Boom (YC W16) signs $2B letter of intent with Virgin, $5B total - <AUTHOR> http://techcrunch.com/2016/03/23/boom-the-startup-that-wants-to-build-supersonic-planes-just-signed-a-massive-deal-with-virgin/ <comment><USER2> Wow, who's doing the marketing? Pretty savvy. If they had launched with this notice, we'd be thinking, "Oh cool, Virgin's making a supersonic airplane with some company!"

Instead, with this tiered announcement: Three days ago, nobody knew about Boom. Within the last two days, they have lots of new press, and and thus lots of skepticism. Today, they 'announce' an effective endorsement with Virgin. Brilliant.

<comment><USER3> Yeah, I didn't agree with the name criticism either. For the small sample of us techies, sure, it has some negative associations (but even still not significantly so). For most, however, it's positive: _Boom_ , drops the mic; Sonic boom, something good in the technical advancements of achieving great speed; and great for a simple, easy to remember, evocative brand name.

<comment><USER4> Why does it have negative associations for us techies? It sure doesn't for me.

<comment><USER5> In the previous thread some associated "Boom" with "Something blowing up" which wasn't perceived as a great name for a plane.

<comment><USER6> Yeah, I thought it was a horrible name in light of the fact that the last supersonic jet program was permanently grounded because of a crash.

[https://en.wikipedia.org/wiki/Air_France_Flight_4590](https://en.wikipedia.org/wiki/Air_France_Flight_4590)

<comment><USER7> That just moved things up a bit - they were already winding it down.

</comment></comment></comment></comment></comment></comment><comment><USER8> Title misleading. The relationship is opposite what's implied. Boom will be hiring Branson's "The Spaceship Company" to do engineering, and Virgin gets an option to buy the first ten planes.

Granting an option means Boom has given something to Virgin, not the other way around.

> a Virgin Group spokeswoman confirmed their plans to The Guardian: "We can > confirm that The Spaceship Company will provide engineering, design and > manufacturing services, flight tests and operations and that we have an > option on the first 10 airframes. It is still early days and just the start > of what you'll hear about our shared ambitions and efforts."

EDIT: Let's hope that we hear Virgin is making a big investment in Boom soon, that will be a stronger indicator. If Virgin really had substantive interest in the planes, and Boom was actually experiencing demand, Virgin would have had to PAY MONEY for an option.

<comment><USER9> My interpretation is that this is pretty standard LOI-speak. The reason it's an _option_ is because Virgin is under no obligation to buy the first 10 airframes: LOIs are usually non-binding and contingent upon the company actually delivering what they've promised, which means Virgin can back out if Boom can't actually deliver on the promised specs. But the money is still flowing from Virgin to Boom.

The bit about the Spaceship Company seems to be systems-integration, not hiring out the full engineering department. If you've ever sold enterprise software, usually a deal with a big company includes a commitment on the part of the customer to provide engineering & testing resources to integrate the new product. For something huge like an SST, they need to ensure it meets Virgin's safety specifications, they need to make sure it can interface with Virgin's maintenance department, they may need to alter the design to meet noise requirements from airports Virgin operates from, and all other sorts of little engineering tasks. These all require engineering resources from the customer, not just the seller.

<comment><USER10> No, because the issue here isn't whether there is a desire for the product, which is what the LOI demonstrates, it is whether the product can be built.

Put another way, Boom won't have trouble selling their plane if they manage to build it, and the only point of the LOI is to put Virgin and Boom on the front page of every news outlet tomorrow.

<comment><USER11> I argued yesterday that Boom would probably have more trouble selling a supersonic aircraft in sufficient quantities to break even than building it, and I haven't changed my mind.

I think you're quite right about the LOI mostly being for the publicity, but from the opposite perspective: I don't think the market for a new player offering a product highly specialised towards transatlantic all premium flights is actually that big, and enthusiastic noises made by an airline run by the British equivalent of Elon Musk who made similar noises about resurrecting Concorde doesn't really change that.

(Related prediction: the undisclosed LOI turns out to be from Odyssey Airlines whose _proposed_ business model is perfectly suited to supersonic business class jets, but at present have nothing but a massive binding commitment with Bombardier and some small change from crowdfunders.)

<comment><USER12> For anybody else needing more context for the last paragraph: [https://en.wikipedia.org/wiki/Odyssey_Airlines](https://en.wikipedia.org/wiki/Odyssey_Airlines)

</comment></comment></comment></comment></comment><comment><USER13> Maybe I am misinformed but I was under the impression part of the reason concorde was retired is because at those speeds you tear up the ozone.

"From their particle measurements, the authors of the Science study calculate that a future possible fleet of 500 supersonic passenger aircraft will increase the surface area of particles in the atmosphere by an amount similar to that following small volcanic eruptions. In mid-latitude regions, such emissions have the possibility of increasing ozone loss above that expected for nitrogen oxide emissions alone. The increase in the number of particles may also affect the ozone-related processes occurring on wintertime polar stratospheric clouds (PSCs) in the polar regions."

-[http://www.publicaffairs.noaa.gov/pr95/oct95/noaa95-65.html](http://www.publicaffairs.noaa.gov/pr95/oct95/noaa95-65.html)

<comment><USER14> >Maybe I am misinformed but I was under the impression part of the reason concorde was retired is because at those speeds you tear up the ozone.

That really wasn't a reason for the Concorde's retirement. It was an old plane. It was marginal economically. It had a fatal accident. And then, just as it was returning to service, the travel slump after 9/11 happened.

Environmental opposition was one factor in the cancellation of the Boeing SST program. Although the bigger one was almost certainly that it didn't make economic sense.

<comment><USER13> >It was an old plane. It was marginal economically. It had a fatal accident. And then, just as it was returning to service, the travel slump after 9/11 happened.

I agree that all those are the primary retirement factors but I did not want to bring them up as they where being discussed elsewhere in the comments.

I'm interested to see that people where complaining about the potential of Concorde stratospheric pollution all the way back in 1972[1]. Maybe it was not so much a reason for retirement but one of the many reasons the concorde received such a poor public reception in the 70s. I think Boom has some serious hurdles ahead of them in this regard. Environmental regulations have done nothing but grow since the 1970s and many countries where outright banning the concorde from their airspace then.

[1][https://upload.wikimedia.org/wikipedia/commons/6/61/ACPTimes...](https://upload.wikimedia.org/wikipedia/commons/6/61/ACPTimes.jpg)

</comment></comment></comment><comment><USER15> Awesome as this is, there's something largely outside of Boom's control that could derail their plans. When Concorde was ready to fly the British and French governments (who paid for the plane's development) had to negotiate with New York for permission to land there. There were concerns about the noise - not sonic booms, just general plane noise, because Concorde was "loud". The problems were actually political ones because Concorde wasn't American. Boom will have to do the same, but London has some _really_ bad NIMBY issues with airports and the expansion of Heathrow at the moment. Problems that will probably continue for decades. If the anti-expansion environmental lobby groups can block this, and they see it as politically useful to do so, there will be _a lot_ of negotiating to wade through.

<comment><USER16> This could be a gain for other cities though. If NY puts up a fuss then what about Boston instead? Same problem for London. Just don't go to Heathrow.

<comment><USER17> This has the same problem as hyperloop, then. Sure the main part of the journey is quicker, but if you have to take a connecting flight from New York to Boston, _and_ a train from Luton to London, it's overall slower than a subsonic plane.

</comment></comment></comment><comment><USER18> I'm disheartened there's no mention of carbon footprint or sustainability. With all the great focus in our community on sustainable land transport (Tesla), data centers, solar and neo-nuclear power, etc., here we have a startup that markets this:

 _" imagine leaving New York in the morning, making afternoon meetings in London, and being home to tuck your kids into bed."_

That is a terrible thing to enable from an environmental impact standpoint. While air travel can be somewhat more efficient per mile than driving alone in a gas car[1], the distances it enables you to travel are vastly greater. Further upping the convenience factor would no doubt encourage more "binge flying".

Perhaps Boom is more efficient than typical airplanes. Perhaps it's less efficient. Perhaps it could make planes that travel at the same speed but at half the carbon footprint. We wouldn't know from this. It's not part of the story.

Let's change that. Let's make sustainability as important a consideration with airplanes as it is with cars.

[1] [http://www.yaleclimateconnections.org/2015/09/evolving- clima...](http://www.yaleclimateconnections.org/2015/09/evolving-climate-math- of-flying-vs-driving/)

<comment><USER19> Hmmm... Aren;t the two separate? Carbon neutral is going to be almost impossible with flight. Why don't we split the two (carbon output and input) into two fields?

</comment></comment><comment><USER20> I would be extremely impressed if they could pull this off. Developing a supersonic passenger plane must possibly be one of the most expensive and complex things to do. Probably harder than what SpaceX does.

<comment><USER21> You know we've had supersonic passenger jets since 1969, right? It just wasn't cost-effective. [https://en.wikipedia.org/wiki/Concorde](https://en.wikipedia.org/wiki/Concorde)

SpaceX has brought reusability to space travel. That's slightly more impressive than a fast airplane.

<comment><USER22> Yes and one went boom in 2000 killing everyone on board. [https://en.m.wikipedia.org/wiki/Air_France_Flight_4590](https://en.m.wikipedia.org/wiki/Air_France_Flight_4590)

The only reason this idea is even being entertained right now is because oil prices are so low. As soon as the oil producers are finished crushing this round of alternative energy companies oil prices will go back up and Boom won't sound so good.

<comment><USER23> Other airplanes have crashed too. I think it was deemed a fairly safe aircraft, they had some trouble with tyres, but that shouldn't be impossible to resolve.

<comment><USER11> It was retired from service largely because the accident was attributed to a critical design flaw.

Sure, that was the only ever Concorde crash, but then they really didn't fly very much compared with conventional aircraft. There are _individual_ commercial aircraft that logged around as many flight cycles as the entire Concorde programme without incident.

<comment><USER23> I know they have recurring problems with tyres (and I'm sure they had other design flaws too).

But afaik the main culprit in the crash was a piece of titanium that fell off from another airplane and was left on the runway. This metal-piece cut into the tyre and caused an explosion.

</comment></comment></comment></comment></comment></comment><comment><USER24> Just for some context 787 cost $32billion dollars to develop.

<comment><USER25> Most important figure here. How could a "startup" design and build a _commercial_ airplane and still be considered a startup? Either they get acquired before launching the final version of their plane or the company goes bust. The margins for building airplanes are very slim, both Airbus and Boeing get massive subsidies from the EU and US respectively. Which investor would be crazy enough to pour billions into the development of such a plane? And don't even think about mentioning SpaceX - building a rocket is orders of magnitude less complex than building a commercial airliner that meets customer's standards, is commercially viable and safe. In contrast spending tax payer money on rockets (which are allowed to fail every now and then) is easy!

<comment><USER26> There isn't a chance in hell that _after_ producing a supersonic prototype, these people _wouldn 't_ also get massive subsidies and investments. Still, right now they're a startup.

</comment></comment></comment><comment><USER27> If building a supersonic passenger plane with an existing engine was viable, it seems like somebody would already be doing it. Which means it's probably not viable, in which case Boom is an aircraft engine company first and foremost; once they have the engine, wrapping a plane around it should be the easy part, relatively speaking. Developing a new engine costs on the order of $1B, so the development cost for the whole plane would probably be between $1.5-2B. So they'd pay for that with their first 10 planes to Virgin, with maybe some money left over to change their name.

<comment><USER28> Can you not just make the plane smaller and lighter and more aerodynamic and use a larger engine? You may also be able to show that current engines can operate at higher energy levels for longer?

<comment><USER29> Doesn't work like that. They want to use a J28D engine modified for super sonic flight. That engine was designed to power MD80's.

<comment><USER30> Its the intake design that makes the difference for supersonic performance.

JT8D [0] is based on the J52 engine that powered the A-4 Skyhawk, and a related design is the RM8 [1] that powered the M2.0+ SAAB Viggen.[2]

[0] [https://en.wikipedia.org/wiki/Pratt_%26_Whitney_JT8D](https://en.wikipedia.org/wiki/Pratt_%26_Whitney_JT8D)

[1] [https://en.wikipedia.org/wiki/Volvo_RM8](https://en.wikipedia.org/wiki/Volvo_RM8)

[2] [https://en.wikipedia.org/wiki/Saab_37_Viggen](https://en.wikipedia.org/wiki/Saab_37_Viggen)

</comment></comment></comment></comment><comment><USER31> So what's the carbon impact (per passenger-mile) of the service Boom is proposing (compared to regular air travel) again?

I'm not sure this is something to cheer, just because it's new and shiny (and because it appeals to tech types who fancy they'll finally get to afford a ride on one of these contraptions, some day).

<comment><USER32> $5,000 for the trip isn't a huge leap for typical business class to London. Economy alone is usually like $1,200-1,500rt. This isn't some huge exorbitant leap like costing $30k for a first-class trip. It certainly doesn't come close to elite "tech types" being able to afford it "some day" like trips on the Virgin SpaceShipOne will.

I think many companies depending on situation will consider this worth it for the quick flight. It certainly doesn't strike me as something that people are excited about just because it's "new and shiny." It adds actual utility to get key players to certain locations on short notice.

In any case, despite it holding fewer passengers than a Boeing 787 or something, I would bet that drastically decreasing flight time goes a long way toward bringing the carbon impact more in line with a typical flight of the same length.

<comment><USER31> Did you understand my question?

I was referring to CO2 impact, not price.

<comment><USER33> My uninformed understanding/guess: Flight is low margin and fuel is the primary cost. So you can make an estimate of the CO2 impact; if the average seat price on a normal airliner for that journey is $1000 and the average seat price on this aircraft is $5000 then I think you can say it's approximately 5x the impact.

Happy to be shown wrong, this is complete conjecture.

<comment><USER31> That would seem to make sense, to a first order approximation.

But there may be other factors to consider: type of fuel that gets burned (and how it is burned); how long it stays in the upper atmosphere (possibly at higher altitudes), etc.

</comment></comment></comment></comment></comment><comment><USER34> I don't know the first thing about how a business in the space operates. Can someone fill me in on why a startup like this would go through YC? How are $120k and Silicon Valley connections going to help a startup in this space in the slightest?

<comment><USER35> We are all here reading and thinking about it. And SV taken as a whole eats its own dog food: I was amazed the first time I worked with a YC company how many other nearby startups they used as vendors.

If you think about Boom as part of an ecosystem, they will eventually need a large number of companies to buy seats on their planes. As with Concorde, only a minority of seats will be saleable to individual consumers. Now Boom, they're here, getting name recognition at hundreds of SV companies, some of which will have offices in London, Singapore (where Concorde also briefly flew), etc.

</comment></comment><comment><USER36> Letter of intent. Not a contract. The article is speaking like it's a done deal.

<comment><USER37> The article first states that they've optioned a purchase - so I assume they've purchased some sort of call option and Boom are the issuers which would mean that some money has changed hands.

<comment><USER38> I doubt any money has changed hands (if it has, Boom would trumpet the figure). This is a pure publicity move for both Boom and Virgin. I doubt, tbh, that Virgin rates highly the chances for this to succeed, but they lose nothing by saying that _if_ the plane is as magnificent as promised, they will buy a bunch.

<comment><USER37> If they purchased an option then Virgin paid for it. Optioning purchases is a common instrument traded in aviation finance. The option to buy this aircraft at some point in the future at a price specified today is worth a lot. The fact that it's a moonshot only means the price of the option would be reduced. _If_ the plane is as magnificent as promised, Boom's order books will be filled for decades and other airlines will be second in line to Virgin.

</comment></comment></comment></comment><comment><USER39> They got $5bn in LOIs, a new YC record: [https://twitter.com/sama/status/712705887853383680](https://twitter.com/sama/status/712705887853383680)

<comment><USER40> That's awesome.

$200M per delivery seems a little tight to design and build 25 planes from scratch (the latest version 787 is ~$300M for comparison) but I'm sure they have smart people working on it.

<comment><USER41> The 787 was almost as bad as the F-35. Somewhat different problem, though. Theirs was the issue of too many subcontractors with subcontractors with subcontractors and poor control over manufacturing. They literally bought companies that made the parts because they:

1) didn't have the manufacturing means themselves;

2) couldn't control the quality enough via contract measures.

That significantly drove up the cost of the 787 project. Someone really needs to do a good write-up on these two projects as today's version of the _Mythical Man Month_ and similar texts.

<comment><USER42> A subcontractor can make way more money by internally making parts of substandard quality to ensure they get bought.

<comment><USER41> This was not deliberate in the cases I'm thinking of. This was a lack of quality control due to the extreme distributed design and development approach Boeing chose with the 787.

</comment></comment></comment></comment></comment><comment><USER43> I love what these guys are doing, but I find it odd that they're using an actively registered tail number (N22BT) in their mockup images.

</comment><comment><USER44> This is _awesome_. Great counterpoint to all the naysayers and middlebrow dismissals on Monday. I'm pumped to see this thing fly.

<comment><USER45> I'd love to have more startups like this to watch, people solving REAL problems and making REAL things, not just a new social thingy or toy for bored suburban residents.

Plus I always wanted to fly on the Concorde but the fleet retired before I got the chance.

<comment><USER46> "toy for bored suburban residents" \+ "Plus I always wanted to fly on the Concorde" = flying on the Concorde as a toy for bored suburban residents?

<comment><USER45> As I recall the majority of passengers on the Concorde flights were businesspeople, the pricing made it prohibitive to regular consumers. But yes, to me it would be a cool experience to save the pennies and get a ticket.

</comment></comment></comment></comment><comment><USER47> Boom is probably my favorite new company in a long time. I wish there were infosec concerns :)

<comment><USER26> I can picture the Mandiant APT press release already...

</comment></comment><comment><USER48> Read about Boom a few days ago, thought this could be a cool idea years into the future, with the right backing.

Today, realize that most things happen a hell of a lot faster than I expect.

</comment><comment><USER49> What is the importance of an LOI? Its non binding. So why does it matter, except as a PR exercise?

<comment><USER50> They're not completely useless, because they can move a negotiation along a step e.g. by ensuring exclusivity, or agreeing on language in subsequent negotiations. PR side effects aren't empty either: investor confidence can keep a struggling firm alive; or for manufacturers, having a LOI in hand may be beneficial to your supply chain relationships.

A word of warning though.

Anyone who thinks a LOI violation isn't actionable hasn't met bigco lawyers. I was taught long ago to basically treat LOIs as purchase orders. They are hard to make completely nonbinding. Whether an LOI, a MOU, or a HOA; all such preliminary agreements fall into basically the same category of potential legal time bombs. An imperfectly drafted LOI may be treated as billable by some parties, with all the actionable response this implies if you withdraw from the arrangement.

So someone asking you to sign a LOI or similar preliminary agreement who suggests "Oh it's just a letter of intent" is probably taking you for a chump. Do not sign without very good legal advice, and (unless you are an excellent lawyer) never attempt to write one yourself.

<comment><USER49> Interesting. Thanks for the clarification/inputs.

</comment></comment></comment><comment><USER51> The article describes Concorde as "ill-fated". Is that accurate?

<comment><USER52> I mean, they only built 20 planes in total, so 5% suffered catastrophic failures with complete loss of life. Over the life of the program there were numerous 'near-misses' with rudders and control surfaces breaking off the plane at >Mach 1. The tire problem that brought down AF4590 wasn't an isolated incident whatsoever, there were dozens of blown tires including at least one other one that punctured a fuel tank and nearly brought down that plane. So yeah, 'ill-fated' seems fair.

<comment><USER53> Only 14 entered airline service, but they made it from 1976 to 2003 which is not that bad.

For comparison 3% of 747's (53) have been a total hull loss. But, the Boeing 707's had 17% hull-loss occurrences and 246 major aviation occurrences out of 1,010 built (172) which is arguably a better comparison.

</comment></comment></comment><comment><USER54> In a prior thread I asked about how they would get the funding they need straight out of YC. I guess this is the answer!

</comment><comment><USER55> Yesterday: Hahaha what a stupid company name! What a bunch of idiots!

Today: Oh shit</comment>


Supertasks - <AUTHOR> https://personal.lse.ac.uk/ROBERT49/ebooks/PhilSciAdventures/lecture25.html <comment><USER2> I'm sceptical about this. Yes, infinity is a weird idea. But it clearly stand beyond the limits of the world as we understand it, maybe the limits of the world as we can possibly understand it. So it's not particularly surprising that we come to confusion when we pretend that infinity is a quality of the world as we understand it, or the world as we can possibly understand it. Just like Kant concluded was true of the idea of God.

In a related vein, it seems characteristic of the kind of philosophy that the later Wittgenstein, and more recently Peter K Unger, criticise as linguistic illusion, of the sort 'If I have a ship and replace a plank, it remains the original ship, but if I replace every plank, does it become a new ship, or remain the same ship?' This is, to them, and to me, thinly veiled wordplay feigning as metaphysical insight. It extracts language from its normal use in concrete life and stands aghast then when one asks weird questions about one gets weird results.

<comment><USER3> Infinity and moreover a hierarchy of infinities is very real and has real consequences. You want your Fourier transform to work, you have to quantify infinities (this was in fact what prompted development of set theory: how to make Fourier analysis precise).

Supertasks are real too. If you take Turing machine something like the _lamplighter group_ pops up at the other end and you have no way to handwave that away.

Unless of course you subscribe to Fictionalism as your philosophy of mathematics, in which case stuff still has consequences just your epistemological stance changes from studying them in favour to some kind of mysticism that absolves you from the effort.

<comment><USER4> You don't need any theory about infinity, hierarchical or otherwise, to get Fourier transforms working. Everything can be done using approximations with bounded error in finite steps. It's just a pain in the butt to write proofs that way.

(And indeed, in practice, we can't perform any infinite processes when we are computing Fourier transforms of real data, in either analog or digital systems. All real-world systems are based on approximations and imperfect models, full of measurement error, bugs in edge cases, etc.)

You have a very strange definition of "real"... or rather, it's like the use in "real numbers" (i.e. a pure thought experiment / set of abstract manipulations of an abstract formal system with no physical embodiment), not the use in "physical reality".

Every mathematical use of completed infinities inherently involves "mysticism", and you seem to have embraced the absolution you mentioned. [Which is fine... accepting Cantor's paradise on faith and not worrying about whether it is "real" or not has been very productive for mathematics, whether or not most of the same results could have been found in a more cumbersome way otherwise.]

<comment><USER5> thank you, you write what I was trying to say but was ultimately not clear enough in expressing my thoughts. I don't understand why people think that because something is good at approximating values that it necessitates its truth or existence.

</comment></comment></comment></comment><comment><USER6> John Baez's "Struggles with the Continuum" ([https://arxiv.org/pdf/1609.01421.pdf](https://arxiv.org/pdf/1609.01421.pdf)) covers similar topics in more detail.

</comment><comment><USER7> Full table of contents here:

[https://personal.lse.ac.uk/ROBERT49/ebooks/PhilSciAdventures...](https://personal.lse.ac.uk/ROBERT49/ebooks/PhilSciAdventures/toc.html)

Looks like I have some new bedtime reading.

<comment><USER8> Thanks for that link - I never would have come across that 'organically'. Now I have some bedtime reading as well.

<comment><USER9> If you like this, you might also enjoy William Poundstone's book _Labyrinths of Reason_. I found _Labyrinths of Reason_ a ton of fun, and it introduced me to a lot of interesting ideas.

(Edit: At first I thought this book and Poundstone's book had a lot more overlap in their contents than they seem to on further reflection, which makes me _more_ confident in my recommendation.)

</comment></comment></comment><comment><USER10> Worth noting is that Aristotle locates the source of Zeno's paradoxes in the failure to distinguish between actuality and potentiality. Achilles does not need to _actually_ cover an infinite number of lengths. A finite length is not _actually_ an infinite number of lengths until we cut that length into an infinite number of lengths, which, of course, is impossible. So until you actually divide the length, the length is merely capable of being divided into an infinite number of lengths, even though it is impossible to perform that division to completion.

</comment><comment><USER11> "For an ideal, perfectly elastic ball, there are an infinite number of bounces before the ball comes to a rest. Each bounce happens in less time than the previous. "

False. A perfectly elastic ball would bounce back to the same height indefinitely.

<comment><USER12> Ah I see you already wrote a similar comment as me. You are more correct. I assumed the ball would bounce lower and lower, but never constantly on the ground.

<comment><USER11> If we put perfect elasticity aside (that is, the coefficient of restitution [0] is < 1) then the ball would bounce back to exponentially decaying heights. However, because of this, the duration of each bounce would also get shorter and shorter in an exponential rate. Now, because the exponential series converges to a finite value, they argue that the ball would bounce infinitely many times in a finite amount of time, after which the ball would be standing still on the ground (the bounce height having converged to 0).

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

<comment><USER12> Okay I guess I see the point is that the bouncing ball converges to a default state, unlike a light switch, which converges to an unknown state. Is it the force of "gravity" which causes this default state, so does the convergence just cancel out all other influences on the system state perhaps?

<comment><USER11> The ball's state can be described by its y coordinate, and it converges to zero. The lightbulb's state can be described by Boolean variable (on/off), but it doesn't converge, just oscillates between on and off with an exponentially increasing frequency. If we have instead used a variable intensity light switch, and turned it like 0%, 100%, 0%, 50%, 0%, 25%, 0%, 12.5% ..., with an exponentially increasing frequency, it would have also converged to the 0% state like the ball did.

So the variables that describe the system's state has to converge.

</comment></comment></comment></comment></comment><comment><USER13> Vsauce did a video on this topic.

[https://www.youtube.com/watch?v=ffUnNaQTfZE](https://www.youtube.com/watch?v=ffUnNaQTfZE)

</comment><comment><USER14> I'm surprised the author didn't consider a finite number of states when mapping the concepts back to physics. Feels like infinity performs a useful function in mathematical reasoning, but there is no reason to believe anything we can really see or measure is boundless. None of this has any bearing on the mathematics, which are interesting.

</comment><comment><USER12> I think the statement is wrong about the bouncing ball light switch: "What state is the lamp in after 1 minute is up? Because of how we've set things up, the lamp will be on!". If the ball was perfectly elastic, it would bounce forever, a smaller and smaller height, but the height never reaches 0 permanently.

</comment><comment><USER15> You know the problem with the hotel room example? Until the last room's occupant has packed up and moved into the newly created +1 room, there is no open space for the newcomer.

</comment><comment><USER16> I opened the comments half expecting comments _more_ inscrutable than the discussion itself. Didn't expect the extant sentiment.

So, maybe, this question isn't so stupid:

...what's the point of this type of discussion? What real-world, non- theoretically-based situations, would I use this type of understanding in?

I've tried to figure it out and I'm not coming up with anything relevant. I know there _is_ relevancy to be had here, I can see that, I'm just not figuring it out myself.

<comment><USER9> Supertasks have a connection to some interesting areas in computer science:

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

But you can also sort of repeat your question with regard to those areas of computer science, because they don't appear to relate to computing devices that we could physically build, even though they might clarify things like how different groups of unsolvable problems relate to one another.

</comment></comment><comment><USER17> It's a little funny to me to talk about infinity in the context of physical systems. Where do you keep all those balls? :)

<comment><AUTHOR> In the box with Schrödinger's cat

</comment></comment><comment><USER18> I love reading about these types of things.

I hate reading about these types of things.

<comment><USER19> But if you vacillate between those positions at an exponentially increasing frequency, what is your position at the end?

<comment><USER20> Enthusiastic apathy</comment></comment></comment>


More than Money... Matter. - <AUTHOR> http://hellobubs.com/post/21354507373/more-than-money-matter

<comment><USER2> We try to track our users level happiness by using basic metrics like time on site, times people share. We're still working out our own formula for doing what matters means to us. We think we're getting there.

Would be interesting to hear about pitch decks that include a "happiness quotient" or some metric tied to the emotion level of their users.

In the long term, I'm curious if focusing on this sort of metric is good for business.

<comment><USER3> Reminds me of Dharmesh Shah's talk at SXSW where he shared the-one-metric-to- rule-them-all that they developed at HubSpot to measure success for everyone on the team (from sales people to developers): CHI (Customer Happiness Index).

The concept is that everything the business does should be focused around the goal of increasing customer happiness, and this single metric aligns everyone's motives around the goal.

You can learn more here: [http://www.hubspot.com/agency-partners/partner- definition-pa...](http://www.hubspot.com/agency-partners/partner-definition- pages/what-is-CHI/)</comment></comment>


Feds explain (sort of) why they really want data on seized iPhone 5S - <AUTHOR> http://arstechnica.com/tech-policy/2015/11/feds-explain-sort-of-why-they-really-want-data-on-seized-iphone-5s/ <comment><USER3> _Previously on iPhone encryption wars..._

Basically, DannyBee was spot on [0]:

> It's actually significantly more likely they want to unlock the phone to try > to get more evidence against the other 6 people he was charged with, > probably because it's lacking.

...but, since IANAL, this to me still doesn't address the question of how much easier would it then be for the government to attain permission to decrypt any further iPhones the government wants to peer into? (As mentioned before[1])

[0] [https://news.ycombinator.com/item?id=10481952](https://news.ycombinator.com/item?id=10481952)

[1] [https://news.ycombinator.com/item?id=10481356](https://news.ycombinator.com/item?id=10481356)

<comment><USER4> I don't know the proper terms, but I wonder if scope or venue should prevent the government from doing this. If they got a warrant in order to get this one guy, and now they have him, maybe it should sort of invalidate the warrant. If this court case was opened to try this one guy and he's now plead guilty, maybe the judge doesn't have jurisdiction to order further searches. But I really have no idea, and I'm hoping an expert will pipe in as they usually do on HN. :) I guess if it were this obvious, the judge would have said no... but on the other hand why does he need to hear their opinion on it if it were obvious in the other direction?

I read the government's letter, and it seemed to be a stretch given what I've said above, but again I'm not qualified to say. They did add that "the Feng [guy whose phone they want] matter remains ongoing until sentencing and judgment is entered in the case", which seems a more fair point to me.

Oh, and what about court-ordering the guy to unlock his phone? I thought that was legal (but maybe not in this circuit court?) This would make more sense and overcome some of my objections. It seems a bit contrived that they can put Apple on the hook to produce someone else's information that wasn't shared with Apple -- if it had been, third party doctrine would kick in.

<comment><USER5> Court ordering someone to unlock their phone has been ruled as a violation of your 5th amendment rights and of 4th amendment rights to privacy by an appellate court (don't remember which, was slightly surprised when it happened). Basic logic as far as I can remember was that court can't order you to expose phone to them because phones are essentially an extension of our private thoughts in this day and age. Even if evidence is demonstrably on it (say, via looking at metadata), similar to evidence in your own head - <USER2> can't force you to fink.

<comment><USER6> Be wary giving out legal advice if you're not a lawyer.. The courts can force you to do many things, especially if they're not trying to prosecute you for information you may have. Much of the case law that I've seen (note: I'm clearly not a lawyer either) with regard to phone searches has been when the police were seeking evidence that the phone's owner committed crimes -- not after they'd been convicted. This distinction can definitely be important.

One concept with specific relevance to the 5th amendment is immunity given for testimony. You can be compelled to testify (even over your 5th amendment objections) if the court grants you immunity for the information that they're after.

Again, IANAL, but I know enough that it's much more complicated than "phones are protected from all searches".

[https://en.wikipedia.org/wiki/Fifth_Amendment_to_the_United_...](https://en.wikipedia.org/wiki/Fifth_Amendment_to_the_United_States_Constitution#Grants_of_immunity)

<comment><USER7> Can state courts give immunity? I would assume yes. What happens if a state court grants immunity to get at the evidence or testimony but the evidence or testimony could lead to federal or other jurisdictional (another state?) charges or prosecution? How can one be forced in one court to be exposed in others? It would seem the immunity being granted would have to be universal. How can one court/jurisdiction grant such immunity beyond its jurisdiction?

</comment></comment></comment></comment></comment><comment><USER8> Since the guy with the locked iPhone already plead guilty or whatever, can't they give him immunity for anything new and force him to unlock his phone that way? I'm no lawyer but as I understand it, that's how prosecutors can generally go about forcing people to give evidence about co-conspirators. From there it's a straightforward contempt charge and the guy sits in jail until he gives up the passcode.</comment>


Ask HN: so many language options my head is spinning... - <AUTHOR>

Here's another "new developer" question for you guys, but it's a bit different.
I've only been coding for the last year (in an arcane language called FAME) and I've enjoyed the creative side of my 9-5 so much I've decided to pick up more languages and CS basics, and maybe look for work in the Bay Area.
I've got a ton of ideas floating around in my head. Visualization/graphics/UX stuff on iOS. A web app for data analytics (something similar to chart.io). Toying around with a mobile OS (maybe messing with Android) some day.
I've picked up the basics of Python, and I've got a copy of K&R sitting next to me, but focusing on just one language is hard!
For those who started with no CS background and tons of abstract ideas: how did you decide what to learn and ship first? What languages would keep my options open to all these different ideas (web and mobile and systems)? Am I thinking too big here? <comment><USER2> Python is a pretty good choice. It's general enough that you can get stuff done in many environments with it, even though it may not be the absolute best possible choice. It's also pretty quick to develop with.

I kind of prefer Ruby myself, but have no hesitations about recommending Python if that's something you've got experience with.

<comment><USER3> I would go with Python as well. If you want to play with Web applications, there's Django. If you want to do desktop apps, there's TK. It has a fairly vibrant community, so getting help won't be hard.

<comment><USER4> There's also a lot of python-specific new developer knowledge out there, like the python version of How to Think Like a Computer Scientist (<http://www.greenteapress.com/thinkpython/>).

</comment></comment></comment><comment><USER5> What I would do:

What is the simplest idea that I have that would hold my attention but at the same time, while simple pushes the boundaries of my knowledge/skill a decent amount. I would run with that one. Why?

Challenging enough to keep my interest. Not so challenging as to seem totally daunting.</comment>


My 7 year old wants to make a video game. Where do we start? - <AUTHOR> Like many others, my kid loves playing video games. But my kid also has a lot of ideas for how to make the games better, or different versions of those games.
Before thinking about what I was getting into, I said, "why don't we make our own?"
Now he asks me every day!
I'm a designer, with some front-end knowledge, but I know nothing about creating apps or games.
As far as platforms, iOS is probably our easiest route, but let me know. Should we go with Unity?
If you have other tips outside of just making the thing, I'd lover to hear those as well. <comment><USER2> First, make the game. Then, make your game playable on a computer platform.

Do not make the technical decisions until you first understand the reasons why they need to be made.

Is the goal of this exercise to have a completed video game as the end result, or to have a child motivated to learn how to make such games? If the latter, it may be prudent to build up to the final product, by starting with "Hello World", implementing command-line interface "Tic-Tac-Toe" or "Hunt the Wumpus", moving on to a 2-D falling tetromino game, doing a simple 3-D demo, and so on.

But either way, the initial focus should be on making a fun game, and the details of the execution subordinate at all times to the question "Does this make it more fun to play?"

<comment><AUTHOR> Yes, this is definitely a combination of learning, bonding, discerning interest level.

We've already began the planning and sketching stages, but we want to get our hands dirty soon.

No matter what the end result is, this will be a great learning experience.

</comment></comment><comment><USER3> [https://scratch.mit.edu](https://scratch.mit.edu) for an introduction to programming your young people.

For simple cross platform maybe gamesalad.com

<comment><AUTHOR> Thanks. I have a young relative that uses Scratch.

My kid has played a few different iOS games that are made to teach programming basics to kids (Hopscotch, Light Bot, etc).

I've also created some simple CSS animation stuff on CodePen for them to mess with colors, speed, etc.

I haven't heard of Gamesalad, I'll check that out.

</comment></comment><comment><USER4> I taught my nephew (8 year old) about making games and he is doing really well. I suggest Scratch[0] as well. I also enrolled him in the edx Scratch course and so far he is doing great solving assignments and quizzes. Usually he gets stuck when he is not able to understand the question (English is third language to us) and he skips those and continues the course. And every alternate days I sit with him for 2-3 hours and explain him the questions. I also got a PDF of the book Super Scratch Programming Adventure [2] (dead tree version isn't available in my country) and he loves it so far. He has made many games, as part of course and also on his own. He is proud of his accomplishments and I think thats great.

[0] - [https://scratch.mit.edu](https://scratch.mit.edu)

[1] - [https://www.edx.org/course/programming-scratch- harveymuddx-c...](https://www.edx.org/course/programming-scratch-harveymuddx- cs002x-0)

[2] - [http://www.amazon.com/gp/product/1593275315](http://www.amazon.com/gp/product/1593275315)

<comment><USER5> It would be awesome if we could also see those games, any available online?

<comment><USER4> sure, some of them are available here: [https://scratch.mit.edu/users/sanjupokemon/](https://scratch.mit.edu/users/sanjupokemon/)

</comment></comment></comment><comment><USER6> You might want to check out the current Humble Bundle, which includes a bunch of game making tools including Stencyl, RPG Maker VX, Play Canvas and App Game Kit, as well as ProMotion, Sprite Lamp and other art tools. You'll have to act fast as it ends in less than a day.

Unity3D is great but it will likely be overwhelming for a 7 year old and for you as well given your background.

<comment><AUTHOR> Awesome thanks! I was looking at Stencyl.

</comment></comment><comment><USER7> Paper and pencil as an adjunct? Games exist in analog too. Maybe a Hoyle card game book, read it together, mark it up, come up with your own rules. All of this not an end unto its self, but a stepping stone to computer games. Maybe thinking of it as an ABC's of "games".

</comment><comment><USER8> Building something like hangman in Racket would be straightforward for father son time. If your son enjoys the making it will be enough, if anything short of Xbox quality won't do, then you'll exceed his interest quickly and he can start on his next project.

Good luck.

</comment><comment><USER9> Wow, that's so cool that you and your child can share this hobby and interest together. I'm a front-end dev who has dabbled with open-source game development before, so my advice is going to be a little different than the 'start small and build bigger' and more like 'start with one thing and expand your skill set'.

I got interested in graphic design as a teenager, and had tons of UI ideas about the desktop, software interfaces, etc. I also loved video games, so it wasn't long before I was trying to find ways to get my designs into the games I was playing.

The first time I ever realized a game could be modded was playing the DOS game Scorched Earth. You control little tanks that shoot each other (like Worms) and when you die they say a quote. Our computer teacher at school had modified the text file to include school-specific quotes and I knew that not every version of the game was like that.

Many PC games have active modding communities. I was a young teenager as Quake3 mods were popular, and so I got a really good glimpse at how add-on content can enhance a game. It wasn't long before I got involved with an open- source FPS project (Nexuiz released 2005, now forked and developed as Xonotic). As a 2D artist, I mostly worked on loading screens, the menu UI, the in-game UI, but I met a team of global volunteers from all around the world that became friends. I learned about programming, I got to 'shadow' and understand every role inside a game development team, and I got to have the thrill of shipping a product and playing against strangers inside the game I helped to create! All this before I was finished high school.

My advice to you and your son would be to start small with Minecraft mods, or something where you can immediately put the skills you have to use and see changes. This keeps you interested as you learn about and develop skills related to game design you don't currently have (3d modelling, game engine programming, audio engineering, etc).

I would also encourage you to contribute or join some open source game projects that are looking for contributors or volunteers. For me this was a social life-saver as a teenager, as well as an amazing educational experience.

Best of luck to you and your child, you have a wonderful adventure ahead of you!

</comment><comment><USER10> I wonder if you both could go through some pygame tutorials? They're very approachable.

</comment><comment><USER11> modded Minecraft might be a nice platform, people do all sort of things in it

<comment><AUTHOR> That's definitely something to look into in the future.

</comment></comment><comment><USER12> Introduce them to Logo, and then BASIC. After that python.</comment>


"Entrepreneur in Residence" – Who are you kidding? - <AUTHOR> http://brajeshwar.com/2012/entrepreneur-in-residence-who-are-you-kidding/

<comment><USER2> and this would frustate _real_ entrepreneurs because?</comment>


Parse makes large many-to-many relations more efficient - <AUTHOR> http://blog.parse.com/2012/05/17/new-many-to-many/

<comment><USER2> There seem to be regular posts about this for-pay service...

<comment><USER3> The service is great and I'm interested in hearing about the new features, which is why I personally vote up the posts.

New AWS features often hit the front page as well, so I'm not too worried that there is a Parse conspiracy at play. :-)

<comment><USER4> Are the new AWS features posted from accounts that are 2 hours old?

blog.parse.com has an rss feed for those who are interested; I'm personally tired of the spam.

<comment><USER5> Me too.

<comment><USER6> Thirded. This should not be on HN.</comment></comment></comment></comment></comment>


Could Google kill the cell phone industry? - <AUTHOR> http://news.com.com/8301-10784_3-9747799-7.html?tag=nefd.only <comment><USER2> Not if Apple kills them first.</comment>


Techcrunch 40, where are they now? - <AUTHOR>

Which companies from Techcrunch 40 besides mint.com are doing well? And is mint.com really doing all that well? <comment><USER2> It's too early to tell, but here's what's happened so far:

powerset acquired $100mm 7/08

cubic telecom acquired $6mm 1/08

viewdle additional funding 3/08

yap series A $6.5mm 6/08

flock seies D $15mm 5/08

docstoc series B $3.25mm 4/08

mint series B $12mm 3/08

clickable series B $14.5mm 7/08

pubmatic series A $7mm 1/08

zocdoc series A $3mm 8/08

befunky series A $550k 6/08

flowplay series A $3.7mm 2/08

metaplace launched 3/08

woome series B $12.5mm 6/08

zivity series B $7mm 3/08

kaltura series B ?? 6/08

<comment><USER3> Cubic Telecom were not acquired. It would have been big news here in Ireland if they had been. You can see from the founder's blog that they actually just partnered with Global Roaming: [http://patphelan.net/cubic-telecom-and-global- roaming-allign...](http://patphelan.net/cubic-telecom-and-global-roaming- allign-forces/)

If anything, it seems like they have completely lost focus on their original, supposedly revolutionary offering and instead fallen back on roaming SIM cards (not so exciting).

Their Crunchbase profile incorrectly states they were acquired (how convenient) and the ostensible acquisition value is oddly similar to the total amount of capital they've raised: <http://www.crunchbase.com/company/cubictelecom>

</comment></comment><comment><USER4> The TechCrunch40 list is here: <http://www.techcrunch50.com/2007/>

... just in case you forgot the names.

</comment><comment><USER5> Xobni has gotten quite a bit of very favorable press. I don't know enough about their market or their product to say whether they're doing well...but the acquisition overtures from MS seem to be indicative of something good.

And, I suspect Mint will be a huge success story. It's a gigantic market, and Quicken leaves a lot of room at the bottom (and, frankly, Quicken fails the online thing in so many regards that even if Mint were to cost more, it'd probably still gather some customers...but Mint is dramatically cheaper than Quicken, practically infinitely so).

Flock and Docstoc had some good press a while back. But, I don't really recognize any of the other names. And, other than Mint, I've never used any of them (and I knew about, and was a fan of, Mint before TC40).

<comment><USER6> I would love to have xobni for my thunderbird/Mail.app on OSX (I don't really want to move to outlook just for it on the mac, if outlook even runs on the mac??).

</comment></comment><comment><USER7> You can see <http://www.crunchbase.com/conference/2007> for funding and exit information for the 2007 companies. You can also see the companies' investors, as well as the list of experts for the 2007 event.

</comment><comment><USER8> IF TC 40 was a VC what would be their rate of return?

<comment><USER5> You can't know yet. It's only been a year. The average exit for a VC-backed venture in the valley takes seven years. Very few companies, even those with smaller angel or seed level investment, have an exit within a year.

</comment></comment><comment><USER9> Viewdle is very, very cool. <http://www.viewdle.com></comment>


Coraline Ada Ehmke Joins GitHub to Fight Epidemic of Harassment - <AUTHOR> https://twitter.com/CoralineAda/status/702594868984459264 <comment><USER2> My take on this:

[https://firstname.lastname@example.com/coraline-2893dc09aea1](https://firstname.lastname@example.com/coraline-2893dc09aea1)

"To be blunt: based on observations of outspoken SJWs like yourself, hackers like myself think that there is an unspoken delta between your stated aims (which as I've said are often noble), and your practice, which is to use open source projects as a weapon against their contributors when they behave in politically unacceptable ways (e.g. OpalGate and Brendan Eich)."

<comment><AUTHOR> Apparently Github was impressed by her amazing community management skills and positive interaction with developers.

Shadow banning abusive pull requests, safe space repositories, perhaps even a search ranking handicap for underrepresented COBAL programmers.

I'm Excited!

</comment></comment><comment><USER3> She opened this issue on the Opal project: [https://github.com/opal/opal/issues/941](https://github.com/opal/opal/issues/941)

It lead to this issue: [https://github.com/opal/opal/issues/942](https://github.com/opal/opal/issues/942)

Which asked for a code of conduct.

It forever changed how Github works, and trolls got involved in the issue threads as well. You can read the threads if you want to hear the arguments from many sides.

Her Github account: [https://github.com/CoralineAda](https://github.com/CoralineAda)

</comment><comment><USER4> There's no possible way that GitHub management didn't know about her past attempts to have open source developers blackballed for their political views. The only logical conclusion is that GitHub's new management is completely comfortable with that kind of behavior.

</comment><comment><USER5> Already transferring all my repos to Bitbucket.</comment>


Show HN: TubePlates – YouTube/Discogs music player - <AUTHOR> https://tubeplates.github.io/ <comment><USER2> This is a very clean and nice way to create free music playlists using youtube. Nice job</comment>


No Magic Behind Google's Magic? - <AUTHOR> http://stack-up.com/stack/2007/05/22/searchology-no-magic-behind-googles-magic/ <comment><USER2> That's disappointing. I had thought that Google finally invented Magic. Oh well, maybe next year...</comment>


Drug recommended to help cut drink dependence - <AUTHOR> http://www.bbc.co.uk/news/uk-29468885

<comment><USER2> It might be worth noting that there are other similar drugs already in widespread use for the same purpose.

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

The submitted article doesn't seem to touch on what differentiates nalmefene from naltrexone, but the dubiously cited Wikipedia article for nalmefene mentions that advantages "include longer half-life, greater oral bioavailability and no observed dose-dependent liver toxicity." Both are recommended for use in conjunction with psychosocial support techniques.

<comment><USER3> The article was disappointingly short of a few bits of information. It didn't describe the class of drug (opioid receptor blocker), give examples of similar drugs or even give a pointer to more complete information.

Yeah, I know, I could look it up (and I will), but even in a brief announcement, I don't think a _little_ more information is too much to ask for.

Naltrexone has shown benefit for alcohol dependence, and other addictive behaviors too. Probably too obvious to say, but no drug is a "magic bullet" and risk of side-effects remains an important consideration. For naltrexone, a particular concern is liver toxicity with higher doses.

The newer drug may be different, but a drug's bad effects may show up only after prolonged use. Registration trials may not be go on long enough, or involve enough subjects to reveal long-term or rare problems.

</comment></comment><comment><USER4> The WHO defines 3 drinks/day for men and 2 for women as "high intake." Meanwhile among those who recommend daily alcohol intake for health, the typical recommendation is 2 drinks/day for men and 1 for women - a difference of 1 drink.

Does anyone have any insight on this small apparent difference between "healthy person" and "drunkard"?

<comment><USER5> One impacts your lifestyle in a negative way and the other does not.

Someone can be consuming an unhealthy amount of alcohol by the WHO's standards which will cause things like weight gain and shorter lifespan, without being a alcoholic.

However conversely someone could drink, on average, below the recommended daily amount but have short periods of dangerously heavy drinking and thus be defined as an alcoholic over the longer term (e.g. some people with unmedicated bipolar disorders).

As I said at the start it really depends how much drinking impacts your life. If it doesn't in a negative way then you likely aren't an alcoholic (but yet still might want to look at your weight and fitness due to overconsumption).

<comment><USER6> But WHO's standards (2-3 drinks/day) won't make you gain weight if you live a healthy life otherwise (if you didn't, you'll gain that weight anyway, so hard to say if that was the alcohol doing that; sure if you drink 10 pints/night yes, but 2 normal sized drinks...) and that shorter lifespan is doubtful, but that's anecdotal from my side (the statistics WHO uses are not very convincing though; they just note everyone who drinks and has ailments and when they run their matlab algo's over it, they attribute all these which are known to be affected by alcohol to alcohol (ab)use, at least in the ones I read).

Btw. I think the WHO recommends no more than 2(3 for men) drinks per day and no more than 6-7 per week, so that would account for the periods of heavy drinking. You cannot really drink heavy and stay below that.

</comment></comment></comment><comment><USER7> According to an article in the british medical journal ,nalmefene in alcohol misuse is bad medicine. I haven't got access but that's the replies to the article, by doctors:

[http://www.bmj.com/content/348/bmj.g1531/rapid- responses](http://www.bmj.com/content/348/bmj.g1531/rapid-responses)

Another place is a the most recent review of alcohol dependency drugs:

[http://www.ncbi.nlm.nih.gov/pubmed/24825644](http://www.ncbi.nlm.nih.gov/pubmed/24825644)

There's only medium evidence for nalmefene use, and the results speak of an average reduction of 2 days of heavy drinking per month and average reduction of 1 drink per day. Not that big.

<comment><USER8> It's recommended for people who don't manage to cut down after two weeks of psycho-social intervention, who also drink more than 7.5 units per day (that's very roughly half a liter of 14% wine per day) but who also drink less than the amount needed for medically supervised detox.

Here's the priminary NICE information: [http://www.nice.org.uk/advice/esnm29](http://www.nice.org.uk/advice/esnm29)

The Cochrane summary is sparse for nalmefene.

[http://summaries.cochrane.org/CD001867/ADDICTN_naltrexone- an...](http://summaries.cochrane.org/CD001867/ADDICTN_naltrexone-and- nalmefene-for-alcohol-dependent-patients)

</comment></comment><comment><USER9> The washington post had an article that basically said the 80/20 rule applied to drinkers (20% consmed 80% of alcohol).

[http://www.washingtonpost.com/blogs/wonkblog/wp/2014/09/25/t...](http://www.washingtonpost.com/blogs/wonkblog/wp/2014/09/25/think- you-drink-a-lot-this-chart-will-tell-you/)

Based on this article (3 pints @ 5% is considered high volume consumption for men) then 30% of the drinking age population falls into that category. If you eliminate non drinkers (less than 1 a week) then it's like 3/5th of drinkers.

<comment><USER10> 3 pints a day of any high carbohydrate beverage is probably a bad idea. No alcohol required.

</comment></comment><comment><USER11> I think a few psychedelic sessions (ibogaine, ayahausca, mushrooms) and meditation/self reflection are a much better solution. Of course, they're also a lot less profitable, so no one besides a small subset of academics and journalists are pushing for more research into this line of treatment.</comment>


Is Open Source Recession Proof? - <AUTHOR> http://blogs.zdnet.com/hardware/?p=1136

<comment><USER2> In a recession, many hackers may end up settling for sub-par jobs in the IT field or even outside of it, many of which may be more exhausting or draining than an ideal hacking job. Would they come home to exhausted to do anything other than nap, eat, or watch TV? Would they have to reduce their entertainment budget, and spend longer recuperating with inferior diversions? Or would they reduce their entertainment budgets and recuperating by hacking open-source projects?

Would a hacker work long hours at an easy job and then need some good mental stimulation at the end of the day? Or would the hacker work long hours at an easy job and then spend a few hours looking for a better one?

Would a hacker feel too anxious about his/her decaying economic situation to hack, or attempt to block out the anxiety by entering the mental bubble of hacking?

Would an unemployed hacker contribute to open-source to "audition" for a job, or would there be too many employers with the all-too-common anti-open-source clauses in employment contracts to even think of leaving a trace of having done that?

In my opinion, there are far too many variables to make much of a good prediction.

</comment><comment><USER3> Seems to me that recession == unemployment. I'd make a guess that contributing to open source is attractive to unemployed people because it's a good way to "audition" for a job. So I'd vote for "yes."</comment>


A revolt is growing as more people refuse to pay back student loans - <AUTHOR> http://www.washingtonpost.com/news/get-there/wp/2015/03/30/a-revolt-is-growing-as-more-people-refuse-to-pay-back-student-loans/?tid=sm_fb <comment><USER2> In regards to student loans, here is a lesson from J.P. Getty: "If you owe the bank $100 that's your problem. If you owe the bank $100 million, that's the bank's problem."

<comment><USER3> Should we just kill off the student loan program now?

<comment><USER2> I don't know but I know this: A bank would not give me a $75,000 loan so I could invest in Bitcoin or the S&P 500.

Respectfully that is what college really is, an investment in yourself and right now the market is down and their are a lot of sketchy investments out there (Read as for profit diploma mills and art academies.)

<comment><USER4> A college degree is considered an investment, but it's not right to compare returns in terms of a person's career versus monetary value achieved from it</comment></comment></comment></comment>


E-books Still Outsold by Hardcover and Paperback - <AUTHOR> http://www.publishersweekly.com/pw/by-topic/industry-news/bookselling/article/64170-e-books-remain-third.html

<comment><USER2> As someone pointed out in the comments, these figures ignore self-published ebooks that don't have ISBNs and thus don't show up in Nielsen, BookScan, etc.

Most U.S. self-published ebook authors don't use ISBNs because they're outrageously priced in small quantities, and none of the major ebook outlets (Amazon, B&N, Apple) require them. The situation is somewhat different in other countries, where ISBNs are issued by government agencies for free.

These books are a _substantial_ portion of Amazon's ebook sales, the majority in some genres.

For a more comprehensive take on sales numbers, see:

[http://authorearnings.com/](http://authorearnings.com/)</comment>


Japanese startup Ispace raises $90M, targets landing on moon surface by 2020 - <AUTHOR> https://www.bloomberg.com/news/articles/2017-12-13/space-startup-raises-90-million-to-bring-ads-to-moon-by-2020 <comment><USER2> Can you really get to the moon with just $90M? My impression is that SpaceX is just about the cheapest launch provider currently available, and they charge something like $50-60M to get to orbit. And then you need to do all the tech required to land on the lunar surface as well.

Do they anticipate getting additional funding or decreasing costs?

<comment><USER3> They're the cheapest (probably) per kilogram; but if you're willing to settle for smaller payloads, you can get to orbit for quite a lot cheaper. For example, the European Vega will get you 2.5T to LEO for under $40M. Half your budget on launch costs isn't bad.

<comment><USER2> This article has some more details on their plans. Apparently they're looking to launch as a secondary payload on something like a falcon 9:

[http://spacenews.com/japanese-lunar-exploration-company- ispa...](http://spacenews.com/japanese-lunar-exploration-company-ispace- raises-90-million/)

I'm not sure if launching as a secondary decreases costs. They do have two missions planned apparently, after which they hope to start generating revenue by carrying up to 30kg of customer payload to the moon per launch.

</comment></comment></comment><comment><USER4> Is this an Onion piece? Or something from the Beaverton?

They want to land on the moon... To set up a billboard? And here I thought that the Silicon Valley model of startups making money by advertising other startups that make money by advertising other startups was insane.

Oh... They want to start a space economy. That's great, but there is no mention of what will that space economy do. They will maybe consider mining water, for a potential future human settlement that will... Do what? They will put up a billboard, to advertise... To whom?

</comment><comment><USER5> A lot less money than it takes to build a social network.

</comment><comment><USER6> First, we should accelerate building better robots to do the work of humans, then send thousands throughout the solar system. This will be cheaper and faster than manned space flight...

Anyway, I went through this a few years ago on HN after the Virgin Galactic accident. People argued that it was only a minor setback. Any setback that involves humans costs a lot of money and time.

<comment><USER7> Such a simple and elegant solution. We could also upload our minds into said robots remotely.

<comment><USER8> So simple!

<comment><USER6> No one said it would be easy. You guys added that. It would be difficult and expensive, but cheaper, faster, and easier than man space flight.

<comment><USER9> So you would prefer JFK to have said: "We choose to send robots to the moon. We choose to go to the moon in this decade and do the other things, because they are easy and cheaper and faster..."

It's worth reading the whole speech: [https://er.jsc.nasa.gov/seh/ricetalk.htm](https://er.jsc.nasa.gov/seh/ricetalk.htm)

It ends with:

"Well, space is there, and we're going to climb it, and the moon and the planets are there, and new hopes for knowledge and peace are there. And, therefore, as we set sail we ask God's blessing on the most hazardous and dangerous and greatest adventure on which man has ever embarked."

There will as many robots as you want in space, but man will be out there right along with them, no matter how difficult or dangerous or expensive it is.

<comment><USER6> Let me blog it. I get tired of answering this question. The short answer is if we had built robots and sent hundreds into space, we'd have more humans in space now because it would be safer and cheaper. We'd also learn more quickly. We'd also have more advanced robots because of the investment.

We reached the moon, spent a few years, then gave up because of cost.

Would you rather have a new robotic explorer, or two or three, queued for Mars, Titan, etc every year or a few people on Mars by 2040?

<comment><USER10> Totally agreed. We could have an army of terraforming robots establish a space on Mars, for instance, then send humans there when we're sure it's hospitable. Or send drones throughout the galaxy with human embryos to potential habitable planets. An ethics nightmare, to be sure, but interesting to consider the implications nonetheless.

</comment></comment></comment></comment></comment></comment></comment><comment><USER11> If NASA hasn't made it back to the moon for decades and all it takes is $90M, they are doing something seriously wrong.

</comment><comment><USER12> Huh. Is Japan company trying to reach to the moon? Haha.

<comment><USER13> Hey, take a look at the guidelines for HN. Its preferrable to have comments here that have something to offer to the discussion [https://news.ycombinator.com/newsguidelines.html](https://news.ycombinator.com/newsguidelines.html)

</comment></comment><comment><USER14> This is just them investing $90M in bitcoin right? To the moon...</comment>


Readability - <AUTHOR> http://lab.arc90.com/2009/03/readability.php <comment><USER2> It's slick, but does anyone else see the irony in the fact that they're not only running banner ads on the Readability site itself, but also (subtly) in the sites they're stripping the ads from?

It's worth pointing out that, like it or not, we're not really _entitled_ to escape banner advertising.

<comment><USER3> > we're not really _entitled_ to escape banner advertising.

"Oh, really?" I type into my heavily modded Firefox browser because some computer graphics give me brain seizures. (Too bad I cannot log into HN from my Lynx browser.)

Last time I checked, the industry term for a browser is "user agent," and page rendering is under the control of the user agent. I can use whatever user agent I want, and so can you. I can fiddle with my user agent as I see fit, and so can you. That's what your browser's Options dialog is for.

Sorry I'm getting really testy here, but I get tired of pointing out to the world that it's the _user_ who is in control, not marketers, not page designers, not Yahoo! CSS Reset...

<comment><USER4> In the technical sense, sure, you're allowed (entitled) to do whatever you want.

But that's not what tptacek is referring to. He's referring to the "I want something for nothing" sense of entitlement. You have no moral right (entitlement) to read their content without viewing the ads the put up. That's why ad-blocking has never sat right with me: it's implicitly accepting that the model of ad supported, free content can not work on the internet.

<comment><USER5> Nonsense.

If you make the content of your site freely available with the knowledge that users can access your site in a way that circumvents your business model you've signed up for a business model that isn't dependable.

This is no different than a street musician wanting money from people that stop to listen to the music they play. Maybe the listener, having heard the music, determines it's not of any monetary value. Are they obligated to pay anyway? No, and the street musician knows this. They understand that only a certain percentage of people that stop to listen will actually pay anything. It's true, too, that maybe someone will listen to the music and be unable to pay. Should they block their ears as they walk past because they cannot give what the musician would like to receive for his service? In the case of a screen reader, maybe the user doesn't even know the ads exist.

If the street musician decides his business model isn't supporting him as much as he'd like, maybe he'll stop playing music. And will the public that decided to not pay him anything really care that he doesn't play it anymore? No. They decided it wasn't valuable enough to pay for.

If you feel your content is worth something or you need money to continue providing it, you should charge people for it outright, or make an explicit request for donations. If people find value in your content and are able to, they will pay for it.

It should not be expected that when you put content freely available somewhere, whether it be publishing a blog or playing music in the street that everyone who reads or hears it finds it of equal value or is willing and able to pay for it. You, as that site owner or musician do yourself a disservice if you expect otherwise.

<comment><USER3> Agree with erso. Much of the internet consists of buskers, and buskers cannot rely on revenue. They sing on the street for the love of it, or for self- promotion, or because they don't have headshots and an agent to book a concert hall, or because they're crazy--not because this will bring them a fortune, because it won't. Pay-per-view, however, is booking a concert hall and charging admission. And selling subscriptions is selling season passes to the shows. Very different. Busking might drum up a fan base, but bona fide concerts are where the real revenue is. Think for a moment: pay-per-view and subscription pr0n are where the internet revenue is.

</comment></comment></comment></comment></comment><comment><USER6> Interesting note, for those of you uninterested in karma or user names, the bookmarklet will hide both. You'll still have your voting arrows and the comment text; you just won't know what everyone else thought of the comment (aside from their placement relative to each other).

It's pretty neat to go on a big thread and hit the bookmarklet. e.g. <http://news.ycombinator.com/item?id=501696>

</comment><comment><USER7> It could use more tweaking - I tried to read the latest pg essay with it, but all it would display was the image with the light "PAUL GRAHAM" text at the top of the page. I then tried to go back to the essay, but it looks like the only way to un-Readability the page is to reload it. I then tried to highlight the text that I wanted to read, but Readability doesn't take this into account when generating the page.

When you have a service that guesses what the input is supposed to be, there should be a way to gracefully fail and allow the user to manually specify it, and if that doesn't work it should be easy to disable the service.

<comment><USER3> If you're a Firefox user and savvy about CSS selectors, I recommend the Stylish add-on (<http://userstyles.org/>). It lets you create blanket tweaks for all sites and specific tweaks for specific sites. And you can turn your tweaks off and on at will. It works even with Javascript turned off. I set colors and fonts and font sizes, adjust column widths, eliminate entire columns, make images semi-transparent so they don't bug me so much, etc.

<comment><USER8> Also, if you're an opera user or have greasemonkey the styles can be loaded as userscripts, which will just use javascript to edit the css style changes you have selected.

There are a few styles for Hacker News as well: <http://userstyles.org/styles/search/hacker%20news>

</comment></comment></comment><comment><USER9> I like this a lot. It's sort of a bookmarklet for people who like to read "Printer Friendly" pages. Unless there's pagination, of course.

<comment><USER10> You should check out the Firefox add-on "Print Hint":

<https://addons.mozilla.org/en-US/firefox/addon/700>

It will search a page for a "Printer-Friendly" link and display a glowing green printer icon in the bottom of your Firefox if it finds one. I find that on some pages, this can be a way to quickly navigate to a "Reader-Friendly" page that does support pagination. Of course, sometimes Print Hint doesn't detect a printer link, though I've never had a false positive.

</comment></comment><comment><USER11> I like it. However, I found a site that breaks it: [http://www.instigatorblog.com/the-art-and-science-of-the- sma...](http://www.instigatorblog.com/the-art-and-science-of-the-small- exit/2009/02/04/) ... When I click my 'Readability' bookmarklet in Chrome, the main article is removed completely, and all that's left is the blog entry's comments. Here is the exact Readability bookmarklet I'm using:

      javascript:(function(){
      readStyle='style-newspaper';
      readSize='size-medium';
      readMargin='margin-medium';
      _readability_script=document.createElement('SCRIPT');
      _readability_script.type='text/javascript';
      _readability_script.src='http://lab.arc90.com/experiments/readability/js/readability-0.1.js?x='+(Math.random());
      document.getElementsByTagName('head')[0].appendChild(_readability_script);
      _readability_css=document.createElement('LINK');
      _readability_css.rel='stylesheet';
      _readability_css.href='http://lab.arc90.com/experiments/readability/css/readability.css';
      _readability_css.type='text/css';
      document.getElementsByTagName('head')[0].appendChild(_readability_css);
      _readability_print_css=document.createElement('LINK');
      _readability_print_css.rel='stylesheet';
      _readability_print_css.href='http://lab.arc90.com/experiments/readability/css/readability-print.css';
      _readability_print_css.media='print';
      _readability_print_css.type='text/css';
      document.getElementsByTagName('head')[0].appendChild(_readability_print_css);
      })();

</comment><comment><USER12> Brilliant. I love the fact that it doesn't really change the look of my blog very much ( <http://www.danieltenner.com> \- once you're inside an article, applying readability with medium margins, newspaper look, large font, only gets rid of the red background and the image, that's all)

</comment><comment><USER13> Interesting, any idea how this works?

Edit: doh, source here: [http://lab.arc90.com/experiments/readability/js/readability-...](http://lab.arc90.com/experiments/readability/js/readability-0.1.js)

<comment><USER14> You edited to include the link to the JS, but here's my reading of it:

1) It pulls out content in <p> tags (presumably those are the ones with data you want).

2) It rewrites double line breaks as paragraph breaks (in case the site isn't as semantic as it should be).

3) In order to pick the "main content" container, it looks for the container elm with the most <p>s inside.

4) It filters the "main content" to remove stuff that looks like trash. Filters include having too much non-<p> content, having too few commas, and too few words.

5) It rips out all of the HTML on the page and puts its own in, which also pulls together the user's selected style info. This is the sketchy step. I think an overlay might've been more appropriate here, but the comments imply the author had some difficulty there.

<comment><USER13> Thanks, had a brainfart and forgot I could just read the code ;)

</comment></comment></comment><comment><USER15> Useful but seems buggy. It disabled keyboard input completely in Opera.</comment>


Shift Card - <AUTHOR> https://www.shiftpayments.com/ <comment><USER2> Unfortunately this card is currently only available to US citizens. I'd like to see this in Europe.</comment>


Show HN: A startup idea in your inbox, every day - <AUTHOR> https://www.startupsfromthebottom.com/ <comment><AUTHOR> Thanks for checking out Startups From The Bottom, a free newsletter where you'll receive a startup idea every day. This is a side project that a friend and I started.

Just a little disclaimer about this service: Creating a startup is not just a matter of implementing some fabulous initial idea. An initial idea is just a starting point. That's it. It should not be an assertion of the final product. After testing and iterating, most startups don't end up anything like the initial idea. The point of this newsletter is to get you thinking. To encourage you to start. Don't get hung up on the idea. Pick one and start.

</comment><comment><USER2> I couldn't find a privacy policy. What do I agree to if I submit my email?</comment>


Ballmer goes out punching at last Microsoft employee meeting - <AUTHOR> http://www.reuters.com/article/2013/09/27/microsoft-ballmer-idUSL2N0HM2KR20130927

<comment><USER2> [https://www.youtube.com/watch?v=xqmj-9XlDzY](https://www.youtube.com/watch?v=xqmj-9XlDzY)

<comment><USER3> When he started talking about a song from a movie I was really hoping he'd do the Puttin' On The Ritz from Young Frankenstein.

[http://youtu.be/m6rqXHX3O48](http://youtu.be/m6rqXHX3O48)</comment></comment>


Getting Started in *Lisp (1991) [pdf] - <AUTHOR> http://people.csail.mit.edu/bradley/cm5docs/nov06/GettingStartedinStarLisp.pdf

<comment><USER2> For context, *Lisp (pronounced "star Lisp") was a parallel programming extension to lisp on the Connection Machine System, which was a series of supercomputers. The front-end machine for talking to the CM was either a Unix box or a Symbolics Lisp machine.

[http://en.wikipedia.org/wiki/Connection_Machine](http://en.wikipedia.org/wiki/Connection_Machine)

<comment><USER3> Thanks. How do current Lisps (CL, Racket) compare to *Lisp on parallelism?

<comment><USER4> They aren't targeting similar hardware, so aren't very similar. The constructs introduced by *Lisp are designed mainly for issuing SIMD-style instructions to a grid of 256+ processors (in some versions, 10k+).

</comment></comment></comment><comment><USER5> Another Lisp variant developed for the Connection Machine was the cleverly named "Connection Machine Lisp":

[http://diyhpl.us/~bryan/papers2/paperbot/25aa007a093cd69bbf0...](http://diyhpl.us/~bryan/papers2/paperbot/25aa007a093cd69bbf070e6db9603c3a.pdf)

The paper on it by Steele and Hillis is well-worth reading, as the language's fundamental mechanism of parallelism bears more than a passing resemblance to the MapReduce of 20 years later.

<comment><USER6> For comparison, what are the other possibilities for parallelism? MapReduce seems the obvious obvious one.

<comment><USER7> My impression was that MapReduce isn't so much parallelism itself, but rather a way of organising the execution of a programme to take advantage of parallel processors. (Maybe this is a meaningless distinction; I have never written (intentionally) parallel code, and am not familiar with the terminology.) In that sense, Apple's GCD ([https://en.wikipedia.org/wiki/Grand_Central_Dispatch](https://en.wikipedia.org/wiki/Grand_Central_Dispatch)) is another well known possibility—one of, presumably, many.

</comment></comment></comment><comment><USER8> Wow, a trip down memory lane!

I used Star Lisp to program a Connection Machine 1 (the SIMD one) in the 1980s.

I could run the simulator under Coral Common Lisp on my original Macintosh, so, development was very nice since I didn't have easy access to the DARPA provided CM-1 (I had to fly to another city to access it).

<comment><USER8> I noticed that the PDF manual was dated 1991. I must have been using an early version of the system since I think I programmed for the CM-1 in 1989.

<comment><USER9> Here are older versions:

[http://www.softwarepreservation.org/projects/LISP/parallel#C...](http://www.softwarepreservation.org/projects/LISP/parallel#Connection_Machine_*Lisp_\(StarLisp\)_)

</comment></comment></comment><comment><USER10> The owner of the manual is also an interesting person.

He has been involving in Cilk, Akamai and Tokutek.

<comment><USER11> Yes, and was my high school teacher and robotics coach :) Wonderful fellow!

EDIT: I take that back. Perhaps this is his brother.

</comment></comment><comment><USER12> Sadly, MESS (mess.org) does not emulate a CM-1 yet ;-)

<comment><USER13> Emulating the CM hardware does not make much sense. CM-1 and CM-2 are not real computers but essentially hardware accelerators as all the brains are inside the front-end system. CM-1 and CM-2 architecture can be described as very wide configurable ALU or as FPGA turned inside-out (the CM-1/2 "processor" is mostly same thing as one macrocell in FPGA, with the important difference that CM processor has different configuration for each clock cycle).

So emulating the hardware itself is not especially interesting as there is no real software for it (because it does not run standalone programs).

<comment><USER12> Well... The front-end was usually a VAX, right? (as remembered from articles on the CM-1)

<comment><USER9> or a Symbolics Lisp Machine

<comment><USER12> I believe someone had a working 3600 software emulation. From there, it's just adding the CM emulation as if it were a peripheral.

That and finding the install tapes ;-)</comment></comment></comment></comment></comment>


Creating a Simple Game in Clojure - <AUTHOR> http://ideolalia.com/creating-a-simple-game-in-clojure

<comment><USER2> Fantastic stuff :)

I've loved dabbling in Clojure, but now between Penumbra, Enlive, Compojure, Clutch (CouchDB), Overtone (in development binding from Clojure to SuperCollider), Clojure has some of the coolest evolving libraries on the block from creative hacking to serious web development.

<comment><USER3> You forgot Incanter :)

</comment></comment><comment><USER4> Very impressive. This is the first example I've seen that made me think functional programming could actually work for games.

I'm still not convinced but the approach described here is really neat and helps me think about the problem in a completely different way (which is what FP is best at).</comment>


Cron in production? That is a double edged sword - <AUTHOR> http://orchestrate.io/blog/2014/03/31/cron-in-production-that-is-a-double-edged-sword/

<comment><USER2> I hate that expression. What's the point of a single-edged sword? Swords are supposed to puncture and penetrate; a single-edged sword won't be able to do that, because it's unable to cut on one side.

<comment><USER3> [http://en.wikipedia.org/wiki/Sabre](http://en.wikipedia.org/wiki/Sabre), [http://en.wikipedia.org/wiki/Sword#Single_and_double- edged](http://en.wikipedia.org/wiki/Sword#Single_and_double-edged)

<comment><USER2> Duly schooled.</comment></comment></comment>