Fliers Must Turn Off Devices, but It's Not Clear Why - <AUTHOR> http://bits.blogs.nytimes.com/2011/11/27/disruptions-fliers-must-turn-off-devices-but-its-not-clear-why/ <comment><USER3> There is actually a very logical, sensible reason to have everyone power off and stow their devices during takeoff and landing, and this story disappointingly failed to cover it:

By far the most likely time for any accidents or incidents to occur is during takeoffs and landings. If everyone has 15 objects out and is busily typing away, it's going to be tht much more difficult for flight attendants to get everyone's attention to give instructions, and crucially, much much more difficult to evacuate the plane as quickly as possible.

This isn't controversial, complex or even hard to figure out. It's the same reason they aren't serving food and drinks at those times, and the same reason you have to stow your carry-ons and put your tray tables up at these times.

Disappointing that the Times did not bother to learn this or to write a more informative story.

<comment><USER4> The FAA/TSA alway justify things in terms of "safety" and "security", but never calculate the massive costs associated with seizing billions in toiletries and productivity.

Let's calculate that. There are about 800 million[0] passengers on domestic and foreign owned airlines in the US market, with many people flying more than once per year.

Each person is taxed between 1-2 hours in terms of "safety" regulations, ranging from backscatter scans to nail clipper seizures to water bottle appropriations. Once on the plane, they are again taxed by about 15-30 minutes on each end from the ban on use of laptops, including the emergency landing song-and-dance that the vast majority[1] of passengers have already seen.

So let's say conservatively about 2 hours in total. So 1.6 billion hours per year. At a conservative estimate of $10 per hour, that's $16 billion per year. This does not include the $8.1 billion wasted on the TSA itself.

[0] [http://www.usatoday.com/travel/flights/2010-03-29-airline- pa...](http://www.usatoday.com/travel/flights/2010-03-29-airline-passengers- revenue-decline_N.htm)

[1] In the unusual circumstance that a first time flyer is on board, a video could instead be played during check-in online, in the lounge, or on the seat back rather than slowing everyone down to look at the flight attendant. Would not be surprised if the percentage of first-time flyers on US domestic flights is less than 5%.

<comment><USER5> I don't understand how planes are seizing productivity when the nearest competitor -- an illegally driven car -- is about 5 times slower. Yes they have quite a bit of overhead during take off, landing, baggage claim, driving to the airport, security screening, etc. But what else can reduce a trip's time from days to hours? The amount of time wasted in that overhead compared to the time gained is minuscule.

<comment><USER6> Unless you are going a long way, it may well be faster to drive. For me: 1 hour drive to the airport, 1+ hours at the airport for check-in, security, etc, 1 hour at destination to retrieve baggage, get a rental car, and get out of the airport... plus the time of the flight. If I can drive in under 6 hours, I'll seriously consider doing that rather than deal with all the hassle of air travel.

<comment><USER7> Except that if you drive for 6 hours, you can't talk on the phone and you can't use your laptop. Your point doesn't make sense to me: if you're willing to drive for 6 hours, you're also willing to stop working during all that time, while if you flight you'll always find some time to work, at the terminal or in the plane.

<comment><USER8> If driving you can talk on the phone for the whole 6 hours. I did something similar at least once.

Also, the driver can't use a laptop, but because of the driving activity itself, the driver is not so easily bored. Boredom is the main reason why I power on my laptop on a plane. Also, the other passengers can easily work on a laptop, watch a movie and so on. If you've got a 3G connection, the passengers can also go online - even I as the driven, I often find myself checking my emails while driving, plus I'm connected on Skype for the whole ride. The only problem here may be the comfort of your car, as you'll have problems having a laptop in your lap if the car is a small one. I also never get anything done on a plane when trying to work, especially because I don't have Internet connectivity, so I would rather listen to Podcasts or read a book and when driving Audio books are great btw.

So, related to comfort, I always prefer a couple of hours in my 10-year old Audi A6 over a plane ride. If the car ride is longer than some threshold, like the mentioned 6 hours, I do agree that a plane ride is better.

<comment><USER9> > even I as the driven, I often find myself checking my emails while driving

Why would you ever do that? If you don't care about your safety, at least make sure you're less likely to kill others, please...

<comment><USER8> Oh, cut the drama. I use text 2 speech.

<comment><USER9> I guess that even for short messages rather than interaction, some of this applies: <http://www.psych.utah.edu/AppliedCognitionLab/cdir489.pdf>

</comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER10> MythBusters covered this awhile back, and busted the myth: "The final explanation is that, even though the airplanes appear to be well-shielded against cellphone interference, there are so many different electronics in a cockpit, as well as so many different cellphones constantly coming out, the FAA doesn't want to do the necessary testing."[1]

[1] [http://kwc.org/mythbusters/2006/04/episode_49_cellphones_on_...](http://kwc.org/mythbusters/2006/04/episode_49_cellphones_on_plane.html)

<comment><USER11> If they actually aren't willing to test whether cell phones interfere with their equipment, they shouldn't be allowing cell phones on the plane at all. Relying on people's compliance (or even just their attention) to ensure the plane doesn't explode is absurd.

<comment><USER12> There are other options than "allow free cell phone use" and "frisk all passengers to ensure they're not smuggling in an active cell phone". Asking passengers not to use them is a decent compromise between safety and inconvenience. Naturally, if a crash were to actually occur due to mobile phone use, the FAA would need to revisit this guideline.

Note that GSM phones in particular _do_ interfere with radio systems - <USER2> irritating buzz you hear when a GSM phone is near a speaker amplifier can affect airplane systems as well (although it depends on where the phone is on the plane, of course). There can also be interference with _ground_ systems - cell networks aren't designed to deal with the rapid tower transfers caused by ultra-high-altitude phones moving at Mach 0.85.

<comment><USER13>
      > cell networks aren't designed to deal with the rapid
      > tower transfers

I always see this argument brought up (on HN), but what does the FAA care about cell carriers' networks? Why don't they ever use this justification when asked to justify their policy?

<comment><USER14> They don't use this justification exactly because they mostly don't care about that. It's interesting that there probably is no regulation that forbids usage of cell phones at high speeds and high altitudes (as opposed to "on board of a plane"). At least ETSI specifications seems to imply that it's perfectly legal to operate whole GSM network on board of plane, while hinting at fact that direct communication with basestation on ground from plane is not intended mode of operation and probably will not work. On the other hand there seems to be an large amount of anecdotal evidence, that it really does work, although with marginal call quality.

So conclusion might be something along the lines of "it's not designed to do that", which seems like pretty good justification when you are talking about airplane safety.

<comment><USER13>
      > So conclusion might be something along the lines of
      > "it's not designed to do that", which seems like
      > pretty good justification when you are talking about
      > airplane safety.

I'm not sure the reasoning follows:

1\. "it's not designed to do that" refers to cell-to-ground communication, nothing to do with the safety of the plane.

2\. cell-to-ground communications issues only apply to cellphones, but the FAA policy applies to _all_ electronics.

<comment><USER14> I intended the second paragraph as my though on why telecommunications related organizations don't exactly discuss whether cellphones works on board of a plane and this intention was then probably lost by inserting that paragraph break :)

FAA's and related regulations are probably motivated by fact that it's essentially impossible to test that aircraft's systems work as intended even in presence of random consumer devices on board. EMC issues can be caused by almost any electronic device not only devices containing radio transmitters (eg. EU regulations require EMC certification for anything that, possibly internally, produces or uses signals >=1kHz).

</comment></comment></comment></comment></comment></comment></comment><comment><USER15> The wikipedia article is more interesting: <http://en.wikipedia.org/wiki/Mobile_phones_on_aircraft>

This sums it up pretty well: "The regulatory agencies and aviation industry take the position that any increased risk is unacceptable if it is avoidable."

There's some technical channel sharing problems where phones have access to more towers than designed on land. The FCC can't predict what would happen if phones were allowed to stay on in regards to cell roaming. They also don't know the effects on the avionics.

It looks like they're developing 'picocells' to have an on-board tower, but there are struggles with the different cellular bands. Though, there are some European carriers that have been successful with just letting people keep their phones on.

That said - I think if your device doesn't have a radio on it, it should be allowed to stay on. Which probably won't fly given the 'if it's avoidable' rationale.

<comment><USER16> They just dont want to say it's ok then get sued to hell whenever a plane goes down.

</comment></comment><comment><USER17> The last time I flew, most of the people around me didn't know the difference between "airplane mode", "standby", and "off". I'd bet that at least 80% of the phones on that flight were full on despite the efforts of the crew and the device's owners.

Everyone turning off everything successfully before takeoff is pure fiction.

<comment><USER12> Cell phone transmissions are much less frequent when the phone is idle than when it is in active use. Even if people just stop talking on the phones, it's better than nothing.

<comment><USER18> True. But I bet a phone on the airplane idle is more active than on the ground idle due to network searching.

</comment></comment></comment><comment><USER19> Easily the most annoying part of flying for me, particularly when doing a quick flight from SFO to LAX is the insistence that I turn off my Kindle while we are lining up for the runway.

* People reading newspapers, and books - both of which are larger, heavier, and just as distracting, and in the case of newspapers, a greater obstacle - are not told to put away their reading material - so the argument that "people need to pay attention on takeoff/landing" is not consistent.

* RF engineers haven't been able to prove that a kindle in airplane mode has a negligible likelihood of impacting the flight systems of an airplane. Really?

One solution, albeit a slightly annoying one, is to have a distinctively colored LED or indicator that is visible from the walkway of the airplane to a stewardess, but not annoying to the reader, which indicates whether a device has been placed in airplane mode.

The new motto then would be "Everyone please place their FAA certified equipment into airplane safety mode. All other electronics, iPads, kindles, laptops, gameboys, iPhones, iPods, must now be put away"

People, being people, would likely start putting the fake LEDs on their electronics to simulate the FAA approved one, unfortunately, not sure what to do about that.

<comment><USER20> How do we know there isn't a bug in a device's airplane mode?

<comment><USER21> How do we know there isn't a bug in a device's off switch? Most of them are software-based these days.

<comment><USER20> Most of them allow you to take the battery out if it comes to that.

<comment><USER21> But nobody actually does, so clearly we're content to trust the software on that matter.

<comment><USER20> They do if the power button malfunctions. Are you aware of any devices that cannot be turned off because of a software error?

<comment><USER22> nknight mentioned iphones, ipads, and unibody macbooks.

</comment></comment></comment></comment></comment></comment></comment><comment><USER23> Yes, absolutely turn off all devices. We know with certainty that ANY transmitter can cause terrible havoc with the plane's electronics.

Unless you're paying the ripoff $10 fee for in-flight Wifi, then the dangers are magically avoided.

<comment><USER12> There's a big difference in power levels between wifi (that only has to go a few hundred feet to the on-plane transceiver) and cell phone radio (that has to go possibly several miles to a ground tower). Additionally, GSM has a transmission pattern that can cause noise in radio receivers and other audio devices - just try holding an active GSM phone up against a poorly shielded speaker sometime!

<comment><USER23> I know all this. I also know that people will forget to turn their phones off, will have phones and laptops and all manner of devices in checked luggage that are possibly left on, and that these signals are all around the plane anyway.

If there were any credible threat from leaving your phone on, or having it actively transmitting, then ALL phones would be outright banned from the plane. Otherwise, a group of terrorists could take down a plane simply by passively not turning their phones off? When you look at all of the other TSA security theater bullshit, it's a safe conclusion (IMO) that the RF from your phone will not interfere with the operation of the plane, based on the simple fact that they are not banned in the first place.

Not to mention, I think that if this were even a moderate concern it would be easy to equip the flight attendants with an RF monitoring device they could walk down the aisle with and detect close-proximity transmitters from cell phones.

On modern flights where coach seats have been spaced at the minimum allowable level and people are forced to bring everything as carry on to avoid bagge fees you see far more safety threats from under-seat luggage sticking out into the seating aisle, potentially inhibiting safe exit of the plane in an actual emergency.

<comment><USER24> Lithium Ion batteries are allowed on planes as well. Is this conclusive proof that they can't damage the plane if they catch on fire?

All decisions are trade-offs, banning laptops and cellphones today would probably bankrupt the airlines since nobody would fly. Likewise, non-critical computer systems in an airplane have less stringent certification standards than critical systems (it's OK for the electronic flight bag laptop to occasionally crash if you keep a stack of paper charts in the cockpit).

It's not like a plane is likely to just go down because of interference, but instruments acting will certainly increase the workload of pilots, making an accident more likely. Likewise, people shining lasers at airplanes tell themselves that this is OK, surely the pilots can deal with a little light disturbing their night vision? They don't appreciate that the pilots already have a high workload during landing.

The wikipedia article (<http://en.wikipedia.org/wiki/Mobile_phones_on_aircraft>) has a link to a NASA study of interference events showing that they can in fact happen (although not often). Of course, you can still claim that these pilots are making stuff up or that this is another NASA conspiracy, but it's actually possible to read up on the subject instead of just offering wild theories and speculations based on your own opinion and wishes.

</comment></comment></comment></comment><comment><USER25> IEEE - Unsafe At Any Airspeed: Cellphones and other electronics are more of a risk than you think:

[http://spectrum.ieee.org/aerospace/aviation/unsafe-at-any- ai...](http://spectrum.ieee.org/aerospace/aviation/unsafe-at-any-airspeed/0)

<comment><USER26> The method used in that article is just counting flight incidents in some historical data that may possibly have been caused by interference. The evidence that consumer electronics are the cause is just anecdotal:

"In one telling incident, a flight crew stated that a 30-degree navigation error was immediately corrected after a passenger turned off a DVD player and that the error reoccurred when the curious crew asked the passenger to switch the player on again."

<comment><USER27> After a 30-degree navigation error was corrected by turning off a DVD player, would the pilot seriously endanger the aircraft by asking the passenger to turn it on again to test? Anecdotal, and probably completely false.

<comment><USER28> > After a 30-degree navigation error was corrected by turning off a DVD > player, would the pilot seriously endanger the aircraft by asking the > passenger to turn it on again to test?

No?

1\. It was already demonstrated that turning it off fixed it. If you see the instruments goof up again, you tell the guy to turn the player back off.

2\. Pilots are extensively trained to deal with equipment failures, including total loss of power and instruments.

<comment><USER27> I don't buy it. Ostensibly, this is a commercial flight where lives are at stake, so I strongly doubt that absent FAA direction the pilot requested this test.

 _It was already demonstrated that turning it off fixed it. If you see the instruments goof up again, you tell the guy to turn the player back off._

It's unclear from the account whether this was an instrument error or an actual flight path deviation. The latter being a more serious and unpredictable error. Who in their right mind would want to repro this given the unknowns?

 _Pilots are extensively trained to deal with equipment failures, including total loss of power and instruments._

Pilots also operate in an environment of substantial regulation where I'm sure a policy exists for investigation of operational interference. I suspect this policy is in line with the FAA's stance that "avoidable interference is unacceptable" and certainly this incident describes an avoidable interference.

I don't see any reason to retract my position that this story is likely a myth.

EDIT: My position depends on a number of assumptions that may be faulty: that this incident took place in the USA, within the last decade, on a plane operated by a significant carrier.

<comment><USER28> You can feel the story is a myth, but it remains hard to argue that it'd "seriously endanger the aircraft" by doing what was described in the story.

</comment></comment></comment></comment></comment></comment><comment><USER29> I recall years ago sitting in the LAX UA red carpet club listening to a portable cd player (yup, long ago). My music cut out, and thru my cd player, that didn't even have a radio as I recall, I was listening to the pilot pulling into the gate outside the window communicating with the ground crews over his headset.

Now, as I understand it, that lovely FCC stamp on the back of our electronics means the device must accept any interference received since it's a consumer product... but I'd also hate for my pilots to unexpectedly get my co- passenger's latest dubstep mix opposed to the air traffic controller during takeoff.

For the record: I'm the guy that intentionally leaves his phone on, in airplane mode, idling. I think this is good enough.

</comment><comment><USER14> There are two sides to this:

EMC is black magic and airplane safety is another and thus nobody is willing to say that using random RF devices onboard of plane is safe - for one reason it's almost impossible to test. By the way owner's manual for my new car contains paragraph that explicitly disallows usage of any RF transmitter inside the car that does not have external antenna (and I would assume that most car manufacturers include similar paragraph in their manuals and also that everybody ignores them).

Cellular networks and cell phones are not designed for relative speeds and RF propagation modes of high flying commercial aircraft. Most access methods of digital wireless networks depend on precise timing where propagation delays are significant and thus need to compensate for relative movement of phone and base station and there are pretty low limits of how fast movement can be compensated (it's almost practical to drive car faster than speed limit of GSM1800). Also higher levels of cellular protocol stacks are not exactly prepared for situation when phone sees large number of accessible cells with quite strong signal and this set changes very quickly.

</comment><comment><USER30> There is zero risk to a regulator in maintaining a pointless yet harmless regulation. There is nonzero risk to a regulator in revoking a regulation that may be blamed in the future by a crash investigator.

Even if the risk is absolutely 0.0001% -- fear and CYA wins. Our system of regulation and collective transfer of responsibility to regulators ensures that like a federal subsidy, nonsensical regulations are forever.

</comment><comment><USER31> Here's what I don't understand, and admittedly I have very little knowledge of the industry.

There seems to be some sort of approval process for electronics to be vetted during takeoff and landing. Several in-chair entertainment systems seem to have this rating/designation and are allowed during takeoff/landing.

So, is there no dollar amount that could be paid to properly test a particular product? Let's say the Kindle or iPod. It may be millions of dollars, but wouldn't there be a huge word-of-mouth and marketing upside if you could get approved for such a thing?

<comment><USER32> I currently work in developmental flight test. Any time we add a new piece of electronics to an aircraft (or replace an existing piece with a new version), be it a radio, a computer, or test instrumentation, we have to conduct an Electromagnetic Compatibility (EMC) Safety of Flight Test (SOFT) to make sure that the new equipment does not interfere in any way with avionics that are critical to safety of flight. Even if it's something that's not being installed per se (e.g. a laptop for collecting test data), it has to be tested. Sometimes there are exceptions, such as very minor upgrades, especially minor software updates.

Generally everything is designed so as to not interfere, but every once in a while something causes unexpected interference. Sometimes it's because the designers screwed up, sometimes it's because a bespoke item wasn't manufactured to the correct spec, and sometimes it's because of something nobody anticipated.

The problem with consumer electronics is that they haven't gone through this process. None of them _should_ cause interference, but we can't be sure because they were never subjected to comprehensive EMC SOFT. Nor would it really make sense to spend that kind of time and money when we can just mitigate the risk of interference by having everyone turn everything off during critical phases of flight.

<comment><USER33> but wouldn't it make sense for Apple to pay to do the testing? Being able to say "The iPhone is the only phone you can use during your whole flight" would be worth quite a bit of money to them.

<comment><USER32> They would have to test every model of iphone against not only every model of commercial airliner in operation in the U.S. (including puddle-jumpers), but against every major variation in avionics suite among each model. This testing is not cheap. Even for Apple, it would be prohibitively expensive.

<comment><USER19> There's probably only 80 different commercial airplane models. This testing probably costs around $1000/hr - figure 5 days testing @ 8 hours a day = 3200 hours = 3.2 million dollars. Seems to be a reasonable price to pay.

<comment><USER32> As I said, it's not just the different models, it's the different avionics suites within each model (e.g. two aircraft of the same model might have different radios or different navigation equipment, etc.). For each plane, you would need a few hours of testing, which probably costs more than $1000/hour: you have to pay for the plane, the crew (who have to be qualified to perform this type of testing), the ground support equipment, maintenance support, and any fuel burned during testing (e.g. running the APU to provide power during testing will consume a small but not insignificant quantity of fuel).

EDIT: Almost forgot: After the testing is complete, you have to pay to have a test report written up and published, and then you have to pay for the FAA certification process. Probably not cheap.

<comment><USER34> The US Treasury has less cash on hand than Apple. Apple makes prepayments of a billion dollars for parts. The numbers you're tossing around are, in context, very cheap.

<comment><USER32> Apple only pays for things that they expect good ROI for. I doubt very highly if they would recoup the money spent to get their phones FAA-certified, let alone the opportunity costs compared to spending that money on something else.

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER35> Let's presume for a moment that some sort of interference which could be generated by a box the size of a laptop might have a non-trivial risk to passenger safety. Now, think as a terrorist might. How about sending your minions onto planes with devices which look like standard consumer electronics devices but are capable of generating high levels of interference? Around the holidays in the US, someone checking or carrying on what appears to be an A/V receiver in a box would not raise suspicion -- just a gift for a relative. Now, inside that "receiver" is a battery and a transmitter (I'm not an electrical engineering sort of guy, so substitute the appropriate components) which emits what signals the terrorists hope will interfere with onboard avionics. Via a remote switch, the terrorist turns on the device during take- off and landing. If the plane crashes, is forced to make multiple attempts at a landing, etc., then the terrorists know they're onto something. They will refine their techniques until they can make plans fall out of the sky. If not, they try other experiments -- different frequencies, etc. Could such experiments even be carried out through transmitters on vans which could be temporarily parked on highways near airports? What if the terrorists could purchase airplane components with which to conduct their own testing and refine their "weapons"? Surely such an avenue of attack, if feasible, would be less effort than training your minions to fly an airplane, even if learning to land was not required? That no known terrorist attacks via this vector have been reported suggests it implausible. A problem with most terrorism "experiments" is that, if the experiment fails, the experimenter ends up imprisoned and thus incapable of further experimentation. Given the obvious recruiting issues the likely outcomes of either imprisonment or death present, terrorists ought to take like ducks to water toward techniques which allow repeated experimentation and refinement. That no incidents have been reported due to avionics malfunction suggests the near impossibility of actual passenger risk. QED?

<comment><USER36> No. There's still a human pilot flying the plane. Even an arc welder (probably) won't magically make it go in to a nosedive.

What could happen however is that certain navigation systems become unreliable during landing. Add that to bad weather, bad information, human error, and bad luck and you have a potential disaster.

But it doesn't seem likely that a terrorist would find such a plan worthwhile to pursue. After all, they want to be the star of the show right? Would they martyr themselves so some pilot gets the blame for landing on the wrong runway during a thunderstorm?

<comment><USER35> Hmmm.....could the terrorists cryptographically encode their flight schedules along with techniques, drop the encoded versions on public repositories, and distribute the keys to the media upon successfully killing people? This way, they could prove their involvement.

Your point about the compound nature of risk is valid, but doesn't it also suggest that the actual risk of allowing electronics during takeoff/landing is quite low as well?

<comment><USER36> The thing that 'accidents' has in its favor over 'terrorist' is volume. Many thousands of takeoffs and landings and millions of passengers with electronic devices _every day_. Even a small additional risk is guaranteed to line up with the right mix of other factors occasionally.

Terrorist attacks in the US are extremely rare, and they typically expend their resources with each attempt so they want a high probability of success. There are far better avenues for a technically sophisticated attacker these days than getting on a plane and emitting harmful radiofrequency interference in excess of FCC guidelines.

> drop the encoded versions on public repositories, and distribute the keys to > the media upon successfully killing people

I'm far from an expert on the mindset of terrorists, but I really don't think that's going to check the box for those aspiring to martyrdom.

Edit: It's an interesting thought experiment though. Let's say the next time an Air France crashes mysteriously into the ocean, the next day some group sends a private key to the media which decrypts a file from Google Cache containing the flight number and their religious slogan of choice. How would the media around the world report that?

A "hoax terrorist" could also encrypt and upload files for _all_ the flight numbers, or perhaps have a smaller set of files that decrypt differently with different keys. If they used CBC mode, they could even choose part of the plaintext when they disclosed the IV. You'd have to trust a cryptographer to know how reliable of an indicator that actually is.

Or a counter-hoax-terrorist could do that to discredit you. Would kinda suck to martyr yourself and have no one believe you about it later. If the CIA were smart, they would be doing just that, in advance.

</comment></comment></comment></comment><comment><USER37> I think part of it is that the flight staff want you to pay attention during takeoff and landing. Having your headphones on/in means you're not listening to them.

Another part is that the flight staff wants fewer things potentially flying around the cabin if there's trouble. of course, they don't usually ask you to put away books...

Cell phone companies want you to turn off your phones because they mess with the ground towers. Flying past towers rapidly puts load on the cell network to transfer your phone's connection between towers rapidly. Your phone can also see more towers than usual, causing it to possibly flap between them in unexpected ways.

The bit about it being unsafe due to messing with the plane's avionics is total bunk, though. I never turn off electronics on flights, except to save battery.

</comment><comment><USER38> For me it's great. The last thing I want is to hear someone's boisterous 4 hour conversation with an excited family member while I'm sandwiched between said conversationalist and some 300-pound whale who keeps leaning on me as (s)he repeatedly drifts in and out of consciousness.

Everyone's phone plays movies now anyway. Isn't that good enough? Do we really have to be plugged in every second of the day? Americans are too spoiled. OMG I can't jabber on my phone while flying? waa waaa ='[

</comment><comment><USER39> What are the consequences for simply refusing to obey a crew member's instruction to power down your Kindle? Sort of like willfully ignoring the distinction between the first-class and economy security lines---something I wish more people would do.

<comment><USER40> If you are getting ready for take-off, the plane returns to the gate and you are escorted off the flight and charged with compromising airline safety and ignoring a steward's order. This happened to a guy two rows in front of me on an American Airlines flight a couple of years ago. He twice refused to turn off his mobile phone as we were taxiing towards the runway.

<comment><USER41> Why not just lie? You genuinely are making the attendant's job harder by telling them point blank that you refuse to comply with the order they have to give to you to take off. It's much easier for everyone if you just act like you turned it off.

<comment><USER40> This particular guy was in the middle of a conversation on the phone :)

</comment></comment></comment></comment><comment><USER42> I was on a flight a few months ago where we stopped on the runway for a few minutes and the flight attendants told us we couldn't take off because "too many" devices were still powered on.

They also told us they had to "reboot Windows".

I'm pretty sure they were full of shit.

<comment><USER43> What airline?

</comment></comment><comment><USER44> I haven't turned off a cell phone while flying for almost ten years now. I refuse to be part of any safety or security charade.

<comment><USER45> Almost there with you. Charade is useful if it prevents a confrontation with someone who does not understand the security theater.

Thus, I turn the screen off for the 3 seconds it takes the flight attendant to walk by. I've been doing this for years. A fair compromise? Silly, but effective perhaps.

<comment><USER46> I turn off my cell phone simply to save the battery power. You don't get any signal above a few thousand feet, so why not save on battery for the next few hours? Heck, sometimes I even use my laptop's USB to charge the phone in- flight so it's full when I land.

I think the dumbest thing is having to turn off a Kindle. Is that even possible? Pushing the power button just goes to screensaver which uses exactly as much power as when you're actually using it.

<comment><USER32> > _I think the dumbest thing is having to turn off a Kindle. Is that even > possible? Pushing the power button just goes to screensaver which uses > exactly as much power as when you're actually using it._

You can turn a kindle off by holding the power switch for a few seconds. I do this every time I fly, for both takeoff and landing (I leave the wireless off for the entire flight). Given how low-power a kindle is, I find it highly unlikely that it could cause interference (unless you leave the wireless on, which could definitely cause interference), but I've seen enough surprising results from Electromagnetic Compatibility (EMC) Safety of Flight Tests (SOFT) to know that you just can't make assumptions about stuff like that.

</comment></comment></comment></comment><comment><USER47> If airplanes were vulnerable to radio frequencies, then terrorists have no need to acquire SAMs. A nice powerful amateur radio should do much better.

<comment><USER48> Avionics systems are better shielded against _external_ interference than they are against _internal_ interference.

<comment><USER47> Based on how Faraday cages work, I don't see how that's possible. Do you have a technical explanation or did you just pull that out of thin air?

<comment><USER48> Planes (well, most of them at least) have metal skins. The avionics -- and the passengers -- are inside this skin.

<comment><USER47> Well, you can easily see that the plane's skin is not a Faraday cage since you _can_ make cell phone calls, use your GPS etc.

<comment><USER48> It doesn't provide complete shielding, no. But it does provide _some_ shielding.

</comment></comment></comment></comment></comment></comment><comment><USER49> There were 769.6 Million passengers carried in 2009 in the USA (domestic and international). If each loses 30 mins of productive time on a plane because they can't use e-books or devices below 10,000 ft, that's 384,800,000 hours per year lost. Not everyone is working or learning something on a plane, but it puts things into perspective.

[http://www.bts.gov/press_releases/2010/bts015_10/html/bts015...](http://www.bts.gov/press_releases/2010/bts015_10/html/bts015_10.html)

<comment><USER35> I have used this sort of reasoning when arguing against low speed limits implemented in the name of safety. Surely, for each 10 MPH decrease in highway speed limits, we will observe a decrease in the number of deaths per year? Presuming both this fact and the presumed political validity of speed limit reduction to decrease death rates, shouldn't our vehicles be limited to walking speeds? The reality is that most people implicitly choose an overall level of risk in their lives and optimize the apportionment of that risk among activities in a way which maximizes their happiness. If it took me four hours to commute to work because I drove 10 MPH to be "safe", I could either spend less time with my family or move my family closer to the office. Would my children end up successful in life if they rarely saw me? The end game of everyone moving closer to the office might be little specs on the globe of uber density -- an unhappy way of life for most. How about subsisting on ration kits (like those currently sold to doomsayers) as a way of minimizing the horrific risks associated with un-necessary trips to the grocery store? Obviously, people have some threshold of risk at which they choose expected quality of life over expected quantity. Airplane travel, either with or without restrictions on "portable electronic devices" can be evaluated similarly. And, given Americans' propensity to drive places at high speeds, shouldn't they be equally willing to incur what seems to be a trivial risk in order to have more productive time?

<comment><USER50> "The reality is that most people implicitly choose an overall level of risk in their lives and optimize the apportionment of that risk among activities in a way which maximizes their happiness."

Do you have anything to support this? Most economic theories say that people make tradeoffs of time and money, but not risk. Risk is generally too nebulous a concept for an individual to make any kind of rational decisions about its allocation - we have no real concept of the risk we're incurring when driving a car or stepping on a plane (and generally, our gut feeling is wrong.)

</comment></comment></comment><comment><USER51> While I don't think the title and point of the article is exactly _wrong_ , it doesn't fairly consider the potential difference between one or two people failing to power down their devices and several hundred people using multiple devices.

Walking across a floor that is a cluttered mess, you might have a small chance of tripping. Cleaning up most of the mess might reduce the risk to negligible, even if you don't get _everything_.

That's the angle I would have liked to understand better.

</comment><comment><USER52> In 1999 I was on a flight and sat next to an EE who worked for Boeing on commercial airliners. He said that there was virtually no chance that a cell phone would cause any interference. He said that as far as he could tell the FAA rules stemmed from the FCC that stemmed from the cell carries pressuring the FCC not to allow it. The reason he suggested was that cell phones at altitude have line-of-sight to dozens of cell towers. As airplanes full of cell phones fly through the air they associate and disassociate with cell towers very quickly. The towers have to switch the handsets from tower to tower more quickly than usual causing a lot of network traffic signaling overhead between cell sites. Here's a wikipedia article on this [http://en.wikipedia.org/wiki/Mobile_phones_on_aircraft#Cell_...](http://en.wikipedia.org/wiki/Mobile_phones_on_aircraft#Cell_tower_channel_re- use)

Edit: added URL

</comment><comment><USER53> Relying on passengers to turn off their phones seems like the most ineffective approach no matter your desired outcome. Isn't it possible to insulate the cabin to prevent RF from exiting? This feels simplistic, but other than that is there a reason this wouldn't work?

</comment><comment><USER54> > 712 million passengers flew within the United States in 2010. Let's assume > that just 0.01 percent of those passengers...

> That would mean seven million people on 11 million flights endangered the > lives of their fellow passengers.

0.01% of 712M is 71200. </pedantic>

<comment><USER55> It looks like the writer meant either 0.01 or 1%, as all the other numbers work out to one one-hundredth. It is a common math mistake to mix the decimal representation and the percentile one. The same thing happens occasionally when people mix cents and fractions of a dollar.

I was immediately suspicious when it was implied that a 737 can hold 20,000 passengers.

</comment></comment><comment><USER56> Fear.

Put your cellphone near your FM radio. Listen in amazement as the digital chatter between your phone and some remote tower causes interference in your radio reception and affects your listening pleasure. Now imagine that same thing happening to the digital signals in the airplane's electronics while attempting to operate the craft. Catastrophe, chaos, etc. ad nauseum.

Realistic? Doubtful for many reasons. But that's the fear the bureaucrats, pilots, and passengers possess.

</comment><comment><USER57> Surprised the author doesn't bring up <http://en.wikipedia.org/wiki/Crossair_Flight_498>.

</comment><comment><USER58> A good friend of mine pilots commercial airlines and I asked her we're forced to turn off devices, she says it's cause cell phones can interfere in the same way as they do with music equipment. If one rings close to a loud speaker you get that tell-tale electronic ticking sound and she says that can make pilots not understand what air traffic control is saying … Not sure if this is true or if she'd actually experienced it before.

</comment><comment><USER59> It's also only in the USA that airlines are so insistent about the lack of electronics. On Asian domestic airlines, you get the same speech to turn them off, but then the flight attendants will just ignore you while you listen to your MP3 player during take-off. Asian domestic airlines don't fall out of the sky _that_ much more often than American ones.

</comment><comment><USER60> I remember an article I've read around 1983 when this regulation was first introduced. Some plane taking off suffered from instrument interferences at take off, and trouble ceased when they asked some guy to turn off his "Game & Watch". Though they tried hard to reproduce the problem, they couldn't, but the rule nonetheless applies "just in case".

</comment><comment><USER61> Next up in the app store: "Terror" - the app that crashes your jumbo jet. This app creates a magic pattern of radio waves that has a 84% chance of crashing the plane you are currently on.

If you plan to use this app for actual terror, be advised to buy an Android phone and not an iPhone, because there is no way this app will be accepted into the Apple app store.

</comment><comment><USER62> My college roommate was a pilot, and his explanation was that _on occasion_ some devices can cause static or interference on the pilot's headsets. Since communication with the tower is critical during takeoff & landing, the policy of power-off is in effect. I guess it's not as critical during taxi, since that is allowed.

</comment><comment><USER63> It was pointed out to me, years ago, that this is an FCC regulation not an FAA regulation, the reason given being that cellphones in the air can/do lock onto many more towers than on the ground (due to the inverse square law), and the network control protocols & software are (or were) not robust against this.

</comment><comment><USER64> If someone has flown on a light plane with analog instruments they've noticed that there's no reason to turn off your mobile (but keep it in your pocket when we're taking off please).

Yet, a B737 or an A320 is a much more complex plane. For instance, it has a lot of different electronic systems, ranging from the displays to the multiple, backed-up computers that enable flight controls (manual flight) and manage auto-pilot inputs.

I've seen a CRJ-200's first officer's (copilot) flight PFD and ND gone black and reboot because someone in the back was trying to call home, without much success.

The thing is, that never happened to my friend pilot before even with passengers trying to call. And the power output of a phone trying to call without much coverage isn't the same as the power needed in the center of a big city (and at 8000ft, inside a huge metal tube, the cell reception isn't great).

That's one of the main reasons. Granted it shouldn't happen and plane manufacturers do test against these kind of things. And really important systems, like backup instruments (standby) or flight computers are hardly going to be affected by any kind of interference, so, no, the plane isn't just going to drop from the sky. Yet an automatic A/P disconnection on long final on the PF's (pilot flying) PFD and ND displays going nuts is something serious.

And on the side of that, you don't want people having unknown electronic devices sending signals when pilots have to be more focused (take off and landing) and you better have them keeping an eye outside (or at their newspaper, but you can't help that). That's pretty much the same reason why they ask you to have everything stowed and leave your window 'opened' (you can see if there's something wrong outside, like fire, and report it) during takeoff and landing.

</comment><comment><USER65> The flight I was on last week mentioned they had some sort of sensor that picked up 8 devices that were still on, and they waited for everyone to turn them off before taking off, so I think they do know if people "forget" to turn them off.

<comment><USER66> Well, my wife always forgets to airplane-mode or turn off her phone on flights... and takeoff/landing makes her crabby so I've given up trying to remind her (esp. when there are no negative personal consequences after a dozen of such instances).

I'm sure she's not the only one.

</comment></comment><comment><USER67> If shutting down the devices where so critical the crew would have portable scanners.

</comment><comment><USER68> Airlines should encourage passengers to keep their mobile devices on.

That would allow pilots to test their equipment and make sure there is no dangerous interference with passengers' mobile devices.

<comment><USER35> Your comment made me think of Netflix' "Chaos Monkey" -- the system which randomly disrupts PRODUCTION systems:

[http://www.codinghorror.com/blog/2011/04/working-with-the- ch...](http://www.codinghorror.com/blog/2011/04/working-with-the-chaos- monkey.html)

Perhaps eliminating restrictions on electronics use would have a similar effect. What if the FAA started out by allowing use on a select number of flights where the pilots were highly trained and aware of the supposed risks? Over time, restrictions could be lifted more broadly presuming these initial experiments showed no cause for concern.

</comment></comment><comment><USER69> This is one of those rules that I feel completely fine breaking. I just wish I didn't have over-zealous flight attendants yelling at me all the time.

</comment><comment><USER70> That there's no recorded incidents relating to everyone switching on/off simultaneously highlights the lack of risk.

</comment><comment><USER71> Even on the slightest chance that a consumer device would cause interference, do you think having to put them away is so bad? On take off and landing you are also near other planes, populated areas.

Also don't forget with the 3.5 oz limitation someone did use that kind(Liquid) as an explosive to try and take down a airplane. poor electronics getting jolted from a peaceful sleep with a bullhorn.....

</comment><comment><USER72> 1\. When so much is at stake to err on the side of caution seems reasonable. 2. I have not been in a plane for a while - so can't quite visualize what it looks like - but in the event of an emergency abort on take off, or a landing that goes wrong - having all loose items stored is a head start in ensuring ones iPad does not become an iGuillotine. Just a thought.

<comment><USER73> This is why I always look warily at the cups of hot coffee, salads, hamburgers and foods with plastic knives, glass bottles, physical books, newspapers everywhere, babies with their toys and more when I fly 2+ times a month, right? On top of the food and drinks being served to people flying anything but economy class.

I'll take my chances with an iPad in somebody's hands flying into my face over a cup of scalding hot coffee splashing everywhere any day.

It's one thing to tell people to put things away or to watch out for safety's sake during important times like landing/takeoff and turbulent areas (and really, that should only extend to things like clearing the aisles and trays and armrests), and it's another to justify a questionable demand like "turn off your cell phone" in the name of "safety".

</comment></comment><comment><USER74> I actually never turned off my phone/gameboy/mp3 player and that since ages.

</comment><comment><USER75> So, when you fly private what do they ask of you?

</comment><comment><USER76> that's why I just don't turn off my devices

</comment><comment><USER77> The luddites win sometimes.

</comment><comment><USER78> I think its because that if there were an accident involving the spill of aviation fuel (even in an aborted takeoff situation, I can see that happening) then the danger of ignition would be that much greater if everyone's phones, tablets, laptops, etc were all in a powered-on or RF transmit mode.

It makes good sense to minimise that risk.

I recall years ago you were not permitted to use a cellphone on the forecourt of a gas station. No one seems to remember or bother about that now.

<comment><USER79> FACT: the risk of my mobile phone igniting vapourised fuel in a gas station forecourt is almost exactly equivalent to the probability that my ipod nano will tangle with an airplane's cockpit electronics.

It's all myth and fud spread by a) people with ulterior motives (see above) b) people who are too uneducated or too stupid to make their own judgement. Like air hostesses, petrol attendants.

<comment><USER80> Inside your iPod nano, or any other device with a computer chip is a radio transmitter. Inside the cockpit are many radio receivers, some of which are pretty critical to the proper flight of the airplane. Your radio transmitter, and radio transmitters being run by other passengers, mix and mingle their signals, producing an unpredictable effect on these key cockpit receivers.

The probability that this happens is not zero or low, but very high.

<comment><USER81> 1\. Not all devices with a computer chip have radios, my TI-84 calculator has a Z-80 processor but there is no radio in it 2\. Aircraft radios operate on a very different frequency then consumer electronics, and I'm pretty sure the FCC wouldn't allow consumer electronics to operate on the same frequency as the radios in a cockpit regardless

<comment><USER82> Technically, yes, there is a "radio" in your TI-84. The Z-80 is clocked by a crystal oscillator, which runs at a few MHz. Some of that energy will escape in the form of electromagnetic radiation. Sensitive instruments (including an ordinary AM radio) can pick up this radiation from distances ranging from a few inches to several yards. This is true of essentially all modern electronics, although the frequencies have obviously gone higher and higher over time.

If it were true that the RF energy levels emitted by FCC Part 15-covered consumer electronics could interfere with aircraft systems, it would be utterly unthinkable to permit them on board in the first place, whether "powered off" or not. The TSA would be confiscating Game Boys, not bottles of water. Since that isn't happening, it's difficult to avoid the conclusion that the prohibition is just one more exercise in bureaucratic security theatre.

<comment><USER83> If all electronic devices were dangerous, airlines would be asking passengers to remove the batteries from their wristwatches for the duration of the flight.

</comment></comment></comment></comment></comment></comment><comment><USER84> It's because everyone hates each other while flying anyway, and if people had to fly 5 hours with some dumbass yelling on his cell phone the entire time there would be a lot more incidents of "air rage".</comment>


On-The-Fly Garbage Collection: An Exercise in Cooperation (1978) [pdf] - <AUTHOR> http://lamport.azurewebsites.net/pubs/garbage.pdf <comment><USER2> (1978)

<comment><USER3> And still relevant. Some things don't change.

<comment><USER4> One of the professors at the University I graduated from used to say: "Basically everything in this(IT) industry was invented during the seventies. It's only now that we're able to use all that knowledge."

<comment><AUTHOR> On the one hand that's kind of cool, but also really sad. We should do better.

<comment><USER5> There was a lot of progress on GC in the nineties, a couple advances in type theory, a new way to organize databases, and at least two new families of compression algorithm. It's not all downhill.

<comment><USER3> I'm not aware of the GC progress. Generational with compacting young and mark- sweep old has been around since Smalltalk irrc. Was it making it concurrent?

<comment><USER5> Every issue of SIGPLAN in the late nineties had a new paper on improvements or alternatives to generational collectors. Off the top of my head, page marking, to reduce old generation collection, then we had pretenuring and that expanded into escape analysis in 99 or the '00s

Superpipelining interpreters and inlining polymorphic dispatch are some of my favorites for the '00s.

<comment><USER6> The first cycle collectors for reference counting too, so backup tracing wasn't required.</comment></comment></comment></comment></comment></comment></comment></comment>


Network Performance issue in Brazil - <AUTHOR> https://www.cloudflarestatus.com/incidents/d13tr9267zkl <comment><USER2> Any chance we'll get to read a postmortem on this incident?</comment>


The Spy at Harriton High - <AUTHOR> http://strydehax.blogspot.com/2010/02/spy-at-harrington-high.html

<comment><USER2> The more I here about this story the scarier it sounds. It's something straight out of 1984 and a complete invasion of privacy. Given that the children were all minors - spying on them secretly outside of school raises all sorts of moral and legal issues. Given that a student was reportedly disciplined based upon these spy photos, presumably the teaching staff (and not just one over-zealous & misguided IT bod) were fully aware of this.

This is the kind of thing the western media perceives as happening in countries like China, not in America, the 'land of the free'

<comment><USER3> While you've got a point, things like being the 'land of the free' aren't self-enforcing.

We are and will continue to be that because the people responsible for this will:

      Have their lives ruined.

      Be out a *lot* of money.

      Very possibly end up in prison.

Whereas we've recently seen that the PRC's response to people being upset that shoddy school construction resulted in the injury or death of their child (singular, One Child Per Family...) in the recent earthquake is to throw _them_ in jail (or the like).

You're always going to have immoral people in a society who think they're above the law, the critical thing is what you do to correct them and to provide harsh object lessons for others who are tempted.

<comment><USER4> The PRC is a bad example for that; they're also likely to execute you:

[http://www.smh.com.au/news/world/china-executes-corrupt- offi...](http://www.smh.com.au/news/world/china-executes-corrupt- official/2007/07/10/1183833517978.html)

Nigeria or even Russia would probably be a better example; at least they're not famous for killing people for corruption.

That said, your main point is completely correct: this is the system working.

<comment><USER3> I don't know that they're _likely_ to, I get the impression that that is more for show when things get too hot, too obvious. In this case it happened in conjunction with events like the FDA advising us to throw out any PRC made toothpaste. And his appeal was denied because "he was a 'great danger' to the country and its reputation" (<http://english.sina.com/china/p/2010/0210/303963.html>).

But you're right in part because they feel like they have to keep up appearances and they will upon occasion reach up high, something that hasn't been true in Russia for who knows how long. (Then again, we don't know if Zheng Xiaoyu's real crime was losing a political battle.)

In this case I used the PRC as the counterexample because it was what the parent commentator used. Another good one would be the place that inspired _1984_ , where ever greater violations of civil liberties, due process and the rule of law as well as privacy are taking place without noticeable push back.

I don't know what would be happening in the U.K. if some school there tried to pull off this sort of nearly literal " _1984_ " (not quite, since the video monitors in Oceania were explicitly there to spy on you, you just didn't know when someone would be paying attention) ... but I wouldn't be sanguine.

<comment><USER5> _I don't know what would be happening in the U.K. if some school there tried to pull off this sort of nearly literal "1984"_

With all the video surveillance and things like ASBO laws in the UK, would a story like this even be considered news?

<comment><USER3> One wonders, but I hope it would still be a stretch from Anti- _Social_ Behaviour ("in a manner that caused or was likely to cause harassment, alarm or distress to one or more persons not of the same household as himself" ([http://www.opsi.gov.uk/acts/acts1998/ukpga_19980037_en_2#pt1...](http://www.opsi.gov.uk/acts/acts1998/ukpga_19980037_en_2#pt1-ch1-pb1-l1g1) )) and cameras in public to a state required camera taking pictures of your disrobed daughter in her bedroom.

</comment></comment></comment></comment></comment></comment><comment><USER6> Really? Nobody's done a full forensic recovery of some of the kid's hard- drives? Since it's a pretty good bet that at least one picture of a naked minor was captured, the child porn cops should be all over the entire IT infrastructure of that school and all of the employees involved.

<comment><USER7> Think about what would happen if I were to donate a pallet of laptops to my niece's school, and then one of the parents accused me of spying on their kids through the camera.

My house would be raided by a SWAT team and _everything_ electronic in it would be taken...TVs hard-drives, computers, computer monitors, networking equipment, routers, servers, camera equipment, _everything_.

The fact that this _isn't_ happening to the school administrators is hideous. Not only did they admit that what they're being accused of is possible, they demonstrated it!

<comment><USER6> They also allegedly put in place official policy designed explicitly to prevent students and parent from ensuring their safety and privacy. Disabling the camera was an offense punished by expulsion.

To put that in perspective, I think most school districts punish students this way if they bring a loaded rifle to school.

<comment><USER8> Can you point to documentation of this?

It definitely sounds like something a school district would do. I am just asking because I have seen this stated in a bunch of hacker news comments, but haven't seen where this information came from.

<comment><USER6> [http://strydehax.blogspot.com/2010/02/spy-at-harrington- high...](http://strydehax.blogspot.com/2010/02/spy-at-harrington-high.html)

I can't find the official school policy from the school. But I haven't found anything disputing this either.

</comment></comment></comment></comment></comment><comment><USER9> I'm just waiting for the inevitable "creeper in the IT department used spyware-laden laptops to take pictures of kids in their bedrooms".

Parents seem to have weird privacy expectations of their kids but you can be sure they will scream bloody murder over a peeping tom.

<comment><USER10> I think by now its pretty obvious that every time there was a "glitch" and the green light on the camera flashed, a picture was sent in. I've had macbooks for years and I've _never_ seen the camera light blink like described.

Someone in that IT dept was collecting pictures of students. My moneys on Mr. Perbix, thanks to his overly smug _god of IT_ attitude. This story is going to get much worse before we see its end.

</comment></comment><comment><USER3> See also this good guess at what actually happened, it even helps make sense of the school's current claims: [http://yro.slashdot.org/comments.pl?sid=1559200&cid=3123...](http://yro.slashdot.org/comments.pl?sid=1559200&cid=31234034)

</comment><comment><USER11> That's insane. Although I find myself a little annoyed at the "can't disable the camera" part.

A little electrical tape will fix that. Sometimes the simple solutions are the best.

<comment><USER12> Presumably, doing something like that could be considered grounds for punishment, based on the school's track record.

<comment><USER13> Please, punish me for putting tape on my laptop at home. Please. Pretty please.

<comment><USER14> Are the laptops school property? I'm sure they could do something if they were.

<comment><USER15> Yeah, but how would they know? They would have to admit to the spying.

<comment><USER16> because they're so very shy about that.

<comment><USER15> Ha! Good point.

</comment></comment></comment></comment></comment></comment></comment><comment><USER17> I am thinking that a custom OpenBSD firewall with some good logging and some counter measures for specific monitoring software might not be a bad idea.

This story is just getting more wrong with each article.

<comment><USER3> A good idea if the state ever hands you a laptop you _must_ use. Then again, this was really in the students' faces, thanks to Apple wiring the camera and its LED together.

<comment> brown9-2 I think that if a state ever starts mandating laptops, they'll probably be mandating firewalls too.

<comment><USER3> I don't think they can (in the US, at least, at least for now) mandate "no firewalls" at your home. Ignoring that the state of the art as deployed (Windows) makes that impractical.

I don't think we're even close to "only government approved firewalls at your home".

</comment></comment></comment></comment><comment><USER18> I grew up one township over from Lower Merion and am frankly shocked to hear about all this going down (part of my home township is split between Lower Merion and my school district)

It's the kind of absurdity that I wouldn't expect - it's a fairly wealthy school district and I'm not surprised at the giving of laptops to students. What I'm shocked at is that they seem to have completely failed to a) Hire competent and reliable IT staff b) Internalized and understood the security and liability issues at an administrative level.

<comment><USER19> UDSD? I can tell you that if they had the technical knowledge to implement something like this, they certainly would have.

<comment><USER18> Presumably you mean Upper Darby, in which case no, I was at Haverford.

I was out before Haverford started really implementing computers (at the time they didn't even have computers for the teachers) but I suspect you're right - if they could have done something like this they would have. I can recall a very particular mentality among the administration there which was much along the lines of 'protect the students from themselves at all costs'.

A shame, though.

</comment></comment></comment><comment><USER20> I wish I had one of those in high school. It would have been fun to crack it :)

Actually I probably would have gone after the remote administration server too.

<comment><USER3> Until you avoid expulsion only because there wasn't (yet) a policy saying you couldn't jailbreak it, according to someone claiming to be a former student: <http://www.saveardmorecoalition.org/node/4216>

(Of course I'm wondering about the physical security on the hard drive (e.g. an unrepairable seal); an obvious thing to do is to image the drive and proceed from there. Although I'm sure that's explicitly against policy and that they're looking for tool marks and so on.)

<comment><USER21> I haven't been keeping up on this much, but they were Mac laptops, right? Boot it holding apple+T (I think), and it acts just like a normal firewire hard drive. No physical damage required.

<comment><USER22> I think this was disabled with the EFI security password.

</comment></comment></comment></comment><comment><USER23> Anonymous is going to have fun with this chap.

<comment><USER24> When did 4chan become the Batman of the Internet?

<comment><USER25> They have a very long history of this behavior - probably as long as their existence (anonymous's existence not 4chan's).

<comment><USER24> They have a very long history of being pranksters -- when did we start to think of them as avenging antiheroes?

</comment></comment></comment></comment><comment><USER26> My two 16 year old cousins go to Harriton. They were thrilled that they got free laptops for use at school. I've frequently seen them or their friends post videos to Facebook which makes me think that they know that if the light is on, the webcam is working. I'm going to give my uncle a call tonight, I'm sure that hes furious about this.

</comment><comment><USER27> I would just stick a piece of tape over the lens. Try writing software to counter that.

(And the administration complains, their "evidence" is "I was trying to take a picture of you getting undressed, but I got a piece of tape instead." Nobody is going to say that, and so nobody is going to "call you" on your tape- sticking.)

<comment><USER3> I wouldn't be surprised if there was a zero tolerance (zero thought) policy against "defacement", including putting "stickers" on the laptops. They wouldn't say _really why_ you had to remove the tape, just that their policy said so.

The plausibly deniable "oil or butter" on the lens suggested by bootload in this topic sounds better to me, only problem there is that you wouldn't know it was enough.

Maybe just rigorous do the tape while it's at home and you have to use it (for classes where it's required).

<comment><USER28> Well tape especially something not as adhesive such as electrical tape can be easily removed without defacing the computer, even half a post it note would work as intended.

<comment><USER27> A post-it note is what I had in mind originally.

If my kid got expelled from school for putting a post-it note over the spycam, I would not hesitate to use my savings to sue the *&$# out of the school district.

<comment><USER3> Business opportunity: ant-spycam stickers with Post-It Note (TM) type adhesive that have relevant for the environment graphics. I.e. I'm thinking of the before my time IBM "Think", something small enough to fit the form factor and that _should_ be unobjectionable in a school setting.

Any zero tolerance policy for "stickers" ought to fail in the aftermath of this Charlie Foxtrot, especially as the nasty details come out or are blatantly suppressed.

</comment></comment></comment></comment></comment><comment><USER29> I have a netbook with a camera (my laptop is 95 percent closed) and it sometimes creeps me out that it's watching me all the time (even though I'm the only person who's ever used it.) If I had a school-issued computer, spying is the first thing I would have thought of.

</comment><comment><USER30> This is really horrible.

But it's largely getting this level of attention because of the shock value (ooh, pictures!). In fact, this is just one more predictable step in the entrenchment of the police state that compulsory school by its nature is.

</comment><comment><USER31> Where's the Fox News at 11 story "Is your school taking pictures of your children?"

... after all, they did cover pleaserobme.com

</comment><comment><USER32> If this is what school administrators do in the suburbs outside Philadelphia -- birthplace of the constitution! home of the Liberty Bell! -- imagine what countries like Libya or Nicaragua will try to do via their OLPC units.

<comment><USER33> > birthplace of the constition! home of the Liberty Bell! -- imagine what > countries like Libya or Nicaragua will try to do

One of the major reasons countries like Nicaragua are what they are is because the country born in the "suburbs outside Philadelphia -- birthplace of constitution" has been sponsoring corrupt dictators there under the disguise of some "war on drugs" or "war on communism". No this is not a diversion of topic. The illusion (I think delusion) of liberty, equality, rule of law is just that -- an illusion. Police, NSA, CIA have long had the ability to spy on US citizen without any warrants. Our beloved President personally voted to provide immunity to the telecom companies that just handed our privacy on a silver platter to NSA, CIA and anyone who asked for it (Choicepoint & friends). Then we turn around and are just "shocked" that a school would pick up the cue from its big brother and run with it.

They are probably thinking: if the government is going to "protect" its citizens by spying on them, we will "protect" our children even more by spying on them harder!

</comment></comment><comment><USER34> So I don't understand why this guy specifically is targeted. He posted some scripts to disable the webcam for normal users, he talked about using the software to do what it was intended to do. I'm not convinced that because he didn't mention "theft recovery" until the middle of the podcast (granted, I did not listen to the podcast), he must have been remotely controlling users' computers. I don't see any evidence that incriminates Mr. Pibrix as anything more than IT guy taking orders, and I think it's irresponsible to post information like this without due process or at least offering Pibrix a chance to respond.

<comment><USER3> "I was just following orders" to set up a system that would _inevitably_ create child porn does not sound like a sufficient defense to me.

The software in question would phone home whenever the laptop was connected from other than the school's LAN and start making pictures; at that point, the only thing the system could do would be to allow retention of them or not.

<comment><USER33> His rational superiors should obviously start scapegoating him by now to divert attention and blame. Their strategy at this point should be to paint this guy as a deranged, power hungry nerd who took matters into his own hands. They should fire him immediately.

(I am not saying whether it is his fault or someone above him ordered it, but I am assuming his superiors are soulless bastards who can hire expensive attorneys. He might be just as bad, but he cannot hire lawyers and PR firms).

<comment><USER35> I was just talking about this with a friend of mine. He seems like the ideal candidate to be thrown to the wolves.

I think the vice principal, and any other staff with _knowledge_ of the spying capabilities should not be allowed to shove the blame onto the tech staff. Everyone involved should be punished to the full extent of the law.

</comment></comment></comment></comment><comment><USER36> I loved the mechanical latches old Macbook Pro's had for this reason. Creepy story and great reporting!

<comment><USER36> I meant the latches to close built-in iSight. Come on now, how can HN have such a clueless member to think that the lid opens itself up:-)

<comment><USER37> i have the original MacBook Pro, bought two weeks after the the line was introduced in 2006. It has no latch to close the isight camera. You sure you're not thinking of a different model? I don't think the older Powerbooks had them either although I could be wrong.</comment></comment></comment>


IBM 5150 Technical Reference Manual [pdf] - <AUTHOR> http://www.minuszerodegrees.net/manuals/IBM_5150_Technical_Reference_6322507_APR84.pdf <comment><USER2> This is one area where progress over the last few decades definitely haven't improved things. Just having a clear memory map available for a machine is something that seems to be a lost art, much less complete register descriptions...</comment>


30 second arithmetic challenge - <AUTHOR> http://christianp.github.io/30secondchallenge/ <comment><USER2> I was doing fine until I got to "multiply by itself twice". Is that "x := x * x * x", or "x := x * x; x := x * x"?

<comment><USER3> This caught me out too.

</comment></comment><comment><USER4> This reminds me of morning routine back in grade school called "Mad Minute" where we would be given a sheet containing 30 or 50 simple equations to solve. You'd have to complete it in a minute and the teacher would stopped grading at the first wrong answer so getting the first one wrong follwed by 49 correct answer would net you a score of zero.

When I first transferred to that school I was terrible at it but I did get pretty good at it later on. I think it did a lot for my arithmetic skills.

<comment><USER5> I _hated_ "Mad Minute." I felt I had to do perfectly on it, since some other kids did - and that was the standard the teacher set.

</comment></comment><comment><USER6> Another fun game you can play in traffic[0] is to factor the license plates of the cars ahead of you.

Weirdly, I found that doing this sort of practice made me better at abstract mathematics. I used to think that Gauss, Euler and von Neumann being excellent mental calculators was a side effect of their talent, but I wonder now if this sort of practice actually amplified it instead.

\---

0\. In your car-- on foot it's surprisingly dangerous.

<comment><USER7> That's surprising. Mathematicians generally are not very good at calculations and it always seemed to me that doing calculations fast is quite different from mathematicians do and need.

<comment><USER8> Back in the time of Gauss, mathematicians needed logarithm tables, and the only ones they trusted making them where mathematicians. So, mathematicians computed logarithms 'in their spare time'

For example, Gauss actually spent time to write a review of a table of logarithms ([http://articles.adsabs.harvard.edu//full/1851AN.....32..181G...](http://articles.adsabs.harvard.edu//full/1851AN.....32..181G/0000095.000.html)).

He also had to compute prime numbers so that he could study their properties. ([http://science.larouchepac.com/gauss/ceres/InterimII/Arithme...](http://science.larouchepac.com/gauss/ceres/InterimII/Arithmetic/Primes/Primes.html) claims he extended a table listing all primes up to 10,009 but never got as far as a million, but he must have spent lots of time on calculations we now call mundane

</comment></comment></comment><comment><USER9> I wrote a small script to solve the easy ones in the browser: [https://github.com/rhnvrm/30s_challenge](https://github.com/rhnvrm/30s_challenge)

Here is the script for solver: [https://github.com/rhnvrm/30s_challenge/blob/master/solver.j...](https://github.com/rhnvrm/30s_challenge/blob/master/solver.js)

and here is the cheat: [https://github.com/rhnvrm/30s_challenge/blob/master/cheat.js](https://github.com/rhnvrm/30s_challenge/blob/master/cheat.js)

Also, I found that since the methods of the game and challenge class are public, you can actually just call it's functions. I also found a useful resource for learning OOPs in js [http://phrogz.net/js/classes/OOPinJS.html](http://phrogz.net/js/classes/OOPinJS.html) and how to make methods private. There is another cool article here on how to make members private and protected here [http://philipwalton.com/articles/implementing-private-and- pr...](http://philipwalton.com/articles/implementing-private-and-protected- members-in-javascript/)

</comment><comment><USER10> This makes me realize my long multiplication above 100 really sucks.

</comment><comment><USER11> Jeez, I got to like operation 3. That said, I am surrounded by beer cans, so... yeah, don't drink and derive.

</comment><comment><USER12> I think hard is bugged? It is around easy's difficulty and much easier than medium.

<comment><USER13> Medium and hard throw in new kinds of operations, but how hard a problem is for me at least seems to mostly scale with the number of digits I have to juggle, not the operation "complexity".

E.g. if I'm at 14, an "easy" multiply "by itself" forces me to multiply long- form (I don't even have 4 x 14 in my mental LUT... so 140 + "uh... 56 plus..."). On the other hand, again starting at 14, a "hard" multiply by 4/7 instead is trivially 8 (mentally rewriting to (14/7)*4)

</comment></comment><comment><USER14> This reminds me of a math game we used to play in elementary school called 24. I also recreated it, uses websockets for multiplayer:

[https://get24.jit.su](https://get24.jit.su)

<comment><USER15> Please allow easy editing of previous wrong guess

</comment></comment><comment><USER16> Really fun, nice game!

4/6 easy, 19.1s 47/77 medium, 16.2s 19/25 hard, 17.8s

I started scribbling numbers on paper without looking down when I got to the hard ones, which helped...but I still think the hard ones were slightly easier than medium ones.

Good question design: forcing you to look ahead simplify things like 69 * 2 - 5 / 7 ...

realizing that 69 is one smaller away from being evenly divisible by 7, when doubled is 2 smaller, minus 5 makes it 7 smaller so the divided by 7 can apply to the thing it's close to...140 as well as the 7 smaller..140/7 minus 1...19

Common core on steroids?

</comment><comment><USER17> Please make / and + more distinct!

<comment><USER18> Yes, it's hard to see the difference.

</comment></comment><comment><USER19> This is the most infuriating thing I've played since QWOP

<comment><USER20> Didn't know that one, lucky it's saturday

</comment></comment><comment><USER21> Looks like a place to practice mental arithmetic tricks, you know, like multiplication by 11:

      11 × 16 = 1(1+6)6
      34 × 11 = 3(3+4)4
      124 × 11 = 1(1+2)(2+4)4

Or multiplication table 10 through 20:

      14 × 17 = (14+7) × 10 + 7 × 4
      13 × 18 = (13+8) × 10 + 8 × 3

</comment><comment><USER22> I don't understand how this works. Are you supposed to enter the answers as you go? Or just the final answer? I tried entering intermediate values and got zero feedback from the interface.

</comment><comment><USER23> The trick seems to be to avoid subvocalising (where possible).

<comment><USER24> Why does that help?

<comment><USER25> supposedly subvocalising is slowing you (resources allocated to your TTS module rather than to your arithmetic coprocessor ;)

</comment></comment></comment><comment><USER19> This is the most infuriating thing I've played since qwop

</comment><comment><USER26> This is a rather fun little exercise. Would be good to use in a classroom, although I found it a little hard going from left to right on a laptop screen

</comment><comment><USER27> Small bug: When you did not solve it in time and the answer is diplayed, clicking on the timer will add it to the solved count.

</comment><comment><USER28> 11 ... ok

+5 ... easy

x itself ... ugh. more coffee.

divide by 7 ... TI83 slides out of desk drawer

Actually it's really fun - thanks :)

</comment><comment><USER29> Fun, reminds me my school classroom exercise in elementary

</comment><comment><USER30> Got an A in calc II but this gets the better of me? GRRR!

<comment><USER31> It's arithmetic, not calculus. In both your performance depends on three factors: technique, practice, capacity. I don't know about capacity, but practising and learning calculus techniques is not the same as practising and learning arithmetic techniques. In fact if you wan't to get good at calculus it is probably counter-productive and inneficient to waste time on solving arithmetic operations "by hand" when using a calculator will be much faster and help you keep focused on the calculus problem at hand.

</comment></comment><comment><USER32> This is amazing, and I need to work on my arithmetic.

</comment><comment><USER33> Its like kind of frappy bird game, some may get addicted, not to lose...</comment>


Should I drop out? - <AUTHOR> http://www.quora.com/Should-I-drop-out

<comment><USER2> I'm not on Quora, so I can't answer there, but here's my take ...

School/College/University is an unparalleled opportunity to learn stuff. If you're bored, it's your problem, and you need to take control. If you're convinced the existing classes only cover things you already know, go and get an exemption. Perhaps you can choose not to attend, but then ace the exams. If so, do that.

You need to find interesting stuff. Audit, and perhaps take, classes that are a year, even two years, beyond where you are. If they have prerequisites that you haven't done, get an exemption.

Believe me that the professors will want to keep you, and if granting a probationary exemption will do it, they'll do it.

But _you need to take control._ You need to show them that you understand their concerns, and that you will not fail and flunk out.

Yes, this is hard work. Yes, this requires initiative, but if you're the kind of person who will do well at a startup then you've got initiative in bucket loads, and you're not afraid of hard work.

So here's a challenge - go and get your degree in one year instead of four. That would look good on your resume, especially if you also have a side- project to demonstrate.

Note: Some of the above might be bad advice for you. But what's certain is that if youre finding college boring, the future is in _your_ hands.

<comment><AUTHOR> It was actually not my question on Quora. I just noticed it and found it very intriguing. However, your advice could be really helpful for the guy.</comment></comment>


Show HN: An interactive comparison chart of the 300 most popular smartphones - <AUTHOR> http://things.gnod.com/smartphones/ <comment><USER2> Wow, this is really cool.

But I wish we'd stop saying "memory" when we mean "storage" ... seeing "Memory" and "RAM" next to each other is a bit confusing, since they're the same thing.

</comment><comment><AUTHOR> I did this type of product comparison chart for Laptops, Solid State Drives, Flash Drives and MP3 Players in the past. Dubbed them "Tourist map of Laptops" etc. The tourist thing caused some confusion, so I simply went with "comparison chart" this time.

If you have suggestions for more features, let me know. Also if you have suggestions which product category to chart next. Either here on HN or on my blog: [http://www.gibney.de/the_smartphone_comparison_chart](http://www.gibney.de/the_smartphone_comparison_chart)

<comment><USER3> Some filter suggestions: camera resolution, year released, battery life, and OS (and version). I don't know where you're getting the info from, but these could all be pulled from gsmarena.

<comment><USER4> Physical keyboard. I only buy phones with physical keyboards. ...Hm, I haven't bought a phone in a while.

<comment><USER5> It seems like there are a lot fewer of us keyboard zealots these days. I've been hoping to see an update to my now 4-year-old HTC Desire Z. Physical keyboard, removable storage, and swappable SD cards are great - I really don't want to give any of those up.

I resigned myself to getting a new Nexus device since so few apps are coming out for Android 2.3 anymore, but then they came out with that 6" monster... I really have no idea what phone to upgrade to. Nobody makes a phone I want anymore.

<comment><USER6> Both of you should look at the Neo900:

[http://neo900.org/](http://neo900.org/)

It is an N900 chassis (inc keyboard) with a GTA04 motherboard plus some cool anti-spying features to isolate the LTE modem (which of course runs a proprietary OS).

</comment></comment></comment></comment></comment><comment><USER7> Looks nice. Might I recommend that you look into adding easing to your animations. It looks like you're using simple linear interpolation to move the points from place to place. If you use cubic easing they'll accelerate then decelerate, it looks a lot more natural that way. Linear interpolation looks robotic.

See this for more details: [http://api.jqueryui.com/easings/](http://api.jqueryui.com/easings/) (specifically easeInOutCubic)

Other than that, very cool. Where do you get your data from?

</comment><comment><USER8> The OnePlus One is $349 for the 64 GB model right now. $299 for 16 GB. I was just on their website regretting my Moto X (2014) purchase.

Edit: I should mention that I _love_ my Moto X, especially with Android L - But the OnePlus One comes with Cyanogen, +1 GB of RAM, double the storage, much bigger battery, probably a better back camera, seemingly better screen/microphones, definitely better front camera... For almost $100 less. Ouch.

</comment><comment><USER9> Battery - that's the killer feature. I got the Huawei Mate 2, which is a cheap plastic build with a near-useless ROM (tons of anti-features), no upgrades (well now they claim Lollipop sometime next year), no open source for Cyanogen.

But the 4AH battery cannot be beat. I never worry about charging. If I'm tired when I go to bed, I just let my phone fall wherever. The only time it discharged was when I didn't charge it two nights in a row.

That kind of freedom of not constantly dealing with power, it's pretty great. Meanwhile, every other phone manufacturer focuses on getting through the day without charging, as if that's some amazing piece of usability.

It also shows how easy it is to make a fantastic phone. Put some parts together, and ship it. Huawei would have a top-class phone if they hadn't run their crap version of Android. And offer a separate model if you want a non- junk camera.

<comment><USER10> My old non-smart-phones lasted at least a week. I miss those days.

<comment><USER11> I missed them so much I sold my Android phone and went back to an old-school nokia. These days I charge my phone once a week, or less, and I miss features far less than I expected to.

</comment></comment></comment><comment><USER12> It has a great visual look, but I got really confuse when I start to adjust the filters on the left hand side. The phones icons started to jump to different spots on graph that does not seem to change.

Let me give you an example, as I changed the filter of the RAM from 1GB to 2GB, the icon Samsung Galaxy S5 G900F 4G LTE 16GB jumped over the icon for Samsung Galaxy S5 G900FD DUOS 4G LTE even though their specs exactly the same. When I saw that, I concluded that their screen sizes changed due to memory configuration as the x-axis of the graph is screen size. Yeah, I know it is a bad conclusion, but that what the graph says.

</comment><comment><USER13> It would be interesting to be able to chart the results with different axis constraints. Maybe graphing a processor index vs. price. It could be useful for scaling if you could set the search filters from the chart, so maybe you could "zoom" into a cluster and then pivot to other constraints.

edit: I suggested customisable axes, but I was on mobile at the time and didn't see that capability. Still, there may still be something to adjusting the scaling to zoom, so I'll leave this comment here and suggest that on mobile the feature should be more discoverable.

</comment><comment><USER14> This is such a great way to contrasting my younger self with my older self.

My younger self want's to adjust all those sliders.

My older self adjusted the screen DPI to 300 DPI, (where I can't see the pixels) and moved the weight slider from lighter to heavier until a phone showed up.

And all that showed was the iPhone.

I could care less about RAM, Sims, SD cards, memory, etc now. These aren't indicative of the experience. My younger self would have loved hunting down the right fit phone from the Android market. My older self? Nah. I'll go take some photos of my kids instead.

<comment><USER15> I just did the same as you and I see way more than iphone. [http://i.imgur.com/ROeAjIA.jpg](http://i.imgur.com/ROeAjIA.jpg)

<comment><USER16> The first weight that has anything (4 ounces) is the iPhone.

</comment></comment></comment><comment><USER17> Would you consider adding one's selection filters to the navigation hash, so that I can reload the page (or follow a link and come back) without having to re-do all of my filtering selections?

<comment><AUTHOR> Definitely. Im a bit undecided yet, if its better to do it in the querystring or in in the hash and if its better to use the parameters like

        ?min_ram=4&min_resolution=100&max_weight=6...

or have save-button and make querystrings/hashes like

        ?preset=384

Decisions, decisions....

<comment><USER18> Query strings should be more reliable, hashes can be lost for example when using an URL shortener. Also URLs should generally be kept to under ~2000 characters, so depending on how many filters you have you might want to take the preset approach.

</comment></comment></comment><comment><USER19> Turn up the storage to 128 GB and come to the realisation that android users are expected to use memory cards if they want to store all their videos/photos/music.

<comment><USER20> That's if their phone has an SD card, of course. Lots of Android devices assume you'll use some kind of cloud storage for anything you can't fit in the phone's internal memory.

</comment></comment><comment><USER21> Something seems wrong with the price of the Nexus 6. It doesn't cost $1150. It is at 600€ on Amazon.de, which is about 740 USD.

This seems like someone is trying to resell the phone at profit while supply is low.

The phone is justifiably getting bad reviews at this price, but Google and Motorola would probably not like this. Why is this possible on Amazon?

<comment><USER22> Same for Nexus 5, it's 432$ (345€) on Google (belgium) but it's $650 in the graph.

<comment><AUTHOR> I keep the prices in sync with Amazon. If the phone is not available from Amazon directly - as is the case for the Nexus 5 - I resort to the list price. I could resort to the lowest price from the Amazon marketplace but I have to check first if that makes sense in all cases.

<comment><USER23> Where is the list price of a 32gb Nexus 5 $649? The price on Google Play is listed at $399, and has been since the phone was launched over a year ago.

</comment></comment></comment></comment><comment><USER24> Really neat tool. I would like more granularity in the screen size selector. Perhaps in half inch increments?

+1 for radio capabilities.

</comment><comment><USER25> Some kind of age metric is often useful in a selector. For example, when was the phone first available on Amazon. Or what OS does it run. In a fast-moving market like phones, age is a dealbreaker. You might find just the right size, memory, price... but come to find out it is stuck at Android 2.3.

</comment><comment><USER26> Can you add the 2014 Moto X? [http://en.wikipedia.org/wiki/Moto_X_%282nd_generation%29](http://en.wikipedia.org/wiki/Moto_X_%282nd_generation%29)

<comment><AUTHOR> I think it's in there. Do you mean this one?

[http://things.gnod.com/smartphones/4155](http://things.gnod.com/smartphones/4155)

<comment><USER26> That's the lower cost Moto G, not the 2014 Moto X

<comment><AUTHOR> Sorry, added it now! [http://things.gnod.com/smartphones/4836](http://things.gnod.com/smartphones/4836)

</comment></comment></comment></comment><comment><USER27> I was just about to suggest customisable axes as a killer feature ... then went and discovered them myself :) This is a fantastic interface.

</comment><comment><USER28> Well done, this is very cool! Where do you get your data from? I would like to use the data in a different type of visualization.

</comment><comment><USER29> Does the motorola RAZR V3 really cost $300? Also, it certainly isn't a smartphone. Other than that I really like this chart.

</comment><comment><USER30> Hi! I was wondering is this a custom built solution? We could use this exact framework for internal reference for our products.

<comment><AUTHOR> Yes, it's custom built. Started it March this year. This is the latest iteration. If you like, tell me more about your usecase via email or irc.

</comment></comment><comment><USER31> it looks really cool . do you mind shedding more light on what all stuff you are using .. frontend and backend ..

<comment><AUTHOR> Sure. On the backend it's all custom code on top of a Linux, Apache, Mysql, Php stack. Frontend is all custom code with some light usage of jquery.

</comment></comment><comment><USER32> cool demo, but lacking xiaomi ?

</comment><comment><USER33> No Nexus 6?

<comment><AUTHOR> Added it!

<comment><USER34> Nope your still missing the 64GB Variation.. You only show apple and oneplus at 64GB memory..

<comment><AUTHOR> I added the Nexus 6 with 64 GB 5 minutes before your message. Either you tried before, or it's a cache issue. Try reloading real hard!</comment></comment></comment></comment>


Ask HN: What's the best service for sending money to your users? - <AUTHOR>

If a start-up wants to support either paying its users or facilitating payments between users (possibly keeping a percentage of the payment), is there an alternative to PayPal?<p>Are there gotchas associated with this process?  For example, ebay has buyers send payment directly to sellers and then bills the seller for ebay's fees after the fact.  Is there a reason for this approach?  Are there other online businesses that facilitate transactions, and what payment services/approaches do they use? <comment><USER2> Amazon Flexible Payments (<http://aws.amazon.com/fps/>)

 _Facilitate transactions between a buyer and a third party seller, take a cut of the transaction, and have control over who pays the transaction processing fees_

This is the payment system used by KickStarter...supporters pay through the site, and when it reaches a certain threshold, KickStarter initiates payment to the project owner, keeping a percentage. Note that the money goes directly from the supporter to the project owner (and 5% to KickStarter) and not all into KickStarter's account first.

I think the eBay approach is good if you want to accept more payment methods, such as money orders and checks. This model ensures that you can always bill a seller's credit card even when the transaction takes place outside of your payment system.

<comment><AUTHOR> Thanks, this sounds promising. I'll take a look. I never cease to be impressed by Amazon's collection of services.

<comment><USER2> Amazon is an impressive company...I sometimes forget that they also sell books!</comment></comment></comment>


Got a new job. No idea about Java but have to use J2EE. What to do? - <AUTHOR>

My new employer wants me to maintain an existing j2ee application but I don't have any idea how that stuff works. I have very little experience with java but I'm quiet comfortable with python. Whats the fastet way to get startet with j2ee w/o prior knowledge about java? <comment><USER2> Apart from the obvious observation that if the Java application is important then you are working for an idiot - then you have to start from the beginning like everyone else and read a good book. You will also need to become familiar with whatever IDE is used (Eclipse perhaps).

Take it slow, resist making changes in the early stages and build a scratch test version of the system at the earliest opportunity. This can be your play area until you are confident that you are doing the right thing.

</comment><comment><USER3> Since "J2EE" has changed a lot over the years, I recommend first that you determine which J2EE version the application was built with [1], which application server it runs on, which middleware it uses and which frameworks it uses (such as Spring). Then look for a book about the relevant J2EE version and frameworks.

[1] [http://en.wikipedia.org/wiki/Java_EE_version_history](http://en.wikipedia.org/wiki/Java_EE_version_history)</comment>