Electric Objects acquired by GIPHY - <AUTHOR> https://medium.com/the-frontier/a-new-chapter-for-electric-objects-75e63e1c0ec6?mc_cid=dd9d2ced66&mc_eid=291c4b4ded <comment><AUTHOR> The EO frame is definitely one of my favorite technology purchases of the last few years, so this announcement makes me sad. I hope the space continues to grow though. My family gets a lot of value out of having one of these in our home...though we use it pretty differently than EO seemed to intend.. their model appeared pretty dependent on users having paid art subscriptions, which we never signed up for.</comment>


Ask HN: Scrum practicioners Does this ring the bell to you? - <AUTHOR>

I'm just testing a video of a product and I'm wondering if it makes any sense at all for agile professionals. Thanks!<p>https://www.youtube.com/watch?v=kN-c189bd_w <comment><USER2> We use Jira Agile (formerly GreenHopper), so sticky notes aren't a problem for us.

<comment><AUTHOR> So no standing at a physical table every morning?</comment></comment>


Tired of being a script kiddie - <AUTHOR>

http://zacharymaril.com/blog/2012/02/15/tired-of-being-a-script-kiddie/ <comment><USER2> Hey Zack,

To put it simply, you rock. You know and understand programming a lot better than most people ever do in their lifetime. And to be honest, you are really better off than I am. Please don't underestimate yourself.

 _Being a script kiddie on Hacker News especially sucks. You see everybody bouncing around with their Phd's in CS or engineering from Stanford or MIT talking about how there are so many people out there who are terrible programmers because they don't know the difference between a linked list and a vector._

I know the feeling. It often gets at your nerves. But here's the thing, those people too were at some time in the past very much like you are right now. In fact, I know a lot of people who'd agree that it is really * what you do with your skills * that really matters.

The primary reason you feel like that is because, in essence, you are a hacker and not a computer scientist. Read pg's brilliant thoughts on this. (<http://www.paulgraham.com/hp.html>)

 _Confession: I have no idea what the difference is between a linked list and a vector. Well, before I wrote this I had no idea._

I didn't too. Big deal? :)

 _I looked it up so I know now in theory what the difference is._

See, that is the whole point of learning things. You always have to be ready to assimilate new things and look up the strange bits as you come across them. And you're doing a blimey good job at that.

 _I can glue things together as fast as the next guy._

An invaluable skill for two reasons:

\- Most great ideas/products come up when two or more existing ideas are glued together.

\- This helps you understand how things connect and inter-operate.

 _But I have no idea how to make my programs go faster or take up less memory. Or why the program actually works._

Don't worry. You will, in time.

 _I got on the phone with the interviewer and one of the first things out of their mouth's was "Sorry, I don't really understand functional programming at all."_

My take on this one? Find people with overlapping interests. There'll be plenty of startups working with Lisp and Clojure. Keep looking in the HN Jobs section. Maybe this one for instance. (<http://news.ycombinator.com/item?id=3580917>)

 _I suspect it will give me more confidence when talking to people about computers. But I don't really know._

I read a very good article recently - "The Biolar Lisp Programmer" (<http://www.lambdassociates.org/blog/bipolar.htm?>)

I don't know about you but I feel like that all the time. I think hackers often suffer from a huge lack of confidence. (Note: confidence is different from self-esteem; in that it is your perception of other people's image of you.)

You seem to have a decent amount of self-esteem. (ready to accept things) So here's to you - Cheers, my friend, you are doing great!

you can write to me here: email@example.com

<comment><AUTHOR> Woah. Thanks for the kind words! Mostly, I just want to be able to say I understand how things are working. Like memory and data structures. Once I grok that I think I would feel much more comfortable. I want to know all of those tricky things so I can forget about them safely.

Also, I was just reading hacker and painters (the book) over dinner tonight. I forced the kids in my clojure class to read bipolar lisp programmer for homework. Excellent, excellent essays.

<comment><USER2> I hope you found some comfort in what I said. And yes, Hackers & Painters is a truly amazing read.

Anyway, take care and have fun. :)

</comment></comment></comment><comment><USER3> Actually, with the sort of knowledge you have in your bag, you could not be considered a script kiddie anymore.

Learn what you want because it moves you in the direction you want to go and don't care too much about the others.

It is all about your ability to hack a problem and the having fun while doing it.

cheers.

</comment><comment><USER4> Don't worry about it too much. IT is a very humbling field of endeavour. To paraphrase Douglas Adams, IT is mind-bogglingly big - you'll never learn it all. You're doing exactly the right thing by identifying new things to learn and then learning about them. Good luck!

<comment><AUTHOR> Thank you! It will be fun.

</comment></comment><comment><USER5> A lot of the insecurity you mention is known as "impostor syndrome": <http://en.wikipedia.org/wiki/Impostor_syndrome>

Basically, you know enough to see the gaps in your own knowledge, but you can't so easily see the gaps in others' knowledge.

<comment><USER6> impostor syndrome sounds like modesty to me.

</comment></comment><comment><USER7> Get yourself an arduino or similar. You'll learn C, and working with such limited memory/cpu/program space will force you to learn all the leet optimisation tricks you crave. Plus you'll be making things flash, beep, and spin around, and probably also burn and explode if you keep at it. What more do you want?

Tip: try and get away from the arduino libraries asap, they are widely held to be awful and they shield you from the intricacies of the hardware.

</comment><comment><AUTHOR> Messed up the submission. Should be a link not a post to HN. If a editor could fix that, I would be really thankful.</comment>


Apple Car(d) - <AUTHOR> http://www.asymco.com/2019/08/27/apple-card/ <comment><USER2> Received a physical titanium card. It looks very solid. Unfortunately many stores do not accept it, even though it uses MasterCard payment network. Some folks are saying that it is because that Apple is hiding a card number expiry date cvv.

<comment><USER3> Interesting, what examples have you seen specifically? You can get the card number and associated info from the wallet app if you need to type it in somewhere...</comment></comment>


Ask HN: Resource for writing text for web applications? - <AUTHOR>

Does anyone have a good resource for writing for web applications? I'm talking about the help text strings, error messages, etc. I'm just wondering about best practices and best phrasing:
E.g., "Successfully purchased product" versus "You have successfully purchased this product" for a confirmation message.
Thanks! <comment><USER2> IIRC, Shneiderman and Plaisant touch upon this somewhere in their book "Designing the User Interface" [0], and Schneiderman's "Eight Golden Rules of Interface Design" [1] may also be applicable. You might additionally want to look into resources that deal with copywriting.

[0]: [http://www.amazon.co.uk/Designing-User-Interface- Internation...](http://www.amazon.co.uk/Designing-User-Interface- International-Human- Computer/dp/1292023902/ref=sr_1_1?ie=UTF8&qid=1434056870&sr=8-1&keywords=Designing+the+User+Interface)

[1]: [https://www.cs.umd.edu/users/ben/goldenrules.html](https://www.cs.umd.edu/users/ben/goldenrules.html)

</comment><comment><USER3> You should read _The Elements of Content Strategy_ by Erin Kissane. It's from A Book Apart. As for shorter display copy, starting with a simple, clean writing style is a great start. From there, validate the assumptions you make with your initial copy. You can use tools like Kissmetrics or Optimizely to test how successful different approaches are.

</comment><comment><USER4> Super idea for a side project! Thanks!</comment>


Apple Has Its "Best Non-Holiday Quarter Ever." Best iPhone Sales Ever. - <AUTHOR> http://techcrunch.com/2010/04/20/once-again-apple-has-its-best-non-holiday-quarter-ever/ <comment><USER2> "Oppenheimer: We're not focused on making a lot of money on the App Store — with the iPad or iPhone. We're just above break-even."

That's interesting to me: that may explain the desire to keep the App store "clean" and the occasional hurt they put on developers. The App store reels people in; if they aren't making money on it the risks of bad publicity is higher than the risk of losing some apps

<comment><USER3> What they want, though, and what makes the iPhone and the iPad so attractive are high quality apps. They might not care about the financial damage of losing a top notch developer, they sure as hell care when that makes iPhones and iPads less attractive.

I think Apple still believes that they can get away with their App store policies because they still are to some degree the only game in town. It will be interesting to see how they will react to Android. We might see their policies change in some shape or form.

<comment><USER4> What do you mean how they react to Android? Is Android doing something new tomorrow that they haven't been doing for the past few years? So far Apple hasn't had to react to Google in this regard and I haven't seen anything convincing me that will change.

And to clarify, I would LOVE to see Google/Android gain on Apple if only because it will benefit consumers, but so far I've been extremely disappointed. Regardless of some developer drama Apple continues to blow everyone else out of the water.

<comment><USER5> Extremely true. I have an HTC Hero and I'm pretty disappointed at the partial shittiness of the experience: Very delayed updates, slow UI, and now they HTC has installed a kernel that blocks all rooting attempts. That's exactly the reason I didn't buy an iPhone.

Say what you want, the iPhone works great.

<comment><USER6> This is one reason why I went for a Nexus One. While other vendors may abuse the freedom Android grants them you can be pretty sure Google is going to keep their flagship phone pure and open and free and also supply it with upgrades.

</comment></comment></comment></comment></comment><comment><USER7> and remember, everyone of those units sold was GSM. No cdma and no EV-DO. I'm not saying it will never happen, but as this GSM-only platform continues to grow, the alternative begins to look less desirable. (and I say this from an area that has EV-DO, but no GSM 3G)

<comment><USER8> In a few years AT&T, T-Mobile, and Verizon will be on LTE and Sprint is thinking about it. One protocol to rule them all.

</comment></comment><comment><USER9> People buy iPhones in Q2? I figured pretty much everyone bought them in the summer so they wouldn't be "obsolete" (ie. not the newest iPhone) almost immediately.

<comment><USER10> _"Cook: We had some staggering growth rates. 474% in Asia Pacific region. 183% growth in Japan. 133% growth in Europe. A lot of this was adding new carrier partners."_

<comment><USER11> hint hint

(hopefully)

</comment></comment></comment><comment><USER12> Who cares?</comment>


Ask HN: How to conveniently get arXiv updates? - <AUTHOR> I want to be informed when new content is posted at a directory like;
https://arxiv.org/list/cs.DC/recent
Opera Mini automatically created RSS feeds for this. I however looked for the RSS feed link to use on my PC  in vain.
Any suggestions? <comment><USER2> [https://arxiv.org/help/rss](https://arxiv.org/help/rss)</comment>


Researchers solve mystery of the galaxy with no dark matter - <AUTHOR> https://phys.org/news/2019-06-mystery-galaxy-dark.html <comment><USER3> It's worth nothing that the authors of the original NGC1052-DF4 article claiming little to no dark matter have disputed the conclusions of the Trujillo+2019 (i.e., the paper the phys.org article is based on): [https://ui.adsabs.harvard.edu/abs/2019RNAAS...3b..29V/abstra...](https://ui.adsabs.harvard.edu/abs/2019RNAAS...3b..29V/abstract)

I think it's safe to say that the jury is still out on this one.

Edit: One reason this is difficult is that you can think of galaxies as having two major contributions to the line-of sight velocity we observe from earth: expansion of the Universe ("Hubble flow") and "peculiar" velocity (motion due to the local gravitational field in which the galaxy lives). The latter velocities are typically a few hundred km/s (or later if the galaxy is in a cluster). NGC 1052 has an observed recession velocity of 1510 km/s ([https://ned.ipac.caltech.edu/byname?objname=NGC%201052&hcons...](https://ned.ipac.caltech.edu/byname?objname=NGC%201052&hconst=67.8&omegam=0.308&omegav=0.692&wmap=4&corr_z=1)). Assuming a peculiar velocity of 300 km/s, that means the peculiar velocity is on the order of 20% of the total velocity. But we don't know what component of the peculiar velocity is along the line of sight or whether it's positive or negative. So with these numbers it's "hubble flow" velocity could be from 1200 km/s to 1800 km/s. If you naive plug those two recession velocities into a cosmology model (e.g., the latest model derived from Planck observations) the distance range you get is 17.3-26.1 Mpc, or a ~40% uncertainty. So we cannot rely just on the Universe's measured expansion to get a sufficiently reliable distance estimate.

So one must use other techniques to measure distances. They each have their own advantages and disadvantages. In general most distance estimates are build on the "Cosmic distance ladder" and accumulate uncertainty as you move up the ladder: [https://en.wikipedia.org/wiki/Cosmic_distance_ladder](https://en.wikipedia.org/wiki/Cosmic_distance_ladder)

<comment><USER4> What I don't understand here is: You have a galaxy where mass doesn't add up. There are rivaling explanations, one being that you estimated the distance wrong, the other that there is no Dark Matter. Isn't the first one the more likely one you should investigate?

<comment><USER3> > There are rivaling explanations, one being that you estimated the distance > wrong, the other that there is no Dark Matter. Isn't the first one the more > likely one you should investigate?

If you look back at the original paper claiming the discovery of the dark matter free galaxy, they do explore several different ways of estimating the distance and argue that they're consistent and imply the more distant value. So that's something they had considered and attempted to cross-check between different distance indicators. Later came the Trujillo paper saying essentially, hey you didn't consider "X" which argues that the galaxy is closer. The authors of the original paper then published a Research Note (that I'd liked in my original post) saying that "X" doesn't agree with the other data.

So people did consider distance errors before claiming the absence of dark matter. But getting accurate galaxy distances Is Hard and there are multiple ways to do it. The original paper considered the distance estimates they could think of and they were essentially consistent. So they did investigate that first.

</comment></comment></comment><comment><USER5> A naive question (not read the actual paper or know much about the field) - <USER2> requiring dark matter to explain galactic physics can be dispensed with by a distance correction, doesn't "we've been underestimating distances all this time" serve as a simpler fact of galactic physics than needing "there is mysterious dark matter everywhere" to explain galactic physics?

<comment><USER6> There are several different features of galaxies that dark matter explains. One of them is the speed with which stars orbit the center of a galaxy—this "rotation curve" is independent of how far the stars are from the galactic center, where if there were no dark matter, you would expect the outermost stars to go slower. That is an effect that is not affected by errors in measuring the distance to remote galaxies. We can see it in our own galaxy! [https://www.e-education.psu.edu/astro801/content/l8_p8.html](https://www.e-education.psu.edu/astro801/content/l8_p8.html)

In general, if you can think of an explanation that does away with the need for dark matter, you can also assume experts have thought hard about it and rejected it for good reason. Nobody likes dark matter as a hypothesis, everyone remembers analogous complications in the history of science that proved to be signposts to a better theory, and everyone knows that a Nobel prize waits for anyone who can find the correct explanation.

<comment><USER7> >One of them is the speed with which stars orbit the center of a galaxy

do we really orbit it? I mean is it a stable orbit (that is the option which requires DM ) or a just a spiral trajectory (no DM required)? The spiral galaxies look like a fireworks wheel [https://depositphotos.com/69366109/stock-video-fireworks- pin...](https://depositphotos.com/69366109/stock-video-fireworks-pinwheel- catherine-wheel.html) , and without DM our "orbital" speed being higher than otherwise expected Keplerian orbital speed means that we're just moving away on a spiral trajectory from the center the same way like the sparks fly away on a spiral trajectory from the center of the fireworks wheel.

<comment><USER8> If they are flying away, something would need to add kinetic energy to the stars over time. Also, galaxies should then start small and disperse as they age.

<comment><USER9> Would the spinning motion of the galaxy affect us any differently than the way the rotation of a planet affects a spacecraft during a gravity assistance boost maneuver?

<comment><USER10> You mean, not?

It's not the rotation that assists, it's the planet's linear -- well, bent, but that doesn't help -- that does it.

There is this notion of "frame dragging" in general relativity, but its effect is practically impossible to measure. They lofted a satellite to measure its effect over several years because it took that long to accumulate enough to measure.

</comment></comment></comment></comment></comment></comment><comment><USER11> If MOND was dealt a near-lethal blow with the discovery of a galaxy that had no dark matter (implying that dark matter was a thing you could put in and take away, not a universal law like MOND), now that the anomalous galaxy is gone, does that mean MOND is back?

<comment><USER12> MOND has other issues, not least of which it _only_ explains galaxy rotational curves, it doesn't explain the larger structures of the universe (which dark matter does explain)

<comment><USER10> Large-scale structure has been attributed to plasma-dynamic effects. It's not a popular hypothesis, apparently in large part because plasma dynamics is hard. So plasma is generally agreed to be there (to the exclusion of everything else, really -- except, y'know, dark matter), but is not allowed to (be said to) do anything dynamical and hard to model.

It will take a future generation of plasma-dynamics-loving astrophysicists to change the ... er, dynamic. Presuming we live that long.

</comment></comment></comment><comment><USER13> _Using five independent methods to estimate the distance of the object, they found that all of them coincided in one conclusion..._

I wish they had listed the five methods, I can't think of that many ... (?!)

<comment> T-A [https://arxiv.org/abs/1806.10141](https://arxiv.org/abs/1806.10141)

</comment></comment><comment><USER14> Weren't these all sparse elliptic galaxies? Didn't they all lack a SMB core?

Is it possible they are whisps of parts of galaxies thrown off in a galactic collision? Like two spiral arms synchronizing and flying off, then coalescing far from the dark matter, which consolidates in the merged galaxy. These degenerate galaxies might then understandably have little/no dark matter of their own.

<comment><USER10> That's called a "just so" story. Scientists are not gentle about those.

It's all, "show me the math or GTFO!". Understandable, really.

<comment><USER14> christ it was an honest/curious question. i luv HN, really

<comment><USER10> It was a valid question. But the details matter too much for it to have an answer.

</comment></comment></comment></comment><comment><USER15> I want to know more about how it was measured incorrectly the first time.

<comment><USER16> This paper is not based on new measurements. It's based on a new analysis of existing data.

<comment><USER17> looks like they overshot by around 50%

Anyone able to explain what the new analysis was that led that existing data to be interpreted so differently?</comment></comment></comment>


Pimp My Code, Part 17: Lost in Translations - <AUTHOR> http://wilshipley.com/blog/2009/10/pimp-my-code-part-17-lost-in.html <comment><USER2> And then there are the small oddball countries who actually enjoy material in their original language. In Finland almost all tv-shows and movies are subbed instead of dubbed, and many people I know prefer (in addition to myself) english software instead of translated. One of the most horrible examples is Microsoft Excel which has actually translated the names of formula functions. Or GCC having translated error messages. Also having "," as a decimal separator instead of "." is sometimes a PITA. Helpdesking people over phone is much harder when you actually need to translate/guess menu items/button label texts etc on the fly from english to finnish. And then there is the problem that there is always some software in english, and its much nicer when the whole system is actually in the same language. And then there is the problem of just plain crappy translations, especially those made by some hobbyists.

English is lingua franca of the internet. Even if having own language is kinda nice, its just not that practical in globalized world.

nb. Localization is a lot more than just translations. Even if no translation is made, proper localization should be still made. Number and date formats are a common example. Another example I have heard is actually having different icons in different areas/cultures.

<comment><USER3> Hear, hear. You didn't mention how frustrating it is when software tries to "intelligently" guess which language you want based on where you are. If you are in Finland and not logged in to Reddit, it shows the UI in Finnish, even though all the articles are in English. When I go to Google.com, sometimes it decides I want to go to Google.fi instead, and then I'm left wondering why my searches are bringing up odd results.

</comment></comment><comment><USER4> i did something similar to this once. i came to the same conclusion as shipley: trying to have other people edit your nibs is madness.

i chose to solve it in a different way, though. i kept all my localized strings in my own simple text file, and did away with nibs altogether, preferring to build all views and windows and menus in code at runtime. probably wouldn't work so hot for really complicated user interfaces, but it worked for me.

<comment><USER5> If you are running your code in an iPhone environment and ever want to modularize code. (Say having a tab in someone else's app without revealing your source) Not having XIBs makes using a static library much easier and cleaner.

<comment><USER4> i am even _more_ anti-xib/nib when it comes to the iphone. they are almost always useless in that case. i've written three fairly substantial iphone apps so far, and i haven't used a nib yet.

</comment></comment></comment><comment><USER3> So by doing some translation effort, you can get perhaps +20% more users, but this should be compared with spending the same amount of effort on some other part of the program. Maybe some nice new feature would also have resulted in +20% users with less effort?</comment>


If you saw INTERSTELLAR and are still confused, this should clear things up - <AUTHOR> https://plus.google.com/105491979847805883344/posts/iY1YGHKHBpP <comment><USER2> Leaving out all the other "mysteries" of the story, I still don't understand how the entire wormhole/tesseract/etc. occurred if Murph had to use Cooper's data to save humanity. Isn't that a paradox? If humanity perished, how did it ever reach the point of manipulating space/time to construct the wormhole, summon Cooper, etc.?

<comment><USER3> I guess it's just better to believe that there was actually another species that actually made them for us but the ego of Cooper is so big that he believed that it was themselves from the future.

<comment><USER4> No, he reasons that it must be humans because why would a completely alien, 5th dimensional race give a damn about some primitive lifeforms on the 3rd planet of a minor star in a minor galaxy.

<comment><USER3> Humans were a 5th dimensional race? That was never the case.

Why would another race give a damn about some primitive lifeforms? Why not? Haven't you heard of Green Peaces?

<comment><USER4> Post-humans are conjectured by Cooper to be a 5th dimensional race. (Post-)Humans would be very interested in setting up the events in the past(woah slippery slope) that set the stage for the eventual emergence of post-humans.

</comment></comment></comment></comment></comment><comment><USER5> I'm confused about how a little shuttle craft was able to climb out of a black hole gravity well with a -61,000 time dilation factor.

<comment><USER4> Gravity assisted boosts, it's how we already travel around the solar system. A little device is better anyways, less stress from tidal forces, less chance you get ripped to shreds.

<comment><USER5> Where was the gravity assist when the Ranger travelled from the huge wave planet (where 1 hour = 7 years) back to the Endurance? They just took off and flew straight there.

</comment></comment></comment><comment><USER6> Bigger size of the timeline :

[http://i.imgur.com/MgwWMFU.jpg](http://i.imgur.com/MgwWMFU.jpg)

<comment><USER7> thank you so much for posting the larger image</comment></comment>


Some more Google+ invite Workarounds - <AUTHOR> http://www.pcworld.in/news/some-more-google-invite-workarounds-51522011

<comment><USER2> None of them work, not even the iOS one.

</comment><comment><USER3> Uh, the ones that don't require iOS don't work at all. Fact checking, anyone?

<comment><USER4> I just tried going to <https://plus.google.com/u/0/me> with a gmail account I don't have a profile for and was prompted to sign in and then create a profile & continue. Seems it's hit or miss just like sharing content from g+ members to non g+ members sometimes allows profile creation and sometimes doesn't.

My email is in my profile I'm more than happy to send share notices to anyone wanting to try and create a profile.

<comment><USER3> I think you made a Google Profile and are sharing with Buzz. What happens when you visit plus.google.com?

<comment><USER4> It comes up with plus just like it's supposed to.

edit for clarity: When I tried this I got the same google plus profile creation screen as when I signed up with my actual google account.</comment></comment></comment></comment>


Soon you'll be able to send letters to incarcerated loved-ones for free - <AUTHOR> https://medium.com/@jessehorne/soon-youll-be-able-to-send-letters-to-incarcerated-loved-ones-for-free-68ff41ad7b8f <comment><AUTHOR> We're hoping to go public with the beta version early next year. Sometime in January is the goal!</comment>


Linus Torvalds: Linux Scheduler Not to Blame for Google Stadia Port Issues - <AUTHOR> https://www.tomshardware.com/news/linus-torvalds-linux-scheduler-not-to-blame-for-google-stadia-port-issues <comment><USER2> Originally discussed here: [https://news.ycombinator.com/item?id=21959692](https://news.ycombinator.com/item?id=21959692)

</comment><comment><USER3> Linus is right. Don't use spinlocks in user-land. The scheduler can't know you're spinning on a lock, so it can't help you. Don't do dumb things -- spinning on a lock in user-land is dumb. Mutexes are as fast as spinlocks in the uncontended case, so use mutexes.

<comment><USER4> Linus is right (for the kinds of code Linus tends to think about). There are good reasons videogame engines tend to use spinlocks, and if the takeaway is "Linux pessimizes for that use case," the implication is "Linux pessimizes for high-performance games atop its kernel."

<comment><USER5> No, linux pessimizes for that case _if you do not cooperate with the scheduler_.

You can implement spinlocks in userspace under specific circumstances. You will need to mark your threads as realtime threads[0] and have a fallback to futex if the fast path (spinning) doesn't work out. And even then you need to benchmark on multiple machines and with realistic workloads (not microbenchmarks) to see whether it's actually worth it for your application. It's complex, linus goes into more detail here[1]

[0] [http://man7.org/linux/man- pages/man3/pthread_spin_init.3.htm...](http://man7.org/linux/man- pages/man3/pthread_spin_init.3.html#NOTES) [1] [https://www.realworldtech.com/forum/?threadid=189711&curpost...](https://www.realworldtech.com/forum/?threadid=189711&curpostid=189755)

<comment><USER6> If you have a fallback to futex, then what you have isn't a spinlock, but an adaptive mutex (which spins, then blocks). Lots of operating systems have those already and you don't need to build your own.

<comment><USER5> If you really want to use a pure spinlock you'll either have to accept that worst-case behavior being worse than a mutex or you have to jump through a lot of hoops (pinning threads, isolating cores, reassigning interrupts) to make sure you don't get descheduled. Because the scheduler won't know anything about priority inversions or even waiting threads, they all look runnable.

</comment></comment></comment></comment></comment><comment><USER7> "do not use xxx, unless you actually know what you're doing. And be aware that the likelihood that you know what you are doing is basically nil."

I got to use that quote at some point. Pure gold.

<comment> rooam-dev Imho the 2nd part applies to those that use the quote too.

<comment><USER8> if you read Linus' post, he says as much immediately after. He says he includes himself in that "you", and notes that the kernel is a result of decades of development by many people working to fix issues that pop up implementing the hard stuff.

</comment></comment></comment><comment><USER9> As someone who has played Doom 2016 (and a bevy of other games from Steam) on Ubuntu at 4k 60fps, I strongly doubt that it's Linux.

Wine/proton and the accompanying libraries are pretty f'ing amazing.

<comment><USER10> They're very amazing, it feels truly magical, but in my experience, they're very fragile. Back in ~2014/2015 I was able to play Skyrim on my trash cheap laptop in Archlinux (don't remember the settings and fps, but the game ran "flawlessly" for me, yet I need to admit I'm not a gamer so I can't tell the difference between 30fps 60 fps etc).

I tried the same in 2018 just for fun and I wasn't able to run Skyrim, there was always some minor issues that made the game unplayable, like mouse not working, crashing on certain screens etc. I essentially kept trying older versions of Wine, and eventually found some version that made Skyrim playable (still not as flawless as it felt in 2015, but playable). Idk if it was my mistake, or some archlinux lib weirdness or something else, but I had to try dozens of wine versions to find something that worked. This is fine for me, since I wasn't intending to play Skyrim, I was just trying to run it (for the "WOW" effect), but I imagine people who actually need Windows software might have been frustrated by this.

<comment><USER9> FWIW, I've found that using the Steam launcher eliminated any compatibility issues which may have cropped up. I'm not a linux _desktop_ power user, and didn't need to be.

> I'm not a gamer so I can't tell the difference between 30fps 60 fps etc

It's like driving a car with a rough idle vs. a smooth idle. You can get used to driving a car with a rough idle, and not particularly care. But once you've driven both, you can identify which is which pretty easily, and the rough idle starts to bug you when you know it can be smoother.

<comment><USER11> I might make a different comparison:

 _Everyone_ who has played more than one video game knows that some just _feel_ better than others. In one, your character is fluid and nimble, and in another, slow and clunky.

This is the result of many things, but a large portion comes from input lag and frame rate. More advanced users aren't necessarily more perceptive, they're just better at pinpointing what they're reacting to. (And in some cases, conscious of how an experience could be improved.)

This is similar to the study of any type of art. Whereas a casual observer might look at a painting and say "meh, I don't like it", someone who has studied art pedagogically can describe precisely what isn't working for them.

</comment></comment></comment></comment><comment><USER12> The original comment from Linus is much more insightful than the "its's complete garbage" quote that was picked for the article: [https://www.realworldtech.com/forum/?threadid=189711&curpost...](https://www.realworldtech.com/forum/?threadid=189711&curpostid=189723)

</comment><comment><USER13> Stadia is just a bad idea and a bad product. Consumer internet access is nowhere near capable enough for it to make sense.

<comment><USER14> But the issue isn't bandwidth, really, is it? I would think the ping would be the killing factor. Do they have a plan for that? Server farms no more than 20ms away from anywhere in the US?

<comment><USER15> >> Consumer internet access is nowhere near capable enough for it to make sense.

> But the issue isn't bandwidth, really, is it?

No, bandwidth isn't the issue, I believe the op was referring to Latency.

I have 75mbps DSL and the Latency is garbage with 29ms being best case. I get frequent periods of 90+ms latency.

<comment><USER16> These seem like pretty common latency numbers for online gaming. I guess it feels worse when there isn't the movement prediction and other techniques to make the latency feel better since the game isn't running locally.

<comment><USER17> Well the issue is that you have input lag on your controller inputs. When I move my crosshair it takes a long to actually show the crosshair moving on screen.

In normal online gaming you do not have that issue. When I move my crosshair in cs:go it moves instantly.

<comment><USER16> Right, yeah that's kind of what I was trying to suggest. Honestly, I don't really see how this can work in the general case all that well given exactly what you are saying. I have seen some examples of fighting games being played over stadia, but many fighting games rely on frame-perfect input (and purists in communities like melee dont even use certain monitors due to this...)

</comment></comment></comment></comment></comment></comment><comment><USER18> I think the more interesting question here is why don't Stadia games use isocpu and sched_setaffinity to ensure their games have the best CPU cache performance and lowest latencies possible.

They control the whole box, it should be more like a console than a regular PC.

<comment><USER19> I'd guess they stack more than one game instance on a single server. The instances need to play fair for resources.

<comment><USER20> There are fairly standard real time scheduling techniques to give whatever time slice you want to each process. Usually you architect it to have a small hard real time and another process for soft real time (e.g. paging data) and you use a priority queue for world updates (intersection tests, gun/missile flyout, updating other player positions). The update thread gets a minimum time quantum and then yields, round robin sharing.

</comment></comment></comment><comment><USER21> What Linus is really saying is that the way Skarupke measured the spinlock being 'bad' is wrong. Skarupke tried to measure it in C, but you can never be sure if you're not being scheduled by anything else.

Skarupke inaccurately defined this as 'mutex vs. spinlock' and an ongoing debate surrounding this as they are comparable, when in no way are they comparable as in userland you simply _cannot_ use spinlocks.

The Windows scheduler apparently _doesn 't_ do this, and _handles_ spinlocks better; whatever that means. But the way it works is that spinlocks should work poorly if you run them poorly. Full manual-control of when running a spinlock in userland, you _will_ be scheduled by other things, and you should know that.

That's what Linux is really about. The ability to do something and not have the system "better-ize" it like Windows does by doing some black magic and running an _unknown_ process alongside your spinlock to make it run better.

A spinlock run in userland SHOULD be scheduled by other things, as Linus says. As Linus implemented in the kernel.

</comment><comment><USER22> My knowledge of linux scheduling has gone up 10x thanks to this debate!

</comment><comment><USER23> BTW, Stadia is incredible, but the lack of high-quality big-name games is disappointing...

</comment><comment><USER24> Are userland spinlocks the reason most games use 100% of one or several cores even when they are minimised and doing nothing?

<comment><USER25> Kinda. Normal Windows applications use a system call to wait for new messages to arrive, and then react to those. This is very similar to waiting for a mutex, and it allows the kernel to put the thread to sleep until a message comes along.

Games often integrates the message loop into their game loop. In their loop, they poll to see if any new message has arrived, and if so handles it. In any case it does it's game thing.

If there's not much to do, because the game is paused when it's minimized for example, this spins much like a spinlock spins. If, in addition, it has some other threads it's synchronizing using spinlocks then yes, it can cause it to burn several cores worth doing nothing.

Better games handles the loop differently while the game is minimized, for example doing the default wait-for-message variant.</comment></comment>


Waymo robot car injures motorcyclist — but human driver at fault - <AUTHOR> https://www.sfchronicle.com/business/article/Waymo-robot-car-injures-motorcyclist-but-13365135.php <comment><USER2> I saw a Waymo almost hit a pedestrian just today (in Mountain View, turning from Central eastbound onto Castro St. southbound).

First, it delayed making the right turn a good 30 seconds because it seemed unable to distinguish the two destination lanes from one and passed up numerous opportunities when the near lane was empty. Then when all traffic cleared, it started its turn without regard to the pedestrian _already in the crosswalk_ just 3 feet to its right. Fortunately, the pedestrian was more aware than the Waymo was.

This wasn't some rare edge condition, either, and Waymo's tech (or if it was in purely manual mode, its driver is an idiot) is just not ready for the real world.

</comment><comment><USER3> Hugh Uy</comment>


YC Seed Deck Template - <AUTHOR> https://blog.ycombinator.com/intro-to-the-yc-seed-deck/ <comment><USER3> Fred Wilson's perspective:

[http://avc.com/2010/06/six-slides/](http://avc.com/2010/06/six-slides/)

[http://avc.com/2011/09/six-slides-three-slides-or-no- slides/](http://avc.com/2011/09/six-slides-three-slides-or-no-slides/)

</comment><comment><USER4> This made me snark loudly

> No money raised means companies are forced to surive on revenue

</comment><comment><USER5> Other references for pitchdecks:

The statistically recommended pitch deck breakdown: [https://docsend.com/view/p8jxsqr](https://docsend.com/view/p8jxsqr)

The original FaceBook pitch deck, including a keg stand: [https://slidebean.com/blog/startups/facebook-pitch- deck](https://slidebean.com/blog/startups/facebook-pitch-deck)

</comment><comment><USER6> I've seen a lot of seed decks and quite frankly while they may have many similar slides (summary, problem, solution, team, etc) I've noticed that the ones that get funded have one of the following:

1) Social proof

2) Significant Traction

That's it. In fact I'd go as far to say that without either of those, you won't get funded period, except through lucky angel connections. In fact I can't think of a case of something getting funded without one of these.

Social proof is typically something of the form of the founders being 3 PhDs in something hot from insert-top-school, or there's a co-founder with a previous successful exit, or there's a top notch advisory board of semi-famous or at least provably successful people. So when Mr. VC throws his money at this startup, hey it's in the hands of the best.

Traction is the other option, and is the typical desired hockey stick graph of users, revenue, deals, whatever. The traction metric often maps really well onto software startups specifically, because very limited labor and capital can lead to real results. Meanwhile for larger enterprises that require legitimate development and manpower to get traction - it's going to be tough to show traction before you have the resources to deliver something. So something like a "nuclear power startup" (which YC has funded for instance) would probably rely more on social proof.

It's a tad disheartening because it makes something like non-consumer hardware a very difficult spot to be in if you're a younger entrepreneur. Maybe an incubator/accelerator (plus personal savings) can get you on the order of $100K, but that's often not enough to prove real traction. And unless you have significant social proof (often not the case for a younger first time founder), then it seems you're going to be stuck in a vast fundraising chasm between $100K and $1M, e.g. between accelerator and seed financing.

In particular I'd be interested to hear people's take on hardware startups in this respect. Consumer hardware has the recently developed option of crowdfunding to bridge this gap. But what about industrial hardware, like a piece of smart machinery, or something in robotics that isn't a sub-$1K developer kit? Maybe then traction looks like a big deal or two that the crafty entrepreneurs are able to hustle.

Anyways, good overall deck template but I don't think people should be under the impression that a good deck is a huge piece of the puzzle. It's social proof and/or traction, plain and simple.

</comment><comment><USER7> "Forced to survive on revenue"

that's a bad thing?

<comment><USER5> The basis of venture capital is the simple statement:

"For every buck you give us, we will give at least two bucks back next year."

You take this extortion because the benefits are ludicrous. "If we get EBay into every country before anyone else, we make silly money" or "We need want <mumble> million to make <mumble> billion in the next few years." The hardest part to get investors to understand that exiting in two years with _only_ a 3x return is still a win.

<comment><USER8> >"exiting in two years with only a 3x return is still a win"

Not for traditional VCs it isn't.

As a rule of thumb, 90% of the startups they bet on will fail outright, and simply burn through the investment. If you're looking to raise, you need to convince them not only that you are in that remaining 10% (ie, those that will generate any revenue at all, let alone profits), but that you're going to generate massive returns to way more than subsidize and justify all the other losses. Pitching VCs with "3x in 2 yrs" is saying you are not what they're looking for.

(That said, it'd be a huge success from a business mgmt perspective.)

<comment><USER9> Philly VCs want 3x, I pressed this q on a panel in Philly, they literally spelled out that they want founders to show them a validated formula where they insert $10mm into adwords or something, press Scale button, wait a couple years, $100mm IPO of which they get 30%. It just didn't really jive with what I know about tech and hypergrowth startups.

</comment></comment></comment></comment><comment><USER10> I'd like to add two more points - unit economics, and bottoms up market analysis. And these are helpful to founders, these 2 give an important insight into viability of business before you start the multi year grind in to make your business work -

Unit economics - what it'll take to make this work with healthy profit margins? This is crucial in case of online-offline startups, infra heavy products, or hardware products. May not be critical in consumer startups until they start monetizing.

Bottoms-up analysis of market - what will be your CAC (cost to acquire customers), ARPU/LTV (avg. rev per user/lifetime value) etc.

Both of these things are quantifiable and it'll answer an important Q - <USER2> much money will it take for the biz to reach whatever milestones that are decided.

<comment><USER11> Those are important, but very difficult to know with any certainty at the seed stage. They've never really come up for me until later rounds.

<comment><USER10> I agree that it's difficult to know exact numbers at the seeds stage, but it's good to do some sort of exercise on user/customer acquisition costs, expected margins (particularly important in case of h/w products or online-offline work startups) etc.. It will help - 1. to know how long will this money last 2. can you build good business (even though it may not be profitable) before next round of financing.

And founders who do this exercise really set themselves apart as they know their business and gives strong signal to investors. Moreover, investors that I've spoken to often talk that they fund startups not only based on growth, or existing business but also ability to raise next round.

</comment></comment></comment><comment><USER12> Seed deck notes that complement the YC info: [https://github.com/joelparkerhenderson/pitch_deck](https://github.com/joelparkerhenderson/pitch_deck)

</comment><comment><USER13> I took the liberty of making it more presentable by remixing the 'wire-frame' template with some minimal color, typography, and images.

enjoy: [https://goo.gl/u3gZuE](https://goo.gl/u3gZuE)

updated ::

Dark Theme: [https://goo.gl/tcLkWY](https://goo.gl/tcLkWY)

White+Orange: [https://goo.gl/i4e724](https://goo.gl/i4e724)

<comment><USER14> I think it's great that you wanted to help others and posted this here for all to use. Thanks!

Personally though, I found the original version to be more presentable.

Perhaps that's just me.

<comment><USER15> I can't tell whether it's a joke or if the person truly believes his version is better.

<comment><USER16> Please stop.

</comment></comment></comment></comment><comment><USER17> > No money raised means companies are forced to surive on revenue

The opposite seems more true: insufficient revenue means companies are forced to fundraise.

</comment><comment><USER18> I like how simple that deck is. Why do people go overboard making it look fancy?

Are there any investors that will take a look at the plain deck and think it is highly unprofessional, turning them down?

I like that YC don't care about the fluff. But I do wonder how "other" investors feel about it.

<comment><USER19> How do you define "fluff"? If you think design (how the story is told) or quality (how easy it is to understand) doesn't matter, then I strongly disagree.

</comment></comment><comment><USER13> ok this is freakier than that FB audio spying system...But I was JUST about to google for "Seed Deck Template"...and boom!

I think YC's stealthy AI is finally on to me..

<comment><USER20> Or you are a wizard that has mastered the Law of Attraction.

</comment></comment><comment><USER21> my 2¢ addition: careful with your abstraction.

Our instincts tend to be all wrong. When making general statements about a business, most try to make the most general statement possible. Otherwise we feel like we're selling it short. It's like when people write resumes. All trees, no forest.

That's why "X of Y" is so common, it's a formula to get past your bad instincts to a better, less accurate abstraction.

People are bad at going to abstraction without passing through specifics. If you'd never heard of jobs, it'd be hard to explain without examples. Fireman would be easier. Policeman would be even easier after that. Once we have two, the concept of job gets easier. Starting from the abstract... we'd be talking about, wages, specializations, uniforms, sick days... hard.

Case in point here, can we see this deck for an actual startup or startupses? It'd be easier to grasp the good/bad points in context.

</comment><comment><USER22> Totally off topic, but this thread shows that sarcasm and irony do not always translate that well over the internet. I had a chuckle at the deck and the comments it generated.

</comment><comment><USER23> "VP of Eng who doesn't sleep".

Would be really great to remove that description, no one should lionize that behavior.

<comment><USER24> Given that the CEO is a muppet, you don't think this is meant to be fun?

<comment><USER23> I do think it was meant to be fun.

My point was that joking about that kind of culture is not a good thing and proliferation of the sleepless founder/employee/programmer that permeates startup culture is a bit ugly.

<comment><USER25> I thinking worrying about how every little saying could possibly harm the world causes more harm vs leaving the slide as a funny joke.

<comment><USER23> "First they came for the Socialists, and I did not speak out— Because I was not a Socialist.

Then they came for the Trade Unionists, and I did not speak out— Because I was not a Trade Unionist.

Then they came for the Jews, and I did not speak out— Because I was not a Jew.

Then they came for me—and there was no one left to speak for me."

<comment><USER26> Please don't do this here.

</comment></comment></comment></comment></comment></comment><comment><USER13> btw, for those who are design illiterate..you will find that Canva's free pitch-deck creator should solve your needs: [https://www.canva.com/learn/pitch-decks/](https://www.canva.com/learn/pitch- decks/)

<comment><USER27> Another plug for those who are design illiterate: My startup [https://www.beautiful.ai/](https://www.beautiful.ai/) is working on providing great design for presentations

</comment></comment><comment><USER28> "$50,000,000 in seed decks per month?" Prove it, said the VC.

</comment><comment><USER29> I'd like to add one more tip: good design. I've seen and designed many decks for startups and some engineers pay zero attention to design. Sure if you have insane traction or other extraordinary data points it becomes less of an issue. But the investors, like yourself, are human beings who want things to look clean, neat and be clear. Nice design doesnt mean add nice colors. It means to make it a joy to go through with visuals of your product, clear font and font color selection, consistent branding etc. don't waste too much time on the design but do treat your deck as a product of its own.

If you need any advice, feel free to ping me.

<comment><USER27> Tackling great design for presentations is what I'm working on with my startup, [https://www.beautiful.ai/](https://www.beautiful.ai/)

We focus on exactly the types of things you're mentioning, but we try to automate it for those who don't have the design skills (or time to invest even if you do have design skills)!

<comment><USER30> What is "AI" about it? assuming AI means artificial intelligence? What is that connotation supposed to represent?

<comment><USER27> Here is an article we wrote about our thinking: [https://blog.beautiful.ai/designai](https://blog.beautiful.ai/designai)

The shorter answer is that we don't have any ML in production at the moment, but we will as we grow. The core of our product is similar to video game enemy AI.

</comment></comment></comment></comment><comment><USER31> Now I'm wondering if there's a viable "seed-deck development" business model that can scale to IPO..

<comment><USER32> A reinforcement learning based pitch bot would be much better.

Blindly pitch investors random ideas then build whatever they fall for.

<comment><USER33> Great, now I have to guess if you are a human or a bot that's both pitching and retelling it's own inception in the same sentence.

</comment></comment></comment><comment><USER34> Sooper

</comment><comment><USER35> If it were a real company, I wouldn't invest in the seed template making company based on the seed template shown. What does that say about the ability of the seed template making company to make templates? It proves they have an inferior product.

Now if a different template making company had a version that was exactly the same in every way but included machine learning, suddenly it's a no-brainer (literally: no thinking required.) The fact that I would invest just shows how effective that template would be.

The above is a very real thought process. If you want a real template, litter it with the buzzwords you need. In 2018 that is AI/machine learning, and for at least a few more months, ICO and blockchain.

<comment><USER36> Not sure what all the downvotes are about. I tend to respond positively to sarcasm and cynicism. So, one (1) upvote for you.

</comment></comment><comment><USER37> Where can I find an investor that will give me 1.5 million so I can hire my insomniac friend as VP of engineering?</comment>