China's Money Exodus - <AUTHOR> http://www.bloomberg.com/news/features/2015-11-02/china-s-money-exodus <comment><USER2> Why is it called an exodus? Other than the central bank selling dollars, for every yuan that is sold there is a buyer on the other side.

Let me try a different narrative that could be equally valid: as the oil price has halved the Chinese are getting a subsidy of 150 billion dollars a year. Coupled with other commodity windfalls, the regular trade surplus, and a domestic slow down that reduces the potential return on domestic investments, they have cash busrting their wallets and must seek alternatives. Overseas investment (a.k.a. the money exodus) is the only way to keep the accounting identity true.

<comment><USER2> Let me add that the accounting identity I am referring to is that the trade surplus must be balanced the capital outflow. Since it is an identity it must be true in the past as well. It is just that in the past the private sector (on a net basis) was not very interested so it was the central bank that controlled all outbound investments. And as a result the PBoC has a very large and visible holding of foreign reserves. Now the time has come that the private sector and individual Chinese want to invest the surplus themselves and maybe then some so we see the central bank's reserve holdings falling. At this stage the central bank may be happy to just get rid of some of their excess holdings (also if they don't intervene and let the exchange rate fall they will get even more squawking and name calling overseas). But if it persists to the degree that the central bank runs out of reserves it will be forced to stop intervening in the forex market and then the exchange rate can fall as much as the market wants to, which by the way will make the trade surplus even larger.

<comment><USER3> The private sector wasn't "not very interested", they were required to sell their dollars to the central bank for RMB. They just were not allowed to hold dollars inside the country. That money was then taken out of circulation by buying US treasuries (what else could China do with it?).

There was a time when China wanted to get rid of some of their USD holdings, so they encouraged companies to take RMB, buy dollars, and invest abroad. But taken to an extreme, eventually China runs out of reserves, has to buy dollars on the open market to satisfy demand, and that leads the RMB to de-valuing as they print more to buy dollars.

China still has to buy most imported commodities using dollars...like oil. A de-valued RMB will most certainly lead to inflation at home, causing prices to rise. And then Chinese will start hoarding dollars if they lose confidence in the RMB, leading to a sort of death spiral.

At this time, China wants to keep money in China, and so is cracking down on banks exchanging to USD too easily. Capital controls are a real thing.

<comment><USER2> I assume that by saying "China still has to buy most imported commodities using dollars...like oil" you are implying that China won't have enough money to buy oil. You do realize that is a direct contradiction to a large trade surplus, right? Or are you predicting that the trade surplus will soon turn into a deficit? If RMB goes into the so called "death spiral" which direction do you think that will push China's trade position?

<comment><USER3> I'm saying that China needs dollars to run its economy, not having dollars anymore can make it harder to run.

> If RMB goes into the so called "death spiral" which direction do you think > that will push China's trade position?

China can't continue being the world's cheap factory. It is horrible for the environment, and it doesn't do as much for normal people as it used to. Say stuff from China is cheaper...so what? Americans and the west win, because China continues to subsidize their wasteful lifestyles, but what does China win? More trade isn't the answer anymore, eventually people actually want to buy things and not just sell them.

And honestly, I'm not a trade position.

</comment></comment></comment></comment></comment><comment><USER4> Fijian here. As of a year ago, foreigners are no longer permitted to buy _residential_ properties within town boundaries.

Outside of town boundaries, they can buy residential property but must build on it within 2 years, spending at least USD$125k on the home. Failure to do so attracts a penalty of 20%(off the top of my head) of the value of the property annually.

The chinese were just buying up too much property and locals couldn't compete.

</comment><comment><USER5> It's a shame property taxes aren't higher. It would be a free ride from the perspective of domestic tax payers.

If one wanted to be protectionist, the increased taxes could be set to only apply to non owner-occupied residences.

<comment><USER3> Chongqing and Shanghai have tried this (applied property taxes to 2nd houses for luxury properties). But that is easily gained by simply throwing in a Smurf or two (put the house in a family member's name).

Any system with rules that can be gamed is not going to work in China. The only solution is a tax on all property.

<comment><USER6> _Any system with rules that can be gamed is not going to work in China._

Case in point: [http://world.time.com/2013/04/29/why-chinese-couples-are- div...](http://world.time.com/2013/04/29/why-chinese-couples-are-divorcing- before-buying-a-home/)

</comment></comment></comment><comment><USER7> Some relevant links:

"(Chinese bank's) nonperforming loans may be at 20 percent to 21 percent, or even higher." [http://www.bloomberg.com/news/articles/2015-10-29/risky- math...](http://www.bloomberg.com/news/articles/2015-10-29/risky-math-how- analysts-calculate-china-s-true-bad-loan-burden)

"by 2018 all of China's excess reserves — cash that it has on hand to use immediately — could be gone." [http://www.businessinsider.com/chinas-record- capital-outflow...](http://www.businessinsider.com/chinas-record-capital- outflows)

"China's 42.2 trillion yuan (US$6.7 trillion) bond market is flashing the same danger signs that triggered a tumble in stocks four months ago" [http://www.thestar.com.my/Business/Business- News/2015/10/10/...](http://www.thestar.com.my/Business/Business- News/2015/10/10/If-you-think-Chinas-equity-bubble-is-scary-check-out- bonds/?style=biz)

<comment><USER8> How long has this "China is about to crash" story been in the news? It's been around for at least 10 years. There's an article almost every month. I should write a big FAQ about why the Chinese financial system doesn't follow western financial system rules and link to it whenever these articles come up.

<comment><USER3> The economy can remain insane longer than you can remain solvent.

You can claim that the Chinese financial system is immune to economic cycles and that the law of gravity doesn't apply. But we've heard that before about American real estate, where people were saying "how long has this real estate is about to crash story been in the news?" in 2007...

If everyone around you is talking about how to get money out of China, then something might be up.

<comment><USER8> >You can claim that the Chinese financial system is immune to economic cycles and that the law of gravity doesn't apply.

That right there is the fundamental flaw in your thinking. You think boom and bust is physics. It's not.

(Here we go again, for like the 50th time explaining how this stuff works)

It's a direct consequence of the fractional reserve banking model that sticks the taxpayer with the bailout. In China, the government just prints the money electronically. They've had trillions in bad loans in the banking system forever and the Chinese gov periodically goes and cleans it up with printed money and shoots a few misbehaving bankers. In the west, we make the taxpayer and savers pay 100 cents on the dollar on the bad loans and transfer wealth from them to the bankers. We also take everyone's property and give it back to the bankers while China just lets all the bad loans sit in default forever without any action being taken. They even periodically let big investment funds default and it doesn't crash the financial system because the reverse money multiplier doesn't kick in like it does in the west because the gov just comes in and prints the money, hands it to the banks and they keep lending.

<comment><USER3> I've talked about this with my colleagues at work a lot. There are only a couple of ways out of this mess:

1\. An assets crash, turning who were winners (the speculators) into losers. Is there really a reason for that 90 sqm apartment in Beijing to be worth $1 million when it can only rent for 9000 RMB a month?

2\. Significant inflation with the RMB, keeping the (well connected, mostly middle class) winners as winners, and turning everyone else who wasn't speculating into losers. Keep in mind that a vast majority of the Chinese population has saved lots of RMB and isn't exposed so much to assets (though they would like to be).

We, like you, think that 2 might be a possibility. Hence my need to transfer my RMB into USD and get it out of the country. Likewise, those who know better than me have been more aggressive about getting out of the RMB, as the article states (I had to go through and get tax receipts, income statements, and a bunch of other hoops to do my transfers). 1 is still a possibility also, which means getting into real estate (the only investment for us mere mortals) is very risky.

And just because you can print your way out of a crash doesn't mean the crash hasn't happened. It sucks when the US does this with its freely convertible currency, it is even worse when/if China does this with its nonconvertible currency.

<comment><USER8> Here's the twist. What if they build a ton of houses and get the second tier cities hooked up to infrastructure such that they create housing booms further inland at the expense of costal property. New capital is always being created and developed and the central planners in China aren't that bad at this. You just have a different set of winners this time around with the marginal profitability of Shanghai slowing down in favor of the Inland cities.

In the US urban infrastructure is garbage outside of a few major metros so all the money piles into those and the rest is is ignored and then bubbles and pops. China actually does development like they mean it and is expanding out thousands of miles of roads and trains building out new markets so the new money injected can find a way to profitably invest itself.

<comment><USER3> So my wife lives in Chenzhou, which is a small inland 3rd/4th tier city by Chinese standards; we visit sometimes. Speculators will speculate, and there is a huge surplus of apartments as a result, with no hope anytime soon of really selling them off and putting them into use...new capital wasn't created, it was just sunk into these buildings. They won't create new capital until they are occupied, those people with jobs doing things to create value. Just building them doesn't create capital. It does create jobs for migrant workers, which I guess is the primary goal.

And the houses are poorly constructed concrete monstrosities, no central heating (I hate visiting in the winter). You just can't help but think they'll be torn down in 10 or 20 years before they are actually used. Even in Beijing, an apartment building built 5 years ago would be considered decrepit by western standards. I was looking for a new apartment to rent and came away thoroughly depressed...the prices were high sure, but there was nothing even close to what I wanted anyways. So I stayed put in my current flat, whose rent hasn't gone up in the 3 years I've been renting it.

Chinese urban infrastructure would love to have US urban infrastructure problems. Trains are wonderful, roads are great also if you want to cut down on 10-day long traffic jams. But they are nowhere near the states in terms of infrastructure, and much of it are white elephant projects that will never contribute to the economy in any meaningful way.

<comment><USER8> I believe you that the construction probably isn't great, but how does it compare to living out in rural areas, or wherever people moving to the cities used to live? There are still a lot of Chinese who are not urbanized and all this building should be a step up for them.

<comment><USER3> Those apartments are being bought by speculators, not urbanizing farmers. Those farmers can't really afford these apartments though, nor can they send their kids to local schools even if they buy them (China hasn't reformed the huko system yet). So they come to the cities as migrant workers, leaving their families behind, living in cheap dormitory accommodations or even in basements (lookup "ant tribe"). China will have to sort out this imbalance before urbanization can drive much of the economy, and speculation doesn't really help here (maybe they could eventually afford a $200k apartment, but $1 million? Really?)

</comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER9> Here in Sydney and Melbourne, 1/4 of all apartments are sold to Chinese, even Chinese government owned corporations.

[http://www.abc.net.au/news/2015-10-12/selling-the- australian...](http://www.abc.net.au/news/2015-10-12/selling-the-australian- property-dream-to-china/6841810)

<comment><USER10> To be fair, recent mainland Chinese immigration has enlivened a lot of otherwise dead areas of Sydney, and I'd wager Melbourne. Places that were ghostly failed malls are now thrumming 24 hour apartment-ringed nexus for food and entertainment. (Eg. Chatswood.) A similar transformation has permanently improved central Auckland. Smiles from China, where I now choose to live ... a Sydney native.

<comment><USER11> Out of curiosity, where are all the jobs supporting the people now living there?

Are they commuting to more urban areas?

<comment><USER9> Mostly investment properties as far as I can tell, renting to students, singles, that kind of thing. So fairly mobile renters, they commute to where they need to be.

</comment></comment></comment></comment><comment><USER12> Apparently it's 'money flooding out of country x' week at Bloomberg:

[https://news.ycombinator.com/item?id=10498040](https://news.ycombinator.com/item?id=10498040)

<comment><USER13> I believe that's what they call "economic contagion". Capital is trying to find safe returns somewhere, anywhere.

</comment></comment><comment><USER14> Where would you like your money - in a country with tight capital controls, an unstable political hierarchy, unclear or unreliable economic data and lack of "institutions" or ... China

:-)

</comment><comment><USER15> Of note is that the recent rise in price of Bitcoin is in a large part due to this outflow of money from China. This article totally left that channel out.

</comment><comment><USER16> Money's also flooding out of Canada:

>Money Flooding Out of Canada at Fastest Pace in Developed World

[http://www.bloomberg.com/news/articles/2015-11-02/money- floo...](http://www.bloomberg.com/news/articles/2015-11-02/money-flooding-out- of-canada-at-fastest-pace-in-developed-world)

<comment><USER17> might be related. a lot of money has flooded into canada because of the chinese. see: real estate.

<comment><USER13> While at the same time, money is flowing out of Canada due to the collapse in oil prices.

</comment></comment></comment><comment><USER11> It seems like the media has been trying to _will_ a crash in global markets to happen with the amount they've been going on about this.

How biased are their opinions and what do more neutral experts say about the direction the global economy is heading? Honest question as I am not an expert.

<comment><USER3> They are reporting facts, really it is as simple as that. People are moving money out of China (I'm one of them), confidence in the economy is not good even if the government says everything is completely spiffy. Bloomberg doesn't have to make anything up to talk about how people are moving money out of China, they just need to follow the money. And if the money is flowing one way, it is completely reasonable to speculate on "why" that is so, and I think it is obvious (confidence is low, better investment opportunities exist abroad then what can be done with the money at home).

<comment><USER11> Thanks for the clear and logical explanation. I find it hard to trust the news in this day and age so always interested in other opinions on the biases of the publisher itself.

<comment><USER18> I feel the same cynicism. But then I remember cynicism !== intelligence. I'm trying to actively cut down on my news, while keeping a few channels open (HN/geopolitics/basketball..), in order to become less of a cynic..

<comment><USER19> When it comes to protecting your money, cynicism is a good thing...

<comment><USER18> Generally I would agree, but what if your cynicism limits you from taking that one high risk opportunity that could make a serious impact on your financial future? I mean we're all start up junkies here (for the most part) would that not be considered a high risk activity that would be avoided by any serious cynic?

I would also make the argument that the majority of the population (myself included) would not benefit from participating in economic activities requiring cynicism. I think financial literacy for most people is a 'learn it yourself' affair that most people choose not to do, and therefore they should avoid the financial world like the plague.

Be as naive as you want in the cushy world of low risk, low yield, investments. Happier lifestyle I'd wager.

<comment><USER3> Are the tables rigged or not? Going in as an optimist into a scam will surely be a bad thing.

Living in China, I've learned to appreciate fair financial systems. Many investments I wouldn't have considered in the states before now look like really good deals, simply because they are much more "fair" than what is available to me in China.

China has no low risk/low yield investments beyond long term savings accounts that don't even beat inflation. That is why so much money was rushing into the stock market, and now again, real estate. Because literally there isn't anything else (ok, maybe some undergound banking deals, but do you want to deal with the mafia?).

</comment></comment></comment></comment></comment></comment></comment><comment><USER20> That money exodus has been happening for a decade from Vancouver's perspective. Maybe it's just accelerating now.

<comment><USER21> And our neighborhoods are emptying out...

</comment></comment><comment><USER22> Good thing China has all of those Treasury Bonds to sell.</comment>


Show HN: DustyBooks is an app to help students make money on campus - <AUTHOR> http://www.dustybooksapp.xyz/ <comment><USER2> Much respect to anyone addressing the huge student-loan debt crisis. Chegg aren't doing anything to help out students sell their books?

<comment><AUTHOR> The system used by Chegg is almost the same as the one used by Bookstores and Retail stores. DustyBooks focuses on facilitating transactions between students themselves without any third party involved</comment></comment>


Space Tethers: Stringing Up the Solar System - <AUTHOR> https://toughsf.blogspot.com/2020/07/tethers-all-way.html <comment><USER2> Tethers shift the economics of landing ships or materials on earth, since they can trade delta v with things outbound.

But it seems like you have to trade power for accuracy; if you can hit a tiny window moving in three dimensions inside of a 3 body problem, then you don't need to be able to manage as much delta V (increasing to leave, or decreasing to land). Smaller rockets, less need for ablative materials.

But if you miss, boy are you fucked.

One solution for this I've heard is you take enough fuel to get where you're going with plenty to spare. If everything goes right, you offload your emergency supplies (reaction mass, fuel) and get a credit.

I'm not sure how much handwaving goes along with moving liquids and gasses in vacuum, at zero g... burst a line you need a lot of reaction mass to reorient yourself.

Maybe there's an emergency venting design where all of the forces cancel out...

<comment><USER3> > But if you miss, boy are you fucked.

Imagine closing in on Mars knowing that if you fuck up a super-orbital speed, split second maneuver by more than a couple of meters you will drift in space until asphyxiated. It makes a carrier landing seem bland.

If you carry enough fuel to decelerate without the tether it defeats the purpose of the tether.

<comment><USER4> The comparison between tethers and an aircraft carrier catch cable seems particularly apt. Thanks you. And yes, most times, you can initiate a go around if you fail a carrier landing. Not really an option with an orbital tether. Some sort of cable pair with a targeted coupler would probably work, each side with a heat emitter an heat seeker RCS system. Obviously, there would need to be slack in the system, (nearly local) winches a ways up-cable in the system, may be an answer.

<comment><USER5> The relative motion drops to zero though, at the moment of capture. So it's more like two cars on the highway that pull alongside each other just as they match speed. Might still be too precise for a human, but automated systems should have little trouble.

And it might be easier to store the emergency retrieval system on the tether's hub. That way it doesn't have to be hauled around to be used (hopefully) infrequently.

<comment><USER2> You have to get the distance and velocities to line up, and it's challenging to change only one of those in a three body situation.

</comment></comment></comment></comment></comment><comment><USER6> Its always felt like a better near term way to boost around is just use massive (literally) platforms that have large installations of solar, batteries and electric thrusters. Have enough ballast that its orbit is only going to change a small amount when throwing something. Then you just keep thrusting until you are back where you were.

Electric thrusters are getting huge specific impulse improvements and the future seems to be pretty bright for them. We can trade time for efficiency essentially.

For interplanetary transit, just keep the platform running a circuit between the planet and earth. It's going to be way easier to hit your entry without getting into an unrecoverable situation.

<comment><USER7> That is similar to the concept of the Aldrin Cycler.

<comment><USER6> Ah perfect, I knew there was a similar concept but couldn't remember the name.

</comment></comment></comment><comment><USER8> For more on space tethers, check out Hop David's excellent blog (cited as such in the article), wherein a laypersons understanding of orbital dynamics and momentum exchange is developed in posts spanning several years.

[http://hopsblog-hop.blogspot.com](http://hopsblog-hop.blogspot.com)

Best read in chronological order.

<comment><USER9> IME the best way to quickly get a very practical grasp of orbital mechanics is to play Kerbal Space Program. I felt like a 6 year old kid who just got his favorite candy when I docked one spacecraft to another the first time.

<comment><USER10> I am, honestly, astounded at some of the videos online of KSP. I can barely get something into orbit (if I can even do that). Let alone set up entire space stations and explore other planets.

KSP is one of my favorite, infuriating things to exist, and I'm not sure why.

</comment></comment></comment><comment><USER11> It seems like this system is crucially dependent on the balance of departing and returning vessels to conserve momentum. While that balance might be maintained over long timescales, it seems unlikely over short ones, especially the first years of operation at earth, which are likely to have many departures and few returns. And anyone who's seen a UHaul lot in a college town on the first week of school knows that departures and returns are often quite out of balance for short periods.

It also seems like there is a conservation of energy issue here that I don't understand. In a state of balanced departures and returns, the energy used to launch departing vessels would be captured from returning vessels, but in the Earth-Mars loop, the returning vessels were themselves launched from the surface of Mars and accelerated by tethers there. It feels like a perpetual motion machine.

<comment><USER12> They discuss this in the article:

" And of course, none of these deltaV savings are for 'free'. Accelerating payloads means the tether will slow down. If it slows down too much, it will de-orbit itself. The momentum lost with each catch-and-release operation must be recovered either by absorbing momentum from payloads being slowed down, or by using its own propulsion system.

A major advantage of an orbital tether is that you do not have to immediately recover that momentum - it gives time for slower but more efficient propulsion systems like a solar-electric thruster to gradually accelerate the tether. A chemical propulsion system limited to 450s of Isp is not needed as the acceleration can be done over time with something that has thousands of seconds of Isp. The propellant needed to run the tether's engines is greatly reduced. Even more interesting is the possibility of propellantless propulsion, such as electrodynamic tethers that push off the magnetic fields around a planet."

</comment></comment><comment><USER13> FYI This concept is employed extensively in the excellent novel Seveneves. The author Neal Stephenson worked at Blue Origin for a time.

</comment><comment><USER14> > It is ironic that the person who first described how hard spaceflight by > rocket is, due to the exponential nature of the deltaV equation, is also the > person who described the best way to side-step that problem with non-rocket > launch.

That's not ironic at all!!

</comment><comment><USER15> It annoys me that Makani (tethered kites) closed this week but released everything from patents to a documentary and a 1000+ page ebook and their modelling software for free [6]

But hardly anyone cares.

But several orders of magnitude harder, maybe impossible, it's exciting?

If we can't tether in our atmosphere what chance is there in space.

[6] [https://www.x.company/projects/makani/](https://www.x.company/projects/makani/)

<comment><USER16> "Nobody cares" because they were solving the wrong problem. Existing wind turbine designs work just fine and they are cheaper and far more reliable.

[https://despair.com/products/mistakes?variant=2457302467](https://despair.com/products/mistakes?variant=2457302467)

<comment><USER15> Gas works fine to create energy, they mention gas in the doco. Wind turbines also solve the wrong problem.

The nobody cares bit is around HN not caring all their info was made open source (Try algolia). There's no reason you couldn't try and pivot. It's something you can contribute code to. Tethers can also supply electricity upwards. You could make permanent platforms, perhaps.

Space tethers are probably impossible, certainly nothing can be started for decades. It's fun to LARP but it'd also be nice to get equally keen about things that are possible and actionable.

</comment></comment></comment><comment><USER17> The tethers in _Seveneves_ were a clear sign that things had _changed_.

</comment><comment><USER18> My favorite part:

> Let's imagine a modestly-sized tether orbiting at a high altitude above the > Earth. It is 1,000 km long...

<comment><USER7> It's modest when you compare it to the 36,000km+ geostationary tether or the 200,000km+ lunar elevators we see proposed!

</comment></comment><comment><USER19> Surprising that no one here has used the term "skyhook" in the comments here. Adding it to increase discoverability of this thread. Could SpaceX's starship reach the tether without the superheavy 1st stage?

The video in the article is here: [1] and the sources to the video [2].

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

[2] [https://sites.google.com/view/sources- skyhooks/](https://sites.google.com/view/sources-skyhooks/)

</comment><comment><USER20> I prefer the idea of a rapidly spinning hoop. It means there are a lot more chances to latch on.

The usual way they talk about keeping these things aloft is to set up an electromagnetic accelerator track on the moon and aim buckets of ore, or industrial product, at the upper rim. They latch on at the top and get dropped off the bottom.

Timing is critical. It takes computers.

All around the circumference you have radial tethers with scoops at the end. You just have to dive into the scoop when it dips down in front of you. Then it's a wild ride up and out.

</comment><comment><USER21> My physics knowledge is quite poor, but I've always wondered if it was possible to use the rotation of the earth as some kind of alternator in conjunction with an orbital station. Is that idea fundamentally ignorant? Or is it something that has been toyed with before?

<comment><USER22> It's not an answer to your question but there are indeed ways to utilize interaction of Earth's magnetic field with spacecrafts.

Power production (or thrust if reversing the process by feeding a current into the wire) is described in [0].

Use for stabilization and attitude control is described in [1]. These might be combined with [2], which have more immediate effect but from time to time need to be 'desaturated' which is where [1] comes in again.

[0] [https://pwg.gsfc.nasa.gov/Education/wtether.html](https://pwg.gsfc.nasa.gov/Education/wtether.html)

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

[2] [https://en.wikipedia.org/wiki/Reaction_wheel#Implementation](https://en.wikipedia.org/wiki/Reaction_wheel#Implementation)

</comment></comment><comment><USER23> Has anyone built something like this in KSP? Is it possible (with mods of course)?

<comment><USER24> Not possible as I believe maximum physics range is 2.5km -- not long enough for these sorts of devices.

<comment><USER25> There are mods that let you extend the physics range, but they don't address the underlying issue of the KSP physics engine bring numerically unstable over long distances

</comment></comment></comment><comment><USER26> I am afraid we'd have to clean up orbital debris first. Even after that, the system to negotiate orbital "corridors" is going to be maddeningly complex.

</comment><comment><USER27> These things always seem like they would be so hopelessly fragile and finicky that nobody would commit to them to do real work.

By the time we can build these we should be up to our eyeballs in fusion energy. Seems like you could just build giant 50km railguns to blast raw materials and a kick stage into orbit and leave rockets for the squishy payloads.

<comment><USER20> If you wait for fusion to work before you do something, be prepared to die first.

<comment><USER28> We are a lot further along with fusion than with alternatives to massive rockets.

<comment><USER20> I expect to die long before we get useful magnetic-confinement D-D fusion.

There are a lot of alternatives being worked on, with venture money, that might yield before I die. But the Tokamaks have always been a jobs program to maintain a good population of high-neutron-flux techs ready to draw upon for weapons programs. It is why p-B fusion has never attracted any gov money: no neutrons.</comment></comment></comment></comment>


An Ex-Apple CEO on MIT, Marketing and Why We Can't Stop Talking About Steve Jobs - <AUTHOR> http://bostinno.streetwise.co/2016/04/08/apples-steve-jobs-and-john-sculley-fight-over-ceo/ <comment><USER2> We can't stop talking about him because he was a charismatic asshole. Don't get me wrong, I'm not trying to insult his memory: he was a type-A personality, extremely driven, and knew when to try alternate methods of attack to conquer a problem instead of trying to just ram through.

Steve Jobs is a benchmark on what CEOs should be, even though his story is extremely unique: what Apple is today is because, as a founder, he was thrown out by his own shareholders... and then came back with his own NeXT army when the shareholders realized they made a mistake.

To make a political metaphor out of this, it'd be like Taiwan (aka the Republic of China) marching back into China (aka the People's Republic of China) and becoming the legitimate government again after being invited to do so.

Steve Jobs never quit. He never stopped. His self-perceived imperfections were magnified ten-fold in his internal mirror, and in the mirrors of others. He knew what he disliked about himself, and he did everything possible to eliminate it.

Even when the Universe singled him out and tried to fuck him over, he kept going, and going, and going. He was one half Genghis Khan, one half Energizer Bunny, and one half salesman. Most of us only get two halves, he picked up another one along the way.

The Apple of today is the largest company in the world by market cap (trading it back and forth with Google), and almost twice the size of Exxon, Berkshire Hathaway, and Facebook, and bigger than Microsoft. If Steve Jobs died a decade earlier, and the Tim Cook of today became CEO then, Apple would not have become the juggernaut it is today.

However, he was still a man. This is largely what irks me about the idol worship that goes on. He was a man, he was flawed, his personal relationships with family and friends were horrendously bad, but he also never prioritized those: he was friends with people whose relationships served him, and when they stopped serving him and his goals he put them on the back burner.

That isn't a bad practice in of itself: but you typically only do that to people who are seriously toxic, those people you consciously cut off. Steve Jobs did it to basically everyone. I'm not passing judgement on him, just stating the facts.

The way he was served him in life, right or wrong. It's a compelling story to tell. He's like a modern day pharaoh, and the story we tell of Apple is the pyramid he was entombed in.</comment>


Ask HN: What do you think of programming contests? - <AUTHOR>

I've noticed a completely contrasting opinion on this topic. Some of the programmers know love participating in Topcoder/ACM kind of contests and then there are others who think it's a complete of waste of time/energy.
I'd love to hear your thoughts on this. Is there any better way you think these contests can be conducted?
Disclaimer: I'm one of the founders of hackerrank and working on broadening the aspects of programming contests. <comment><USER2> Hi Vivek. I just got an email from Hackerrank checking in on why I haven't submitted any new code since the transition from InterviewStreet.

I do not feel like it is a waste of time or energy, particularly since I use sites with problems as learning tools. For example, I used InterviewStreet for a few problems while playing with Clojure. But if I had good opportunities at the day job for hard-core hacking with Clojure, I may never have fished around looking for something like InterviewStreet.

I don't care about the contest part but really like the problems from sites like yours. I do like seeing how many hackers have attempted vs successfully solved a problem. Can't remember if InterviewStreet did that. Rosalind (a bioinformatics problem/learning site) has a really nice "level" system and I'm guessing you have something similar setup for badges at Hackerrank.

I very much like that you offer a variety of programming languages, but I might slightly prefer the Rosalind bioinformatics problems where you submit a solution within a time window rather than actual code to run. But it's cool since you don't force an "only python or ruby" language choice.

Hackerrank's FAQ mentions building a community. I would participate much more if I thought the community of same language coders would offer feedback/code review and mentorship. I'd be willing to also give feedback on an anonymous basis. For example, say I solved challenge X in Clojure. I'd probably take time to review another successful solution for challenge X from another participant that also used Clojure - I would hope I could offer constructive feedback or learn how I could have solved the challenge better myself.

</comment><comment><USER3> Can be fun, but rarely measure the same skills necessary to work on real-world programs. People responsible for building real-world programs ought to know this, so they're of limited use in signalling your programming competence.

<comment><AUTHOR> What if you had contests that are real-world? Example challenges: quora.com/challenges

<comment><USER3> Those aren't actually real-world challenges, those are the sorts of questions I give in a job interview. Their scope is too narrow to be real-world. Almost by definition, a real-world programming challenge involves working with a software system too big to build in a weekend, because virtually all of the complexity of modern software engineering comes from managing large codebasess.

We do have "contests" that are real-world, except they're not really contests. We call them open-source.

</comment></comment></comment><comment><USER4> It really depends on the contest. I've found that most are algorithm-based, which is fun, but doesn't leave too much room for variety. Programming contesta also have a relatively high barrier of entry. Maybe some sort of restriction so only accounts with less than x 'experience' can participate could help make it easier for newcomers to join.

</comment><comment><USER5> I usually don't find them very interesting. They tend to use somewhat contrived algorithmic questions that just aren't the kind of problems I'm interested in solving.</comment>


The San Francisco exodus is real - <AUTHOR> https://www.sfgate.com/living-in-sf/2020-San-Francisco-exodus-is-real-and-historic-15484785.php <comment><USER2> I read the article and looked at the Zillow analysis. Of the fasting growing large cities only Seattle was considered for comparison. The fastest growing big cities being: Austin, Seattle, Fort Worth, and Charlotte.

[https://en.m.wikipedia.org/wiki/List_of_United_States_cities...](https://en.m.wikipedia.org/wiki/List_of_United_States_cities_by_population)

In Fort Worth they cant build houses fast enough and developers are giving up on building houses to instead focus on apartment complexes. I wonder what impact Covid has had on these areas with astronomical growth.

</comment><comment><USER3> Link is broken, this is the correct one: [https://www.sfgate.com/living-in- sf/article/2020-San-Francis...](https://www.sfgate.com/living-in- sf/article/2020-San-Francisco-exodus-is-real-and-historic-15484785.php)</comment>


Widespread mask wearing could prevent second waves of COVID-19, study says - <AUTHOR> https://ottawacitizen.com/pmn/health-pmn/widespread-mask-wearing-could-prevent-covid-19-second-waves-study/wcm/ad849de3-1dd7-4290-ba66-16ff9e09b99d/ <comment><USER2> I must admit I was wrong when I thought that people could handle wearing masks properly. I took my first trip out in months this weekend to visit family at their house in the mountains. We stayed away from people the whole time and only went out to get groceries. When driving through the town (its a small Colorado tourist town with one strip of shops) only about 50 percent of people had masks on at all. Of those with masks most had them around their chin or not covering their nose. I know that its not as simple to get a perfect air tight fit with n95/p100 but I am not talking about that. People literally just had them hanging on their chin while in large crowds. This was during the day and after dusk. I also noticed a person at the store pull their mask down to talk or sneeze which is the time when its most important to be covered.

<comment><USER3> Viruses are a part of life. Those 50% have accepted this and moved on.

<comment><USER4> How do those type of people explain safe sex? I hope it's not the "sheep" defense...

<comment><USER3> Why weren't officials demanding everyone wear condoms all the time during the HIV scare?

<comment><USER4> Because someone choosing to have unsafe sex and getting aids isn't going to give their e.g. grandma aids. They are choosing to risk themselves, which is not the same as risking others that have not chosen to partake in the risky behavior. This may be hard to reconcile for those who think the world revolves around them.

</comment></comment></comment></comment></comment><comment><USER5> The irritating thing is seeing people walk around a grocery store, talking on their cell phones, with their masks off.

<comment><USER6> Don't let it irritate you man. People have collectively decided they don't care. Accept what you can't change.

<comment><USER7> I can accept dying of a virus but dying from another person's stupidity is not acceptable.

</comment></comment></comment><comment><USER8> Widespread banning of individual owned vehicles would prevent far more deaths and amongst younger people too. Millions saved. Millions more "life years" saved. Pollution reduced.

The science is also very clear on that.

Is that what we want though?

<comment><USER9> I mean. Vehicles do provide mobility at the downside of pollution in a world designed for vehicle mobility. Its a non trivial and expensive change.

Masks protect for cents a day from a deadly disease leaving many people with damage for life, crippling medical bills at the downside of what exactly? Many professions wear them day in and day out.

People have forgot that government means making choices we may not want but have to,

<comment><USER10> dupe from a month ago: [https://news.ycombinator.com/item?id=23473335](https://news.ycombinator.com/item?id=23473335)

(junk study; assumes the masks are effective and then makes predictions based on that assumption [https://news.ycombinator.com/item?id=23477485](https://news.ycombinator.com/item?id=23477485))

RE: Forgot? That's backwards. The government operates only with the consent of the people. It's why we have juries.

For how long are you ok with the fake masks that say right on the box not designed for viruses? Forever? Pretending a it's going to just go away is getting old. Roughly 1/3 of common cold viruses are corona-class.

We all know the typical hand wave explanation about droplets. Sneezing or coughing are the only significant producers of large particles that the fake masks catch, and I haven't seen a person sneeze or cough in public in a oddly long time.

CDC Influenza and pneumonia deaths by influenza season and age: United States, 2008–2015: [https://www.cdc.gov/nchs/data/health_policy/influenza-and- pn...](https://www.cdc.gov/nchs/data/health_policy/influenza-and-pneumonia- deaths-2008-2015.pdf) (these are not estimates, see the footnote)

      2015-2016
      Flu: 7,961
      Pneumonia: 131,858
      All: 1,769,940

Mask psychology: [https://stpauls.vxcommunity.com/Issue/Us-Experiment-On- Infan...](https://stpauls.vxcommunity.com/Issue/Us-Experiment-On-Infants- Withholding-Affection/13213)

Deliberate problems: [https://www.youtube.com/watch?v=FGAlQbWCi6Y](https://www.youtube.com/watch?v=FGAlQbWCi6Y)

Covid-19 death vs COVID-19+ death: [http://v6y.net/1541e03e6cfd1442590bc7b5476f88c30a29a0d881bdb...](http://v6y.net/1541e03e6cfd1442590bc7b5476f88c30a29a0d881bdb943bb48c3cfb6cdf527.mp4)

Excess deaths are the only real measure: [https://www.cdc.gov/nchs/nvss/vsrr/covid19/index.htm](https://www.cdc.gov/nchs/nvss/vsrr/covid19/index.htm)

<comment><USER9> Or we observe reality of every Asian and European country with mandatory masks crushing the curve after introduction.

But hey, a 30 cents a day intervention is clearly too much to ask of Americans

<comment><USER8> Where in these places has normality been resumed? When can we go back to seeing smiles?

Have you considered the long term social cost of reducing interaction between people? Or is that the plan?

There is no end goal here. Just a bunch of short term reactions that are based upon fear and propaganda not hard data. Why so much social change for a virus where the median age of death is over 80, and the majority of the population under 40 are not impacted at all.

There have been an estimated 31.5 million deaths this year so far on Worldometer. 1.5% of those were Covid. How many of that 1.5% would have made the end of the year? It's time to get some perspective and control those amygdalas.

<comment><USER11> > Why so much social change for a virus where the median age of death is over > 80

The "social change" is why the media age of death is so high; the elderly are the least able to withstand the supportive measures necessary to survive serious COVID-19 illness, and it is the "social change" that has kept the number of simultaneous cases down to the level where those who need it are likely to get the proper supportive care.

Without that, the median age of death would drop considerably, as well as the number of deaths skyrocketing.

Of course, just because death is both the most serious adverse outcome and the one for which statistics are easiest to compile doesn't mean it's all we should care about.

> How many of that 1.5% would have made the end of the year?

The vast majority of those in the developed world. Sure, in the US the median age of death may be a little over 80, but life expectancy at age 80 is 9 years for women, 7 for men.</comment></comment></comment></comment></comment></comment>


Ask HN: Procedural or object oriented programming? - <AUTHOR>

Hey everyone.
I recently deleted my scripting language since I wasn't happy with it, and I knew it wasn't popular anyway. I want to know if I should make the language more oriented or procedural, but am unsure myself.
So I ask you: out of the two, do you prefer procedural or object oriented programming? <comment><USER2> Creating a language for someone else rarely works - you need to create it for your own compelling use case. If you don't find it essential and natural for something, why should anyone else? And if there is a compelling use case, write up why your language is a better fit. People will then prove you wrong, and if you can convincingly refute all their arguments, then you might have something.

</comment><comment><USER3> Most object-oriented languages are also procedural, so that isn't a dichotomy.

Procedural vs. functional and imperative vs. declarative are more interesting dichotomies to focus on. If you are designing a new language, especially one for a particular problem domain, it generally makes sense to make the language fairly high-level and declarative. SQL is the classic example of a declarative domain specific language, you use the language to specify _what_ data to retrieve, and behind the scenes the database engine figures out _how_ to retrieve it.

Anyway, what is your purpose or goal in creating a programming language? Are you trying to create a general purpose language that can substitute for Python/Ruby/Perl? Or are you trying to solve any specific problem with it?

</comment><comment><USER4> Procedural vs. object oriented isn't an interesting distinction. Every good general purpose language in use supports some sort of run-time polymorphism, but it's an open definition as to what constitutes true object orientation.</comment>


Unreal Engine used to render the Weather Channel tornado graphics - <AUTHOR> https://www.fastcodesign.com/90176637/the-weather-channels-new-storm-graphics-are-totally-insane <comment><USER2> In many ways I thought the segment was quite good. A bit over-acting, but nothing terrible. My only real gripe is they should be clearer about the whole thing being a simulation/example.

Yes, the stuff in studio is obviously fake, but they should be clear that the tornado on the screen was too.

Also, if this require a special rig to process today, how is magic leap gonna fit that into a pair of glasses?

<comment><USER3> > Also, if this require a special rig to process today, how is magic leap > gonna fit that into a pair of glasses?

The same way the PC which rendered the first Jurassic park found its way into your pocket.

And also the glasses of today aren't targeting that level of detail / realism.

<comment><USER2> But magic leap wants to launch this decade.

They may not be targeting that, but magic leaps add sure as hell is showing off that</comment></comment></comment>


Barnes & Noble introduces a touchscreen E-Ink NOOK - <AUTHOR> http://www.barnesandnoble.com/nook/index.asp?PID=35699

<comment><USER2> I love my Kindle and don't have an iPad, but have been an iPhone user for a few years now. So it was surprisingly amusing when I found myself tapping my Kindle, expecting it to respond. I could suddenly relate to my friend's kid who we caught tapping a TV screen, expecting to interact with it.</comment>


Server-Side Rendering Is a Thiel Truth - <AUTHOR> https://timr.co/server-side-rendering-is-a-thiel-truth <comment><USER3> I feel like we are going to go full circle pretty soon, with more people realizing that server-side rendering is better for most websites/apps. I say this as someone who has used Angular and Vue extensively (and still do). The problem is, it is extremely easy to get things wrong, and I have seen mediocre (not great, but not bad) front-end devs make a complete mess using these frameworks.

<comment><USER4> The fundamental problem with serverside rendering is that it requires a round trip if the model changes. With modern interactive apps, the model changes a lot. People don't like waiting for things.

<comment><USER3> That is why I said most, not all. There are also things like intercooler.js ([https://intercoolerjs.org/](https://intercoolerjs.org/)) which provides a nice middle ground.

<comment><USER5> Laravel LiveWire looks like a good middle ground for enabling more dynamic user interfaces from a server application:

[https://laravel-livewire.com/](https://laravel-livewire.com/)

There are similar projects for Phoenix/Elixir and Django:

[https://github.com/phoenixframework/phoenix_live_view](https://github.com/phoenixframework/phoenix_live_view)

[https://github.com/edelvalle/reactor/blob/master/README.md](https://github.com/edelvalle/reactor/blob/master/README.md)

</comment></comment></comment></comment><comment><USER6> Even for small projects, I would choose Vue client-side rendering over back- end rendering. I'm a back-end dev so I don't do it because I love front-end work, I just haven't found a better way to do it. I can update the back-end API and front-end use on one machine and deploy both in a minute.

Sometimes all the work is client-side with third-party services as back-ends.

The only other solution I like is to have server-side rendering with live updates like Phoenix/Elixir, Vaadin/Java, or Rails/Ruby. These have scaling limitations but probably beyond what most of our apps need to support.

<comment><USER7> I think the other thing to worry about with live updating is client interaction security footprint. In most platforms you better be damn sure that your client rerendering code is bulletproof, because if an adversary finds an input permutation that hogs CPU or worse, panics your backend you'll really be up the creek, though Phoenix/liveview can take advantage of erlang process isolation in a way that it's way less of a concern.

</comment></comment><comment><USER8> I believe it was LinkedIn who took a hybrid approach a while back. I have no idea if this is still the way things are done, but somewhere in the 2012/2013 time period they would in general render things server-side. If the site was having load issues, they would turn the server-side rendering off and then the clients would render instead.

This was achieved using their fork of DustJS: [https://github.com/linkedin/dustjs](https://github.com/linkedin/dustjs)

       Asynchronous Javascript templating for the browser and server

</comment><comment><USER9> > So is your app mostly forms or displaying content? User preference panels? > Mortgage applications? Implement it with server-side rendering with a > sprinkling of JS to implement widgets the web lacks. If only part of your > app requires low-latency interactions, use client-side rendering only there.

While I understand it's easy to make the argument that SSR is better, lighter, etc. It's easy to quickly violate the "Single Responsibility Principle" in that you now have two systems with little knowledge of each other both in control of rendering the UI.

I lived the era of jQuery with apps just being a bunch of jQuery extensions + SSR. Eventually the app needs to make XHR (type ahead search, nested picklists, etc), and you end up in a situation where there was just one thing controlling presentation.

<comment><USER10> well no, you have a very strict layering of control

server owns it at first, and generates the base system

client-side js then owns it, and does whatever it wants

there's no back and forth, or dual simultaneous control of the UI. There's only one owner at a time; just two different systems who ever own it (and single-responsibility-wise: separating static UI from dynamic UI)

<comment><USER11> The concern is not about race conditions or shared memory where two things would be editing it at a time. Even though the server always renders it first then the frontend, you still need to share knowledge across both the backend and frontend about all the details of all the components to know how to change the values in jquery or whatever you want to do. Any time you change something on the backend, you have to make sure the jquery stuff is updated to still work, and potentially in many different places if you have different interactions that can update the same state. It makes for very tightly coupled and brittle code.

It's still a matter of preference, you might still prefer that over a full frontend react codebase. But having seen both nightmare jquery messes and react messes, they can both be painful to work with. I definitely don't agree that things were much simpler in the old days.

</comment></comment></comment><comment><USER12> Ah but there's alot more "front end engineers" who know some javascript in the world than graybeards who know how to write server-side code well. So the business case for saving money on new hires is a strong argument for "make a javascript mess".

<comment><USER13> Who said it needs to be written well? I'd wager that the kids these days making messes in JavaScript could probably manage to do the same in Python or Ruby. Also, heck, this has been going on long enough that this point that some of them may even be starting to have a bit of grey in their beards and recognize a few of these tradeoffs...

<comment><USER14> Especially since back in the day they made those messes in PHP.

</comment></comment></comment><comment><USER15> I've seen another problem, that's probably not going to happen with any of you careful hackers, but still seen it: where developers barely implement any security on their backend API and just go with filtering the results on the frontend side ...

With server side rendering of course you can still not-secure user input, but at least with template rendering, what you see is what you can see.

<comment><USER16> It "feels" (my personal biases and experience caveats apply) like "full stack" engineers aren't really that, but are rather great front-end developers with the back-end being an after thought.

<comment><USER15> Agreed, for me "full stack" really means the opposite: system and networks, backend / databases, and frontend. In most projects, even just mastering half of jquery does the job, as long as you at least know HTML with SEO and CSS well.

But then again, that's also IMHO

</comment></comment></comment><comment><USER17> It adds _optional_ infrastructure at the back end.

Infrastructure has direct and indirect costs, must be built maintained scaled monitored paid for etc etc.

You need a very very good reason to choose to implement optional back end infrastructure.

None of these reasons would be strong enough to convince me to start building and maintaining and paying for that infrastructure.

<comment><USER18> Are you implying that you would not need a back-end service without server side rendering?

</comment></comment><comment><USER19> > "Many important, profitable, applications aren't used enough to make a > native mobile app worthwhile. Most online shops, banking, festival > ticketing, government forms, etc. Therefore you will not have to support > both server-side rendering and an API for your native apps"

A well done native app is always, faster, more robust and more enjoyable to use than a web UI. Even if your app is used relatively rarely, offering a significantly better user experience means it will be used more. And that's a very important thing.

<comment><USER20> But users won't install it though. Your app can be a smooth magical experience but you have to get over the hump of getting users to go to the store and download it.

Unless I'm using your service daily I'm not going to bother with an app and just use the website.

<comment><USER19> You may not install apps without a good reason, but people install apps at a high rate. They love apps.

<comment><USER21> Hmm... I've seen claims that a 10% install rate is phenomenal when it comes to getting users to install your app, with 1-2% more typical.

Do you have data that shows otherwise?

<comment><USER19> Install rates ... depend on many factors. It can be difficult to get installs using advertising and other marketing channels.

But getting regular visitors to your web to install your app is by far the easiest way to get installs.

</comment></comment></comment></comment></comment><comment><USER22> Nice responsive site. How is this site implemented?

Oh no, you say. The article didn't say "all" apps should be done with server- side rendering, it said "many."

OK then, which ones? Well since we're quoting the article, I'll just put this here:

"the less complex your client-side is ... the less justification there is for client-side rendering."

Now again, tell me, how is this site implemented?

<comment><USER23> What site are you criticizing exactly? The blog is a bunch of HTML served up with only the usual google panopticon JS, and is certainly not doing client- side rendering. HN is also a bunch of HTML with just a titch of JS - <USER2> little of it generates HTML (which would be client-side rendering). Tell me again, what are you complaining about?

<comment><USER22> Relax, I was complimenting the site, which performs beautifully on a mobile device. And rhetorically pointing out that it is rendered by browser technology (WebKit), which, last time I checked, was considered client side. But hey I could be wrong, so feel free to educate me.

<comment><USER23> In web dev parlance client side rendering refers to dynamically generating HTML from some data format (eg, serving a template and having the JS render it and add it to the DOM, instead of applying the template on the server and sending the resulting HTML). You're right that the browser's rendering engine ultimately does all the work of generating the images that get displayed, but that has to happen anyway and isn't a distinction that gets talked about (much) in web dev land.

<comment><USER22> OK I see,thank you.</comment></comment></comment></comment></comment>


Ask HN: Ideas for 24 hour Hackathon at college - <AUTHOR> Hello, I'm an undergrad in Computer Science, and our college is conducting a Hackathon based on the theme Computing for Society. We have been given the problem statements from the UNSDG link - https://www.un.org/sustainabledevelopment/sustainable-development-goals/ which comprises of various problems faced by society and we need to develop solutions to tackle these problems from a Computer Science perspective in 24 hours, like making an app which can track the vaccination details for a child. Please comment on any ideas or anything which will be helpful. Thank you. <comment><USER2> Browser plugin/something so that when I search a route on Google Maps, I get the calories I'd lose if I walked it, how much money I'd save from not driving and much of a carbon saving it is. You know something like that.

<comment><AUTHOR> Yeah, Thanks a lot!</comment></comment>


Taʿârof, the ceremony of courtesy - <AUTHOR> http://riowang.blogspot.com/2015/11/taarof.html <comment><USER2> Funny, "na merci" is basically the same as "non merci" in French - since the words are so similar I wonder if that expression does not come from French somehow.

Other than that, the whole process is not unique to Persians. Maybe they are extreme about it, but in Japan you can see pretty much the same kind of situations as the ones they described... while I must admit the taxi driver telling you the trip was "nothing at all" is rather amusing and unique.

<comment><USER3> I've been trying to learn Farsi lately and keep getting struck by the large number of French loanwords. Including at least one that goes back to time of the Crusades - my wife's Iranian and she always calls me a "Firangi," which basically just mean "Westerner" now, but is a transliteration of "Frank." Apparently it also ended up becoming the name for an Indianized variant on the medieval European broadsword:

[https://en.wikipedia.org/wiki/Firangi_(sword)](https://en.wikipedia.org/wiki/Firangi_\(sword\))

<comment><USER4> Oh wow, thats crazy interesting... There's a beach area on Penang in Malaysia called Batu Ferringhi. It means Foreigner's Rock.

I guess the loan word spread throughout the muslim world somehow...

<comment><USER3> Amazingly, it even made its way into Chinese as folangji (佛郎機):

[https://en.wikipedia.org/wiki/Farang#Etymology_and_related_w...](https://en.wikipedia.org/wiki/Farang#Etymology_and_related_words)

Sort of reminds me of an anecdote I read somewhere in a book about medieval fashion - one theory is that those curvy-toed shoes you see in late medieval artwork originated in Tang dynasty China, and the fashion took ~500 years to slowly make its way west across Eurasia.

<comment><USER2> Your link also mentions the word is used in Thai as _Farang_ as well.

<comment><USER5> It's also in Hindi as Firangi as well.

</comment></comment></comment></comment></comment></comment><comment><USER6> I don't believe Tārof is specific to Iranians. I've seen it among Asians and some Indian coworkers.

It's not a good behavior. It's dishonest and confusing.

</comment><comment><USER7> Beautiful and interesting. And the comments section is an object study in why you have to be very careful about which comments services you use on a blog, if indeed you decide to use one at all.

I'm still not sure why people still do it, though if I had to pick one I've liked using G+.

</comment><comment><USER5> That first paragraph, some beautiful writing there.</comment>


Low-cost 3D printers and crowdfunding suicide - <AUTHOR> http://3dprototypesandmodels.com.au/blog-2/ <comment><USER2> This was an interesting article. Primarily about the inexperience in people building printers (and some evil people) who through Kickstarter or Indiegogo are making promises that it is mathematically impossible for them to keep. People have been doing this since forever but the Internet makes it easier than ever.

That said, the 3D printer "market", if you will, is remarkable. It is being created in exactly the same way that the microcomputer market was created, and from that we can potentially predict its path and some opportunities there.

For those of you too young to remember, IBM was not a participant in the microcomputer market, which was called microcomputers (as opposed to minicomputers from the likes of DEC or Data General). Between 1972 (introduction of the 8008 microprocessor from Intel) and 1981 (introduction of the IBM PC from IBM), the market consisted of lots of documentation (datasheets) from manufacturers, re-using 100 pin edge connectors for wiring busses, and lots of source code published in "magazines" which were no more than photocopied pages stapled together. And then, as with 3D printers today, the nerdiest of the nerds all had to have one but they didn't know why, and the rest of the world felt that owning your own computer was a ridiculous idea. Why pay all that money so that you could play 'hunt the wumpus' in a painfully slow loading stripped down version of the BASIC programming language?

Stepping back though, the excitement, the nerd fests, the people going nuts over these things, like a spinning top in a maze randomly bouncing off the walls, eventually found a solution, or a use, for this technology that non- nerds could relate too. Initially that was spreadsheets, then small databases, and data collection and analysis that the 'big' computers had been doing since the start. There is a lot of capital trying to figure out which company is the next Microsoft.

When I was at Google, a relative of one of the Makerbot founders worked at Google as well, and sought out volunteers to help build their first 'Cupcake' printer kit and give feedback. It was an amazing little box which, when the stars and planets aligned, would actually print reliably for the 3 hours or so needed to make a print of any decent size. It was a marvel, and sometimes it worked reliably.

I ended up buying a Makerbot Replicator 1 at a weak moment at Makerfair when they were 15% off list (they were clearing out old stock to make room for the Replicator 2) I printed a few test prints and then it sat on the shelf for nearly two years. I recently fired it up again because my daughter wanted me to print her a measuring spoon for chai.

Diving back into it I realized that there are a lot of people "building" 3D printers but not nearly so many "engineering" 3D printers. Circuit design for example on the RAMPS 1.4 board has little to no self protection circuitry and so it is prone to being damaged by things like moving the steppers when the power isn't applied. Extruders of all types with varying levels of material feed, feedback, and consistency. Machines that require amazing amounts of calibration to print correctly assembled with fasteners without any locking capability at all. It is so much like early S-100 microcomputers it is practically a deja-vu experience.

3D printing is a 'thing', and its going to be a huge thing. While I get that there may not be anything today you want to print, I can also imagine a day where all your currently disposable plastic goods (cups, utensils, clips, etc) would be printed on demand and disposed in a hopper that would recycle them as raw material for the next round. Because of the amount of investment going on, I don't worry about novices who go bankrupt trying to build a printer after a successful crowd funding campaign. I feel feel badly for them sure, but I don't think it will derail this particular technology bloom.

<comment><USER3> >I can also imagine a day where all your currently disposable plastic goods (cups, utensils, clips, etc) would be printed on demand and disposed in a hopper that would recycle them as raw material for the next round.

Is this the killer app for home 3D printing? Printing plastic spoons? The same spoons you can buy mass-produced in packs of fifty for eighty cents or something?

<comment><USER2> Its a fair question, and in truth just printing plastic utensils is not a killer app, just like calculating sums on a microcomputer made less sense than buying a calculator. Rather I expect the transition to 'user focused' 3D printing to be the point where nearly _every_ gizmo you use around the house is printed and then recovered after use. Any container, tool, decoration, replacement part, mounting bracket, paper good, or packing material, pretty much anything that you have to go out and buy today, and have to recycle responsibly. The value proposition will be that it is exactly what you need, right now but you don't have to store it for a future need. I'm still on the fence as to whether or not it will ever be practical to 3D print clothing but given the Disney demo of soft printables I know people are thinking along those lines too.

Step past thinking that it is a spoon that you can buy a pack of 50 for (which you have to in order to keep the costs down) to thinking that in the space where you would store a pack of 50 spoons, knives, forks, plates, and napkins you can have an nearly inexhaustible supply of spoons with a birthday theme, serving, color matched to a table setting. Every time you set the table you can print it all out, from place mats to drink cups. And then throw it back to be recycled again with just the organics left over.

And to return to my previous theme, having been the first person in my family to build their own computer in 1978 and listened to everyone about how stupid and inane it was to own a useless computer, only to live my life and find them become the 'smartphones' of today. When I walked through Makerfair this year and saw all of the 3D printing stuff there and heard the same sort of dimissive comments which I had heard at the West Coast Computer Faire in 1980, it really struck me. The same feeling you get when you are halfway through a book and realize you've read the same story but set with different characters and in a different place, but fundamentally the same story.

Its going to be interesting.

<comment><USER4> _Its a fair question, and in truth just printing plastic utensils is not a killer app_

I'd say the most relevant word there is "plastic". I don't want replacements for my cheap plastic objects. I'd love to "print" with other materials.

<comment><USER2> That is coming too but on the industrial scale. You can print in metal at Shapeways now, but owning a laser metal sintering machine is not going to be practical unless you can grind up previous things to make new things. There are already at least two filament creator projects out there that make a credible replacement filament out of scrap plastic.

</comment></comment></comment></comment></comment><comment><USER5> Another big problem that makes it hard to raise this kind of money is that none of these FDM printers have anything that differentiates them from every other printer. There are only a handful of different gcode interpreter/motor driver boards. Almost all of those boards use the same Marlin firmware. They all use Repetier Host has the PC software. They all have roughly the same printing resolution. They all use the same hotends. They all require too much tinkering, maintenance, and learning curve to ever be a mass market product. On top of that, ask any hobbyist who owns one how often they use it after the initial wow factor wears off. Most people run out of stuff to print pretty quickly.

Besides Makerbot, who has the advantages of 5 years of experience and VC money, none of the low end FDM printers have any sort of moat to make new customers want their printer over the newest kickstarter project. And Makerbot isn't even competing on price anymore.

Without some major innovation in ease of use, print resolution, print time, print material, or reliability, I don't see how a startup FDM printer can raise the kind of money outlined in the article.

<comment><USER6> I've thought about getting a 3d printer to mess around with for a long time. But before I drop the money and spend the time, I sit around and try and figure out what exactly I'd _do_ with one once I had it.

I don't really have any useful modeling skills, so I'd be reliant on 3d models I could find elsewhere. So I go to [http://www.thingiverse.com/](http://www.thingiverse.com/) and to be honest, even at the price of free, I can't find a single thing I'd ever be interested in having sitting around my house. Almost every object available is a novelty statue made by a fan of some geek favorite property, or some incredibly specific part for things I don't own.

I mean, do I _really_ need to invest a couple hundred to a couple thousand dollars and hundreds of hours of my time to print off a low quality t-slot hinge when I could just stop off at my local home deport and pick up a high quality metal hinge for $2.95?

In almost every case where I think it'd be cool to have a printer sitting around in the off chance I _really_ needed to spend $3 in ABS plastic and spend a half hour assembling a lens cap, I can usually find an actual version of the part cheaper and higher quality on-line somewhere and I don't have to muck around with anything.

I'm obviously the wrong kind of audience for 3d printers as they are now. But I don't think I'm that atypical of the general audience that's out there. The economics and ROI on 3d printers don't remotely work out for anybody who's not a tinkerer. Until I can start printing off exact-to-quality copies of my favorite shoes for 1/3rd the store price, or entire working keyboards I don't have to assemble and find electronics. I just don't see much of a general market.

<comment><USER5> I think your sentiment is true of technology and tools in general. If you have a pain point that a particular tool solves, then that tool is probably a good fit for you.

But if you buy a tool because you've been sold on all of the cool things you _could_ do with the tool, and you weren't necessarily looking to do any of those things before you knew about the tool, then buyer's remorse is almost certain to come your way.

99% of smartphone apps fall into this category. The internet of things, at least currently, is also an example of this. There tons of products out there that solve problems that no one actually has, but can be construed as game- changing with romantic notions and polished marketing.

<comment><USER7> My "Internet of Things" concept is a BT/WiFi appliance power monitor... would be able to detect whenever power usage changed.

Use case: you get a push notification when the dishwasher/washing machine/dryer/etc finished.

Thoughts?

<comment><USER8> There are wireless power monitors which have their own smartphone apps. I don't know if any of them can be set up to give you that sort of notification, but some of the manufacturers make enough information available that you could write your own app.

[http://www.belkin.com/us/p/P-F7C029/](http://www.belkin.com/us/p/P-F7C029/)

[http://developers.belkin.com/wemo/sdk](http://developers.belkin.com/wemo/sdk)

</comment></comment></comment></comment></comment><comment><USER9> Something I've noticed at Makers Faires and Expos is there's a lot of people with 3D Printers, but they tend to fall into two groups.

One one side you have college teachers wearing suits sitting at a table with pamphlets advertising their school's fabrication lab. These guys all have commercial 3D printers they bought from a company, and examples of fairly boring objects they printed.

On the other side you have the hackers from the maker spaces. These guys all have 3D printers they have made themselves which favor extreme colors, and bizarre and interesting features that commercial units don't have and can't support. These guys will have mohawks, crazy clothes, piercings, tattoos, and be showing off amazing objects they designed themselves, often to solve actual real life problems.

Currently the market is bifurcated into suits vs artists.

The suits try to sell their printers to other suits and to soccer moms.

The artists are doing the cool stuff.

The problem is that suits and soccer moms don't want 3D printers. It's like when the industry tried to sell early 8 bit computers to women using a marketing message "You can manage your recipes." Sure, but the reality is a card file works even better for that purpose.

The startups are marketing their printer kits to the freaks, rebels, punks, artists and mad scientists. And that's the people that are able to actually use 3D printers right now. Not suits and suburbanites.

Things will change later, but right now this is an early market that appeals a lot to early adopters, who are non conformists by definition, otherwise they wouldn't be early adopters.

It's not about cost either. The author of the article talks about a $299 printer. The custom kit printers tend to cost a lot more than that including all the various costs. Users can save money by buying a commercial fully assembled printer. But that doesn't give you street cred and it's not hot roddable.

<comment><USER10> _These guys will have mohawks, crazy clothes, piercings, tattoos, and be showing off amazing objects they designed themselves, often to solve actual real life problems._

I don't agree. A small number of the items are useful, most often replacement parts for things that would either require replacement with much larger parts (custom patches for damaged plastic shell) or which are difficult to replace (item no longer manufactured or firm no longer in business or part so obscure as to hinder repair). I've also seen some novel items that are good prototypes for industrial production.

However, the majority of stuff I see at the 'freak' tables is _junk_ , and samey junk at that. Expansible plastic jewelry, dodecahedral plastic hats (admittedly intended to draw attention to the large print area, but couldn't you find something more interesting?), and a lot of kitchenware, which strikes me as a particularly poor sector; ABS filament is non-toxic but I wouldn't use it where it's likely to encounter heat or alcohol, as would many examples on this page: [http://www.pinterest.com/mekitso/3d-printed- kitchen/](http://www.pinterest.com/mekitso/3d-printed-kitchen/) Toys are a more obvious application, but most kids are not so into a monochromatic toy, and cheaper printers don't have the resolution to make good multi-part toys. An awful lot of printer offerings I see appear to be motivated by an 'if you build it they will come' approach, but are being offered for sale more on novelty than utility.

 _The problem is that suits and soccer moms don 't want 3D printers._

Suits love 3d printers for industrial design/prototyping, architectural models, anything related to physical products where you might want to go into volume production later. And I do think there's a market for soccer moms: the most commercially interesting offerings I've seen at the lower end of the market in the last year or two is chocolate printing. It turns out that sugar works well enough for extrusion, low resolution is not that big of a deal when you're going to be eating it, and quite a lot of people are into doing really elaborate things with food. OK, such people tend to be artistically inclined too, but since everyone eats that translates into a huge number of people. Martha Stewart is already there: [http://www.marthastewart.com/1065207/3d-printing-101](http://www.marthastewart.com/1065207/3d-printing-101) ...although note the bias towards services like Shapeways that can do one-offs in high quality materials, vs home printers. But I bet you'll see a Martha Stewart-branded 3d printer within a few years that's optimized for confectionary use.

Now I'm not into baking or sweets, but I'm willing to bet that confectionery printers become by far the most widespread, while most people will go to a local print shop for quality 3d fabrication, whether that's sintered metal, multicolor paper, or very high resolution multifeed plastic. Makerbot-type printers have about as much future as dot matrix paper printers.

The boring presenters at Maker Faires tend to be offering actual utility, if you can get past the eye candy. If you doubt this, go to a large hardware store; they have quantitites of boring-looking things with very high utility.

<comment><USER11> Back in my days, we had to put hours and hours into gluing together and painting our warhammers! Surely todays kids shold be able to 3d print the parts and do the gluing and painting by hand.

<comment><USER10> Ah, I was thinking of action figures although now that you mention it I was into painting wargaming/roleplaying figurines myself as a teen. In fact one of the first things that got me interested in 3d printing was my good memories of things like building model aircraft and so on, but that also made me pay attention to how crude FDM is :-/

<comment><USER12> there are some SLA printers in the consumer market that are more suited for small detail prints, like the Formlabs form1 or the pegasus touch.

</comment></comment></comment></comment></comment><comment><USER13> Most new manufacturers price things too cheaply (source: own manufacturing company). I did so myself 10 years ago, but luckily some industry people convinced me to raise the pricing before it was public. I changed the pricing from $89 to $150 and that was not quite enough, and I raised it a few months later. Cost to produce the product at the time was $50.

Now with some automation we can make the same thing for $18, and we can wholesale it for $59. That is after 10 years and thousands of units, so we learned a little on the way.

I think this article is a little simplistic about manufacturing costs, but the point is true - raise the price. Sounds like what patio11 says about SaaS products.

</comment><comment><USER14> Yes there are a lot of yet-another-3D printer project that are trying to do what others are doing and the only real difference is that they are promising to be cheaper.

But then there is for example the Peachy Printer that is trying to be cheaper ($100) by innovating and reducing the components: no motors, no big rigid frame, no external power besides what comes from the computer. Sure it will not be the most accurate printer and it's still in development, but it looks feasible and shows that with innovation you can reduce the costs.

[https://www.kickstarter.com/projects/117421627/the-peachy- pr...](https://www.kickstarter.com/projects/117421627/the-peachy-printer-the- first-100-3d-printer-and-sc)

<comment><USER15> I love the Peachy Printer guys...I really do. They're taking a unique and interesting approach towards 3d printing. The only problem is they are about a year behind schedule in shipping. Furthermore, without advanced and expensive optics (like an F-Theta Lens, at >$300), they never will be able to print much larger than 2"x2" footprint objects. It's a problem inherent to galvanometers. Furthermore, they've only shipped a handhold of units--most of their kickstarter supporters (myself included) have not yet received their units.

Honestly, after backing Peachy and researching SLA printers considerably, I'm more intrigued by SeeMeCNC's DropLit when looking at the future of 3D consumer printers.

<comment><USER16> Adding a $300 lens to the Peachy Printer would still bring the total cost to less than half of the price of the typical extrusion-based 3D printer, most of which have a fixed build area of no more than about 8"x8".

One of their milestone goals is to use the Peachy Printer to build a usable sixteen-foot single-piece canoe, and actually test it out on a lake. If they can manage that, even if they have to install some specialized optics to make it work, it will be extremely impressive, and demonstrate capabilities that far exceed those of more expensive 3D printers.

I think the biggest weakness of the Peachy Printer is the specialized consumables it requires. The resin solution it uses as a build material is going to be considerably more expensive, harder to obtain, and more difficult to store in volume than the spools of cheap ABS or PLA used by more conventional 3D printers.

</comment></comment></comment><comment><USER17> Initially I thought, other than some toy stuff I wont have anything to make with that. Then I broke down and got one. Now everything like a nail that needs a 3d printed hammer. Built test replacement parts for my wife's antique knitting machine, for the antique spinning wheel, fixed my waterproof mp3 player, and can easily make custom enclosures for my electronics project. I cad something up and then play dota while it prints which is perfect as I can check it every 30 minutes to am hour which is the right interval for these things

</comment><comment><USER18> "I then had detailed talks with an injection molding consultant. I was quoted around 50k for all the molding all up.."

I think you can have an injection mold made for a lot less in China. Maybe 5-10K? Anyone have accurate numbers?

<comment><USER19> Molds are extremely complex objects, amongst the most complex mechanical objects that I've worked with. The precision to which they are fabricated, the thermal management to allow for fast cycles and high numbers of product produced from the same mold are absolutely incredible. The principles are simple but moldmaking is an absolute art form and unless you've seen a moldmaker at work at a reasonably high end facility I don't think you should be throwing out price points and opinions.

50K is actually _very_ much on the low end for mold making, of course everything depends on size, expected # of products, cycle speed. An sizeable edm produced mold of tungsten with copper laminate for heat management is going to be a lot more expensive than a small mold for a protoype run where speed and number of products are not critical.

<comment><USER20> I agree that you're completely right for the kind of "consumer" scale injection molding.

But they're talking about making perhaps only a few thousand parts. The number I saw was 2400 or so. For only 2400 parts (per YEAR!) you could make aluminum molds which are much, much cheaper. 2400 parts a year is 50 per week or one every three hours. Even if your cycle time was 10 minutes (which is an eternity even for old shoddy equipment) you can still make all the parts in 400 hours which is 2.5 weeks straight or 10 weeks of 9-5 production.

There is a company in the US which will make simple molds for much less than $50k. For that you could get 5-10 molds and all the parts and possibly have money to spare. [http://www.protolabs.com/protomold](http://www.protolabs.com/protomold)

If you're talking about the kinds of molds necessary to do something like this: [http://www.youtube.com/watch?v=WHwTHarf8Ck](http://www.youtube.com/watch?v=WHwTHarf8Ck) then yes I agree $50k is a total joke. But for the batch of parts necessary to build a semi-successful production run for a 3d printer, $50k might be overkill.

<comment><USER19> Is there a description available of the parts that the quote refers to?

<comment><USER21> I have used ProtoMold and they are very good. They are aluminum molds and there are fewer options with regards to custom details, but if you are making basic parts it works fine. I would think it would work very well for injection molding parts for a 3D printer because surface finish is probably not critical and the quantity will be relatively low. I generally think of the scaling up process as 3D printing -> ProtoMold -> steel molds.

That said, when he said $50k in molds, I pictures $50k in ProtoMold molds, not $50k in steel molds. I imagine steel molds would be more on the order of $250k.

</comment></comment></comment></comment></comment><comment><USER22> Well worth reading to the end of this article, some very good lessons regarding the realities of scaling, applicable for many startups.

I'm planning to see "Print the Legend" later this week, so this was very interesting. I see the Variety review of the film says "Because Lopez and Tweel are tracking the rise but not the fall, "Print the Legend" doesn't have the falling-apart-before-your-eyes immediacy of "Startup.com" - but is seems pretty clear from this article that there will be a lot of falling apart happening.

</comment><comment><USER23> Actually this is true of any Crowdfunded project.

Always crunch the numbers and do a feasibility report before you decide to crowdfund it.

This is why 90% of Startups fail as well, they focus on making the product but they fail to plan ahead and make sure that the costs aren't higher than the investment money and figure in salaries, taxes, fees, etc.

</comment><comment><USER24> I think we got to this point over a year ago. 3D printers are the new "I can build you a home page on the web."

Printrbot has had a good $300 FDM solution for a long time; to get significantly better, you really need SLS or Resin lithography solutions. And even there, the competition is hearing up as old patents expire.

</comment><comment><USER25> The link has been taken down for some reason. The Internet Archive to the rescue! [https://web.archive.org/web/20140810205859/http://3dprototyp...](https://web.archive.org/web/20140810205859/http://3dprototypesandmodels.com.au/blog-2/)

</comment><comment><USER26> Wonder how much this would affect the pricing model? [http://www.injectionmolder.net/](http://www.injectionmolder.net/)

</comment><comment><USER27> So this man is spending 50K in molds alone and four people before he proves the viability of his business?.

You don't need to make molds, printrbot started without those, and you don't need four people for starting.

Another whining article: [http://www.3dprinterworld.com/article/can-we-get- wrench-crow...](http://www.3dprinterworld.com/article/can-we-get-wrench- crowdfunding-spigot)

A gem from it:"A suicidal price war has ensued, but unlike most price wars, this one does not necessarily benefit the consumer."

Of course it benefits the consumer, but does not for those selling cheap, like in any price war.

Companies already established have an advantage over new comers like in anything else. If you get late to the party, the party is gone.

I am engineer and entrepreneur, and I have designed my own 3D aluminum-steel printer from scratch in my spare time!! in less than a year. Most of the hard work is already done, a Prusa i3 structure is already designed and open. So are the extruder, hot ends, electronics.

If you create a new company, you need to provide value. Something unique that does not exist.

If you can't, just crying on Internet is useless. You are not entitled to have a business.

<comment><USER21> I have a friend who has built a bunch of 3D printers from scratch (of his own design) as a hobby. Hobby != business. And it's not a price war unless you can buy the printers, what we have is a crowd funding war.

I know a couple people that work at MakerBot. They're not dumb. The reason the printer keeps getting more expensive over time is because that's what it takes to make a nice one.</comment></comment>


New type of black holes – Non interacting low-mass black hole - <AUTHOR> https://science.sciencemag.org/content/366/6465/637 <comment><USER2> I still think one of the most terrifying tropes in sci fi is not alien invasion but destruction by black hole. It's impersonal, and once it starts it's inevitable, because of physics.

I really hope we never learn of the existence of black holes in the kiloton range. If you think intelligences can annihilate themselves with nukes... how about sucking your planet away from the inside out?

<comment><USER3> The cross-section for capturing on the Sun is _much_ larger. The Sun is there, and it is old. There are many Suns, and they are old. I'm unaware of the observed sudden disappearance of a known star.

Ergo, the number of planet-destroying black holes running around is likely to be small.

The much bigger risk is having Earth's orbit disrupted slightly by a passing solar-mass scale black hole. We wouldn't get much warning that such a thing was coming, but it could alter our orbit enough to get us into thermal trouble.

<comment><USER2> So that'll depend on why the black holes arrive.

This article is about a binary system, which I would argue meets your criteria.

If the black hole were manufactured, and/or being used as a weapon, there's no reason it should hit the sun, and every reason it would hit a planet.

Now I think some of the other responses illustrated why this is not a problem _if our current model of black holes is valid_. The "what if" in one of those books I mentioned is "what if there was more exotic physics that allowed small black holes to be stable?"

</comment></comment></comment><comment><AUTHOR> The low-mass black hole is thought to be 3.3 times the mass of our sun. Previously, the smallest black hole discovered was 3.8 times the mass of our sun. I guess this opens up a new breed of stars that are somewhere between massive neutron star and low-mass black hole.

</comment><comment><USER4> A completely non-radiating mass — that's smaller than any black hole we've seen — in a binary orbit with a radiating star.

Doesn't this fit the general criteria of a Dyson Sphere or Swarm?

Not to be all tin foil hat, just neat to think about.

<comment><USER5> Dyson spheres/swarms do radiate heat (infrared).

<comment><USER6> Why? Couldn't it absorb almost all energy that "touches" it? Making it impossible for us to detect the tiny amount of heat generated? Genuine question.

<comment><USER7> Energy can't disappear or be consumed - if energy doesn't get released out then it gets absorbed i.e. accumulates; if it accumulates then the Dyson sphere heats up a lot, if it heats up then it glows with blackbody radiation.

<comment><USER6> Can we detect tiny amounts of blackbody radiation? Not that such a sphere would release tiny amounts, but I'm curious about this as well.

<comment><USER8> We can detect the CMB which, using the Stefan-Boltzmann law [s-b] and a CMB temperature of 2.725 K, is about 3.12e-6 Watts/square meter. But, the CMB is pervasive. The blackbody sphere you're asking about is very far away, and the amount of power you'd receive scales like the inverse square of the distance from the sphere to us here. So forget it, the CMB's blackbody energy flux on/near Earth is ENORMOUS compared to the star's.

[s-b] [https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law](https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law)

</comment></comment></comment></comment></comment></comment><comment><USER9> Reading the article, it seems that non-interacting is referring to the fact that the black hole is hard to detect as there is no other star or gas source to cause it to generate X-Rays as matter falls into it.

I find the name interesting since, mini black holes are one hypothesis concerning Dark Matter, and also Weakly Interacting Massive Particles. Google also doesn't seem like Non-interacting black holes are common nomenclature. How do these names get created?

<comment><USER5> Someone writes a paper using the terminology, others refer to it, and it sticks.

<comment><USER10> Considering "weakly interacting" is already a very stuck name. By most accounts these are typical black holes, which do not interact weakly, let alone not at all. I don't think this name will stick.

<comment><USER11> "quiescent" is already in wide use referring to black holes, and "quiescent" appears in the 2nd paragraph of this paper. Some stellar binary systems are called "interacting".

<comment><USER12> And according to the full title of the paper, it is not the black hole that is noninteracting, it is the binary system.

</comment></comment></comment></comment></comment><comment><USER13> While the title of the paper says a low-mass black hole, the abstract does say it could also be a high mass neutron star:

> Constraints on the giant's mass and radius imply that the unseen companion > is 3.3+2.8−0.7 solar masses, indicating that it is a noninteracting low-mass > black hole or an unexpectedly massive neutron star.

Presumably, further observations will help determine what it is.

</comment><comment><USER14> This is happening in binary systems. The black hole is not emitting any detectable X-rays from objects falling into it. There are none falling into it then. It is non interacting.

But we know it is non interacting because it Doppler shifts a nearby object in the binary systems these scientists are observing.

Being a binary system, unless the objects are at beyond perfect equilibrium with respect to their accelerations, the objects will eventually collide (in a true binary system). In other words, the Doppler shifting object must be actually falling, however slowly, into the black hole.

My question is this: Can we assume that the object is heating up and emiting additional x rays</comment>


Show HN: I published a book on Django - <AUTHOR> I recently published a book on Django and wanted to share it with the HN community. The book takes a beginner Django developer through a series of 7 projects that use various parts of the Django framework.
I would have loved to provide a full sample chapter, unfortunately all I have is part of the first chapter. You can see it at https://www.packtpub.com/books/content/quick-user-authentication-setup-django.
I'd love any feedback you guys can give. And I'll answer any questions that you may have as well. The book is available on Amazon at https://www.amazon.com/Django-Project-Blueprints-Jibran-Ahmed/dp/1783985429/ and on Safari Books Online at https://www.safaribooksonline.com/library/view/django-project-blueprints/9781783985425/. <comment><USER2> I have the impression that building a website for a book is a recent practice that helps authors promote their work. That might be worth considering for the next one.

Good luck.

<comment><AUTHOR> Thanks. You're right, creating a web site dedicated to the book seems like a good idea. I might even try that for this one.

<comment><USER2> Hmmm...I wonder what technology it might use. Anyway, my impression is that the critical time for the website is at launch and that after that it's diminishing returns.</comment></comment></comment>


Solr Power FTW: Make NoSQL Your Bitch - <AUTHOR> http://schedule.sxsw.com/events/event_IAP7455 <comment><USER2> Making something "my bitch" isn't a compelling metaphor for a lot of people, myself included.</comment>


Show HN: Papyrs – build wiki/intranet sites drag&drop or Markdown - <AUTHOR> https://papyrs.com/ <comment><AUTHOR> We've worked on this for the past years and we're finally launching!

Papyrs is for teams and companies who want to create an (internal) site to share knowledge, news, docs, etc. It's a new take on the old-school "intranet" (like Confluence/SharePoint) with a widget-based editor (which you can toggle between visual drag&drop and markdown mode). You can jump in the trial right away at [https://papyrs.com/try/](https://papyrs.com/try/) and we're really proud of how well the editor works. With the Sublime-text style command bar creating pages is super fun. Any feedback is welcome!</comment>