 am to 7 pm). Seems fine, I think?

(Source: www.bahn.de, the official website of Deutsche Bahn)

</comment></comment></comment><comment><USER26> Well, that took very long... it's 2018 and finally a real high-speed connection between Berlin and Munich. In France they had that since forever, and also Spain and Italy have a much better high speed network than Germany.

If anything, why Germany is so late to the party?

<comment><USER25> Does France still have the problem that a lot of the connections are via Paris because there are no connections that run between the lines that are connecting cities to Paris? The image of the rail network on the TGV article in Wikipedia is giving the impression.

Did you know that mathematicians named a metric after that? It's the SNCF metric when the distance between two points (cities in real life) is defined as the sum of their distances from the origin (Paris in this case). (that is: go from city A to Paris and from Paris to city B, no matter how close A and B are geographically).

<comment><USER27> Yes they still do. You can arrive in Paris North in a fancy Thalys or Eurostar, but will then have to somehow get to Paris Lyon or South using weird subway like trains which are often packed, dirty, smelly and confusingly inefficient unless you're used to them.

This is why I don't travel by train to the South of Europe. It's a waste of time, and an uncomfortable one at that.

</comment></comment></comment><comment><USER28> The distance appears to be about the same as Los Angeles to San Francisco.

<comment><USER29> Not with the route the California High Speed Rail is using. Phase 1 of CAHSR will be 840 km, this route is quoted at 623 km.

<comment><USER28> About 135 miles.

Will the CA train run at 186 mph or 220 mph?

This will translate to an extra 30-45 minutes?

<comment><USER29> Parts 220, parts much slower (more like 120 from San Jose to San Francisco, for example).

By the way, CAHSR predicts ridership 20-30x higher than that mentioned in this headline.

</comment></comment></comment></comment><comment><USER30> I rode that train (Munich to Berlin) after I got stranded in Munich during the 2014 Bardarbunga, Iceland volcano eruption. It was kind of slow for an ICE at the time, and quite expensive (IIRC like 150 EUR in second class).

It was one of the nicest train rides I've ever taken though - you got to see so much of Germany. The onboard restaurant was awesome.

<comment><USER20> I thought train systems were heavily subsidized by the state across Europe. Why are tickets so expensive? The distance isn't far at all, by American standards I'd expect to pay roughly $20-30 for a train ticket across that distance. 150 EUR you should be able to fly for that price.

<comment><USER31> _150 EUR you should be able to fly for that price._

Taking the train between major cities is often more expensive than flying in Europe. People choose the train because it's comfortable and convenient, not because it's cheap.

Also 150 EUR is a full price ticket. If you book a few weeks in advance, and are willing to take the 'slow' train you can probably get a ticket around 30 EUR.

<comment><USER32> Depending on the route, often even on the day before. On more popular routes, prices rise more quickly though.</comment></comment></comment></comment>