Intel Delivers 17-Qubit Superconducting Chip - <AUTHOR> https://newsroom.intel.com/news/intel-delivers-17-qubit-superconducting-chip-advanced-packaging-qutech/ <comment><USER2> I talked with Intel's director of quantum hardware about this.

[https://techcrunch.com/2017/10/10/intel-moves-towards- produc...](https://techcrunch.com/2017/10/10/intel-moves-towards-production- quantum-computing-with-new-17-qubit-chip/)

What they're really proud of is essentially bringing Intel's manufacturing advantage to bear on an extremely new and different form of computing. Being able to iterate with new materials and architectures every few months is critical for testing, and it's there (as opposed to sheer numbers of qubits or whatever) that Intel hopes to outstrip the competition.

I was also surprised to learn that the cryo systems that get things down to a fraction of a kelvin are only the size of 50-gallon drums. I was picturing something much larger for anything that low. Now I know!

<comment><USER3> Would be fascinated to hear anything you (or anyone in a related field) has to say on the challenges for cooling to such low temperatures.

Is it essentially just heat-removal + lots of layers of isolated, effective insulation, or are there fundamental differences when you're going that low?

<comment><USER4> I worked with NMR about 8 years ago in the uni. We used regular liquid helium to get to about 4.2 degrees K. The next step is He 3 isotope which is an order of magnitude more expensive but gets you an order of magnitude cooler (in degrees K). That usually runs in a closed system (heated He is not vented into the atmosphere) because of its cost.

The way cooking it was explained to me is that you try to slow down atoms with lasers, but I don't know any of the details.

<comment><USER5> From memory: you fire a laser at a frequency that is only absorbed if relatvistically shifted the way an electron that goes towards the laser would observe. This, the laser delivers momentum only to atoms coming towards it, and is invisible to those at rest or going away. Do from multiple directions and you've reduced absolute momentum in every direction.

Claude Cohen danucci received a nobel and a wolf for this (and other things)

<comment><USER6> [https://en.wikipedia.org/wiki/Doppler_cooling](https://en.wikipedia.org/wiki/Doppler_cooling)

</comment></comment></comment></comment></comment><comment><USER7> After reading the press release it seems to me its a Topological Quantum Computer[0].

They mention surface codes which are related to toric codes and toric codes are a part of topological quantum computation [1]. A explanation of toric codes can be found at [3]

Their website says that they specialize in Topological Quantum Computers and Quantum Error correction (which are a feature of Topological Quantum Computers. Also the link to the researchers website mentions similar projects . [2]

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

[1] [https://arxiv.org/pdf/0904.4165v2.pdf](https://arxiv.org/pdf/0904.4165v2.pdf)

[2] [https://qutech.nl/roadmaps/](https://qutech.nl/roadmaps/) [http://dicarlolab.tudelft.nl](http://dicarlolab.tudelft.nl)

[3] [https://physics.stackexchange.com/questions/29310/what-is- co...](https://physics.stackexchange.com/questions/29310/what-is-code-in- toric-code)

</comment><comment><USER8> Given the quantum computing chip space is getting increasing heated in competitions[1], can someone with industry experience and knowledge to compare Intel's chip with D-Wave's, Alphabet's and IBM's?

[1]: [https://www.bloomberg.com/news/articles/2017-09-13/ibm- makes...](https://www.bloomberg.com/news/articles/2017-09-13/ibm-makes- breakthrough-in-race-to-commercialize-quantum-computers)

<comment><USER9> Hopefully someone can expand on these comments since I'm not an expert, but I know a little.

D-Wave [1] is shipping quantum computers with thousands of qubits. The difference seems to be that D-Wave qubits are not generalized qubits, but rather they are simply designed to solve problems using quantum annealing [1]. Annealing is just one algorithm which efficiently (but probabilistically) looks for the global minimum of a function, but it is prone to getting stuck in local minima. Quantum annealing exploits quantum phenomena to do this better and probably more efficiently [2].

On the other hand, we have "general" qubits: these can implement and carry out any arbitrary quantum computing algorithm (for example, Grover's search algorithm or Shor's factorization algorithm). It seems to me that researchers at Alphabet, Rigetti, Intel, IBM, etc. are trying to build these general qubits, since that's where we can finally unlock the full power of quantum computing. It's also much harder to build these general qubits, and that's why we only see 17 qubits announced here, or Google claiming to be working on 49 qubits [3].

[1] [https://www.dwavesys.com/sites/default/files/D-Wave%202000Q%...](https://www.dwavesys.com/sites/default/files/D-Wave%202000Q%20Tech%20Collateral_0117F2.pdf)

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

[3] [https://www.bloomberg.com/news/articles/2017-07-17/google-s-...](https://www.bloomberg.com/news/articles/2017-07-17/google- s-quantum-computing-push-opens-new-front-in-cloud-battle)

<comment><USER10> Why the odd numbers? It seems like it would be simpler to run algorithms on something with 16 or 48 qubits.

<comment><USER11> The numbers come from quantum error correction and the goal to build a logical qubit (error protected qubit made of many actual qubits). In the surface code (planar version of a toric code), a single logical qubit protected with a code distance d = 3 corresponds to 17 physical qubits, and a distance d = 5 corresponds to 49 physical qubits.

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

[2] [https://www.nature.com/articles/s41534-016-0004-0](https://www.nature.com/articles/s41534-016-0004-0)

<comment><USER12> The number of physical qubits is 2d^2-1 in case anyone was wondering.

</comment></comment></comment></comment></comment><comment><USER13> It isn't clear to me from the press release whether these are similar to D-Wave's quantum annealing qubits, or if these are another type (e.g. more like a "true" qubit). Is there another source with more information?

<comment><USER14> These are transmon qubits... they're designed for long coherence times, in other words, to store quantum information for long periods of time. D-Wave qubits do not have long coherence times-- by D-Wave's own admission. They argue that long coherence times are not necessary for quantum annealing. Many don't buy this argument.

</comment></comment><comment><USER15> After 20 years in VLSI, I have no clue about quantum computers, and haven't found a good source explaining them. Anyone have any idea how they work?

Like, how does one produce logic gates out of them? How do you create an IEEE 754 Floating point multiplier? I get that they're supposed to represent overlaid states on the same device due to Pauli exclusion, but how do you separate out states and use them in logic? Or save states? What happens if logic produces the same state for one device? Is standard metal used to send signals, or is it something fancy-dancy like neutrinos?

It's honestly the most exotic thing I know of in tech, just trying to even begin to get a handle on it, never-mind trying to perform useful work out of them.

<comment><USER16> You are not supposed to reproduce classical systems on a quantum computer just the same way you're not supposed to reproduce electric circuits on a classical computer, even though it's made out of them.

For me myself one of the easiest concepts to understand was quantum annealing ([https://en.wikipedia.org/wiki/Quantum_annealing](https://en.wikipedia.org/wiki/Quantum_annealing)). It does not mean that's the strongest point of quantum computers, but it's a nice way to start.

<comment><USER17> I get where you're coming from with that analogy, but there is probably a better way to put it. Circuit simulation is a long-time application of computers ([https://en.wikipedia.org/wiki/SPICE](https://en.wikipedia.org/wiki/SPICE)).

<comment><USER16> You're down the Turing machine rabbit hole - I implied you could do that. Just the same way you could simulate a processor using an another processor - it's just not as efficient.

By the way - you could as well simulate a quantum computer on a classical computer; it'd just be incredibly slow.

</comment></comment></comment></comment><comment><USER18> Another interesting piece of news this week is that it seems that even 56-qubits can now be simulated, so the 49-quabit quantum computer Google planned to release this year likely won't achieve "quantum supremacy" anymore. To be _really_ sure, we may have to wait for the 100-qubit one first, before declaring quantum supremacy.

[https://phys.org/news/2017-10-quantum-computingbreaking- qubi...](https://phys.org/news/2017-10-quantum-computingbreaking-qubit- simulation-barrier.html)

</comment><comment><USER19> Ok well it's _definitely_ time to start planning a replacement for your 64 bit RSA keys.

</comment><comment><USER20> I'm really getting the sense that we're going to need to upgrade all our asymmetric crypto soon -- as in 10-15 years time frame.

Best contenders I see so far are supersingular isogeny ECC and NTRU or other lattice based algorithms.

</comment><comment><USER21> Slightly unrelated question but does anyone knows how quantum computing will change if Copenhagen interpretation is invalid and instead De Broglie–Bohm theory proves to be correct?

<comment><USER22> Not at all. Interpretations are interpretations, not changes to the mathematical mechanisms.

<comment><USER21> I have to disagree. EM drive is theoretically impossible with Copenhagen interpretation but with Pilot Wave not only it's possible but we can improve its efficiency. It would make sense that similar situation is possible with quantum computing.

<comment><USER23> How does pilot wave theory make violating conservation of momentum possible?

<comment><USER21> [https://www.sciencealert.com/physicists-have-a-weird-new- ide...](https://www.sciencealert.com/physicists-have-a-weird-new-idea-about- how-the-impossible-em-drive-could-produce-thrust)

<comment><USER24> Quickly looked at what is written in other articles by these authors, and it's total BS. Sadly that these 'research' made it way to sciencealert.com.

</comment></comment></comment></comment></comment></comment><comment><USER25> Article confused superconducting with superposition.

Edit: I was incorrect. Today I learned that Copper Pairs are being used as the qubits.

<comment><USER26> In any practical chip design, isn't one required for the other? i.e. it _is_ a superconducting chip, and that _is_ a major engineering problem and a key difference between this and a semiconducting chip. Superposition just happens to also be how a qubit works.

<comment><USER27> > In any practical chip design, isn't one required for the other?

No. Superposition (in a qubit sense) is not necessary for superconductivity. Most quantum computer designs require superconductivity, but it is not a strict requirement. Photon based quantum computers don't need any superconductivity iirc.

> it is a superconducting chip, and that is a major engineering problem

Superconductivity is not a super high bar. The bigger issue from quantum computing is coherence time; and it just happens that low temperatures are critical for lengthening it.

<comment><USER26> Well the point is whether or not this is a superconducting chip. It is. Since it is a superconducting chip, I'd like to know what OP meant when they said they mixed it up, because I don't see where they said superconducting where it isn't true and relatively relevant.

edit: also, I meant superconducting was (practically) required for superposition, but not vice-versa. I guess I misused the phrase one-required- for-the-other.

<comment><USER27> > Since it is a superconducting chip, I'd like to know what OP meant when they > said they mixed it up, because I don't see where they said superconducting > where it isn't true and relatively relevant.

I believe that everywhere superconducting was used it was correct and using superposition instead would be wrong. So I agree with you there.

</comment></comment></comment></comment></comment><comment><USER28> How much money have Intel, Microsoft, and Google sunk into quantum computing so far?

<comment><USER3> I think there are analogies to the article the other day on fear-driven investments in automation industries. As well as post-WWI naval construction.

To wit, can they afford _not_ to sink money into it, if their competitors are, even if success if less than certain?

The rewards that seem like they would be realized are generational enough so as to render much of the existing market obsolete. So to be caught without any expertise, on a risk-basis is more costly than seemingly dumping money down the drain.

</comment></comment><comment><USER29> What did I just read? "Any noise or unintended observation of them can cause data loss." Unintended observation?

<comment><USER30> Measurement requires interaction with the system, and interaction with the system breaks entanglement.

<comment><USER23> Or, more precisely, alters entanglement in an unkown way. Since the alteration is unkown, it interferes with execution and interpretation of the quantum algorithm.

</comment></comment></comment><comment><USER31> It's weird to me that (afaik) we can't use a small number of qbits to make attacks against large crypto easier.

<comment><USER32> Let's say you have an utterly amazing chip, that can solve any n-bit problem in a single second.

If n is 20, you're not really beating a 6502.

Being quantum lets a chip _scale_ its speed better. But that's about it. At this size, it's worse in every single way than a normal processor.

</comment></comment><comment><USER33> Wow. A small step but this shit is starting to get real.

</comment><comment><USER34> So, is it 1 (qu)bit faster than i8086? ;-)

Congrats Intel!

</comment><comment><USER35> So when can I have one for my desktop?</comment>


The Rolling, Lurching, Vomit-Inducing Road to a Seasickness Cure - <AUTHOR> https://www.hakaimagazine.com/features/the-rolling-lurching-vomit-inducing-road-to-a-seasickness-cure/ <comment><USER2> When I was doing the flight school, the first 20 hours were early morning or late evening to avoid turbulence. At around 30 hours, I was flying light planes very low over fields and forests in the middle of the day, I had motion sickness so bad that I was barely able to ride my motorcycle back home. I asked the instructors about this and they said something in the lines of "we all had it, it is going away with time".

The next year I never had motion sickness when I was in control of the plane, but if I had a copilot when we were switching control I still had some motion sickness in bad conditions. Several years later I almost never have any problems, unless I spend too much time looking at the maps and not outside of the cockpit. It goes away with time, it seems. I never tried sailing in the past few years to check if I can get seasick, but I noticed I am almost unaffected by car sickness that I had a lot when I was a kid.

One way to partially train for this was doing a couple of in-flight maneuvers that provoke sickness to almost anyone, including some seasoned pilots: inducing close to zero-g conditions, either by doing short slingshot maneuvers (point at 20-30 degrees nose-up and then push the stick keeping 0.5g, then 0.3g, then 0.2g) or doing it faster while extending the flaps to full, the sensation is very bad if someone does it to you, but it can be even enjoyable if you doing yourself flying alone. I practiced the slingshot part for a few weeks, this is what it took me to get to ~ 0.2g without feeling sick.

<comment><USER3> Do you get motion sickness in VFR conditions, especially having to focus on instruments?

I'm contemplating getting a PPL, but I'm very prone to motion sickness trying to read while flying. If I'm not resting, turbulence is just fine. First- person-shooters make make me sick, but third-person do not.

<comment><USER2> Yes, I used to get it in VFR, IFR flights are heavily restricted in my country (they are completely forbidden for light planes, same as night flights).

<comment><USER4> What country is that?

<comment><USER5> Romania, judging by the profile.

</comment></comment></comment></comment></comment><comment><USER6> Stephen wolfram turned me on to these goofy glasses ([https://www.smithsonianmag.com/innovation/could-these- glasse...](https://www.smithsonianmag.com/innovation/could-these-glasses-cure- your-motion-sickness-180969722/\);) his description said that he could code in the back of a car with them on.

I find them very effective at reducing seasickness below decks. I won't say there are no funny feelings being below with roll, but I will say I could definitely work hanging upside down angled to roll direction with only mild discomfort: a HUGE improvement over folk remedies.

The way they Are said to work is the liquid in the glasses shows a real horizon and this settles your brain into being able to believe your inner ear. I think a less goofy version of this could be built out digitally on the inside of sunglasses; I think it would be pretty popular.

<comment><USER7> That link is dead, I am interested though!

<comment><USER8> it just has two extra characters at the end. cleaned: [https://www.smithsonianmag.com/innovation/could-these- glasse...](https://www.smithsonianmag.com/innovation/could-these-glasses-cure- your-motion-sickness-180969722/)

<comment><USER6> Thank you and sorry!

</comment></comment></comment></comment><comment><USER9> I tried numerous ways to combat motion sickness when I'd fly passengers in light aircraft.

Everything from those wristband-watch type devices that use pulses of electricity to stimulate nerves, to dramamine and other OTC options.

The most effective treatment by far was ginger root powder. You can take it in capsule form and it was the only really effective treatment I came across.

<comment><USER10> I suffer from pretty bad motion sickness. Can you share the sort of dosage and/or brand you use?

<comment><USER11> Not who you asked, but I absolutely love Chimes ginger chews. They are strong, and I've had excellent results using for nausea.

If you look for Chimes on Amazon , you can find a 1lb bag for around 15 bucks.

</comment></comment></comment><comment><USER12> Unfortunately, I am extremey susceptible for any kinds of motion sickness. As a passenger of a car I regularly get sick, sometimes even when driving myself. Trains are mostly ok, if I keep looking into the distance. I even experience it with other kinds of irritation, like a malfunctioning mouse, where the mouse motion and the pointer reaction are not tightly enough correlated. It took a while until they made optical mice I could use.

I agree with everything said in the article, perhaps one tip: if you have someone whom you know that that person is susceptible to motion sickness, don't ask that person if she or he is still feeling fine, that might push them over the border. You should of course watch them closely, as the dangers described in the article are absolutely real. At minimum you loose any concern about your own wellbeing when affected.

One substance, that has been quite effective for me, has not been mentioned in the article, and that is Cinnarizine. It has to be taken at least 3 days before you plan to take part in any motion sickness inducing activity and from then on every day, e.g. during travel, in low dosages. While not granting complete immunity, it allows me to ride cars as passengers - once I was even texting on my phone! - and travel by plane etc. If you are suffering from motion sickness to an extend preventing you to travel otherwise, I can only encourage you to talk to your doctor about it.

So, indeed, I wish desperately for a cure for motion sickness, preferrably before self-driving cars become a thing :).

P.S. I am probably one of a few people who have never watched a movie on a plane :p. Despite of this, I managed to acquire a sailing boat license, due to the help of cinnarizine. Speak of braveness/stupidity.

If any of my experience might help, please ask me any questions.

<comment><USER13> I'm the same. It drives me absolutely insane when software developers (especially games designers) don't think about motion sickness.

Things like scrolling a web page can induce vertigo-like feelings if the content lags while it's scrolling. Mouse lag, which you mentioned, is unbearable.

I've had to stop playing certain games such as Overcooked or Lovers in a Dangerous Spacetime because they incorporate elements where the entire screen's perspective moves.

</comment></comment><comment><USER14> I was a little disappointed they had no cure for seasickness yet, other than looking at the horizon (which works, unless the seas are so rough the horizon is rolling as well). You can control some of the symptoms (upset stomach, lethargy, and nausea) with Diet Coke. The soda calms the stomach, and the caffeine keeps you alert to fight the nausea. Crawling into the fetal position and hoping you would die also helps :)

<comment><USER15> I used to have a couple of bottles of coke and ginger biscuits for the first few days. My theory is that you need energy/stimulant and hydration. The coke is basically sugar and caffeine and liquid. The longer it is in your stomach the more you will have absorbed. I like ginger biscuits anyway and they are also very sugary. Oh, and the coke doesn't taste any different coming back up.

The article started with the phrase:

      The worst thing about being seasick is knowing you are not going to die.

but I've heard this phrased better as:

      At first, you are afraid you are going to die,
      but then, you are afraid you are not going to die.

<comment><USER16> I like those. I have also heard: "Nobody has ever died of being seasick, but many have wished they could."

</comment></comment></comment><comment><USER17> No mention of the most interesting recent development, low frequency vibration applied to the skull. Unfortunately development is moving incredibly slowly but I think it has promise. [https://otolithlabs.com/science/](https://otolithlabs.com/science/)

<comment><USER18> I guess their main market is VR motion sickness.

What is the mechanism of how vibration disrupts nausea? This article says it is like how white noise can block annoying sounds... But also some bits about targeting certain nerves and not other.

[https://www.defenseone.com/technology/2018/11/inventor- may-h...](https://www.defenseone.com/technology/2018/11/inventor-may-have- cured-motion-sickness-without-drugs-and-could-mean-lot-us-military/152960/)

<comment><USER19> if i had to wager a guess it would be to apply noise to the liquid in the tubes that control balance. if it can disrupt the rocking motion or even induce artificial motion it could counteract it. that said it's a wild guess.

</comment></comment></comment><comment><USER20> Another tidbit that may be interesting to those that suffer from motion- sickness, especially on boats, that I was taught by sailors in northern norway (was stranded there during the pandemic) is that a lot of them are more affected by the rolling of a boat rather than the waves that hit the boat perpendicularly. Thus, their advice was to face the direction of the roll - either by turning your chair or sitting sideways - and face the horizon on that side as that motion is easier to acclimate to. I've tried that one and I admit it did help. By no means a panacea though.

</comment><comment><USER21> If you're curious about an engineering approach to attack the root cause of seasickness, check out the Sea Keeper ([https://www.seakeeper.com](https://www.seakeeper.com)). It's a big gyro that eliminates boat roll, which is one of the main culprits of seasickness.

The landsickness treatment thing is something I would have paid money for. I was on a 3-day sailing trip and when I got off it was a couple of weeks before everything stopped spinning.

</comment><comment><USER22> Nothing seems to help me when I go sailing, nothing other than just doing it regularly and if I'm out on a multi-day sail I'll get my "sea legs" and it seems to stop. Only to return back on land where I'll be hallucinating waves with my eyes closed and feeling like interior spaces are rocking back and forth for days if not weeks.

</comment><comment><USER23> I am mildly prone to motion sickness in actual motion situations, e.g. small planes (love to get my pilot's license, but cannot), reading in a car, etc. But I am _extremely_ sensitive to motion sickness induced by visual stimuli. I have to take Dramamine just to watch a movie. Switching to a larger smartphone will trigger it for a few days. Putting on reading glasses will have me really sick in about 10 minutes. It has a huge impact on the things I can do, and the reading glasses problem is now a big problem because I'm getting old enough to need them.

I'm going to try the 'see sickness' treatment that I see on the net, but it almost seems scammy, though they claim they're not selling anything. But if I can find a way to even partly cure it, the quality of life improvement would be worth paying real money for.

</comment><comment><USER24> The adaptation to sea and then to land reminds me of the adaptation to space (and back to Earth) described by this NASA doctor:

[http://omegataupodcast.net/34-space-medicine-and- telemedicin...](http://omegataupodcast.net/34-space-medicine-and- telemedicine/)

</comment><comment><USER25> Pot right? Hemp for ropes, flowers for sea legs? Adam Savage mentioned something about it on Tested. I don't think I've personally been motion sick when I had some pot around.

I didn't see it mentioned? I have a bad habit of skimming but no mention at all?

<comment><USER22> I get sea sick pretty badly and for a couple years went sailing regularly on the SF bay.

Tried marijuana edibles multiple times, it only made the vomiting a more intense experience and going overboard more likely.

It also made the sailing more error prone.

</comment></comment><comment><USER20> For those considering the glasses I can find two versions of them [1] and [2] at 90€ and 80€ respectively (latter on sale). I've never tried them but they're too ugly-looking not to work .

[1] [https://boardingglasses.com/](https://boardingglasses.com/) [2] [https://lifestyle.citroen.com/en/shop/_/pr4619/lunettes- seet...](https://lifestyle.citroen.com/en/shop/_/pr4619/lunettes-seetroen- inspired-by-you)

</comment><comment><USER26> Article mentions scopdex (scopolamine) for treatment found these links which are interesting:

[https://www.ibtimes.co.uk/scopolamine-devil-s-breath-nasa- us...](https://www.ibtimes.co.uk/scopolamine-devil-s-breath-nasa-use- medical-342346) [https://youtu.be/ToQ8PWYnu04](https://youtu.be/ToQ8PWYnu04)

<comment><USER11> Regarding scopolamine, Vice magazine made a documentary about the way it's used in Columbia. It's rather unsettling, but worth watching if you're interested in this kind of stuff.

[https://video.vice.com/en_us/video/worlds-scariest-drug- colo...](https://video.vice.com/en_us/video/worlds-scariest-drug-colombian- devil39s-breath-part-1/55ef5be749b3d5591cf227c4)

</comment></comment><comment><USER15> Well this article was about seasickness but nothing about a cure, sigh. I'm about immune now but my partner is not.

I thought it was interesting that they say those who never get seasick have a "dysfunctional" vestibular system; they have a slow vomit response, even if poisoned. I wonder if I am just adjusted or if my vestibular system is now dysfunctional.

</comment><comment><USER27> I'm surprised to find no mention here or in the article of the Bárány chair, as it's very effective for some: [https://en.wikipedia.org/wiki/Bárány_chair](https://en.wikipedia.org/wiki/Bárány_chair)

</comment><comment><USER28> I've spent a few months at sea and the trick that worked well:

Stare at the horizon. Seems to help calm the senses down.

<comment><USER12> Yes, that helps. And anything, which reduces the confusion for the brain. It can help a lot to stand instead of sitting down. So when my stomach gets iffy in trains or busses, standing helps me a lot. This is, because you get a better feedback about the motion. Fresh air is also always very welcome in difficult situations.

</comment></comment><comment><USER29> Interesting!

I just had the idea to take Vomex A before using a VR headset. :D</comment>


By 2012 Koreans Will Get 1Gbps Broadband Connections - <AUTHOR> http://gigaom.com/2009/02/01/by-2012-koreans-will-get-a-gigabit-per-second-broadband-connection/ <comment><AUTHOR> This is absurd. <http://www.speedtest.net/> I barely get 10mbps download and less than 2mbps upload speed and I'm happy with it. How are connections in South Korea 100 times faster than mine? Does anyone know if there is any special technology behind it?</comment>


Richard Feynman and The Connection Machine (1989) - <AUTHOR> http://longnow.org/essays/richard-feynman-and-connection-machine/

<comment><USER2> I never can get enough stories about Richard Feynman. I thought I'd heard them all, but somehow I missed this one. It's well written and captures many of the things he worked on later in his life; not to mention it's a really cool article about the beginnings of a rather ambitious project to make a parallel computer in the early 1980s.

</comment><comment><USER3> I took Alan Edelman's 18.337 class (Parallel Supercomputing) at MIT a few years ago, and on the first day he brought in some boards that had been used in the original Connection Machine - it was like looking into a piece of living history to see circuits that had been influenced by Feynman. Fantastic article!

</comment><comment><USER4> This article was from the Physics Today memorial issue on Feynman iirc. When I read it at the time, I seem to remember that it was also the weakest article in that issue. (It was before Thinking Machines crashed and burned.)

</comment><comment><USER5> Amazing!, very good Feynman story that I didn't know. I love how Feynman accepted those challenging problems.

</comment><comment><USER6> Favorite part:

"Since the only computer language Richard was really familiar with was Basic, he made up a parallel version of Basic in which he wrote the program and then simulated it by hand to estimate how fast it would run on the Connection Machine."

<comment><USER7> I would've hoped someone of Feynman's level would've easily picked up a better language.

<comment><USER8> Someone like Feynman is capable of _inventing a new language_ for parallel computing and _correctly simulating its execution by hand_.

That's a much more impressive skill than just learning another language.

<comment><USER7> I don't think so. He didn't invent a new language, but extended an existing one. And I simulate what a program does in my head all the time when debugging (including multithreaded stuff, but I agree that's hard).

</comment></comment></comment></comment><comment><USER9> """So why were people always asking him for it? Because even when Richard didn't understand, he always seemed to understand better than the rest of us."""

What a gift of a human.

</comment><comment><USER10> previously: <https://news.ycombinator.com/item?id=191212></comment>


Headphone and Amp Impedance (2011) - <AUTHOR> http://nwavguy.blogspot.com/2011/02/headphone-amp-impedance.html <comment><USER2> This guy also built and open-sourced a universally admired headphone amplifier and DAC.

His O2 amp: [http://nwavguy.blogspot.bg/2011/07/o2-headphone- amp.html](http://nwavguy.blogspot.bg/2011/07/o2-headphone-amp.html)

His O2 DAC: [http://nwavguy.blogspot.bg/2012/04/odac- released.html](http://nwavguy.blogspot.bg/2012/04/odac-released.html)

JDS Labs and others sell them commercially for those who don't feel like building them by hand.

<comment><USER3> He/She has also inspired some other manufacturers to rethink their products. IIRC Schiit was formed when some engineers thought they could improve the O2/ODAC design on their own[0]. I own an original Schiit Stack (Magnus & Modi) and would definitely recommend them.

[0]: [https://news.ycombinator.com/item?id=8834176](https://news.ycombinator.com/item?id=8834176)

<comment><USER4> Not exactly, you may want to actually read the source you linked :)

The company existed before O2 and M/M were independent designs.

<comment><USER3> Thanks. I had read that someplace else and went digging for the link and simply assumed that was it.

</comment></comment></comment></comment><comment><USER5> I wonder what nwavguy does for a living these days. He disappeared from the Internet in that persona shortly after the release of his designs and dropping some serious allegations at some manufacturers for a transient overvoltage issue. He's a solid engineer and I hope he's just quietly improving the state of audio somewhere.

</comment><comment><USER6> On a tangentially related topic:

When I used to listen to music on my previous phone (a Nexus 4) I would have to constantly adjust the phone's volume: all the way to maximum when using an aux cord in my car, and way back down when using headphones. Recently I upgraded to a Nexus 5X, and noticed a surprising new feature. Somehow, the phone detects which device it's plugged into, and remembers a separate, previously-set volume level for each device.

Does anyone know how this works? It's really convenient, which makes it surprising that I can't find it documented or even mentioned anywhere online. I'm assuming the audio hardware is somehow sensing the impedance of whatever it's connected to, but is that really a reliable indicator of headphones vs. line-level inputs?

<comment><USER7> In my opinion as an EE there would be some reasonably reliable ways to detect either a line or headphone connection. Headphone impedances are typically between 16 and 600 Ohms, and line impedance is typically in the 10's of kOhm range. That's one way to differentiate. There has to be an output signal (presumably audio) first, however. Another way is to apply a very small DC current (that would certainly not damage headphones, so I would guess in the micro-ampere range) and check if there is continuity or measure the DC resistance of the load outright. For line inputs, as they're usually AC- coupled, DC resistance would be infinite, and for (DC coupled) headphones it is very low. It's an interesting subject and I wouldn't be surprised if there are some patents involved.

<comment><USER8> Detecting AC vs. DC coupling would be obvious to a practicing EE, if presented with the problem, yes? I'm just a software guy with an electronics hobby and I think I could have figured that one out.

That said, DC vs. AC coupling detection could probably be granted a patent if nobody had "disclosed" the idea prior to filing of such a patent, based on my experience with software patents.

Sorry to vent, but patents on this sort of thing drive me crazy. I don't have any gripe with you or your post.

<comment><USER7> I did a quick search on google patents: [https://www.google.com/patents/US9084035](https://www.google.com/patents/US9084035) \- it uses a combination of AC and DC methods.

</comment></comment></comment></comment><comment><USER9> This guy is fantastic. Having spent a little time around professional audio, it doesn't surprise me that he did amazing stuff for 18 months (anonymously) then vanished from the web.

This piece on his site has lots of interesting insight into the audio industry. It also relates to objective, critical thinking in general.

[http://nwavguy.blogspot.com/2011/05/subjective-vs- objective-...](http://nwavguy.blogspot.com/2011/05/subjective-vs-objective- debate.html)

<comment><USER10> He had an interesting mind. Absolutely too objective, in my (subjective) opinion. It was almost as if his entire purpose was to remove the validity of all opinion from the discussion completely, and frankly, it was sad and inhuman—despite his amazing technical contributions.

<comment><USER11> I think his viewpoint is spot-on. The goal of most audio systems should be to accurately reproduce the original waveform. If you want to add "warmth" or "color" or whatever to the sound, it's better to quantify what that means, then purposefully distort the audio in a dedicated device (or in software).

Think about what life would be like if displays were built and reviewed like audio tech. Imagine companies like NuForce and Schiit sold screens that didn't accurately reproduce colors. Owners of these displays would praise them for their "warmth" or talk about how much green colors "pop" or whatever. It would be absurd.

We can actually measure contrast ratio, color accuracy, viewing angles, etc. That's how we evaluate displays. People who prefer a different gamma or white point change it in software. They don't buy defective monitors. But switch the topic to audio and people forget all that. It's bizarre.

<comment><USER12> I greatly respect NwAvGuy and agree with almost everything he says, but I think in practical terms that's a slightly over-simplified perspective. Look how inaccurate even these headphones are [1], arguably the best or one of the best ever made.

Getting the inaccuracies to be the _right_ inaccuracies is quite subtle and very important in my opinion. See for example this review of his [2] and in particular the paragraph near the end:

>AN EQ EXPERIMENT: I tried using highly configurable parametric EQ to tweak my Denon D2000s to be similarly forgiving and I failed. When I filter out equivalent amounts of sibilance and harshness with the Denons, more of the music is gone and the result sounds veiled and artificial. The HD 650, to my ears, somehow works more like polarized sunglasses. They largely remove what I don't want while revealing more of what's left. It's not just a simple frequency response difference. My objective side wants to pin down what's going on but I don't have a full explanation besides the HD 650's lack of distortion.

[1] [http://www.innerfidelity.com/images/StaxSR009.pdf](http://www.innerfidelity.com/images/StaxSR009.pdf) [2] [http://nwavguy.blogspot.co.uk/2011/06/sennheiser- hd-650.html](http://nwavguy.blogspot.co.uk/2011/06/sennheiser-hd-650.html)

<comment><USER11> I was mostly talking about DACs and amplifiers, not headphones. Headphones have to deal with more trade-offs: comfort, size, isolation, and the fact that it's really hard to get them to accurately reproduce sound. Still, so what if current headphones suck at reproducing sounds? That doesn't mean we should ignore quantitative measurements. If the "right" inaccuracies are so subtle- yet-crucial, it's important to quantify them! Then we can evaluate headphones based on how accurately they create those inaccuracies.

And I think you're missing the point of the EQ experiment. NwAvGuy wanted to see if there was more to quantifying headphone quality than a frequency response curve. He was right. That just means that objective evaluations of headphone quality will need to include more measurements. That doesn't mean we should disregard measurements and go with subjective impressions. Otherwise, something as mundane as a warm drink can skew the reviewer's opinion.[1]

1\. [http://news.bbc.co.uk/2/hi/health/7688315.stm](http://news.bbc.co.uk/2/hi/health/7688315.stm)

</comment></comment></comment></comment></comment><comment><USER13> Circuit theory becomes much more elegant if you start to use complex numbers (conceptually, the Laplace transform [1]). But for an introductory lesson, this page seems nice, though perhaps a bit long.

[1] [https://en.wikibooks.org/wiki/Circuit_Theory/Laplace_Transfo...](https://en.wikibooks.org/wiki/Circuit_Theory/Laplace_Transform)

(If you grasp this reference, then you understand, I'd say, about 25% of what electrical engineering is about)

<comment><USER14> But only if you use linear components (meaning L,C,R). Introduce just one diode and the system of diff equations needs to be solved numerically. In which case you have switch to simulations like spice anyways. Therefore there is no reason to even bother with Laplace transforms nowadays. For hobbyists (and the vast majority of professionals) I would consider it completely useless knowledge.

<comment><USER15> > Introduce just one diode and the system of diff equations needs to be solved > numerically

Not really. Maybe that's why nobody invented anything with a diode in the signal path before computers were commonplace right? Like radio and guitar distortion pedals

> Therefore there is no reason to even bother with Laplace transforms nowadays

Sure, let's forget the math and make engineers totally dependent on numerical simulation without knowing the basics, I'm sure that'll work just fine

> For hobbyists (and the vast majority of professionals) I would consider it > completely useless knowledge.

LOL

Sure, in the same way that sorting algorithms don't are useless for computer science students, right? Just call .sort() and you're done!

Also don't forget Digital Signal Processing, that also relies on that "useless knowledge"

<comment><USER14> > Not really. Maybe that's why nobody invented anything with a diode in the > signal path before computers were commonplace right? Like radio and guitar > distortion pedals

No, those problems were solved via ultra simplified models. E.g. The current through a diode is described as I = I_0 \Theta(U - 0.7 V). And the rest was done via try and error.

> Sure, let's forget the math and make engineers totally dependent on > numerical simulation without knowing the basics, I'm sure that'll work just > fine

How about, lets learn how to solve every differential equation you will ever come across in electronics using e.g. Runge-Kutta.

> Just call .sort() and you're done!

If you want to get shit done you do exactly that. This is a great problem of many fresh CS graduates. Instead of doing the actual work they would rather first implement their own sort function. In 99.9% of the cases it is a complete waste of time.

> Also don't forget Digital Signal Processing, that also relies on that > "useless knowledge"

In Digital Signal Processing you mainly need to Fourier transform and know the properties of the sin(x)/x function, Nyquist, Shannon etc... Learning how to solve a very special case of systems of differential equations using the Laplace transform won't help you there at all.

<comment><USER16> >Instead of doing the actual work they would rather first implement their own sort function.

Strawman much. On the otherhand I regularly come across people who call library functions without understanding their runtime consequences, well those are the good ones, the bad ones 'get shit done" by calling sort just to find the maximum. Yeah they do get exactly that done, that is, shit.

</comment></comment></comment></comment></comment><comment><USER17> I could have done with reading this article a week earlier.

I just built a converter to allow earphones to be used in aircraft audio panel outputs which are typically 150-350 Ohms. Another bizarre thing I learnt is that 1/2" and 1/4" stereo jacks are wired opposite ways.

<comment><USER18> Not sure if we are talking about the same thing, but on a flight with a Boing 777, I found the throw-away headphones that they hand out upon boarding with the very strange connector (dual mono jacks) to be so bad as to be nearly useless.

I tried to cut the cable, remove the isolation and connect my Apple earbuds, which worked somehow but not very well because the (very thin) wires were individually isolated. Did you come up with a solution?

<comment><USER19> There are adapters you can buy for like 3$.

</comment></comment></comment><comment><USER20> Nice, good and cheap amp ($19) mentioned at the bottom of the article, in case you need immediate boost over stock audio from your phone - [http://nwavguy.blogspot.bg/2011/03/fiio-e5-headphone- amp.htm...](http://nwavguy.blogspot.bg/2011/03/fiio-e5-headphone-amp.html)

<comment> ju-st Or when you are annoyed by a shitty soundcard in your business notebook, get a Behringer external DAC/soundcard for $29 ( [http://nwavguy.blogspot.de/2011/02/behringer- uca202-review.h...](http://nwavguy.blogspot.de/2011/02/behringer- uca202-review.html) )

<comment><USER21> I have a UCA202 (and a UFO202 - AFAIK it is identical but with a phono stage on the line ins) to use with my Surface (the build-in card is very noisy) and it is a noticeable improvement over the built-in card. Definitely recommended if you need a USB DAC without spending a fortune.

<comment><USER22> I use an Acer C720 Chromebook running Linux to drive my virtual piano software. I had no complaints with it's on-board audio performance, but after reading multiple exhortations on the internet about how much better external soundcards are, I bought a $5 USB soundcard widely available from multiple vendors on ebay. OK, I can just barely hear an improvement over the on-board. It's better in the sense of "significant" (ie definitely there), but it just isn't a material difference to me.

If I'm that deaf to the differences between these two sources, I'm curious if people think the UCA202 will change my life?

<comment><USER23> The noise floor is the main issue with most cheap sound hardware. It's often loud, and not spectrally flat. You'll be able to hear more of your music at lower volumes if you get a high quality DAC with a low noise floor.

The other big issue is distortion/nonlinearity. This is much less of an issue than the noise floor, but can still be noticeable on cheap DACs.

It's likely that you can do a lot better than a $5 DAC on both of these factors.

</comment></comment></comment></comment></comment><comment><USER24> I currently use a Schitt ([http://schiit.com/](http://schiit.com/)) Modi and Magni stack with my Beyerdynamic DT880 600 ohm headphones. When I tell you that music is a completely different experience at home with these cans, believe it. I'm a DJ and honestly prefer staying in and listening to mixes than going to my mate's parties to hear what they're spinning because they absolutely obliterate any live system (and I've been to some of the best venues in North America.) I know it's a poor comparison of course, but I'm never going back to monitor speakers for personal use again. If you're looking for a decent AMP/DAC combo, I highly recommend Schiit.

<comment><USER11> NwAvGuy has some not-very-nice things to say about Schiit. Basically, that they don't know how to design audio gear. He discovered that one of their amps could damage your headphones. For this warning, he was banned from the Head-Fi forums: [http://nwavguy.blogspot.com/2011/07/banned-at-head- fi.html](http://nwavguy.blogspot.com/2011/07/banned-at-head-fi.html)

<comment><USER25> NwAvGuy has his side of the story, Schiit has theirs.

[http://www.head-fi.org/t/701900/schiit-happened-the-story- of...](http://www.head-fi.org/t/701900/schiit-happened-the-story-of-the- worlds-most-improbable-start-up/765#post_10463052)

Personally, I'm extremely satisfied with the variety of Schiit gear I own, from my work Modi/Vali setup to my home Ragnarok/Yggdrasil

<comment><USER11> I have some issues with Schiit's accounting.

First, that much DC is simply unacceptable, even when removing power from an amp. Amps don't just lose power because they're deliberately turned off. Sometimes people trip over a cord. Sometimes, a circuit breaker trips. Sometimes, the power goes out. Sometimes, batteries die. None of this circumstances should endanger downstream equipment.

Second, the fix is _extremely_ simple. As Schiit admitted, it took less than a day to develop and ship boards without this issue. There is only one reason why a company would sell a device with this problem: incompetence. If they'd cop to screwing up, I'd respect them. Instead, they dissemble and equivocate.

Third, so _what_ if their own experiment didn't manage to _destroy_ a pair of expensive headphones? "I can't reproduce this failure." doesn't mean, "This failure can never happen." The headphones only survived because they were designed with extremely robust safety factors. Even then, it's quite likely that Schiit's amp damaged the headphones. 1-2V of DC is _way_ out of spec and has –in some cases– damaged and destroyed equipment. There is video of Schiit's amp distorting headphone drivers. That's crazy. No equipment should be doing that.

Fourth, "other audiophile gear also does it" is not a valid excuse. As NwAvGuy has shown, Sturgeon's law[1] applies to this stuff. Just because there's lots of terrible gear out there, that doesn't mean it's OK to produce more terrible gear.

After reading Schiit's accounting, I'm certain they lack the engineering knowledge to build safe, effective audio equipment. I think their intentions are good, but there's simply no excusing such a glaring oversight. In my book, Schiit is an anti-brand.

1\. [https://en.wikipedia.org/wiki/Sturgeon%27s_law](https://en.wikipedia.org/wiki/Sturgeon%27s_law)

</comment></comment></comment></comment><comment><USER26> On the one hand, any loudspeaker amplifier with feedback is going to have very low output impedance (minimum acceptable damping factor of 20 with an 8 ohm load or .4 ohms max). So for at home, AC powered use just hook your headphones to the speaker outputs.

On the other, things do get interesting with low power / battery powered amplifiers, for example where they use a low power OP-amp for headphone drivers. For this case, the article is very relevant.

Heh, or get headphones with nearly flat impedance, for example Sony MDR-v600: [http://www.cliftonlaboratories.com/headphone_impedance.htm](http://www.cliftonlaboratories.com/headphone_impedance.htm)

</comment><comment><USER27> Good grief, headphones do not need electrical damping. This is relevant to large speakers, and only at around their resonant frequency (as mounted in the cabinet). If you're getting some funny resonance in your headphones, electrical damping isn't going to do anything; it's a mechanical issue.

</comment><comment><USER28> one further point to keep in mind is the rule for the inductive reactance of a device (either an amplifiers output or a speakers input) is stated for 1000Hz which is an old rule for the mid range of audio for the clear hearing of intelligible speech, and of course the most efficient transfer of energy is when the output of an amp matches the input of the device it is driving.

To understand a given amp and speaker you also need to know the inductive reactance for the full range of frequencies you want to use.. so amp and speaker maybe matched at the rated impedance is at 1000hz but way off at 15khz</comment>


Tech company patterns - <AUTHOR> https://richg42.blogspot.com/2018/10/types-of-tech-companies.html <comment><USER2> Nice post, I would like to ad a super-category/type: companies of various kind that think to be independent companies in a "free market" while are only slave that works for few bigger one.

To explain this mega-pattern I start to the bottom: in the past we have had blacksmiths that build their own tools regularly, it was common in chemistry industry produce in-house any "glass made lab equipment", it was common between carpenters to build most of their tools, these were mostly made of wood and blades are made by the nearby blacksmith that also buy wood stuff from the carpenter and I can keep going for long. Now without tools essentially designed and made by very few subjects (yep, there are tons of electric/pneumatic/... tools producers but they do not really produce them, only design few aspects around pre-made components) nobody can work anymore.

In IT it's no different: in the past we have had many different architectures, software etc, now anything is built essentially around ARM or x86 and mostly around very few key software components.

Long story short: most type of companies you identify are not free player of a free market but only lego player that depend on lego brick suppliers that are more and more few, more and more powerful.

<comment><USER3> This is brilliant and is true across so many industries outside of software. I don't think there's anything "wrong" with it, but it seems like we get fewer choices every year and that doesn't feel like progress.

Who knows how things will end up because of the state of things. It'll be interesting to look back ten or twenty years from now and see where our current trajectory took us.

<comment><USER2> Thanks, Well... IMO Being interdependent is not much a wrong thing until such interdependency became too unbalanced between too many that depend on a subject and to few subjects but to evolve we need few things: diversity is one of them, without diversity interaction goes down and without interaction good ideas hardly came up and spread.

Another problem is actual kind of private polarization, I mean if we end up after an "evolution cycle" with few universities that essentially hold, build and spread knowledge is not much a problem as long as universities are public/open it's only a matter of how distance we have to travel to study well. But when knowledge start to be concentrated in private hands things change for worse.

Imaging few scenarios: what if we all communicate trough $bigEnterprise services and $bigEnterprise have extensive data mining knowledge? How easy for them became knowing anything that going to happen between anyone else and so direct their investments for their own good possibly against anyone else interest? What if our communications relay on "aggregators" from such big subject so that it can spread certain news and reduce diffusion of other news?

An ancient proverb say that power corrupt, when we get "corrupted" as a society it's dangerous but It's a thing we can handle between us all, when we get "natural dictatorship" because of centralization well... It's easy to understand that's not good for us.

<comment><USER4> > diversity is one of them, without diversity interaction goes down and > without interaction good ideas hardly came up and spread

Diversity will sacrifice efficiency and that's unlikely in current capitalistic scenario where pinching every ounce of performance from tools and employees is the norm.

<comment><USER2> True but we are humans, not machines, we work to live not live to work.

</comment></comment></comment></comment></comment><comment><USER5> Aardman Animation becoming a coop has captured my imagination. I am very curious how well it could work in the context of a tech company.

<comment><USER6> There are a fair number in the UK, there's even an group to help [[https://www.coops.tech/](https://www.coops.tech/)]. Speaking to those who've done it they say you should try to legally form as a co-op as soon as you can as it gets expensive the longer you leave it (legal fees).

<comment><USER5> Interesting, thanks for the link! I'm strongly considering doing this for my next project and all the information I can get is helpful.

</comment></comment></comment><comment><USER7> Been through this - >3\. The Acquired Company Pattern >Resistance is futile: Either the firm ultimately becomes fully absorbed into the megacorp or it will be shut down.

There was massive attrition despite retention bonuses.

<comment><USER8> It should be noted that many of the time(most?), acquisitions are simply press releases. I mean they actually happen, but the ability to spew out a true press release is the actual value of the acquisition; not the data or the customers or the software or the employees.

Just the ability to tell the market they acquired some company is the reason for the acquisition. That should inform where you fit post acquisition.

</comment></comment><comment><USER9> I not sure about #4: "The Legendary Company Pattern", and which example companies the author had in mind:

> _Products are legendary and set the bar. There are two types of employees: > The "Old Guard" that worked on the earlier legendary products, and everyone > else. Can be a very good choice if you can fit in and get shit done. Don't > expect to become an insider anytime soon if ever. Only old guard workers can > be insiders._

Quite frankly, this sounds like what the top level at EVERY place would select, if you asked them to identify which pattern their company fits.

</comment><comment><USER10> Every time I read richg's blog post like this one (there's at least a few more), I'm glad that I mostly do tech outside the tech industry (in boring enterprise - telco, banking etc.). Things there seem so sane in comparison.

<comment><USER11> I've worked for two megacorps. One non-tech and one tech (hardware and software). Both fit the description on that page well. I came to these two companies from a smaller tech company and each megacorp definitely seemed insane.

IME The difference is that at the non-tech company all the decision makers saw individual contributors the same way - didn't matter if you were a PhD scientist or a Business Analyst. Individual contributors were cogs in a business process.

At the tech company some of the decision makers seem to understand that technical people are "advanced cogs" and not just regular cogs. To me, that's the difference between feeling totally useless at the non-tech company and occasionally useful at the tech company.

<comment><USER12> I have seen that too. I tend to tell young devs that it's better to work for a company where the CEO has at least some basic grasp or appreciation for your work and doesn't just see you as a cost.

<comment><USER13> The difference between tech and non tech companies is the value factor of the employee.

If you're a software guy at a large global hotel, it's meh. You are a tier 3 or 4 employee. They make money booking rooms - anything else is a cost component.

Software companies see developers as an asset because they build the product. The dynamic is different and the pay and respect reflect that.

One time I almost quit a start up to take a little more money at a hedge fund to do their internal software. The start up CEO talked me out of it and I learned an important lesson about my trade.

</comment></comment></comment></comment><comment><USER14> The content is interesting, but if the author is reading - gray text on white is an awful color scheme - impossible for some people to read and difficult for everyone. I had to copy/paste the content into another editor to get through it.

<comment><USER15> Is your screen calibrated? I had the same issue (especially with HN) before adjusting my monitor.

</comment></comment><comment><USER16> Those are fun. I have also found companies that move from one kind into another based on the situation. (like multi-subscriber to one subscriber).

There are also healthier companies out there (healthy in that they are managed by non-sociopaths and share a respect for their employees) as well. Two that I'm personally familiar with would be:

Lifestyle business - company has a diversified revenue stream which remains relatively constant over the years, management runs the business for continuation, there aren't big hiring binges or firing binges. Same offices as they have been in for a while, everyone gets along in a family sort of way. Little in the way of advancement, just jobs that pay a given amount for as long as you want to do them.

Services business - where the day to day activity consists of new customers signing up for the service, old customers falling by the wayside, there is a sales group, a 'customer facing' group, and a maintenance group. Maintenance consists mostly of adding new features, porting to new environments, retiring what technical debt there is. Customer facing consists of solving specific problems with the service for that customer. And sales are sales.

</comment><comment><USER17> Another semi-related write-up on internal company dynamics: [https://www.ribbonfarm.com/the-gervais- principle/](https://www.ribbonfarm.com/the-gervais-principle/)

<comment><USER18> yep - I think this is the original article -and a good primer / explainer for these patterns: [https://www.ribbonfarm.com/2009/10/07/the-gervais- principle-...](https://www.ribbonfarm.com/2009/10/07/the-gervais-principle-or- the-office-according-to-the-office/)

</comment></comment><comment><USER19> "The we have our own product but its 100% big customer driven because money"

You have your own product? Your own idea? Great! Sell your product to bigger customers to keep you afloat and do whatever they want because you only have 2-5 of them and they keeping you afloat not realising that you just became a service provider.

</comment><comment><USER20> What pattern would Tesla be described as?

</comment><comment><USER21> This is amazing.

</comment><comment><USER22> Reminds me of: [https://darkpatterns.org/](https://darkpatterns.org/)

<comment><USER23> How, other than the word "patterns"?</comment></comment>


What the MIT Mystery Hunt has to teach about free games - <AUTHOR> http://www.pocketnext.com/stories/getting-a-clue/ <comment><USER2> This reminds me of last night's Parks & Recreation. Fans of puzzles would have really enjoyed the episode.</comment>


High Tech Swimsuits Banned - <AUTHOR> http://www.nytimes.com/2009/07/25/sports/25swim.html?_r=1&hp

<comment><USER2> Ass backwards! It makes it more interesting to watch if these people are wearing super swim suits that help them swim crazy fast. Its not like they have jet packs and flippers atached to the suit. How bout we say they are not allowed to shave too.</comment>


Javascript, locking and sound - <AUTHOR> http://www.jwz.org/blog/2015/07/javascript-locking-and-sound-brought-to-you-by-the-letters-w-t-and-f/ <comment><USER2> This sounds like a good use case for a Shared Worker[0].

A shared worker is a web worker which can be shared by multiple pages / windows / tabs, and can easily be used for coordination of this type. The shared worker can listen for the asynchronous event and then send a message to an appropriate tab to play the sound as necessary. Unfortunately, Shared Workers aren't supported everywhere yet[1] (only on Chrome, Firefox, and Opera), but hopefully support will come to the other browsers soon.

Regarding playing sounds on iOS, the Web Audio API is a good way to go here. While it's true that you need a user gesture to trigger sound, you only need it for the first sound you play. So you can add a button to your web app which when clicked plays a short "empty" sound (just silence), and after that point you can play whatever sound you like at whatever time you like; it no longer needs a user gesture for it to be played.

[0]: [https://developer.mozilla.org/en- US/docs/Web/API/SharedWorke...](https://developer.mozilla.org/en- US/docs/Web/API/SharedWorker)

[1]: [http://caniuse.com/#feat=sharedworkers](http://caniuse.com/#feat=sharedworkers)

</comment><comment><USER3> As a developer I hated when I couldn't make my webpage play sound on ios. But as a user, it's the biggest relief in the world.

I hate autoplay, and if my phone had it, I would have to keep in on silent all-the-time, to stop from being rickrolled.

<comment><USER4> I agree but I wish they would have added a permissions dialog instead of outright blocking. If a site injects an autoplay audio tag iOS could prompt you once if that behaviour is OK or not for that particular domain. Apples creative interpretation of standards is pretty annoying to me as both a user and a developer, sometimes auto playing audio is actually wanted, in games for instance.

<comment> SG- I dunno, I think the last thing anyone wants are more dialogs on websites, especially mobile.

<comment><USER5> Rant:

Moreover I think the whole "let the user decide" attitude is just a lame excuse developers hide behind when they can't figure out a decent UX. (It's no wonder design-by-committee software like we see on desktop Linux has so many UI options... Nobody can come up with anything people can agree on so "make it a checkbox so the user can decide" becomes the solution.)

Unsolicited sound is a horrible idea on any platform, it's a good thing that iOS only allows it when there's a touch event somewhere in the call stack. Dialogs would only worsen the problem; disallowing it altogether is the only sane solution.

<comment><USER4> A Belated Rubuttal Rant:

Developers do lean on users too much to solve UX problems, but I still maintain that giving users a choice here would have been the better alternative. Access to device sensors are almost always behind some kind of permissions dialog on major platforms. Personally I like web/iOS model best, it prompts me when an app/site wants to use my microphone, gps, camera, etc, and then remembers the choice I've made. Making potentially invasive or offensive application behaviour completely transparent to the user is a good user experience in my book, and it discourages developers from using those sensors unless they actually need them. Although I can concede that getting permission for unsolicited access to the phones speaker might be going to far from the small sample size here, and I am just as annoyed at the recent auto playing video trend on the web as anyone else.

Unsolicited sound is pretty important for games, and increasingly the web is becoming a pretty good platform for them. I wrote a little game a while back and I worked around the sound issue in Safari by initializing my sounds (just a few) on the users first tap, not a back breaking workaround or anything, but still annoying that I had to work around Safari. Here's the thing though, if I hadn't been testing on iOS a critical (the sound actually was) part of my game would have been broken on iOS. I guess I'm just grumpy about that... :-/

</comment></comment></comment></comment></comment><comment><USER6> Pretty much agree with his general concerns, although IPC between web pages would probably bring some terrible security concerns, but this is a little off, IMO:

"Oh, and speaking of sound: on iOS, you flat-out cannot play sound unless somewhere higher up on the call stack is a touch gesture. Asynchronous sounds can't be done using the HTML5 audio tag, because... Apple are dicks, I guess?"

I'm fairly sure this is actually because I don't want a web page on my iPhone making sounds without going through notification preferences, and I'm the one that paid Apple, not the person who made the web page. ;)

<comment> vezzy-fnord _although IPC between web pages would probably bring some terrible security concerns_

Given that CORS and cross-document messaging have largely made the same-origin policy a mere formality, it wouldn't be unsurprising for this to be next.

The gist is a lot of people want to treat the browser like a universal operating system, and by definite it will be mangled into one by any means necessary.

</comment></comment><comment><USER7> Sometimes rants like this are biting indictments of the state of things, but sometimes they're just a bit of laziness.

The web is a constantly evolving platform. There used to be many things that were impossible to achieve on the web; that number is less now than it used to be thanks to the addition of new APIs (LocalStorage among them), but it's not yet zero. In particular, we don't yet have an API to achieve what jwz wants to do. LocalStorage was clearly not designed with this use case in mind; acting surprised when your awful hack turns out to be unreliable seems a bit disingenuous.

<comment> vezzy-fnord His point is that these are pretty much Operating System 101 features that the browser doesn't supply since its intended purposes were quite orthogonal, though it has since painfully evolved into ostensibly usurping the host OS.

</comment></comment><comment><USER8> You don't need to poll. One can subscribe to storage events, and that way you can broadcast ordered messages to all your tabs without any polling.

[https://w3c.github.io/webstorage/#the-storage- event](https://w3c.github.io/webstorage/#the-storage-event)

<comment><USER9> Wouldn't you still have to poll to check if the "leader" still exists?

<comment> nathan-muir If playing the sound isn't latency sensitive, you could just have each tab pick a random delay [1].

When the tabs receive the event, they each wait X milliseconds. The first timer to expire marks the event as "played". Other tabs receive this event, and abort their timers.

If a "leader" disappears, it will simply fall to a tab with a larger delay.

[1] Something like, rounded to 50ms increments, in a range, 100 - 1000ms. Avoiding collisions / ensuring uniqueness is left as an exercise for the reader.

</comment></comment></comment><comment><USER9> For anyone else who finds green-on-black hard to read:

        document.body.style.color = "#333333";
        document.body.style.backgroundColor = "#EEEEEE";

</comment><comment><USER10> Good rant, jwz, and thanks for the micro-knowledge that a) it's impossible to play a sound without a touch event in an iOS browser and b) multi-tab localstorage access can be problematic if you use it to coordinate activity

I think another way to solve this problem is to simply check shared memory to see if the request has been handled by any tab - if so, then don't handle it. You don't need to poll, however you might need to stagger the checks a little since playing a sound can happen so quickly. Note that this implies that every sound triggering event gets a unique id, which can be a timestamp, GUID, hash or something like that. (I'd timestamp and hash every event at the server).

</comment><comment><USER11> Can anybody explain what this sentence on MDN means?

 _Normally, scripts on different pages are allowed to access each other if and only if the pages that executed them are at locations with the same protocol (usually both https), port number (443 being the default for https), and host (modulo document.domain being set by both pages to the same value)._

[https://developer.mozilla.org/en- US/docs/Web/API/Window/post...](https://developer.mozilla.org/en- US/docs/Web/API/Window/postMessage)

What access is it talking about? I get the feeling they are talking about parent-child windows.

<comment><USER12> It probably means accessing another contexts' global object directly via an iframe (or child window), which works for matching domains and throws a security exception otherwise.

<comment><USER11> Right... I suppose the author presupposed you have a handle on the other window, which you can only get from window.open(), <iframe>, etc.

Makes me wonder what kind of race conditions can happen between contexts sharing global objects. Are they guaranteed to behave as if they were one context? i.e., single threaded?

</comment></comment></comment><comment><USER11> Broadcast Channel API attempts to solve this but only Mozilla has implemented so far,

[https://developer.mozilla.org/en- US/docs/Web/API/Broadcast_C...](https://developer.mozilla.org/en- US/docs/Web/API/Broadcast_Channel_API)

[http://caniuse.com/#feat=broadcastchannel](http://caniuse.com/#feat=broadcastchannel)

</comment><comment><USER13> I used to have this same problem with cookies way back in the day.

If you had a number of windows that all needed to communciate with the streaming server, and share a session, and you closed the master, one of the others would have to take over the connection. We used cookies in a similar way to local storage is used in this story. Ugly ugly code.

These days of course, I'd want to use service workers.

</comment><comment><USER14> Once you start adding mutexes / atomic compare-and-swap statements you start going down the rabbit hole of concurrent programming ([https://twitter.com/themitcho/status/308026012455821312](https://twitter.com/themitcho/status/308026012455821312)).

Even though there is an apparent shift in the creation of web applications resembling desktop applications more and more, due to security concerns native applications will always have more control over the system and this includes the choices for threading. If not, you're essentially writing a new operating system but now in a browser, following the (too often seen) anti pattern of implementing the same functionality already available but then on a higher level, only resulting in performance loss.

JavaScript for web development should merely be a scripting language, augmenting the functionality of your web page. If, for performance reasons, you require multiple threads then switch to a native app.

Furthermore, if JS is only used to augment the functionality of a page, the costs of the theoretical concurrency issues are negligible and a mere check for whether the sound has been played, if not play the sound and set a flag, if not do nothing should suffice and be correct in the overwhelming majority of cases.

<comment><USER15> The point of this post is that they've _already_ gone down the rabbit hole of concurrent programming, but none of the standard tools for it are provided.

Performance is irrelevant here. Concurrency isn't being used as a performance tool, it's happening as a consequence of the user's actions. The programmer doesn't _want_ it, but they have to deal with it.

</comment></comment><comment><USER16> i had to this for webrtc calls before, and I ended up managing it all server side (there was a shared game state on the server, so it was fine).

Although, LocalStorage is the best way i've seen to handle the situation in a single page app, where you log out on one of the open tabs, and the other ones still think they are still logged in.

In general, there's a lot of really "fun" edge cases when it comes to modern web apps and multiple open instances ...

</comment><comment><USER17> You don't get to just arbitrarily play sounds when I visit your website on my phone, sorry. Yeah, Apple are real dicks for that one.

</comment><comment><USER18> Correction: LocalStorage is synchronous not asynchronous.

<comment><USER19> I think it acts asynchronous if you have multiple tabs for the same domain open at once.

The example given was: "it spans multiple documents, and you want a sound to play in reaction to some external, asynchronous event if any of your documents are open."</comment></comment>


How to offer internships? - <AUTHOR>

I was wondering for advice on how to offer internships at my startup for undergraduate students. Thank you for your time. <comment><USER2> Contact the local universities and high schools. The computer science teachers at local high schools all know the stand out programmers who are hungry for work and experience. Most colleges have an internship program where CS/EE students will work for next to nothing for the recommendation or experience.

If you can afford to, offer to pay them, especially if they'll be making money for your company. Treat them as regular employees by bringing them in on meetings and listening to their advice. Even if they lack the experience of a full time employee, they can always provide insight that you would otherwise not have.

Be flexible with their schedules, especially around exam time.

<comment><USER3> * computer science teachers at local high schools all know the stand out*....

The same is true for other subjects, in case you weren't hiring programmers.</comment></comment>


Biggest YouTube collaboration ever – to plant 20m trees - <AUTHOR> https://teamtrees.org <comment><AUTHOR> The Internet challenged MrBeast to plant 20m trees for his 20m subscribers. Let's do it!</comment>


Custom Models in Ember.js - <AUTHOR> http://joefiorini.com/posts/custom-models-in-emberjs

<comment><USER2> If you're looking for more meat on the subject of starting off with Ember- data, Tom Brandt has an excellent post that still (mostly) applies to the latest builds.

[http://twbrandt.github.io/2013/02/22/Ember-Data-Quick- Start-...](http://twbrandt.github.io/2013/02/22/Ember-Data-Quick-Start-Guide/)</comment>


EBay Sues Amazon, Alleging Sellers Were Illegally Poached - <AUTHOR> http://fortune.com/2018/10/18/ebay-amazon-poaching-sellers-lawsuit/ <comment><USER2> Having had periods of fairly active selling on eBay, I can say eBay has done as much as anyone to get sellers to leave their platform.

<comment><USER3> Who doesn't want to pay 20% commission?

</comment></comment><comment><USER4> I'm sure no one would ever admit it, but I'm like 75% positive Amazon did the same thing on Etsy when they launched Amazon Handmade.

75% because I'm just recalling based on some forum posts I read around the time they launched, which of course I might be mistakenly remembering or interpreting incorrectly.

</comment><comment><USER5> What law was broken?

<comment><USER6> Maybe violating the eBay terms of use? They are pretty explicit about not trying to lure people to buy from you outside of eBay, iirc. What happens when a corporates violates another companies terms of use aggressively to promote competition?

<comment><USER7> The eBay terms of use are not law. Breaking those kinds of agreements is a civil matter. The lawsuit is alleging serious criminal things, like fraud, in addition to breaking the terms of use.

<comment><USER8> Fraudulently creating accounts for the purposes of performing activities known to be against the ToS prior to even creating the account.

"The Amazon employees acknowledged they were breaking eBay's rules and actively tried to avoid detection, the lawsuit says."

<comment><USER7> Yeah, but is that actually criminal fraud according to the law?

<comment><USER8> As debacle notes [0], the CFAA is a hell of a drug. [1] I could certainly see a case that this is "exceeding authorized access", with "authorized access" being defined by the rules established by the ToS when the account granting access was established.

[0] [https://news.ycombinator.com/item?id=18250970](https://news.ycombinator.com/item?id=18250970)

[1] [https://en.wikipedia.org/wiki/Computer_Fraud_and_Abuse_Act#C...](https://en.wikipedia.org/wiki/Computer_Fraud_and_Abuse_Act#Criminal_offenses_under_the_Act)

</comment></comment></comment></comment></comment></comment><comment><USER9> Didn't they do this to Angie's List too? Awful ethics.

<comment><USER10> If a start-up did this, we would just call it "growth hacking".

</comment></comment><comment><USER11> Lawsuit complaint document available here: [https://cmportal.scscourt.org/Portal/DocumentViewer/Index/Q9...](https://cmportal.scscourt.org/Portal/DocumentViewer/Index/Q9EzCn1UFbPgZcNdA53-STDlgd1zLeEzQRdpMlGJbBHTfoab7aEpFjS04YRxNdUrEuBIZueiMtw5FHHFNN2nIRLkdJ1o-_omHAE4ylIrUIvQe2k6rRkuJEJLW7Ir9_4s0?p=0)

</comment><comment><USER12> This suit is frivolous - in a free market sellers and platforms should be free to do as they please, including pitching an alternative platform.

That said, Amazon deserves this suit - remember, this is the same company that routinely sues former employees for non-compete, & pays wearhouse employees to favorably post on social media. They deserve a taste of their own corporate BS lawsuit

</comment><comment><USER13> I don't understand the issue here. Seems to me that in free market, Amazon has the right to reach out to perspective partners wherever they may doing business. Ebay, likewise, could do the same.

Many years ago, I use to shop ebay and always dreaded the clumsy checkout process (among other things including the issue of _trust_ ). I don't know if it's improved... To me, that's the core issue. Companies like eBay, Walmart and others want to compete on the same level as Amazon but they don't do enough to improve services (customer service, shipping, checkout, UIs, etc).

Instead of competing on overall value, they turn to "IP" lawsuits, poaching and general bullying.

There's a flipside too. Large companies tend to have an advantage but in this case, eBay isn't small. They can improve in many ways but like Sears... they are stuck in a specific and closed mindset.

I give Amazon lots of credit for being free-thinking and innovative. They started with books and somehow managed to get into cloud services in a huge way. They don't corner themselves. Ebay needs to think outside of their comfortable box because, down the road, consumers will need the competition.

<comment><USER8> This post is a little ironic on the pro-Amazon front, what with the complaining about Ebay's checkout process while Amazon holds the one-click-buy patent...

<comment><USER14> the patent expired last year. ebay could've had some version of it ready to roll out automatically within seconds of whatever expiration time was approved by the legal department.

personally i've never used one click purchasing on amazon, and their checkout still feels better than ebay's.

the real irony is:

> (among other things including the issue of _trust_ )

when amazon is comingling inventory and generally confusing people about who they're purchasing from.

<comment><USER13> > sigstoat: the real irony is:

>> me: (among other things including the issue of trust)

> sigstoat: when amazon is comingling inventory and generally confusing people > about who they're purchasing from.

I was referring to sellers being allowed to include their own JS and Flash on listings[0] and the high-profile hacking cases along with ebay's response[1,2]. Sellers were also allowed to include 3rd-party templates to list their items (which can lead to yet another attack vector). This may still be happening but like I said, I abandoned ebay some time ago.

Also, when purchasing on ebay, you're always dealing directly with a seller. It's a marketplace, a bazaar. It's their business model (but like I said, it can mutate into something else). Unlike Amazon (where you always "feel" you're dealing with a single company - comingling aside), on ebay you never feel like you're dealing with a single entity.

As a result, I always felt on high alert: investigating sellers, viewing their reputations, etc... it's time-consuming and an effort. It constantly forces me to question... to trust.

[0] [https://hacked.com/biggest-hacks- breaches-2014/](https://hacked.com/biggest-hacks-breaches-2014/)

[1] [https://www.eecs.yorku.ca/course_archive/2015-16/W/3482/Team...](https://www.eecs.yorku.ca/course_archive/2015-16/W/3482/Team12_eBayHacks.pdf)

[2] [https://news.netcraft.com/archives/2016/02/18/ebay- scripting...](https://news.netcraft.com/archives/2016/02/18/ebay-scripting- flaws-being-actively-exploited-by-fraudsters.html)

<comment><USER15> Good news! EBay doesn't allow active content anymore. So no JavaScript.

</comment></comment></comment></comment></comment><comment><USER16> Why should the court reward eBay's poor business controls?

Their messaging system, and they permitted the messages. How is this Amazon's fault?

eBay is taking the ridiculous stance that it's TOS provides liability to the customer for using their service wrong. If I made a website with a TOS that said "Anyone who browses to this website and fails to click the 'get lisence' button in the footer on EACH PAGE owes me $1 Million Dollars!", I'd be laughed out of court trying to enforce it.

<comment><USER17> You're holding up a massive straw man.

A C&D like this is pretty standard fare between competing businesses. If you sell widgets and WidgetCorp sells widgets, you are completely allowed to try and poach their customers, but WidgetCorp is allowed you prevent you from doing that _in their store_. Furthermore, if the accounts were specifically created for this purpose it's a clear violation of the TOS and there may potentially be damages there, or even possible criminal charges (thanks to the wonderful CFAA - ack).

<comment><USER16> Asking the courts to enforce a cease and desist seems fairly reasonable (perhaps a bit heavy handed), but I absolutely disagree with the idea the courts should impose monetary damages on Amazon for using eBay's website 'improperly'.

In your example, it'd be reasonable for WidgetCorp to trespass you from the store if you're trying to compete on their property. However, I believe it would be unreasonable for Widgetcorp to try to sue for the revenue of the sales that were successfully made before they trespassed you.

</comment></comment></comment><comment><USER18> I don't understand how some people are saying this would be an unethical action. This is competition, which is how better services end up being provided to users, and for better prices. It's _not competing_ that's unethical, and is what leads to monopolies, price fixing, and other anti- competitive behavior. If they don't like Amazon "poaching" users of their site, then they should offer even more desirable terms to their users.

That it's even possible to try to sue for something like this is a sad reflection of how much our laws have interfered in normal market operation, and enabled companies to try to create ways to legally sidestep competition. _You can 't inform our users you could offer them a better deal. It's against our terms and services! We sue!_

<comment><USER19> > I don't understand how some people are saying this would be an unethical > action. This is competition, which is how better services end up being > provided to users, and for better prices. It's not competing that's > unethical, and is what leads to monopolies, price fixing, and other anti- > competitive behavior. If they don't like Amazon "poaching" users of their > site, then they should offer even more desirable terms to their users.

This is a really weird perspective. Not all "competition" is the same; there are such things as _fair_ competition and _unfair_ competition. Having your employees seek work at a competing factory to sabotage its operations is definitely a kind of competition, it's just the _unfair_ kind.

<comment><USER18> Providing basic information to people is about as fair a notion of competition as there is.

I think the most reasonable real life metaphor for this scenario would be a for-sale bulletin board on private property where people put things up for sale, and the owner of the land where the bulletin is placed takes a cut of all sales. The owner of this property also wanted to try to protect their profits and so made people sign a piece of paper stating 'I won't inform other users about better deals'. Amazon signed it and then told the sellers about better deals anyhow.

In my opinion the behavior that was both unfair and unethical was eBay trying to prevent fair competition for their users.

<comment><USER19> Let me put it simply and clearly:

Amazon has no right to use Ebay's systems however it chooses and against Ebay's wishes, full stop. Ebay has every right to forbid that its systems be used for anything it dislikes, including as an advertising platform for its competitors.

If you disagree, and still think that Amazon should be able to exploit Ebay's systems to give "basic information to people"; then you must agree that I should be able to hack your computer to play audio loops giving the people around you "basic information" about how your ideas are wrong.

If Amazon wants to advertise, it needs to restrict itself to avenues that are legitimately available to it, such as Google adwords, etc.

For competition to work, the competitors need to have something like "bodily integrity." One competitor shouldn't be able to "infect" another to weaken it. We want the competitors to focus on strengthening themselves, not weakening others.

<comment><USER18> You're setting up quite the extreme straw man. Amazon was using the site in a 'normal' fashion to do something that eBay did not want. This has nothing to do with hacking or other sorts of nonsense. Sites can put whatever they want in their terms of service. This does not make them law, and in many cases the clauses are in no way enforceable.

Amazon could add in their terms, 'You may not speak negatively of Jeff Bezos on our software.' and it's completely meaningless. They could close any accounts that do as much, but they could do that for any reason they want already - making the term rather pointless. And the same is true here. eBay tried to shove in ridiculous anti-competitive rules in their terms. Amazon didn't care. So now they're adding just another chip on the mountain of lawsuits they're already involved in as a spiteful hail mary.

<comment><USER19> > You're setting up quite the extreme straw man. Amazon was using the site in > a 'normal' fashion to do something that eBay did not want. This has nothing > to do with hacking or other sorts of nonsense.

That hacking aside is a red herring.

> Sites can put whatever they want in their terms of service. This does not > make them law, and in many cases the clauses are in no way enforceable.

Sites are owned by particular people and organizations, and they have a right to set the terms (withing reason). It's just a like a landlord who puts a term in their contract saying you can't exercise your right of free speech by yelling your opinions through the wall of your apartment at 3AM.

> Amazon could add in their terms, 'You may not speak negatively of Jeff Bezos > on our software.' and it's completely meaningless.

That term is not meaningless, even if it's in bad taste, and I think that's the fundamental point of our disagreement.</comment></comment></comment></comment></comment></comment>


Dinosaur Footprints on a Cave Ceiling - <AUTHOR> https://scienceblog.com/516341/dinosaur-footprints-on-a-cave-ceiling/ <comment><USER2> I used to work with a guy who during his misspent youth was part of a group trying to set a record for the tallest cave systems, so they were looking high in the mountains and for certain geological formations.

The insight he shared with me was that caves don't form in the softest or most permeable layers of rock. Instead they tend to form above the hardest layers - water wants to seek the lowest level and the only thing to stop it is a layer that's hard, or impermeable. Whatever is above that is where the water does most of its work, even if there are softer layers further up.

So if I have it right, these dinosaur footprints were made upon a softer layer above very hard material that makes up the base of the cave, and the layer above those two was hard enough that it has so far resisted erosion, leaving effectively a stone cast of a dinosaur foot, rather than a footprint that has somehow been flipped 180 degrees.

<comment><USER3> > (...) leaving effectively a stone cast of a dinosaur foot, rather than a > footprint that has somehow been flipped 180 degrees.

Yes, I also share that opinion. In fact, just by looking at the photo from Nature it seems like the cave's floor is comprised of upper strata that have cracked, broked off and fell down. If just so happened that the layer currently exposed has the imprint of some dinosaur footprints.

Perhaps other visitors didn't noticed it because the previous layer broke off recently?

<comment><USER2> Do archaeologists use the term 'footprint' differently than we use it colloquially, or is the title just wrong?

To me a footprint isn't shaped like my foot. It's something that my foot fits into.

</comment></comment></comment><comment><USER4> Here's a link to an article from April 2nd that actually shows a picture of the cave ceiling: [https://www.nature.com/articles/d41586-020-00972-y](https://www.nature.com/articles/d41586-020-00972-y)

<comment><USER5> Thanks, here's a somewhat higher resolution image. [https://media.nature.com/w3000/magazine- assets/d41586-020-00...](https://media.nature.com/w3000/magazine- assets/d41586-020-00972-y/d41586-020-00972-y_17851312.jpg)

</comment></comment><comment><USER6> Party hard

Apart of that, the presence of the footprints in the upper strata is not particularly strange. Dinosaur footprints are not so easy to spot for a non specialist. Often just a round concavity in the floor that could be done by anything.

</comment><comment><USER7> This is a really neat discovery. For those in the western US there is a pretty accessible sauropod trackway in Grand Staircase National Monument at a place called Twenty Mile Wash that is well worth checking out.

</comment><comment><USER8> At first, my mind was blown by the facts dinos could walk on the ceiling, then I read the explanation.

A little disappointed here.

</comment><comment><USER9> Antigravosaurus was here.

</comment><comment><USER10> Sounds like top trolling by the dinos in question.

<comment><USER11> The article describes that dinosaurs made footprints on the ground, it took ages and a number of geological processes for the footprints to appear on a cave ceiling.

<comment><USER10> Thanks. I have stopped thinking they were lying on their backs and smiling to themselves.

</comment></comment></comment><comment><USER12> Creationists are going to have a field day with this.</comment>