The $11185 Connector - <AUTHOR> http://www.bigmessowires.com/2015/02/06/the-11185-connector/

<comment><USER2> The title is very misleading... it's not an $11,185 connector, that's the price of setting up custom tooling for this component. After-which the factory quoted a very reasonable $0.13 per piece.

The author went into this stating he'd be willing to pay for their tooling... then is sticker-shocked when they quote him for so. It's like the author went into this thinking they'd pay a few hundred bucks (for the custom tooling) and get a short fab run (< 100) back out. These factories aren't going to tool-up unless they're about to produce thousands... it doesn't matter if it's PCB's, connectors, action figures, jewelry display stands, etc. It's not worth their time at small scale.

The reason these connectors are difficult to find (if possible at all) is people aren't buying them... so you have to make it worth the factory's time to custom fab them for you. And if they think you're going to be a one-time- run, then you aren't going to get as good of a price as if you signed some long-term production agreement (10,000 a month for 12 months, etc...),

He also didn't go about finding a fab in the best way.. he went to Alibaba which is essentially the Amazon of factories... definitely not the "best price" you can get.

<comment><USER3> Since you seem to be familiar with this sort of thing, what _is_ the best way to find a fab if not going to Alibaba?

<comment><USER2> There is no specific place to go to... a lot of it simply comes from working within the industry and learning the key players. My company doesn't buy/sell electronics, but the factories operate more-or-less the same.

Going to Alibaba is like shopping on Amazon. You wouldn't go to Amazon to purchase bulk (> 10,000) pieces of some item... you certainly aren't getting the best deal. Amazon takes a cut (so does Alibaba), and retailers listing there have catered their prices towards end-users (so significant mark-ups).

If it were me, I'd post on electrical engineering forums and ask who people recommend for fab jobs. Sometimes a nice supplier/distributor will tell you who they use for fab jobs (but a lot do tend to guard this).

Alibaba just isn't the best way to get the best price...

<comment><USER4> Yeah and my cousin Vinny can get you a better deal, too bad you aren't family.

<comment><USER2> > Yeah and my cousin Vinny can get you a better deal, too bad you aren't > family.

I can appreciate your sarcasm here, but it's not constructive and doesn't change the economics of custom fabrication.

These factories don't sit around waiting to get small-time jobs to fab a handful of some custom components.

<comment><USER4> Alibaba was a reasonable place to look, the other suggestions require insider knowledge, and are significantly more speculative.

<comment><USER2> A possible analogy:

Would you accept a consulting gig if it was a one-off job, required a 2 hour commute in both directions, and you expected to be onsite for only 1 hour? Maybe...

You might accept if you were really desperate to get any job, or you might accept if your contract pays for your commute time and expenses. But if neither of those conditions are met, you would probably turn it down as it wouldn't be worth your time.

This is over-simplifying this a bit, but it's along the lines of how the factories view this sort of thing.

The author is asking them to spend more time and expense tooling up than they will in actual production (your 4 hour commute round-trip). If they were already tooled for this component (you lived in the same city), then they'd be more open and provide a better rate (you charging just your on-site fee). But since those conditions are not met, they will make you foot the bill for tooling (you charging for your commute and expenses), especially since the likelihood of some other buyer coming along and commissioning this component are very slim (the consulting gig is a one-off).

</comment></comment></comment></comment></comment></comment></comment><comment><USER5> Talk to Sullins Connector Corp directly. [http://www.sullinscorp.com/](http://www.sullinscorp.com/)

The last time I had a connector I needed, they took something they had off the shelf, milled it, stuffed it with different pins, and charged me $100 for 5.

 _I_ _was_ _stunned_. I haven't had customer service that good in decades.

Really. Call them. Even better, take a factory tour.

They may not be able to do it, but they have 30 years of designs archived. One of them will probably work.

<comment><USER6> Except he did. They declined. Maybe if he knew somebody higher up at Sullins?

<comment><USER7> They declined because, "we are currently phasing out our d-sub line and will be going obsolete in June."

That's basically permanent.

</comment></comment></comment><comment><USER8> A quick search suggests that they're still made:

[http://www.connectworld.net/cgi- bin/rrdata/DB19FS](http://www.connectworld.net/cgi-bin/rrdata/DB19FS) (female)

[http://www.connectworld.net/cgi- bin/rrdata/DB19MS](http://www.connectworld.net/cgi-bin/rrdata/DB19MS) (male)

<comment><USER9> He bought all those ones:

[http://www.bigmessowires.com/2015/01/28/in-search-of-the- elu...](http://www.bigmessowires.com/2015/01/28/in-search-of-the-elusive- db19/)

</comment></comment><comment><USER10> DB-25-connector, meet hacksaw and belt/disc sander. Welcome, DB-19 connector!

While this would be a no-go for a 'regular' product, it would be perfectly acceptable for the niche application - floppy emulators for old personal computers - these connectors are used for.

<comment><USER11> I did pretty much exactly this a few weeks ago to make a DB-23 video cable for an Amiga :]

</comment></comment><comment><USER12> I worked in the nuclear industry a long time ago. The reason some parts are expensive is the documentation (chain of ownership) and testing involved. Some parts must be flame tested (set on fire and self-extinguish in X seconds), so that 50% of the batch are destructively tested in order to meet specific requirements. It doesn't justify excessive profiteering on a setup or per-part basis, but there is reason for connectors costing $90/part.

<comment><USER13> Do you have any nuclear industry war stories to share?

</comment></comment><comment><USER14> I think you might be better off a) finding and contacting an original mfg who still has the tooling, or b) making some kind of adapter board by pulling the pins from a DB25 and soldering them onto a pcb.

I wouldn't be shocked if you paid them and got the first parts and had a problem.

Then they will point to your lack of tolerance or chamfer specs or somesuch and then want more money to modify the tool.

</comment><comment><USER15> For a completely custom connector, that seems like super cheap NRE to me. I work as an EE and have paid more than that on small run prototype stuff that is simpler to manufacture than a connector (think prototype circuit boards). Connectors require multiple sets of tooling and specialized processes unique to the connector industry. Even getting the tooling for the simplest plastic part is goig to be thousands of dollars.

</comment><comment><USER16> I have a package of DB25 connectors left over from a product I used to build and sell that has slowly been whittled down over the years. It's because of things like this that I have been reluctant to toss them out. At sometime in the future I think they might be useful to me or someone else. Likewise the bag of 50 Centronics connectors. They _have_ to be valuable sometime, right?

Or maybe I'm just a packrat.

</comment><comment><USER17> This just reminds me. I wanted to buy a couple of extra allen wrenches for my camera tripod just so I could put them in various bags and hopefully never be without one.

Check Amazon...

1 wrench $6

100 wrenches $12

I now have a box of 100 allen wrenches all the same size.

<comment><USER18> Give them away at the office as a reward for a job well done.

</comment></comment><comment><USER19> Presumably the reason that the other factories did not make an offer was that they would have had similar set up costs and already expected that the volume wouldn't be large enough to make this viable...

</comment><comment><USER20> That's too bad: Steve Chamberlin appears to have taken the post down probably due to unwarranted "UR DOIN IT WRONG" in his page comments.

There are a couple other comments [1] [2] that touch on this. But it does seem like there are some shortcuts that could be taken with DB-25 connectors. Anyone who's still manufacturing them (which may not be many) might be able to modify their tooling to not add 6 pins on one side and not add the protective cowling.

Is it a safe, strong connector? No.

Would it cost $11k in tooling? I have no idea I'm a biologist.

It'll be interesting to see what he settles on.

edit: Ha, he's already doing that: [http://www.bigmessowires.com/2015/02/01/designing-a- db-19-su...](http://www.bigmessowires.com/2015/02/01/designing-a- db-19-substitute/)

[1] [https://news.ycombinator.com/item?id=9012293#9012602](https://news.ycombinator.com/item?id=9012293#9012602) [1] [https://news.ycombinator.com/item?id=9012293#9012695](https://news.ycombinator.com/item?id=9012293#9012695)

</comment><comment><USER21> Bargain for everything in China. It is the culture. They will haggle over the price of anything. It's actually kind of fun once you get used to it.

</comment><comment><USER22> I'd strongly recommend looking into 3d printing these. You could pretty easily 3d print a plastic version of the connector itself (and shell, if male), then add aluminum tape to the inside if you need EMF protection. Then you just pop in pins (which you can get at Fry's by the hundred for a couple bucks), and you have a finished connector. A few hundred dollars in setup and you're done, with a unit cost of under a dollar, all in.

<comment><USER23> None of the low-end 3D printers could hold the tolerances needed. Even a Form 1 isn't that precise.

Connector tolerances are very tight. That's why intermittent electrical connections are mostly a thing of the past.

<comment><USER22> I regularly print tighter tolerances with an FDM printer (modified Makerbot Replicator 2). D-sub connectors just aren't that tight; if you were printing the pins themselves, it'd be different, but the plastic side of things is not an issue at all.

<comment><USER23> For connectors where the pins are crimped to wires, then inserted into the connector block, the hole into which each pin fits has a complex form. It has to be shaped so that the pin clicks into place, but isn't pushed out by ordinary connector insertion forces. FDM extruders extrude a thread bigger than the tolerances required for that.

Getting a longer D-sub connector and machining the plastic down is more likely to work. 3D printing isn't magic.

</comment></comment></comment></comment><comment><USER24> [http://www.digikey.com/product- search/en?x=0&y=0&lang=en&sit...](http://www.digikey.com/product- search/en?x=0&y=0&lang=en&site=us&keywords=db-19)

<comment><USER8> Those are all DB25s that happen to have a part number starting with "DB-19".

</comment></comment><comment><USER25> Do you need to support older hardware? Or is there a particular reason you can't use DB-25 and just use 19 pins?

</comment><comment><USER26> Good story, but I flagged it for the misleading title. Perhaps a less sensational one would be, "Making new DB-19 cables is expensive."

</comment><comment><USER27> The Chinese are tired of being paid a fraction of what citizens in developed countries make for doing the same work.

This is a blog about how a citizen in a developed country is "shocked" at the concept that other people should be paid a fair wage even if - gasp - they're Chinese.

<comment><USER28> The phrase "shocked" doesn't occur in the post, so I'm not sure where that term comes from. He does say that the quoted figure is more expensive than he hoped for, which is reasonable, since he goes on to present a number of quick calculations suggesting he can't justify purchasing them at that price.</comment></comment>


Bloxels – Build Your Own Video Games - <AUTHOR> http://home.bloxelsbuilder.com/ <comment><USER2> I bought this for my kids about a year ago. The novelty wore off quickly, and they ended up only playing the demo game included with the app. The process of creating an image with the blox takes so long that the effort doesn't seem worth it. I've purchased a lot of these "get kids into tech" type toys over the years. I find that none of them have kept my kids interest nor have they really actually taught anything technical. Some were downright patronizing (I'm looking at you GoldieBlox).

If we want to get kids interested in technology, we should be teaching them about technology, not creating abstractions on top technology and then teaching them the abstractions. I learned about computers with Murphy's Laws of Dos and Dos 4 on a monochrome screen. I knew that what I was doing was the same thing that professionals did, and I knew that the knowledge I was acquiring would be applicable in many settings. Later I learned Basic and HTML, and again these were tools used by professionals.

We should stop lying to ourselves that these toys teach technology, and sit down with our kids and teach them how to build Pong with Pygame.

<comment> le-mark I suspected this maybe the case. I think there's an important distinction when relating your (and my) experience in the previous era with the current era. That is: expectations are _much higher_ now. In the 80's we watched Matthew Broderick in Wargames having fantastic adventures with a green screen terminal and modem. We played pong, space invaders, and pac man. Today, kids use touch devices to watch videos on youtube and play triple A console games with incredible production quality.

 _I learned about computers with Murphy 's Laws of Dos and Dos 4 on a monochrome screen. I knew that what I was doing was the same thing that professionals did_

It's not obvious to kids today that that's what professionals are doing. As an adult I made a simple platformer and showed it to a few nontechnical friends. Their reactions were, 'why can't it do this', or 'are you going to fix the graphics?' ie very un-impressed, and honestly quite dis-spiriting. Imagine a kid creating a simple game today, won't impress her peers, and probably even lead to ridicule and scorn today.

<comment><USER3> I strongly believe consumers are blissfully unaware of how complex software can be (and what software is by nature more complex than what other software). It's not only a problem with the people you show your independent work to, it's a problem with non-technical management as well. I'd be very interested to understand a few of the ways non-technical people think programming works. If someone would put together some non-trivial demo, and get 100 non-technical people to speculate (in detail) on how they imagine it was made, I'd imagine the answers would be fascinating.

<comment><USER4> I'd agree, except for the word "blissfully". Go visit a games subreddit and you'll see tons of people who think programming is easy and are _screaming_ that the devs are lazy money-grubbing idiots that should be doing things better. They aren't "blissful", just ignorant.

<comment><USER5> I think part of the yelling is the subconcious painfull realization of ones own lack of capabilitys.

These guys want to participate- as they did in cowboys and indians, and are unable to do so with just a stick and imagination.

</comment></comment></comment></comment></comment><comment><USER6> Honestly, whenever I've wanted to teach people how to get into programming, I usually just try and teach them the "real" tools for it; something like Unity or Scirra Construct is powerful enough to actually make something commercial, but simple enough to get started that it's not super intimidating (in my opinion). While it's (rightfully) lambasted nowadays, I actually feel like Flash was a good way to get started as well, since it's a lot more interactive than opening up Vim and writing C++.

That said, as a grown-up I quite like these "intro-to-programming" kits for myself. I spent more hours making little toys in Pico-8, eventually leading to a simple raycasting engine.

</comment><comment><USER7> We purchased this for my 11 year old at Christmas, and he's been enjoying it very much. He's also into Scratch, and I asked him why he likes them both: he said the Bloxel code is more limited, but is easier to prototype ideas. Scratch is more flexible, but also more time consuming.

</comment><comment><USER8> I support tools and software that help kids learn technology and coding. I really like the idea and the simplicity, and the cool 13x13 pixel concept, but I can't get over the pricing just to get access to its online EDU hub (license is $100 for 25 students) or classroom packs (which is more expensive but also more acceptable since it includes physical pixel boards). Perhaps I feel grumpy for its over-commercialization of education from Mattel, one of the largest toy company in the world. Another is the several patents that they have on the concept, which irks me.

Scratch is not perfect, but it is at least free, and access to own accounts and community is free.

Also, I think we're giving our kids too much screen time. When I was a kid, the most helpful concept of programming was not a programming language or software, but rather it was just learning the concept of logic and playing with "and" and "or" with electronics and transistors / gates / switches. For that, I think electronics kit (Heathkit) were awesome.

</comment><comment><USER9> Makes me remember learning how to do sprites on my C=64 using graph paper. But, then I got a proper sprite editor and never looked back.

I kinda think this would get old quick like the graph paper did for me.

<comment><USER10> Yea the photos made me think of The 8-Bit Guy videos and him showing how to create sprites using graph paper.

</comment></comment><comment><USER11> We got this for my son and he plays it now and again. He's fairly creative and loves Scratch too. A good gauge is if your child likes Scratch then this is a good compliment.

</comment><comment><USER12> I found out about this yesterday when I posted this thread: [https://news.ycombinator.com/item?id=16282594#16286614](https://news.ycombinator.com/item?id=16282594#16286614)

What I don't see, when visiting their site is now to order less than a 5 pack. It seems you can't just order one board and blocks.

<comment><USER13> I highly recommend GameMaker for teaching programming (this is actually how I started programming). The drag and drop interface is easy to understand, while also being powerful enough to use on real projects. There are even numerous examples of successful indie games that have used GameMaker. It's pretty great for rapid prototyping in game jams as well.

<comment><USER10> Hotline Miami I and II were both in GameMaker (IIRC).

</comment></comment></comment><comment><USER14> As a learning/teaching tool that fosters creative thinking, this looks really cool. I think the idea of having a physical medium that represents an abstract model of an area of your world is also a really neat idea. I will definitely be picking this up for my kids (once they're a bit older).

</comment><comment><USER15> This seems a lot more like 'build your own maps' for a side scrolling engine than 'build your own video games'.

</comment><comment><USER16> Takes the block-as-a-unit thing from Minecraft and has a side scroller engine to start with. There art editor cleverly separates the pixels, though I prefer more traditional paint programs.

Reminds me of Klik & Play. That product relied on a spreadsheet or prompt- based effect definitions.

</comment><comment><USER17> My son has enjoyed making games in Roblox Studio more than anything else. It's scripting language (Lua) has been easy for us to learn together.

</comment><comment><USER18> Tried the demo in Firefox on my Linux box and load average spiked to 20+ and froze the computer for 10 minutes till FF eventually crashed. That is NOT how one should write JavaScript. Considering this a malicious concept will never purchase.

<comment><USER19> That's a bug in Firefox or some other part of your setup - no matter what the JS of a website does, even if it is deliberately engineered to be malicious, it should not be able to cause the computer to freeze.</comment></comment>


1+2+3+4+ . . . = -1/12 - <AUTHOR> https://www.youtube.com/watch?v=w-I6XTVZXww

<comment><USER2> This has been discussed a lot, but there is something real and genuine going on here that is, unfortunately, masked by the obvious nonsense.

Briefly let me introduce the main ideas.

When -1<x<1, sum_{n=0}^{n=oo} x^n = 1/(1-x). We might be tempted, then, to say that

        1 + x + x^2 + x^3 + x^4 + ... = 1/(1-x)

But that's obvious nonsense when, say, x=2. The LHS clearly makes no sense, even though the RHS exists and has the very sensible value of -1. It therefore cannot be said that:

        1 + 2 + 4 + 8 + 16 + ... = -1.

However, underlying all this is the concept of _Analytic Continuation_ which says that under certain circumstances, this is a reasonable thing to be doing.

Sort of.

Here it is being done properly:

[https://terrytao.wordpress.com/2010/04/10/the-euler- maclauri...](https://terrytao.wordpress.com/2010/04/10/the-euler-maclaurin- formula-bernoulli-numbers-the-zeta-function-and-real-variable-analytic- continuation/)

Here is a Hacker News discussion of that:

[https://news.ycombinator.com/item?id=7078744](https://news.ycombinator.com/item?id=7078744)

If that has whetted your appetite for more you might like to follow some of the discussions and links given in previous submissions:

[https://news.ycombinator.com/item?id=7078489](https://news.ycombinator.com/item?id=7078489) : 53 comments

[https://news.ycombinator.com/item?id=7073976](https://news.ycombinator.com/item?id=7073976) : 29 comments

[https://news.ycombinator.com/item?id=7057049](https://news.ycombinator.com/item?id=7057049) : 19 comments

[https://news.ycombinator.com/item?id=7038809](https://news.ycombinator.com/item?id=7038809) : 6 comments

[https://news.ycombinator.com/item?id=7081885](https://news.ycombinator.com/item?id=7081885) : 4 comments

[https://news.ycombinator.com/item?id=8843219](https://news.ycombinator.com/item?id=8843219) : 4 comments

Other submissions:

[https://news.ycombinator.com/item?id=7033444](https://news.ycombinator.com/item?id=7033444)

[https://news.ycombinator.com/item?id=7074820](https://news.ycombinator.com/item?id=7074820)

[https://news.ycombinator.com/item?id=7079921](https://news.ycombinator.com/item?id=7079921)

[https://news.ycombinator.com/item?id=7096326](https://news.ycombinator.com/item?id=7096326)

[https://news.ycombinator.com/item?id=7176024](https://news.ycombinator.com/item?id=7176024)

[https://news.ycombinator.com/item?id=7602317](https://news.ycombinator.com/item?id=7602317)

[https://news.ycombinator.com/item?id=7638147](https://news.ycombinator.com/item?id=7638147)</comment>


How Early Academic Training Retards Intellectual Development - <AUTHOR> https://www.psychologytoday.com/blog/freedom-learn/201506/how-early-academic-training-retards-intellectual-development

<comment><AUTHOR> There is now a lot of evidence that structured learning (like memorizing ABC's) is useless or even harmful for small children and that children should instead be able to play freely. This applies to older children as well.

Examples of stimulating free-play school-alternatives for older children are unschooling or democratic free schools, like Sudbury Valley School.

[https://www.youtube.com/watch?v=awOAmTaZ4XI](https://www.youtube.com/watch?v=awOAmTaZ4XI)</comment>


51% of Tech Workers Believe President Trump Has a Point About Fake News - <AUTHOR> https://www.buzzfeednews.com/article/josephbernstein/tech-industry-survey <comment><USER2> Interesting survey, but some points to keep in mind:

This is a survey of all tech workers in the US. It's not focused on Silicon Valley, and it's not focused on startups (in fact they only surveyed people in companies with 500+ people). Of course the tech giants + startups are not all of tech, but on the other hand, a lot of press coverage of tech is of them. The difference matters here - for example, people in the top tech companies are much more left-leaning on average than the people in this survey, since many are in the left-leaning Bay Area and Seattle, and we have political donation data on them confirming that.

And to be specific, just 20% of people surveyed are in the West (which would include the Bay Area and Seattle), while 37% are from the South and 20% from the Midwest. So over half are not from the stereotypical "tech industry" that the media covers.

Also the survey shows that many tech workers have mixed feelings about the media. The article tries to explain it by right-leaning politics (that the media is too liberal, a backlash against feminism, etc.). However, the article states,

> women in the tech industry are less likely to hold a positive opinion of the > media than their male counterparts.

The article spends only this one sentence on that topic. But it may matter quite a bit, since women tend to be more left-leaning in their politics, and make up almost half of the people surveyed (44%). Given that, the article's explanations don't seem sufficient - there's something else going on here.</comment>


Turn off ad-blockers or don't read us, say top Indian newspapers - <AUTHOR> http://factordaily.com/adblocking/ <comment><USER2> I am not sure how effective are the methods to detect whether adblock is enabled or not.Most popular method seems to be checking the size of the ad content.There are other methods being discussed here [http://stackoverflow.com/questions/4869154/how-to-detect- adb...](http://stackoverflow.com/questions/4869154/how-to-detect-adblock-on- my-website)

In the article itself there is reference to anti-adblock killer.If anyone installs an adblocker plugin,they can probably install an anti-adblocker killer too.

</comment><comment><AUTHOR> Goodbye, Times of India, and Hindustan Times. And anyone else who joins the bandwagon.

What's surprising is, that unlike in the US, newspapers in India aren't in a decline and have no need to do this. Subscriptions (the print variety) are strong despite print ads getting increasingly in-the-face. I'm pretty sure this will get them to the cesspool soon enough.

<comment><USER3> Exactly, when I clicked on google news item linking to NDTV it blocked the article from showing up. And I was like 'So be it'.</comment></comment>


Annotated version of Bell's inequalities, Quantum Mechanics' ultimate test - <AUTHOR> http://fermatslibrary.com/s/on-the-epr-paradox <comment><USER2> You have to allow scripts to see the annotations. Unfortunately, allowing scripts also activates the site's "nag you with overlays about subscribing" feature. So might as well just leave them blocked and read the paper as-is.

Also the site seems to be half-down. Here's an alternate link to the paper (w/o annotations): [http://www.drchinese.com/David/Bell.pdf](http://www.drchinese.com/David/Bell.pdf)</comment>


Ask HN: What would be the cons of exterminating all Aedes aegypti mosquitos? - crypto-jeronimo <comment><AUTHOR> As someone who worked hard to stop GMO mosquitoes in the US's first test (proposed for Key West, Florida) and watched Intrexon/Oxitec nearly bankrupt itself trying, I can tell you it's not going to happen. Some folks like to say, "Nature finds a way."

The most effective way to prevent mosquitoes is still what we call "boots on the ground," eliminating their fresh water supplies. The Cayman Islands' highly publicized test of GMO mosquitoes was a complete failure.

<comment> crypto-jeronimo Thanks for the answer! The question was a bit more general though - not only pertaining to the GM-related side.

</comment></comment><comment><USER2> [https://www.thoughtco.com/why-it-matters-when-species-go- ext...](https://www.thoughtco.com/why-it-matters-when-species-go- extinct-1182006)

just one reference, it comes with breadcrumbs tho. the way an ecosystem persists, is like a standing wave. a small change can initiate a large degree of enharmonic disorder</comment>


Why the NSA Can't Listen to My Mixtape - <AUTHOR> https://medium.com/@huertanix/why-the-nsa-cant-listen-to-my-mixtape-739c147d9c04

<comment><USER2> _The use of a giant-ass Arduino and wave shield was chosen since the (shitty) 44KHz wave file format gave it roughly the same audio quality I figured a wiretapped AT &T phone conversation would have._

Oh dear. With that attitude I have a feeling the NSA might soon send him back a track listing just to mess with his head.</comment>


13 Investor update emails that turned our dots into a line - <AUTHOR> https://blog.shoelace.com/13-investor-update-emails-that-turned-our-dots-into-a-line-42f337dd7d71 <comment><AUTHOR> I always tell my startups to just send me a short monthly email containing 1) their growth-metric-of-choice 2) their cash/runway remaining, 3) anything fun they want to share (a new hire etc)... Then get back to growing the business! But if you want to go above and beyond, these _actual_ investor updates from the guys at Shoelace.com have been a joy to receive.</comment>


Microsoft Whiteboard - <AUTHOR> https://blogs.office.com/en-us/2017/12/05/microsoft-whiteboard-preview-the-freeform-canvas-for-creative-collaboration/?eu=true <comment><USER2> "It's designed for teams that need to ideate, iterate, and work together both in person and remotely, and across multiple devices." _So long as all those devices are running Windows 10._

I'm sorry - in this day and age any software billing itself as a collaboration tool had better be able to run on Windows, Mac OS, Linux, Android and iOS. Those are the platforms people use, those are the people with whom I need to collaborate.</comment>


Travis Kalanick Still Wants Back in at Uber - <AUTHOR> https://www.vanityfair.com/news/2017/08/dara-khosrowshahis-biggest-nightmare-at-uber-travis-kalanick <comment><USER2> This is such a click bait. The author provides no real proof for the title except for "a source close to Uber thinks the path still exists for Travis to come back." He is the founder the path is always going to exist. I do not doubt that Travis will want some control over decisions of the company and any founder would wish that. But let there be some real proof before these reporters jump on publishing such crap. Their new CEO does not even start till next week.</comment>


Google and Box Announce Partnership - <AUTHOR> http://googleforwork.blogspot.com/2016/09/Google-and-Box-partner-to-transform-work-in-the-cloud.html <comment><USER2> We use Google and Box for work at a 100 person Series C startup.

 _Searching across all the locations for my files is a disaster_ : \- one Local files on my work laptop (mostly synced via dropbox), \- two Box (mostly in their web UI, with ~2 folders being "synced" locally), \- three Google Drive (shared and authored files a like), \- four Email, \- five Slack, \- six Files stuck in our business systems (like contracts that sit in Salesforce.com, Jira, etc)

It's an absolute mess. I can't imagine I'm the only one to be annoyed and losing productivity.

<comment><USER3> Sounds like we need a startup to connect the services of all these other startups together.

<comment><USER4> But then some companies won't play ball with their own storage services e.g. iCloud.

<comment><USER5> There's nothing unique about iCloud, so just go with another provider that's less awful?

</comment></comment></comment></comment><comment><USER6> Box has always promoted this notion that you can make applications/addons/extensions that use Box as a backing datastore [1]. This was quite obviously a play at the B2B line-of-business market, which could conceivably develop cloud-hosted apps [2] that operate on data that employees upload into Box.

This is to the detriment of those who sell traditional desktop-based line-of- business apps, including potentially Microsoft Office.

Box could -- for a while now -- open Google Docs documents [3][4] and the like. I guess now it works the other direction, where Google Docs works on files that are sitting in Box?

Google Drive, as funny as it sounds, is actually in a different market: they're the catch-all storage space for Google stuff, while at the same time marketed at nothing in particular. Meanwhile Box aggressively goes after the 'medium business' market. From this odd partnership, a realistic competitor to Microsoft and other office-y application makers may result.

[1] [http://readwrite.com/2013/06/06/box-pay-developers-based- on-...](http://readwrite.com/2013/06/06/box-pay-developers-based-on-app- usage/)

[2] [https://app.box.com/services/browse/57](https://app.box.com/services/browse/57)

[3] [https://blog.box.com/blog/how-to-use-google-docs-in- box/](https://blog.box.com/blog/how-to-use-google-docs-in-box/)

[4] [https://blog.box.com/blog/box-and-google-docs- accelerating-t...](https://blog.box.com/blog/box-and-google-docs-accelerating- the-cloud-workforce/)

</comment><comment><USER7> I like Aaron Levie too. But my thoughts on this can be summarized by quoting one of the responses to the blog post:

        Why use Box and not just use Drive?

<comment><USER8> Google drive is terrible for shared directory structures. it's not that box is better than drive, everyone is better than drive at organizing files

<comment><USER9> I'm fed up with complex director y hierarchies. Namespaces are cool and all, but flat is better than nested.

<comment><USER10> Flatness can result in much more overwhelming complexity.

<comment><USER9> I suppose that depends on what you mean by complexity. I prefer lists to trees, in general. After I reorganized my Dropbox into only 1 layer of folders, I've found it much easier to navigate. But hey, that's just my anecdote.

</comment></comment></comment></comment></comment><comment><USER11> At my day job we are asked to use Box (enterprise), and while it is ok (not great, but not totally awful) as a solution for sharing/distributing files for both internal and external recipients (avoiding those emails with huge attachments)...It absolutely sucks at searching for your files. I starting using tags - similar to Gmail's excellent labels - with the hopes of finding my files without getting a ton of irrelevant stuff...but no dice. Searching for files in Box still so often brings up irrelevant files as to be counter- productive. Again, Box has its benefits, but point blank, search is broken within Box...which means for my team and I to find things we can not depend on search (or tags/labels)...which means we have to depend on old school folder hierarchies; and all the potential downsides that it brings. My hope is this partnership DOES bring some of google's search prowess into the Box product.

<comment><USER12> I seem to regularly have problems with Gmail's searching. Searching for an email composed and sent on a device other than the one you're using to search is a crap shoot. I don't know if it's sync issues but I've had a lot of trouble trying to find emails I know I sent only to open another device and find them.

<comment><USER13> Have you made sure that your devices are putting emails sent from them in the right folder?

I had this issue for a while and it turned out that my phone made it's own "Sent" folder in addition to Gmail's existing one, which completely screwed up search.

<comment><USER12> I only use the Gmail app on Android and the web interface.

</comment></comment></comment></comment><comment><USER14> It'll be interesting to see what Dropbox does in response to this. Box has always been the "business" solution, but partnering up with Google positions Box better to build on this. I feel like this is really bad news for Dropbox who has been trying to get into the business market, but are clearly failing.

<comment><USER15> IPO once and for all?

<comment><USER14> Box? Yes. Dropbox? Eh.

</comment></comment></comment><comment><USER16> Interesting! Why not Dropbox? How might this impact Google Drive?

<comment><USER17> I think Dropbox is drifting towards Microsoft (which is not a bad thing I think). They're collaborating with MS Office.

<comment><USER18> So are Box: [https://www.box.com/partners/microsoft](https://www.box.com/partners/microsoft)

</comment></comment></comment><comment><USER19> It drives me nuts to read an announcement regarding $some_product when they don't spend a single word on explaining what the hell $some_product actually is. What the hell Google PR???

disclaimer: I work at Google :|

</comment><comment><USER20> Is this star of the end of Google Drive?

</comment><comment><USER21> Sort of thought that anything you put in Drive belongs to or can be used by Google according to their TOS. Correct me if I am wrong but that is the main reason no rational business would ever connect anything to Google if they can avoid doing so.

<comment><USER22> I believe if you purchase Google Apps (like most businesses would) the TOS are different.

EDIT: In case any one is curious, this page links to both: [https://support.google.com/drive/answer/2450387?hl=en](https://support.google.com/drive/answer/2450387?hl=en)</comment></comment>


Why nothing can go faster than the speed of light - <AUTHOR> http://www.reddit.com/r/askscience/comments/fjwkh/why_exactly_can_nothing_go_faster_than_the_speed/ <comment><USER3> For those not familiar with RobotRollCall (the author of the linked comment) check out his profile and other answers. He is one of the best contributors to AskScience and can explain almost any theoretical physics topic in understandable terms. People joke that he is actually Neil deGrasse Tyson and that he should really get this own column / talk show.

<comment><USER4> _She_ is one of the best contributors to AskScience

<comment><USER5> Meta-comment: I often see the above pattern on HN. Someone writes a very informative comment with a minor inaccuracy. Someone replies to it only to correct that inaccuracy. The reply then gets way more upvotes than the original comment.

I don't particularly care about "karma", so what bothers me is not that the original commenter didn't get enough points, but rather what people in the community think it's important in a conversation.

<comment><USER6> This is called anal-retentiveness and is very frequent amongst geeks. Just ignore it.

<http://en.wikipedia.org/wiki/Anal_retentive>

<comment><USER7> Actually, it is called pedantry.

<comment><USER8> There's a joke there somewhere.

<comment><USER9> Wait... this whole thread wasn't a running meta-gag?

</comment></comment></comment></comment></comment></comment></comment><comment><USER10> I found that the author gave a great setup for an explanation, and then balked at giving the actual answer.

> For right now, if you just believe that four-velocities can never stretch or > shrink because _that's just the way it is_

In other words, nothing can go faster than the speed of light because that's the way it is? The author needs to explain why the magnitude of this four- velocity vector is the speed of light! I was hooked after the first few paragraphs, but then felt like it dead-ended in a circular argument.

<comment><USER11> She wrote several followup answers in the comments thread, one of which addresses your question (though it might not be satisfying!): [http://www.reddit.com/r/askscience/comments/fjwkh/why_exactl...](http://www.reddit.com/r/askscience/comments/fjwkh/why_exactly_can_nothing_go_faster_than_the_speed/c1gi47a)

Someone else wrote my favorite answer: "Basically, the way to think of it is not that light is the fastest thing, but rather that there is a speed, c, which the geometry of space and time demands is the fastest possible speed.

One can also work out that anything without mass must travel at this fastest possible speed c. Light is one of those things, therefore light travels at c. It's only an accident of history that we call c "the speed of light": that's the context we discovered c's existence in.

As for why it's the speed it is, well, it's the speed in our universe. It's actually much more natural to say c=1 and all speeds are then unitless numbers between 0 and 1. From this point of view c is 300 Mm/s because of how we chose to define the meter and the second." [http://www.reddit.com/r/askscience/comments/fjwkh/why_exactl...](http://www.reddit.com/r/askscience/comments/fjwkh/why_exactly_can_nothing_go_faster_than_the_speed/c1gi276)

<comment><USER12> As of today, meter is defined in terms of the speed of light. We have come a full circle!

> The meter is the length of the path travelled by light in vacuum during a > time interval of 1/299 792 458 of a second.

via: <http://physics.nist.gov/cuu/Units/meter.html>

<comment><USER13> So how long is a second?

<comment><USER14> via Wikipedia: The duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom.

So I guess that means a meter is 30.66331898849836976219 cesium-133 transition periods.

</comment></comment></comment></comment></comment><comment><USER15> It's a shame that about 30% of the comments in this thread are about how the author of the Reddit comment is female. I have a feeling the discussion on Reddit actually trumps the discussion on HN for this one. What's worse is that you have to wade through this irrelevance to get to the "good" comments on here.

</comment><comment><USER16> People keep asking this, and similar things like "if you were travelling in a vehicle at the speed of light and you turned on the headlights, what would happen?"

For me the easiest answer is to understand that from the point of view of the person travelling _near_ the speed of light the beam of light moves away from them at the speed of light. So after ~1 second they are 300,000Km apart.

On the other hand, from the point of view of a 'stationary' observer, the light and the spaceship emitting it are moving at almost exactly the same speed. So after ~1 second they are maybe 1 meter apart.

How can this be? Our minds naturally want to reject this as nonsense. But the thing the gripping hand is holding that makes this true is that to the stationary observer and the person travelling near the speed of light time is moving at different rates.

The person who is moving ~1m slower than the speed of light is experiencing time enormously much slower than the person 'standing still'. The time difference is 300,000,000 times (sic).

Our brains reject this, because we think of time as an absolute rock solid constant, when in fact even with our primitive understanding and slow speeds we can demonstrate experimentally that time is in fact flexible, and it _does_ slow down the faster you get.

<comment><USER17> Say you just flick the lights on and off quickly just to let one photon escape. Where will that photon be in reality in one second? 300kkm apart from the rocket? one meter apart?

<comment><USER18> The part that makes this so hard to grasp is that this question is ill-posed. The "in reality" part is nonsensical.

A primary insight to general relativity is that it makes no sense to define location (or motion) except relative to an observer. This means there's no "true" position or motion, simply an infinite set of equivalently meaningful but disagreeing ways to observe them.

(For interest's sake, acceleration is the lowest order local phenomenon. An object does not need an external observer to measure it's own acceleration due to the appearance of locally measurable "forces".)

So the answer is to excise "in reality" and then state that both answers are equally meaningful and correct.

<comment><USER17> When I say 'in reality' I mean physically. Say the rocket earthbound and is 2x300kkm from the earth, the question again, will the photon collide with the earth or still be 300kkm from it?

The problem I have with light as a unit of reference is that 'perception' is not the same as 'reality' in the physical world.

<comment> T-hawk Relativity demands and demonstrates that there is no such thing as "'reality' in the physical world". Events only occur and exist in the context of an observer.

From the perspective of an Earthbound observer, the photon emitted by the ship will travel from 600kkm away to 300kkm away in one second. (Actually the observer cannot see the photon until another second elapses and it collides with him on Earth.) This observer will see the ship and the photon moving almost together, the ship slower by whatever infinitesimal fraction of c.

From the perspective of a shipborne observer, the photon emitted by the ship will travel from 0 kkm (away from the ship) to 300kkm away also in one second. How do we reconcile this with the knowledge that the Earthborne observer sees the ship and the photon staying together? Length contracts in the direction of travel. So the shipborne observer's meters are very short. The small distance perceived by the Earthbound observer is perceived as a 300kkm distance by the shipborne observer. <http://en.wikipedia.org/wiki/Length_contraction>

In general, this is how you resolve paradoxes in relativity: work it out from the perspective of each observer and understand that there is no central objective reality. You will find that you made an assumption that does not hold true across both observers.

<http://en.wikipedia.org/wiki/Ladder_paradox>

If you can wrap your mind around the Ladder Paradox, you're well on your way to understanding space-time transformations in relativity. The key to the ladder paradox is that there is no such thing as an objective standard of "simultaneous". Simultaneity is specific to each observer; two observers perceive the simultaneity of two events differently.

</comment></comment></comment></comment></comment><comment><USER19> Once you understand that, then read about (what I think is super-cool) : frame dragging.

<http://en.wikipedia.org/wiki/Frame-dragging>

It causes satellites around earth to move a few feet each year.

<comment><USER20> As I read the Wikipedia article, the frame dragging effect is hypothesized and has not yet been observed, though experiments have been designed and some are in progress.

<comment><USER19> They put two dummy satellites in orbit and measured the effect.

Tried to find a better source but this will do for now:

[http://articles.cnn.com/2004-10-20/tech/warped.space_1_black...](http://articles.cnn.com/2004-10-20/tech/warped.space_1_black- hole-lageos-frame)

</comment></comment></comment><comment><USER21> Here is what seems like a reasonable "explanation" to me -

\-- We figured out a few things about electric and magnetic fields. In particular, a changing electric field creates a magnetic field and a changing magnetic field creates an electric field. So if you setup a changing electric field in a specific way, you can setup a cycle between the two field types. Now, these fields hold energy and by virtue of this cycle, become capable of carrying away this energy - what we call "light" - just as waves on water carry energy away from the starting point at a certain speed. The strange thing about E and B though is that this "speed" is a constant that is independent of the reference frame you choose to monitor it. In other words, this wave would move at the same speed relative to you no matter how you happened to be moving and you can therefore never "catch up" with it. Therefore no "thing" (matter) can move faster than light. \--

In physics, recursive "why"s always lead to "that's the way it is" tautologies. For instance, if atoms are mostly empty space, why don't we fall through the floor? Pauli figured out that no two fermions with same spin state can occupy the same space. Why can't fermions do that? They are spin-1/2 particles and their wave function amplitudes cancel out if you account for the fact that fundamental particles of the same type are indistinguishable. Why does the combined wave function cancel out? .. 'cos that's what seems to agree with experiment - i.e. because you don't see people falling through floors.

Progress seems to be about trying to extend this "explanation chain" by one step more. So string theory can step in and add "because vibrating strings, which is what we're made of, behave like this" .. and then it stops at some point again.

</comment><comment><USER22> Two comments. First, as she alludes to in her edit, the "rotated arrow" picture that RobotRollCall uses here is subtly backward. It does suggest the right things and I used to think of it that way, but it eventually gets you in trouble. (In actuality, as you start to move through space, your motion through time _speeds up_... but this still leaves your arrow the same length because the geometry of space-time is hyperbolic: the Pythagorean theorem reads "x^2 - t^2 = c^2" instead of "x^2 + t^2 = c^2". This ends up avoiding LOTS of issues, some of which were stumbling blocks for people in the comments to her post. But it's certainly harder to visualize!)

Second, several people have complained that RRC avoided the underlying question by saying "the arrow is always the same length". I think they may not be giving that answer the credit it deserves. Her claim isn't that the speed of light is the longest possible arrow (which I agree wouldn't help at all), but rather that _every_ object's arrow has exactly this same length. That shifts the speed of light from being an arbitrary constraint to being simply a label for this universal fact. The question "Why is every arrow the same length?" is still valid, but there's much less reason to worry about it: no known process can change that length, just as no known process can change the rest mass of an electron.

<comment><USER22> It doesn't stand on its own terribly well without some substantial discussion in class to back it up, but here's a handout that I've given to classes to try and discuss this stuff a little: [http://othello.alma.edu/~jensens/teaching/classes/spacetime....](http://othello.alma.edu/~jensens/teaching/classes/spacetime.pdf)

</comment></comment><comment><USER23> No answer can be given to this question, it is one of the _axioms_ of relativity theory. The explanation is trying to explain the axiom in terms of the theory built on it.

I found these answers to be more informative: [http://physics.stackexchange.com/questions/2230/why-and- how-...](http://physics.stackexchange.com/questions/2230/why-and-how-is-the- speed-of-light-constant)

</comment><comment><USER24> The top answer on Reddit was not helpful to me, and seemed tautological even in the face of its length.

WHY can't the arrow stretch? That is the crucial question; that is the original question. The original question was not "is there/why is there a tradeoff between space and time." The question was "Why can't the arrow stretch, why can't we go faster than light allows?"

</comment><comment><USER25> I found her lengthy explanation patronising and unhelpful.

"you change your direction of motion through spacetime, but not your speed of motion through spacetime."

This is article a long-winded way of restating the question, and leaves the reader thinking they know the answer when they simply have a different understanding of the same problem.

<comment><USER18> Yeah, but a _mis_ understanding that's somewhat closer to the truth than before. Unless you want to explain Minkowskian spacetime, hyperbolic rotation, and its connection to Maxwell's equations... I think that coupling "motion through time" and "motion through space" like she explains is a good step forward from "cosmic speed limit".

</comment></comment><comment><USER26> I would just explain that a photon has zero mass, but nonzero energy and momentum and finite velocity. Intuitively (meaning: in a Newtonian universe), one would think that a particle with zero mass would have to have infinite velocity to have nonzero energy and momentum, right? And yet, its velocity is finite. That demonstrates that the universe is not Newtonian. It also sets up an intuitive connection (which is what we're looking for here, right?) between the speed of light and one's intuitive sense of an infinite velocity.

Again, of course, this brings us to the question of why the universe is this way: why it is Einsteinian rather than Newtonian. But that question really belongs to the realm of metaphysics, not that of physics.

<comment><USER27> Actually that question is easy to answer.

The universe is Einsteinian because otherwise e could not equal mc2.

And if that were the case then stars could not shine, and a TON of other things would not work. Atoms could not exist either.

The reason is that as you go faster you have more energy (obviously) and since you have more energy your mass increases. Since your mass increases you need even more energy to increase your speed (since now you weigh more).

Take that to the limit and you find that as you reach the speed of light your mass goes to infinity.

So it's necessary that it's impossible to exceed the speed of light - <USER2> example if you had two objects each traveling at 51% of the speed of light (relative to third placed in between them). Then relative to each other they are going faster than light - which means they have more than infinite energy.

Can't do that.

So relativity is necessary if you want mass to be interchangeable with energy.

<comment><USER28> You mean to say they will be approaching each other at 81%~ speed of light.

<http://en.wikipedia.org/wiki/Velocity-addition_formula>

Surely you must read up on modern physics a little bit, sir!

<comment><USER27> That's the point - because relativity exists, the measured speed is not simply the addition of the two.

I was explaining why that is necessary if you want e=mc2

<comment><USER28> The way you'd phrased it confused the matter further, though. I'd consider rewording some of it.

<comment><USER27> So it's necessary that it's impossible to exceed the speed of light.

For example if you had two objects each traveling at 51% of the speed of light (relative to third placed in between them). You only gave them a certain amount of energy, but if speeds were additive and you compared them then it would appear that their comparative speed was greater than the speed of light!

And that would imply an infinite amount of energy, which would be a problem.

Even if they were each traveling at 49% of the speed of light, so there are no issues of infinity, it takes a lot less energy to accelerate two object to 49% of the speed of light than it does to accelerate one to 98% of the speed of light (because it's a lot heavier when it's going that fast, so it contains far more energy), so you would have issues with conservation of energy.

Because of all that, speeds are not additive, and they get adjusted in a way that keeps conservation of energy exactly correct.

Therefor relativity is necessary if you want mass to be interchangeable with energy.

<comment><USER28> I understand that you say that they're not additive, but I have a feeling you aren't really understanding what the actual math behind it is. Two objects traveling at 51% the speed of light relative to a third object placed between them (or anywhere else) would STILL travel at 81% the speed of light relative to each other.

Please take a look at a very simple relativity homework solution to see if you misunderstand the math or the concepts of relativity (that happens to be the top result for "two spaceships approach each-other" on google)[http://www.phy.duke.edu/courses/143/homework/hmwk3_solutions...](http://www.phy.duke.edu/courses/143/homework/hmwk3_solutions.pdf) [It's problem #2]

<comment><USER27> You are utterly missing my point.

I'm trying to show why relativity is necessary, I'm not trying to explain relativity.

I'm giving an alternate universe where relativity does not exist and showing why that universe could not work. And because it does not work, relativity is necessary.

Please go back to the original question I am answering: Someone wanted to know why the world is Einsteinian not Newtonian.

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER29> What helped me with a better understanding of time dilation is short paragraph from RobotRollCall:

"""

If you're moving through space, then you're not moving through time as fast as you would be if you were sitting still. Your clock will tick slower than the clock of a person who isn't moving.

"""

<comment><USER27> Maybe it helped you, but it's utterly inaccurate and incorrect.

There is no such thing as "moving through space". There is only moving relative to another object. And BOTH of your clocks tick slower! Relative to each other.

<comment><USER30> "[...] it's utterly inaccurate and incorrect. There is no such thing as "moving through space"."

I think you're missing the point here. She's not trying to teach people the perfect semantics, she's trying to progressively teach them concepts that are tricky to understand and assimilate, step by step. And in a way they can relate to.

By the way, she addresses what you brought up in her first followup (with yet another compelling and easy to understand explanation).

<comment><USER27> This is not a matter of semantics, if you ever want to understand relativity the FIRST thing you need to do is get rid of the concept of absolute motion. As long as you think in those terms you will never be able to understand it.

And addressing something in a followup is no good - fix your initial post to be correct in the first place. Reddit allows you to edit your post.

<comment><USER30> If she had started by explaining relativity her post would have been twice the size and she would have lost half the audience. Doesn't it matter to you that people were actually interested in the topic and participative?

And why is a follow up no good? She didn't follow up to fix anything. She followed up to follow up. (And mentioned it by, yes, editing her article).

<comment><USER31> The problem here is that when explaining things improperly to be "good enough" you have to be very very careful to make it clear what you're doing.

In my opinion, she failed to properly do that and crossed the line between "helpfully simplifying" and "incorrect".

<comment><USER30> I went through your comments and you mentioned that "in a nutshell" the fact that there's no such thing as a full stop in space is why "this explanation is actually doing a disservice". But that's confusing to me because she clearly stated - relatively to motion - "Those things are true, but we're ignoring that kind of stuff right now."

Can you point out exactly where she crossed the line in your opinion?

<comment><USER31> The confusion being expressed among commenters here is what I'm basing my assertion off of. Simplification is fine, but I think in this case it pretty clearly set a lot of people down the wrong track.

<comment><USER32> Some confusion is to be expected. After all, a lot of the concepts are pretty tough to comprehend cleanly.

</comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER33> Awesome explanation. But what I've never understood is what the universe looks like to photons. What does it mean for a photon to travel between two points from the frame of reference of the photon?

<comment><USER27> Time does not exist for the photon, so from the photons point of view it is at both locations simultaneously.

<comment><USER33> erm, i looked up the answer. frames are inertial, thus photons don't have a frame of reference.

<comment><USER27> How so? Photons are inertial - meaning non-accelerating.

</comment></comment></comment></comment><comment><USER34> Stephen Hawking predicted that things can travel faster than the speed of light through quantum uncertainty. This is how information can escape from a black hole.

<http://en.wikipedia.org/wiki/Hawking_radiation>

Put simply it works like this: light travels at a constant speed, but due to quantum uncertainty nothing is in one exact place, it 'teleports' around an average point. Thus, if it 'teleports' in the direction that the light was travelling it has moved faster than the speed of light.

<comment><USER35> So this would mean that _on average_ nothing can travel faster than the speed of light?

<comment><USER27> No, it means that the quantum world is very very weird.

It's a strict limit, not an average. It's just that the quantum world has strange definitions of location.

</comment></comment></comment><comment><USER36> Another way to look at it that is arguably simpler (and with greater loss, of course): Imagine the XY plane with every point described by integers in both X and Y marked. That is, (0, 0), (1, 4), (-2, -5), etc. Connect each of them to their four neighbors with a line segment. Now suppose you are at (3, 4) and you want to move to (4, 5), and you may only use the lines given to you. You move to the right, you move up, you're there. And you can move the other way, too, all the line segments are bi-directional.

That works in space; that does not work in time. You can't stop moving or change direction in time. You can put X and Y on that grid and have something meaningful, but you can't say it's X and T; that would imply the ability to freely move back in time or forward at your discretion, which is not true.

A simplified explanation of space and time's actual shape is that when you are at (3, 4) and you are moving through time (in the first coordinate, let's say), you've got lines that lead to (4, 4.1) and (4, 3.9) and so on, but the lines only go to a certain angle, which for simplicity's sake I'll say is the obvious 45 degree angle, which means you've got lines that go to (4, 3) and (4, 5), but nothing else below 3 or above 5. You can only move along those lines, and as there is no line to (4, -2) from your start position, there is no way to get there. The bound of those lines is the speed of light. The pictures of the "light cone" you may have seen are in some sense not merely a helpful picture but actually a true picture of the universe.

You can not move faster than the speed of light because you can only move between connected points in the universe, and to move faster than the speed of light is to bypass that restriction. The universe is literally not shaped that way. The shape of the universe forbids faster-than-light. You don't have any choices other than those lines and none of the lines go faster than light.

This is a grotesque simplification, but I think the core point is accurate. Exceeding the speed of light is impossible for reasons above and beyond the mere "exceeding the speed of sound" or other things were. To travel faster than the speed of light requires _changing the shape of the universe_. (And to the extent that certain theories permit it under some circumstances, such as the Alcubierre drive theory[1], I suspect that we'd find that even if we could implement one of these things the universe would still find a way not covered in those theories to shut it down, cosmic-censorship-style[2], or like [3]. I would also note that all "practical" FTL drives proposed to date have inevitably required the existence of at least one impossibility, such as stable negative mass, and it means little to prove that if I have one impossibility like stable negative mass I can have another like FTL.)

Also, because this is a grotesque simplification, please note that picking apart holes in my picture is not even remotely the same as picking apart holes in the theory of relativity, let alone picking apart holes in the Universe. In particular don't get caught up with things that may appear to be going backward; that's an illusion of this attempt to embed an explanation into Euclidean space, not a real problem with the physics.

[1]: <http://en.wikipedia.org/wiki/Alcubierre_drive>

[2]: <http://en.wikipedia.org/wiki/Cosmic_censorship>

[3]: [http://books.google.com/books?id=_mo4AAAAIAAJ&pg=PA132&#...</a> (reading pages 132 and 133)

</comment><comment><USER37> I remember reading an article a while back:

"Scientists Make Radio Waves Travel Faster Than Light"

article:

[http://www.universetoday.com/33752/device-makes-radio- waves-...](http://www.universetoday.com/33752/device-makes-radio-waves-travel- faster-than-light/)

the paper it's based on:

<http://arxiv.org/abs/physics/0405062>

Anyone with a Physics background care to comment on the validity of this study?

</comment><comment><USER38> She's got a lot of good stuff in her comment history.

I really wish Instapaper worked with reddit comments. Lots of good reading there.

</comment><comment><USER39> My gut feeling is that article is dragged :-) into somewhat irrelevant things like Poincare group et al.

Why maximum limit exist at all? How Universe without this limit will look like? How Universe with limit which is not equal to speed of light will look like?

Antropic principle inevitably pops up.

<comment><USER27> See my answer here: <http://news.ycombinator.com/item?id=2244559>

In order for e=mc2 you are required to have relativity. And a world without that could not exist.

</comment></comment><comment><USER40> This explains why there's a limit to speed but not why this limit is light's speed.

<comment><USER41> Afaik the answer is that the limit is the limit, and the speed of light is unlimited - but there is a limit, so the speed of light is the same as the fastest speed possible. So the limit is not the light's speed, they just happen to be the same.

</comment></comment><comment><USER42> What I want to know is what happens if the arrow is rotated more than 90 degrees?

</comment><comment><USER43> eh, it's more fun to imagine we will one day surpass the speed of light. It hasn't been disproved so conclusively that I know about said proof, so as of yet I can continue imagining the barrier will be broken.

<comment><USER44> I like the way the Asimov talks about hyperspace, a currently unknown dimension that allows for "jumping" through/over huge segments of space without technically traveling faster than light, completely circumventing the issue of faster than light travel and extreme time dilation.

</comment></comment><comment><USER45> If you were moving in a "completely horizontal" direction, wouldn't you not be moving through time at all, but only through space? That means you could move infinitely fast, not with a strict limit.

<comment><USER46> Yes, but that kind of motion (tachyonic) is unphysical. It violates causality: you can imagine that by "rotating" the "horizontal" motion very slightly "downwards", in a different reference frame it is backwards time travel.

The salient thing is that there are three disconnected classes of 4-vectors: timelike (massive particles), spacelike (tachyons), and lightlike (massless particles). Lorentz coordinate transforms can only take you between 4-vectors of a particular type: e.g. there's no inertial reference frame where timelike motion looks like tachyonic motion.

</comment></comment><comment><USER47> It's a good explanation, really, but do we need to have only one? Can't we keep Reddit things in Reddit and HN things in HN?

If I am in a Reddit mood, I will go to Reddit. If I'm more in a HN mood, I will come here.

<comment><USER48> Following your argument to its logical conclusion, HN should stop linking to external sites because if people are in a _site X_ mood, they will go to _site X_ , for any value X.

For myself, I don't visit Reddit unless there's something interesting linked to from elsewhere, such as HN. Thus, I appreciate this being posted to HN.

<comment><USER47> > HN should stop linking to external sites because if people are in a site X > mood, they will go to site X, for any value X

Your reasoning is flawed. The value of HN is its community and the discussions it's capable of spawninf. There are sites for discussing an ampler spectrum of subjects (like, for instance, the nature of the universe and laws of physics) and sites for discussing news that interest specifically to hackers (according to the definition implied in the "Hackers and Painters" book).

<comment><USER49> And that argument is exactly why the comment should be linked here. If the Reddit comment had been a blog post, everything would have been fine, right? I want to see the comment and get to stay here for the conversation.

</comment></comment></comment></comment><comment><USER50> Oh, finally we got here cool discussion. Here is how I explain that one "could" travel faster then the speed of light! HOWEVER, and this is VERY IMPORTANT, this depends on your definition of the speed. So imagine following experiment:

There are two space ships which are built like these russian matroshkas. One smaller space ship is in the hangar of a bigger one. The bigger one starts from the earth and accelerates to the speed of light (or just until 0.999c). Now, the smaller ship starts and can again accelerate from the bigger ship point of view until 0.999c. So, if there is just a simple velocity measure instrument, which is measuring acceleration by F = m*a, and we know the relative space ship mass "m" as it was relative to the earth, then knowing how much force our engine produces we can compute the acceleration. And hence our velocity measurement device will add small "a" to the current velocity by every thrust of the engine.

So given that type of measurement, our smaller space ship can accelerate to the speed of 2c relative to the earth. HOWEVER, due to the relativistic effects the people living on the earth would never ever realize that this ship was moving with 2c, since they are measuring speed by looking how far the ship went in the certain amount of time. And due to the time dilation they will never realize that this ship was actually much farther away then it looks like.

So, regarding to this experiment, we can travel faster then the light. However, this is only due to the definition of the speed.

A counter argument would be that the mass "m" is also changing. However, one could argue that the mass is represented by the amount of particles per volume unit and hence remain constant if volume remain constant. Ok, another guy could argue again that the size of the volume shrinks, but I could then argue that if size of the volume shrinks, then the density of the particles per volume unit from the earth point of view would increase and could end up in a singularity or just black hole, so big bang ?:confused:

This kind of experiment fits well into my experience of the world, where I just cannot accept some of the constraints we get from the nature :) Yes, you cannot travel faster then the speed of light, BUT this is only because I stay at the earth and measure your speed by looking how fast you come back. But this pure guy who is traveling could measure the speed as I've proposed and would then realize that, in deed he was faster then the "earth's speed of light" :)

<comment><USER51> Unfortunately, you are trying to impose a traditional world, where speeds are additive, onto relativity. It just doesn't work that way. A light beam fired from Earth would overtake the smaller ship, so in Earth's frame it is going slower than the speed of light.

<comment><USER50> Yes, you are right, but you just didn't get the point what I was trying to say. In deed I was expected that I will be downvoted by this comment :)

I never claimed that speeds are additive. I've just claimed that it fully depends on what you define as a speed. If you define the speed the classical way (space unit per time), then due to the relativistic effects, it will never work out for you.

However, and this is the point, if you define the speed as just some counter running in front of you which add a value on every engine thrust, then it will work out for you that you are traveling faster, then the "earth's" speed of light!!!

Imagine just another experiment. You are waking up at a space ship and there is nothing around you where you can fix your view to see if you are moving or not. So, the speed-counter on this ship shows you 0.9c (here c is "earth's c"). No, you press the accelerate button and accelerates to additional 0.2c. There is nothing which would stop you accelerating, because in your frame you can assume that you are at rest! So, adding now the new velocity amount to your previous you get 1.1c, HOWEVER, this the "earth's c" ,so the speed of light as it is measured on the earth!!! In your frame, since you have no clue if you was moving or not, you should assume that you have now only 0.2c or just 0c, since you cannot measure the speed in the classical way anymore (there is no other point to fix on).

So, this is the way how to understand the relativistic effects. There is no "super-dooper" spaghetti-monster hand, which will for some reason stop you accelerating. No, this is just because everybody around you will never be able to measure your real speed, because they can only measure the speed relative to their frame.

</comment></comment></comment><comment><USER52> Wave cannot travel faster than speed of wave in medium.

Matter is form of electromagnetic wave, thus matter cannot travel faster that speed of electromagnetic wave in medium ("vacuum").

Everything that is not a form of electromagnetic wave, OR disconnected from electromagnetic medium, will be not bound to speed of light.

Imagine water and water waves. Water waves will never travel faster than speed of wave in water.

BUT, you can freeze water and push it faster than water wave just because it is not a part of water anymore.

I hope, super-cold vacuum (below 0K) or matter in cocoon of super-cold vacuum will be able to travel faster than speed of light.

PS.

Of course, I cannot even imagine, how we can freeze vacuum, because we cannot even interact with it.

<comment><USER27> The entire point of relativity is that there is no medium. There are plenty of particles that do not interact electromagnetically - the neutrino for example.

The speed of light has to do with the nature of reality, not the method of transportation.

<comment><USER52> Relativity is theory. We are talking about real world.

We already know, that vacuum can generate particles, thus it is not completely empty:

[http://scienceblog.com/40901/theoretical-breakthrough- genera...](http://scienceblog.com/40901/theoretical-breakthrough-generating- matter-and-antimatter-from-the-vacuum/)

You can find much more information about faster than speed traveling here: <http://en.wikipedia.org/wiki/Faster_than_light_travel> .

<comment><USER27> Relativity describes the real world.

You seem to want to talk about theoretical ideas that have no evidence.

You quite misunderstood that article, it's not the vacuum that produces the particles, it is the massive energy they are beaming that produces them.

The stuff in the wikipedia article is just ideas that may work mathematically but have little bearing on the real world. At least for now. Maybe someday we'll figure them out, but for now it's just ideas.

<comment><USER52> > Relativity describes the real world.

Any theory describes real world to some degree.

> You seem to want to talk about theoretical ideas that have no evidence.

:-/ We can test my ideas in your laboratory, of course.

> You quite misunderstood that article, it's not the vacuum that produces the > particles, it is the massive energy they are beaming that produces them.

Do you really read article? Of course, energy is necessary, because two vacuum particles will cannot escape each other and will annihilate. But you cannot produce particle using just energy.

> The stuff in the wikipedia article is just ideas that may work > mathematically but have little bearing on the real world. At least for now. > Maybe someday we'll figure them out, but for now it's just ideas.

Some far galaxies are traveling from us much faster than speed of light because of space expanding. Thus theory of relativity will work correctly for distances less than 1B of light years, but it is not correct for larger distances. Are you agree?

<comment><USER27> "But you cannot produce particle using just energy."

Yes you can.

And no I don't agree with your last sentence.

<comment><USER52> No, you cannot.

Do you know about Big Bang?

<comment><USER27> What do you want to know about the Big Bang?

And why in the world do you think you can not produce particles using just energy? It happens all the time.

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER53> Good explanation of space/time -- in short, you're always moving in space and time, and the more you move in space, the less you move in time. Vice-versa.

Brian Greene does a pretty good job of explaining all this in the Elegant Universe. If you're into this kind of thing, check it out.

<comment><USER27> But there is no such thing as moving in space.

You can only move relative to another object. You may even move fast relative to one object and slow relative to another, meaning your clock ticks at a different rate relative to each of those objects.

There is no absolute clock - you can only compare your clock with someone else's clock.

<comment><USER54> Can you move relative to a point in space? Even if there are no objects around?

<comment><USER27> No, because a "point in space" has no definition - without other objects you can't even locate such a point.

You can only move relative to other objects.

</comment></comment></comment></comment><comment><USER55> Does it work in the other direction, or can you only take away time velocity to give to space velocity?

i.e., can you make your time slow down by coming to a full and complete "stop" in space, since I assume nothing in the universe is truly at rest?

<comment><USER31> _"So is there any such a thing as a complete and full "stop" in space"_

No, and that is why in a nutshell why this explanation is actually doing a disservice.

<comment><USER56> No analogy is perfect, in particular many analogies are trying to link our everyday experience with things that extend outside of it.

If we take this and your statement further, we could just declare that all analogies are doing a disservice, and all pop science writers should be flogged.

</comment></comment></comment><comment><USER57> what I don't understand is why the light is the point of reference. Just because it's the fastest "thing" we know ? Or is there some other reason ?

<comment><USER58> Photons and gluons are the only two particles that we know to be massless and therefore capable of moving at the speed _c_ (some neutrinos might be massless, but we know at least 2 of them are not).

Since gluons are never observed as free particles and we're all familiar with photons, we call it the speed of light.

</comment></comment><comment><USER59> _The motion I'm referring to is motion in the futureward direction._

May be you should consider the fact, that while you are not moving- let's assume that your are in space and way far from earth or any other thing-, your brain, heart and blood do. If they don't, you wouldn't exist. It's in my believe that we are living in a single dimension world, and it's not quite different than a dream; actually it's the same thing. Just think about it ;)</comment>


Google's Ethos, Applied to Dining? - <AUTHOR> http://thelede.blogs.nytimes.com/2008/07/01/googles-ethos-applied-to-dining/index.html?ref=technology

<comment><USER2> This seems more like Wikipedia's ethos, rather than Google's. A Google restaurant wouldn't actually serve food, they'd just give you a list of (hopefully the best) places to get the meal you had requested. Of course there would be restaurants that would have bid get listed as well as ones who did black-hat SEO to get to the top.

But often the top entry would be a Wikipedia restaurant. The food would be prepared by what seemed to be a big group of people, but it was really controlled by a small group of Chef Ramsey types who would slap the hands of wannabe chefs and quickly remove the side of lutefisk some joker slapped on your order of vegan tacos just before it left the kitchen.

</comment><comment><USER3> I'd rather eat at "Apple applied to dining". Pick a few very specific dishes and the cook them exceptionally well.

I wouldn't always be in the mood for Apple dining, but when I was, I'd know where to go.

<comment><AUTHOR> And you'd pay out the ear for it!

</comment></comment><comment><USER4> It's funny that it's possible to use Google to make this kind of comparisons... but I've found that Google can't answer the question "how to send a bug report to GMail". There are links that take me to "help" pages (I don't want "help") that insist that I should subscribe to a mail list.

</comment><comment><USER5> "Freedom is a terrible gift, and the theory behind all dictatorships is that 'the people' do not want freedom. They want bread and circuses. They want workman's compensation and fringe benefits and TV. Give up your free will, give up your freedom to make choices, listen to the expert, and you will have three cars in your garage, steak on the table, and you will no longer have to suffer the agony of choice." \-- Madeleine L'Engle, in "Walking on Water"

</comment><comment><USER6> Re-post: <http://news.ycombinator.com/item?id=233207></comment>


Ask HN: How do you think Snowden's "dead man's switch" works? - <AUTHOR>

<comment><USER2> 2 options: Active: he has a server or service where if he doesn't check into or send an email to, passwords and instructions are sent to his collaborators.

        Passive: he has collaborators whom he actually trusts, and who will open the contents and release if something fishy happens to him.

My bet is on the former as it limits the odds that his contacts could 'defect' and release the contents early which would limit his leverage (assuming that this plan actually gives him any).

<comment><AUTHOR> Interesting idea. Seems like the NSA could easily shut this down given the dossier & data stream they must have tied to Snowden by now. He probably can't even turn a computer on without red flags going off.</comment></comment>


Have Studies Linking Trading Performance and Testosterone Caused Bad Behavior? - <AUTHOR> http://www.nakedcapitalism.com/2009/12/have-studies-finding-links-between-trading-performance-and-testosterone-encouraged-bad-behavior.html

<comment><USER2> Is he saying that these studies are encouraging traders to take steroids? That _would_ be a way to fuel "testosterone-based behavior" and it would get _really_ dangerous quickly.

Of course, I can see no mention of that in the article, just enticing suggestions...</comment>


Ask HN: How to become good enough in UX to sell your apps? - <AUTHOR> I am constantly developing little web applications and became very good in a basic Full Stack environment with JavaScript and some database. Good enough to serve to a few hundred customers, fix bugs etc. I am a full time JavaScript developer, and what I am lacking are the skills for a good enough design to present my apps to a broader audience or investors. Also, UX/Design plays a huge role in if customers pay for a service or not (in my opinion).
There are many books and courses out there, and I am kind of lost.
So, does anybody have tips of how to get started to polish web applications to a good enough design to go public? <comment><USER2> If you mean the visual "look", I would just buy a template or engage a designer (even 99 designs). This is for graphic design in the sense of layout, color, fonts, etc.

If you mean UX in the sense of "how it works", learn about user testing (just watch people use your app) -- that's the biggest bang for the buck, IMO. Krug's "Don't make me think" is a good start.

If you mean UX in the broad sense of "your user's life is improved by using your app" \-- this is more of a product design thing -- my go-to recommendation is learning about Jobs-to-be-Done theory. Start here: [http://jobstobedone.org/radio/the-mattress-interview-part- on...](http://jobstobedone.org/radio/the-mattress-interview-part-one/) and then look around that site. Learn about "job stories": [https://medium.com/the-job-to-be-done/replacing-the-user- sto...](https://medium.com/the-job-to-be-done/replacing-the-user-story-with- the-job-story-af7cdee10c27#.mpvd4nqcr)

</comment><comment><USER3> Who are your customers? Businesses? End Users? And how much of an improvement in sales would you expect? 10x?

I'm pretty bad at UI too, and I'm building a project with a partner, which we hope will become a startup, so we hired some freelancers to help with the UI and UX part :) . If you expect a 10x improvement in sales, maybe it's worth it :)

So far it's not as expensive as we feared, but we haven't launched yet.

There's also another thread on Ask HN about it. It basically says to copy and to practice:

[https://news.ycombinator.com/item?id=10948099](https://news.ycombinator.com/item?id=10948099)

</comment><comment><USER4> Realated: [https://news.ycombinator.com/item?id=10948099](https://news.ycombinator.com/item?id=10948099)

</comment><comment><USER5> I wouldn't over think it. Read a couple of books, study UIs you use more critically and keep practicing.

</comment><comment><USER6> tldr: iterate, iterate, iterate.

Learning how to generate and test design hypotheses both with and without users is really important. I too am programmer and design did not come naturally at first; I had to develop it through practice (and much failure and dead code). I realized after a while developing good UX is not a linear process its cyclic. I'll share some HCI practices that I found worked well for me. These are the steps I usually when making apps for clients or for myself.

Before beginning a project I always like to have solid answers to two these questions. They pretty much motivate all my design choices. \- Who is going to use your app? What drives and motivates them to use your app specifically (i.e. why would they use your app and not something else)? \- What do they do right now to solve this problem? What is their next best option? What are the problems with the existing solution?

Next I'll make prototypes. Usually I start with paper and pencil or Powerpoint in a very low fidelity. Though it is tempting, I never write a single line of code until maybe a week or two into this process. Right now, your focus should be in exploring as much of the design space rather than committing to one single possibility - nothing is too crazy or outlandish at this stage. Don't use a ruler or be neat - just get it out so you can understand and evaluate it later. Don't worry about the technicalities of how things will be implemented you can worry about that later.

Once I have enough ideas I pick my 3 winners. The way I do this depends on the specific problem and its constraints - you should base this on the two important questions I mentioned first. For example, if your user is unfamiliar with technolgy, readability and simplicity might take priority over adding a useful but complicated feature. But if he's a developer, you might keep the jargon and add the features to enhance his experience. Don't stress over this process too much because in the end, this is all just based on just your own educated guesses.

Then I make a powerpoint mockup of my favorite idea - basically just slides linking to other slides, with different pictures and animations to make it look like an app. This next step is all about verifying your beliefs and ideas about what you picked. I try to make this as real as possible, adding slides to simulate page loading, using actual iOS or android icons and fonts in my designs but that is a personal choice. Use this mockup to evaluate and test with some users and/or the clients - the things that sometimes you assume or overlook about your users or the problems will surprise you. Consider the feedback and update your assumptions. Now reevaluate your original designs (even the ones you maybe threw out) and fix your mockup. Test it with some users 2-3 times again till no more important issues remain.

Now you write your code. This will be your first prototype. Try to be quick and use familiar technology as far as possible. You should have no problems converting your PowerPoint reference to code since you've done it a hundred times before. Add some sort of analytics / tracking so that you can measure important metrics in your app when it comes time to test.

Now find a set of users that you would like to test your app with - you could ask friends on HN or Facebook, post on Amazon MTurk or go door to door. Try to get your testers to be as close to the target demographic of your users - ideally your testers ARE your users but sometimes you can't be picky. Show your testers the app and get them to use it. If you can, get them to talk aloud as they use it, describing their thoughts process and action in a think aloud. If you can record this process in a video/audio or screen recording so that you can review it later.

Now organize that feedback and analyze it. What is the most common complaint/request your users have right now? Are the problems due to design or implementation? What are the differences between your initial mockup and your prototype and how do they affect the result? Based on this analysis improve your designs, update your code. Do it again a few times if necessary. Once your testers are reasonably happy release it to your actual users and see what they say - chances are by now you should have caught and fixed a lot of the design problems that were too domain specific or hard to discover for you alone and your users will be a lot happier!</comment>


My Simplicity Focused Website Tech Stack - <AUTHOR> https://merki.ca/blog/simple-tech-stack <comment><AUTHOR> I'm specifically enjoying Fathom and Netlify. Both tools seem to be created with superior UX in mind.</comment>