Inside Magic Leap - <AUTHOR> http://www.forbes.com/sites/davidewalt/2016/11/02/inside-magic-leap-the-secretive-4-5-billion-startup-changing-computing-forever/#7e4ba0c9e83f <comment><USER2> So clearly the author is sympathetic to the aura that Magic Leap is cultivating through secrecy and selective media engagements:

> _When it arrives–best guess is within the next 18 months–it could usher in a > new era of computing, a next-generation interface we'll use for decades to > come._

...which may be a pretty valid statement or sentiment overall, but later in the article, we get to the crux of the "potential" future of the device / platform:

> _Eventually Magic Leap sees its greatest impact in business applications, > especially medical imaging and retail (imagine "trying on" garments at home, > seamlessly). But as with most technologies, entertainment offerings will > lead the way._

I might be picking on a low hanging fruit here, but seriously, one of the compelling reasons to look forward to Magic Leap is so it can have a tie in with the Home Shopping Network or QVC or Nieman Marcus?

The more and more I see the little teaser images (and the occasional demo reel like the office game) I'm cautiously suspicious the technology is perfectly reasonable but figuring out great content for the platform will be the difference between whether it will align with the hype and promotion or be closer to the storyline of the Nintendo Virtual Boy.

I'm just frumpy after years of seeing the difference between renders for PR purposes and actual in-game / in-environment footage as a player / user, which, I do think as tech has improved, isn't happening as much anymore in commercials and whatnot, which I like. This particular situation and eventual roll out will prove a lot I'm sure, one way or another..."soon-ish" as he says...

<comment><USER3> This has about as much hype as Ginger (Segway Transporter) did before it was launched. Disrupting multi-billion dollar industries in a single bound, changing the world forever at it's launch.

But in reality what it really takes to disrupt an industry is both a disruptive product and a really compelling mass-market price point. One of the reasons the Segway PT failed is it was $6k to buy. That severely limits the addressable market to only the rich and those that really want a new form of transport.

This is the same problem Magic Leap and Microsoft's Hololens have. If the product is more than say around $700, it's not going to be a mass consumer product, and it's not going to disrupt entire industries. The iPhone is a good example of a product that is sold for about the maximum price point a user can tolerate in most countries, and even then a lot of iPhones are sold in installments to bring the upfront cost down.

I find it hard to imagine that Magic Leap can hit that entry level price point in a Version 1 product, and if they can't then there will be quite a few big tech companies gunning to catch up with their technology by the time they hit a V2 to erode there exclusivity. Just look at how Google turned Android around after the iPhone launched to go with full screen touch just 6 months after the iPhone.

<comment><USER4> Counterpoint: the classical POV is that you start with a niche and worry about crossing the chasm later (and they require very different marketing strategies etc.). I'd argue Tesla is a modern example of executing that overall strategy from the getgo.

<comment><USER5> Tesla is / was only a half-niche though, cars are a strong and established market. They also had the (huge) benefit that their customers got tax breaks and subsidies because their cars are emission-free, dropping their effective price.

</comment></comment></comment></comment><comment><USER6> I've been hearing rumors about these guys for years and it never seems to be any more than what's in this article-- "we saw some special effects and our wallets flipped themselves out of our back pockets onto the table and began spewing money".

People so often underestimate the difficulty of productizing significant UI changes, not realizing that getting content to migrate to the new shiny will be at least as hard as getting rid of Flash on the web.

<comment><USER7> John Carmack joining Oculus was a quick reason to think: "hm, this team has people who know how to get things done and launch."

Maybe Magic Leap has the same types of engineers [does Graeme have the same reputation as hyper productive dev?], but there are reasons Carmack has this reputation [1].

And I've known and worked with people like this. People who are utterly relentless. Insanely productive. And honestly? I would always bet on them. Every single time. It's just a major key that I don't know anything about on the Magic Leap team.

[1]: [http://venturebeat.com/2015/01/27/how-john-carmack- pestered-...](http://venturebeat.com/2015/01/27/how-john-carmack-pestered- microsoft-to-let-him-make-minecraft-for-gear-vr/)

<comment><USER8> By the time Carmack joined the Oculus Rift's CV1 technology and design was mostly finished. Carmack is reportedly focused on Oculus's mobile offerings which we have yet to see or is indeed the Santa Cruz prototype which, if rumors are to believed, is a mobile SoC powered inside-out markerless VR headset. When I saw the SC prototype I instantly thought this is what Carmack must has been working on. Not shoving cellphones into $20 goggles and working out the kinks like many think mobile VR would turn out.

I think there's some practical considerations here with the "magic engineer" who can do anything quickly and, of course, the laws of diminishing or even negative returns outlined in books like the Mythical Man-Month. Even the impressive Santa Cruz is years out from being sold. Graphically it cannot compete with the PC-based systems it would ultimately compete with.

<comment><USER9> The history between Carmack and Oculus goes much further back and predates the company itself:

[https://en.wikipedia.org/wiki/Oculus_Rift#Initial_prototypes](https://en.wikipedia.org/wiki/Oculus_Rift#Initial_prototypes)

</comment></comment></comment></comment><comment><USER10> I'm thinking that Hololens rev. 2 will be out before Magic Leap rev. 1 is out and will be cheaper. So unless Magic Leap is an order of magnitude better than Hololens, they have failed.

Say what you will about Microsoft, at least they already have a platform on which this "new era of computing" can be based: Windows. That is to say, it makes tremendous more sense to evolve from what we have now into the "new era of computing", than to write an entire platform from scratch, which is what I assume Magic Leap is trying to do.

<comment><USER11> Hololense = 1268 * 720 pixels per eye

Magicleap = supposedly infinite (or they don't exist at all?)

Hololens says they have 2.3 million "light points". I don't know much about light points other than a few paragraphs, but I wonder how Magicleap actually measures light density and how/if it compares or correlates.

<comment><USER12> MLeap is scanned, but they'll have a limit on the switching speed of the laser + color components.

<comment><USER13> Diode lasers can easily amplitude modulate at 10s of MHz, which can provide more effective pixels than 4k displays. If they're still using the piezoelectric beam steering they demo'd a while back, then that will likely be their scanning speed limiter, and thus the pixel density limiter. Their most recent patents suggest they've moved on to something more advanced, though, so it's tough to say for sure.

Regardless, GPUs will likely limit the render resolution for the first one or two products. Upscaling might be possible, though.

</comment></comment></comment></comment><comment><USER14> I may regret this comment in the future, but Magic Leap represents the worst of tech to me. Extreme secrecy while at the same time pushing vapid press releases in the media without sharing any real information.

Either collaborate and share or be secret and reveal, but this is the worst combination. If there was a way to short this company I would do it.

</comment><comment><USER15> I believe Magic Leap has a new kind of display technology, but the article is pretty bullshit-sounding with statements like this:

 _" Throw out your PC, your laptop and your mobile phone, because the computing power you need will be in your glasses, and they can make a display appear anywhere, at any size you like."_

Yeah sure, they not only made a new display tech but integrated the computing power of desktops or laptops into glasses. I wonder how they cool the GTX 1080 cards on your head...

<comment><USER8> Uploadvr demystified this stuff a couple years ago:

[http://uploadvr.com/magic-leap-how-it-works/](http://uploadvr.com/magic-leap- how-it-works/)

Magic leap is a pair of glasses you wear on your face that displays AR imagery through a clear glass lens. There's a cable leading from these glasses to your pocket where you have a tablet-size device doing all the heavy lifting, most likely using mobile SoC's. Pretty sure you can't run a desktop CPU and GPU on a pocketable device.

You don't get 1080gtx performance or anything remotely close to that with a setup like this. Its mobile-level graphics. Oculus's recent showing of its mobile SoC-based Santa Cruz prototype shows fairly poor graphics compared to PC-based VR like the Rift or Vive. I imagine the Magic Leap has less pixels to push considering it isn't doing any backgrounds, but still, those very impressive marketing shots of high resolution dragons flying around and interacting with you might not really be possible without a lot of compromises on graphic quality, fov, framerate, etc. Worse, no one wants to talk about transparency, especially in well-lit rooms. The few hands-on Hololens reports we've gotten make this out to be a big issue, as well as fov, and fundamentally the Magic Leap and what hololens is using could be the same or very similar technologies.

My gut feeling is that no one has yet to handle the transparency issue (and this is why MS can show off the hololens with confidence) and because of that it makes sense for Magic Leap to keep its product secretive. The tech press was not too kind to Hololens prototypes due to transparecy issues and Magic Leap doesn't need that kind of negative press as it continues to fund-raise and develop its product.

<comment><USER16> One important differentiating factor between this and other (consumer) HMD's is the scanning display.

The Oculus et al need to render a rectangular matrix of evenly spaced pixels. If you want a larger field of view or higher resolution this comes with an exponential increase in number of pixels. With a high frequency scanning display and eye tracking you are not locked to a static spatial resolution (see [https://en.m.wikipedia.org/wiki/Foveated_imaging](https://en.m.wikipedia.org/wiki/Foveated_imaging)).

There's a whole bunch of other problems when it comes to a render pipeline for something links this, but at least on the physical front it enables super high perceived resolution with less overall points of light to render.

<comment><USER17> Foveated rendering only became relevant when Nvidia recently started supporting Multi-Resolution Shading. As new techniques and tools like this get better support we can be a lot more efficient with lower powered hardware.

It was interesting to hear Carmack last year talk about re-introducing interlacing as a way to reduce latency.

Although, I'm just reinforcing what you're saying =)

<comment><USER18> Huh, interlacing is a neat idea to reduce latency, but I'm guessing you'd want a form of intra-frame temporal anti-aliasing, otherwise it might look pretty fugly. Whether or not this would neutralise any latency advantage due to the computational overhead of doing this, I'm not sure...

<comment><USER17> Found where Carmack talked about it[1].

For VR, the consensus I've seen seem to push for multi-sample AA > full-screen AA > temporal AA (I feel like I've even seen no AA is better than temporal AA). I'm not quite sure if it's performance, architecture (they really prefer forward renderers instead of deferred renderers for low latency), or aesthetics. In the little bit I've done, when just playing with knobs temporal AA looks better to me. Without AA specular highlights are way too distracting and pop too much.

This reference[2] talks about the extra velocity buffer needed for temporal AA and the fact it tends to over-blur which can fuzz out fine details (low resolution is a touchy subject in VR).

There's a lot of moving pieces when making decisions. In talking about interlacing, he was ideally talking about not having to create a whole image buffer before sending data to the hardware--just rendering parts (well, scanline) of the image that moved.

[1] [https://youtu.be/gn8m5d74fk8?t=10m54s](https://youtu.be/gn8m5d74fk8?t=10m54s) [2] [https://www.youtube.com/watch?v=Xk3WUk5T2TQ&feature=youtu.be...](https://www.youtube.com/watch?v=Xk3WUk5T2TQ&feature=youtu.be&t=2525)

</comment></comment></comment></comment></comment></comment><comment><USER19> Ok - it seems that they 'absolutely' have something bewildering, and eye- popping. There are enough 'no information' testimonials by smart people to get that.

 __BUT __

I 'm still pretty weary of billions getting pumped into a business that remains unproven.

\+ Maybe development is very expensive \+ Maybe the goggles cost to much \+ Maybe they just don't have quite enough content to justify the high costs \+ Maybe the experience 'isn't quite there'

So many times these 'wow' toys have proven to be near-duds when they actually hit market reality.

I can't wait to try it, but I'm also looking forward to seeing the reality of it.

<comment><USER20> I remember that we were going to revamp existing cities and build new cities in accordance to this wonderful transportation device that would change everything, of which I cannot recall the name. I currently see them used as joke props in movies.

<comment><USER21> If you include 'hover-boards' these battery powered, two wheeled, self balancing, things sold over 2.5 million of the things in just the USA in 2015. So, it really is becoming increasingly widespread.

You can see this as and extension of the skateboards vs scooters vertical stick argument.

PS: For comparson 17.5 million cars where sold in 2015 and 12.5 million bikes with 20+" wheels.

<comment><USER22> > So, it really is becoming increasingly widespread.

I don't know if this is really true. I saw a lot of hoverboards on my university campus last year. I don't see nearly as many this year. I'd like to see sales data for at least another year before declaring that anything is becoming increasingly widespread.

<comment><USER23> Earlier in the year I would have attributed this to issues with the supply chain and how hard it was to get the upgraded devices. Now, however, I believe that the exploding battery issues heavily reported in the media and the subsequent Amazon refund program put a massive cool on purchasing and usage.

</comment></comment></comment></comment></comment><comment><USER24> Magic Leap goes against all the concepts we learned in "startup schools" \- launch fast and iterate, get feedback, pivot and grow with your users etc..

they work away from the public for product they don't know if the public want. it's a bet, i hope it will pay off.

<comment><USER25> These guys aren't building an invoicing app. They're building a brand new high-tech platform. The traditional startup approach clearly isn't going to work well here. The line for what a "minimum viable product" could be is pretty high... and once it is out, you can't upgrade it again (well not cost effectively at least). Hardware has a different cycle. Traditional waterfall methodology is still kind of essential for hardware. Frankly, I'm super excited something like this is coming out of a startup, and not Apple. It's nice to have some diversity.

<comment><USER26> > Traditional waterfall methodology is still kind of essential for hardware.

I mean, if you read the article they claim they're doing Agile-hardware instead

</comment></comment></comment><comment><USER27> Has there ever been a company that built this kind of hype over years and then in the end actually delivered something truly revolutionary? Judging from companies like Cuil (not sure if the name is right), Segway or Color they will fizzle out once their product gets on the market, if ever.

<comment><USER28> If past history is the only thing to go on you are correct. However there are quite a few level A players investing huge sums of money in this. I have to think they are paying attention.

<comment><USER27> I have Theranos as counterexample for the A player argument :). But my main question is: is there a an example where such an approach worked and revolutionized the industry? I can't think of any.

<comment><USER23> I'm not exactly sure how to classify it. Would you consider early institutional investors in Microsoft, Amazon, or Facebook?

Anecdotally I've heard that lots of VC firms passed on all three during their very early days, but I'm not convinced that those are good examples of completely new markets.

</comment></comment></comment></comment><comment><USER29> Magic Leap is starting to set off my Theranos detectors...

<comment><USER30> It's not setting off your Segway detectors?

</comment></comment><comment><USER31> Here's a peek at your future....

[https://vimeo.com/166807261](https://vimeo.com/166807261)

<comment><USER32> Honestly it would take that level of visual fidelity and environmental awareness for the leap to live up to the hype and expectations.

<comment><USER31> Leap most certainly won't do this. But give it twenty years.

</comment></comment></comment><comment><USER33> Magic Leap has been bleeding talent as a result of their relocating from the Bay Area to Florida [1]. As I understand it, this decision was made by and for one of their (independently wealthy) founders.

[1] [http://www.sun-sentinel.com/business/careers/fl-magic- leap-n...](http://www.sun-sentinel.com/business/careers/fl-magic-leap-new- building-20151013-story.html)

<comment><USER10> This article brings up a big issue: even if Magic Leap fails to deliver, they just might own all of the relevant patents. This could make AR needlessly expensive for decades.

<comment><USER34> except they seem like they're all business method or software patents which will much hard to enforce:

At the time the Mayo case was decided, there was some uncertainty over whether it applied only to natural principles (laws of nature) or more generally to patent eligibility of all abstract ideas and general principles, including those involved in software patents. The Alice decision confirmed that the test was general.

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

<comment><USER34> Federal Circuit has been invalidating software patents at an alarming rate ever since, all relying on the Alice decision.

[https://www.linkedin.com/pulse/patent-eligibility- criteria-l...](https://www.linkedin.com/pulse/patent-eligibility-criteria- light-alice-concept-idea-fatih-ozluturk)

</comment></comment></comment></comment><comment><USER35> I thought this analysis[1] of how it might work based on the patents was really illuminating, and made at least some of the hype seem deserved.

[1]: [http://gpuofthebrain.com/blog/2016/7/22/how-magic-leap- will-...](http://gpuofthebrain.com/blog/2016/7/22/how-magic-leap-will-work)

</comment><comment><USER36> I stopped reading Forbes.com because of their "malware" policy.

<comment><USER37> Me too - and because their web site sucks. Fortunately, there's usually an adequate TL;DR for anything posted to HN

</comment></comment><comment><USER38> These guys might just be the WebVan of AR. Building a campus before you've sold V1 of your product? That's idiotic.

Don't get me wrong, this could be incredibly cool in a vacuum. But reality often has different needs.

I hope I'm wrong.

<comment><USER12> I think the factory is part of the campus. And they need a factory because the parts are custom.

<comment><USER38> And WebVan _needed_ a distribution network and warehouses.

I'm not saying they're not making an awesome product. I'm saying it's possible not enough people will want to buy it in order to justify _building_ a factory and campus.

It's not my money though and I've never seen the product. This is obviously a HUGE gamble that will either be a raging success or will become a joke about the follies of venture capital (i.e. WebVan 2.0).

<comment><USER12> Some kind of AR will pretty clearly be a big wave (processing components shrinking, but input/output still human size, so they get virtualized).

The funds need to make big bets, this one looked good: best tech from UW prof, a founder who's sold a hardware co for >$1B before.

It depends very much on execution: polish, price, apps.

</comment></comment></comment></comment><comment><USER39> "Changing Computing Forever" is the new "Making the world a better place" ?

</comment><comment><USER40> Sorry, but this article is way to fluffy. Big words, and not much to show for it. The way I see it, it's basically an ad for the author's upcoming book.

Magic Leap itself does seem to be doing amazing stuff, given how much money has been pumped into it. At least, I hope that's the case!

</comment><comment><USER41> When a headline follows the format /change(d|ing) .* forever$/. I figure it's fluff and not worth my time. Am I wrong?

<comment><USER42> I put on a Magical Leap and you won't believe what happens next!

<comment><USER43> Pun intended

</comment></comment></comment><comment><USER44> The author did an AMA on Reddit where he answered a bunch of questions: [https://redd.it/5azhtx](https://redd.it/5azhtx)

</comment><comment><USER45> Uh huh... this is a case of, "Maybe it is, maybe it will, but I'll believe it a week after I see it."

</comment><comment><USER46> This is going to end up like that one episode of Angela Anaconda where they're all really excited about the new Jiggle Fruit but it ends up tasting bad and they don't like it.

</comment><comment><USER47> Asking to turn off the adblocker and at the same time showing the following quote:

"I'm doing the thing that scares me the most every single day."

Like what? Browsing without an adblocker?

</comment><comment><USER12> AR headsets already exist, are not vaporware, already are selling into enterprise markets (e.g. Atheer, Lumus). They're clunky and expensive.

MLeap is the only one I know of which has raised the $ needed for consumer- level polish and price. Probably because of the mini fiber-scan display and diffraction zone plates for natural focus. The other major pieces (waveguide or holo lens, IR TOF camera, SLAM, eye tracking, voice) have been done before.

</comment><comment><USER48> > Ask your virtual assistant to deliver a message to a coworker and it might > walk out of your office, reappear beside your colleague's desk via his or > her own MR headset and deliver the message in person.

Why do people buy into this junk.

The easiest way is plain text. email/slack etc

VR is useless for the office. Things are solved via text/speech, occasionally a graph helps but we all know they are mostly for show.

A magical ability to make things 3D doesn't make work easier.

> In one of its demos the Magic Leap team shows off a computer-generated > "virtual interactive human," life-size and surprisingly realistic. Abovitz > and his team imagine virtual people (or animals or anything else) as digital > assistants–think Siri on steroids

How does a 3d Siri make the backend suddenly easier?

The AI to analysis what you are saying? The AI to answer correctly? The tech to speak smoothly to you? The things that actually matter and work fine in 2d.

A good computer game can costs 100's of millions. These are going to be even more expensive. Even gaming will take a while to kick off.

</comment><comment><USER49> I just watched the Season 3 of Black Mirror, which gives a totally different perspective to this article

</comment><comment><USER50> I've tried the Hololens dev version. It's very cool, unlike anything else I've had on my head. Those who let me try it don't seem to be overly worried or impressed with Magic Leap, but there's no way of telling until we see both side-by-side.

<comment><USER51> It's cool, but the fov is narrow, and the area of visible pixels changes significantly with the position and orientation of the device relative to your eyes. Reach up and slide it a little bit up or down on your nose and you gain/lose enough area that you can spend minutes adjusting knobs and fittings to find something that seems usefully minimal. It's not particularly comfortable in general. And, as a wireless standalone unit compared to a desktop computer, it renders relatively very low quality 3d graphics because of the need for high framerate stereoscopic output and the typical constraints of a several-years-ago smartphone.

</comment></comment><comment><USER52> I want to believe Magic Leap is going to deliver.

With investments from tech companies AND banks AND movie studios, and with half-a-dozen R&D outposts all over the world, it's hard to believe these investors just bought into vaporware.

<comment><USER53> Having worked with VC's before, there isn't always a clear domain understanding of the problem they are investing in. Additionally, once funding snowballs, later investors can incorrectly assume due diligence has been taken care of by earlier investors.

I would expect that we've seen what MagicLeap is targeting in both Google Glass and later Microsoft HoloLens. So conceptually the systems and optics are proven at some early stage. Instead of projecting into a lens that is then reflected into the eye, they claim they are projecting directly into the eye. Either way the optics should be similar. This means that as with any AR (instead of VR) system, they will not be able to project the absence of light in a brightly lit environment. (Creating shadows/darkness should be impossible)

<comment><USER12> Probably similar to HoloLens, very different from Glass.

There are ways to hard-occlude, e.g. LCD mask, but might be punted til a later version.

</comment></comment></comment><comment><USER34> This seems to me a lot like the segway.

</comment><comment><USER54> The fact that Beeple was impressed with this is enough to get me excited about it. Granted, his reaction may have something to do with the ML team sitting right beside him as he demoed the product... so, cautiously optimistic then. It will be something cool. [https://twitter.com/magicleap/status/752540648323026944](https://twitter.com/magicleap/status/752540648323026944)

</comment><comment><USER55> I saw some video from Magic Leap some time ago, some animated character got behind the chair in augmented vr. Aren't they just using infrared to get distance to object, then they are using ML to classify and distinct them all, then when they have sizes of object they calculate behind which element their character will be so they can position it good and make parts of it transparent while crossing under the chair?

</comment><comment><USER56> Does anyone know if it works the same as the hololens in that it is purely additive light - it can only make the image brighter rather than being able to make black pixels. This severely limits the kind of thing hololens will ever be able to do - it certainly isn't going to be replacing any screens.

</comment><comment><USER57> I get this feeling that Magic Leap is marginally better than Micrsoft's Hololens. But after seeing the Hololens, they decided that they need more work to beat Microsft. Marginally better isn't going to cut it.

</comment><comment><USER58> I originally heard the projected images directly onto your retina, if that is the case I don't know how it would work with eye movements? Very interested to see what is underneath all the hype.

</comment><comment><USER59> Seems like most people here are skeptical/dubious of ML. I don't blame them there is a lot of hype. But it is quite fascinating technology. If you look seriously at the detailed technical coverage on how the technology works [1] and watch the recent Stanford lecture by Brian Schowengerdt [2], Co-Founder of Magic Leap, then I think you will see why ML is actually quite special.

Personally I am fascinated and optimistic about the potential represented by scanning fiber + waveguide display for AR and VR. I'm optimistic about the future of this tech platform far more than any other AR/VR tech out there mainly owing to form factor it affords (lightweight glasses) and the superior bio-compatibility of the light-field it produces (all day use). On principal its imagery is clearly light-years ahead of anything using a flat screen with lenses and its potential form factor could be surprisingly close to regular glasses. The image quality and form factor are huge part of why this tech could replace phone or a tv or a laptop. I am sure the first iterations will be cool but not perfect. I expect a progression much like that of the iPhone. It works, its awesome, then it keeps getting better and better and better.

IMHO this really does look like a viable platform for the future of computing for the next 10-20 years. People still buy PCs but the laptop largely replaces most uses for it other than hard-core gaming. Similarly I could see the same effect happening with screens vs ML over time. I say all this with the caveat that the form factor really is much much closer to glasses than something like HoloLense.

Here are couple things I have learned about the tech that kind of blew my mind:

* The same tech used to display the light-field can also be used to capture images of they eye for eye tracking, no extra camera needed. It is conceivable that the same scanning fiber technology could be used to dramatically miniaturize the sensors needed for SLAM inputs as well.

* The detail falloff of human vision from a small point in the center is huge. We largely piece together a detailed picture over time in our minds with quick eye movements. This means that good eye-tracking + foveated rendering largely mitigates concerns about achieving a very high perceived resolution with manageable IO.

* I assumed this kind of display would only be able to produce semitransparent ghostly images. Not so. Apparently it can block incoming light from points where it is projecting.

* It is not simple stereoscopy, the light hitting the eye is focusable at the distance the virtual object appears to exist in real space rather than at the surface of the waveguide. This is why it is so compatible with the human visual system and can be used all day as opposed to other tech. This has to do with how the visual system to point both eyes at an object in space is wired in sync with the system that focuses the lenses. No other system, to my knowledge, accommodates this linkage and thus causes strain. Watch the video to understand this more.

[1] [http://uploadvr.com/magic-leap-how-it-works/](http://uploadvr.com/magic- leap-how-it-works/) [2] [https://talks.stanford.edu/brian-schowengerdt-human- sensory-...](https://talks.stanford.edu/brian-schowengerdt-human-sensory- systems-perception-and-immersive-digital-experiences/)

<comment><USER60> Hi there, About usability: I have used the hololens for entire battery charges (about 3hours). I work on various experiments in AR, including path finding, assembly, etc. Had no noticeable eye fatigue. Hololens works great already, and although light field may bring a technology imporvement, ML seems to come a tad too late (I mean, all the ML videos I have seen can be produced with an hololens)... but I'd love to be convinced.

<comment><USER61> I don't think that hololens with its tiny FOV can do anything vaguely comparable to what ML can do with a much larger one from what I've read around.

<comment><USER60> I'd say yes and no. Many people who have complained about the small FOV of Hololens expect applications where you want virtual stuff everywhere. Certainly nice for all around usage, but not necessary for many others. Again, after hours of continuous use, I've come to "forget" the FOV problem. The key is to switch from eye movement to head movement. When you know you have to look straight at the virtual content to see it, it's actually quite manageable. Don't get me wrong: I'll take 120° anytime, but I _know_ it's around the corner, with Hololens or ML. In the meantime, I'll take what _exists_. I've seen so much vaporware in 25 years in the AR field...

</comment></comment></comment></comment><comment><USER18> So what makes this display tech any different (more special) from that in Hololens? Because it sounds very similar, if not identical..?

<comment><USER62> In a nutshell, Hololens has a fixed focal depth of 2m and objects are scaled proportionally to mimic distance. Magic Leap uses stacked optical elements that can be turned on/off (source of the name digital wave guide they use) and each plane is a different focal depth. So, by mimicking the way light would reach the eye normally, the ML results in more realistic objects in the world.

</comment></comment><comment><USER63> i'm hoping its real... but all that time and all the hype with no substance is confidence shaking. i mean, why would you not allay the obvious fears of investors and potential customers?

there are also the deep technical problems which are widely acknowledged in the field and clearly not addressed. a top spec desktop machine struggles to keep up with your eyes movements /if they are known in advance/ \- the idea that a pear of glasses coupled with /any/ peripheral, even one the size of your house, can contain the hardware to do this in real-time is quite far- fetched - even accounting for sensors with feedback and clever mechanical tricks.

there is no mention of how to deal with occlusion. no amount of throwing light at your retina can solve that problem... you need something to intelligently block it out. the marketing hype images make this seem like a solved problem...

maybe there is something that works, but i have no faith that magic leap is anything more than a scam targetting VCs. the same opinion i have grudgingly kept since i first saw anything of it... because its a cool idea and i want it.

i hope these issues are publicly addressed so i can buy it early in confidence instead of waiting to see if its as good as the sales-pitch... which, sadly, there is no indication it will be - because none of the obvious issues have been addressed.

</comment><comment><USER4> Some sort of near eye light field display maybe? Funny company regardless with the hype updates and secrecy.

</comment><comment><USER64> Next Theranos I'm calling it.

</comment><comment><USER65> I wish I can combine Magic Leap with AR glasses.

<comment><USER66> Or maybe already get a Magic Leap!

<comment><USER65> Nobody knows if the tech exists yet!

</comment></comment></comment><comment><USER67> Nothing really new in this article, we have read bunch of these before...

</comment><comment><USER68> They need to merge with Palantir</comment>


STRONG HINT == Use Vim as a Python IDE - <AUTHOR> http://liuchengxu.org/posts/use-vim-as-a-python-ide/ <comment><USER2> sds111: per [https://news.ycombinator.com/newsguidelines.html](https://news.ycombinator.com/newsguidelines.html), for this and other submissions, "please use the original title, unless it is misleading or linkbait," not your interpretation or opinion of the page.</comment>


Facebook and Twitter Say China Is Spreading Disinformation in Hong Kong - <AUTHOR> https://www.nytimes.com/2019/08/19/technology/hong-kong-protests-china-disinformation-facebook-twitter.html <comment><USER2> While Twitter takes money from those spreading the disinformation. How the f is that not biased, or illegal?</comment>


CosmoFlow: Using Deep Learning to Learn the Universe at Scale - <AUTHOR> https://arxiv.org/abs/1808.04728 <comment><USER2> I took a quick look because I'm aware of the work that has gone in to producing the best estimates of \Lambda CDM parameters from CMB data. This has been done by large-scale MCMC - not DL at all. But, the CMB signal really is Gaussian, so MCMC is well-suited.

By going to the trouble of making a principled forward model including error statistics, you get error bars on all reported parameters, such as the age of the universe - these error bars are critical to later analysis. ("This model requires a Hubble constant in the range ... which is not supported by current observational evidence.")

Parameter estimation from large scale structure is not as "easy". OTOH, I wonder about the accuracy of their map from (cosmological parameters) -> (Large scale structure), because that's what their system is inverting. That is, I wonder about their training data.

From sec. 4C of the current paper, and comparing to their reference to Ravanbakhsh et al 2017 (ICML, [1]), they seem to be using numerical simulations (N-body sims representing gravitational coalescence). These models might have large systematic errors, and their inverse may have its own problems.

Long way to say: I wonder how these estimates of Lambda CDM parameters are viewed by the astrophysics community? The present paper is more of a systems/methods paper than an astrophysics paper. The estimates will come with no error bars, and will be critically based on the simulations used, and the NN limitations.

[1] [https://arxiv.org/pdf/1711.02033.pdf](https://arxiv.org/pdf/1711.02033.pdf)

<comment><USER3> Honestly it seems a bit like stirring the linear algebra pile for the sake of stirring, I don't think fitting parameters to observation is a space that needs deep neural nets.

They talk about their method allowing fast experimentation with how to train dnn, but what is really needed computationally is fast n-body sims to explore the theory space not a fast classifier once you have a fully converged simulation.

I just can't see what role the trained network has in cosmology.

<comment><USER4> Recently there was some very interesting work on solving ambiguous inverse problems with Invertible Neural Networks: [https://hci.iwr.uni- heidelberg.de/vislearn/inverse-problems-...](https://hci.iwr.uni- heidelberg.de/vislearn/inverse-problems-invertible-neural-networks/)

>We can for example say that this specific observation y either corresponds to a young cluster with large expansion velocity, or to an older system that expands slowly.</comment></comment></comment>


French police clash with firefighters during Paris protest - <AUTHOR> https://www.theguardian.com/world/2020/jan/28/french-police-clash-with-firefighters-during-paris-protest <comment><USER2> There is a serious problem in how France (my country) manage protests...

While countries like Germany adopted desescalation technics that proved to be effective... France moved to more violents tactics, seriously injuring a lot of people (most of them peacefully protesting) while radicalizing many protestors...

<comment><USER3> The fish rots from the head!

[https://www.theguardian.com/world/2018/jul/20/macron- securit...](https://www.theguardian.com/world/2018/jul/20/macron-security- officer-alexandre-benalla-in-custody-and-will-be-fired-over-violent-video)

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


Show HN: Listkit – A simple list share Mithril.js app demo - <AUTHOR> http://listkit.co/

<comment><AUTHOR> Hi everyone, OP here. In those last rushing weekends busy with my startup I needed something simple to quick share my shopping list with my girlfriend as she is also working in my core team. So, bored of upgrade gdrive docs all the time lol, I've decided to write this as a Mithril.js tech demo, inspired from a standard todo list to have a shorter dev time. I'm on Mitrhil a lot on my current project, so I've preferred to keep the focus on the same modus operandi.

I've also added some simple features and absolutely went with a no-login logic based on UUID_URL sharing. I quickly wrote a node.js server side app to deal with mongodb and expose some simple API functions. This was also a test, cause I wanted to double-check how to deploy 2 different applications on the same dokku instance. So I'm actually serving the Mithril client as a single app with nginx, and commute data through the API's on the server site, also for some route logic, launching the node app in a docker container. At the end I don't like it so much, I'm still considering to switch back serving with Express 4 static, also to get rid the '?' from the URL as root in Mithril and not be forced to use rewrite methods.

Flow: Absolutely no need to login, fast search engine to check if the recipe/list exists in mongodb and load it to have it ready on the fly, and a quick list of the most forked ones. Forked cause can be logical your GF to modify and re-save your shared list, but can be also logical for another person to load it, check is quality and then take this list as a basis for his/her new fork. Then the last point is just sharing, as many way as possible for free.

At first, using it on my android is pretty nice and fast, and I like the experience, tap and start typing. Friends are also happy. I'm still working in really spare time to add some other features (edit an item, a desktop icon) and some fixing (I know a couple of bugs here and there), but it's logical message is pretty clear. Also the mobile custom grid is not perfect, but should work on most of devices. I will share some Mithril.js coding technique on a blog-post too. At first, using it on my android is pretty nice and fast, and I liked the experience.

I would love to hear your feedback! I am CTO acting temp CEO right now on my startup. If somebody likes the idea and would knock to be a tech co-founder on REALLY spare time to give this concept a serious look and add some custom features (like an optional twitter login), I would appreciate it a lot and for sure I promise to find some time to give it a business dev and some much more serious feedback.

Thanks for your time reading this, appreciated, and thanks Leo, I really like Mithril. [https://lhorie.github.io/mithril/](https://lhorie.github.io/mithril/)</comment>


How to Deal with Conflicting Health Advice - <AUTHOR> https://danielriley.blog/conflicting-health-advice/ <comment><USER2> I'm one of the carnivore nuts :|</comment>


Show HN: Hindley-Milner Type Inference Algorithm in OCaml - <AUTHOR> https://github.com/prakhar1989/type-inference#hindley-milner-type-inference <comment><USER2> This is cool! It's nice to have a bite-sized runnable illustration of HM. Maybe I will finally be able to understand it — both the code and the linked lecture notes ([http://www.cs.cornell.edu/courses/cs3110/2011sp/lectures/lec...](http://www.cs.cornell.edu/courses/cs3110/2011sp/lectures/lec26-type- inference/type-inference.htm)) look pretty informative. I don't think I can digest it in time to comment before it scrolls off the HN front page.

It's a little unfortunate that this version doesn't include let-polymorphism, since that's necessary for parametrically polymorphic functions to be actually polymorphic, and it's not a recent addition — it's in the original Damas- Milner paper. All the other stuff about tuples, lists, sum types, and whatnot can be emulated with functions, but not let-polymorphism, not without a potentially exponential blowup in the program size.

<comment><AUTHOR> Thanks for the feedback! This is actually a smaller part of a much bigger full-blown type-inferred programming language[0], we've been working on as a part of course in school. Our plan was to directly add type-inference in the language but after reading through Stephen Diehl's tutorial[1] we were intimidated and wanted to have a working version on a bite-sized language.

I'm assuming a lot developers like me would be keen to understand how HM works, so I was considering writing a detailed tutorial of the unification algorithm step-by-step. Would you be interested in something along those lines?

[0] - [http://www.cs.columbia.edu/~sedwards/classes/2016/4115-sprin...](http://www.cs.columbia.edu/~sedwards/classes/2016/4115-spring/proposals/JSJS.pdf)

[1] - [http://dev.stephendiehl.com/fun/006_hindley_milner.html](http://dev.stephendiehl.com/fun/006_hindley_milner.html)

<comment><USER2> I don't know if I understand unification well or not; I feel like the control flow in Algorithm W is still a bit of a mystery to me, but I suspect that this is more a function of the effort I've put into understanding it than of the adequacy of the explanations I've found. [http://canonical.org/~kragen/sw/dev3/term- rewriting.scm](http://canonical.org/~kragen/sw/dev3/term-rewriting.scm) was the last time I implemented unification, in August, and sort of represented my understanding of unification at the time — but looking at it now, I see that it only does pattern-matching, which is really only kind of half of unification. I think I did a more general first-order vaguely unificationy thing for queries on triple stores some years back, but the details are now fuzzy in this thing of mine that I flatter by calling it a mind.

So, yes! I'd love a detailed tutorial of unification step-by-step (or perhaps recursive function by recursive function, if that turns out to be simpler). Maybe it already exists somewhere, perhaps in a textbook, and I just haven't found it. Or maybe I got intimidated and need to calm down and work some exercises instead of going off to read Facebook and HN.

<comment><USER3> I second that. But I would also love to know why type inference and unification are so closely related. I mean, I learnt about Prolog (and thus unification) years ago. Like a decade or more later I'm learning about type systems (properly I mean, via type theory) and type inferencing and unification shows up. I kind of get that intensional typing schemes define typing relations and that logic programming is synonymous with relational programming but is that all there is to it?

The second thing I would like to say. And I've said this before. Languages like Ocaml and Haskell (never mind Agda, Coq, what have you) already have too much typing 'smarts' built into them. I would like to see -- hint, I'm probably going to have to get my hands dirty! -- an implementation in either a dynamically typed language like Ruby/Python/Perl/PHP/Javascript/… or a non- functional language like C/C++/Obj-C/…

What think ye?

<comment><USER4> > I would like to see -- hint, I'm probably going to have to get my hands > dirty! -- an implementation in either a dynamically typed language like > Ruby/Python/Perl/PHP/Javascript/… or a non-functional language like > C/C++/Obj-C/…

I understand where you're coming from. I'm working on a mini-ML in Python as a learning exercise for myself and possibly as a tutorial for others; will open source it soon.

As such, I've come across a few good resources:

check out Robert Small's Hindley-Milner in Python[0], as well as alehander42's Hermetic language in Python[1].

I also just found out about Hask, an implementation of many Haskell language features in Python. Looking at the source code, it's well-commented and clear, so I suspect I'll learn a lot from it as well [2].

Finally, even though it's not in a dynamic or non-functional language like you request, I highly recommend Andrej Bauer's Programming Language Zoo[3], which contains very simple and easy-to-understand implementations of various type systems in OCaml. Very elucidating.

0\. [http://smallshire.org.uk/sufficientlysmall/2010/04/11/a-hind...](http://smallshire.org.uk/sufficientlysmall/2010/04/11/a-hindley- milner-type-inference-implementation-in-python)

1\. [https://github.com/alehander42/hermetic](https://github.com/alehander42/hermetic)

2\. [https://github.com/billpmurphy/hask](https://github.com/billpmurphy/hask)

3\. [http://andrej.com/plzoo/](http://andrej.com/plzoo/)

Edit: Oh, and one more resource that's been _extremely_ helpful has been "Introduction to Functional Programming through Lambda Calculus" by Michaelson. Well worth the cost of the book.

<comment><USER3> Brilliant, I'm attempting something very similar in Ruby :)

Will check out those links.

When I have something workable, I'll post it to Github as well and then we can see about creating some kind of umbrella structure?

A related idea I have is that what is needed is some kind of grammar interchange format, or typing-relation interchange format -- kind of like JSON (or Amazon's ION) but for this sort of work. In some ways that is what S-expressions are, maybe there is no need to reinvent the wheel but my hunch is that a domain specific format is needed. Apologies if this is a bit vague, it's a hunch, and I'm going by intuition.

<comment><USER4> Check out RAML: [https://github.com/raml-org/raml- spec](https://github.com/raml-org/raml-spec) Maybe it will fit the bill? It can even encode sum types. But I'm not sure if that's what you're looking for.

I'll ping you when I put my mini-ml in Python on Github.

<comment><USER3> That's not really what I mean. Take the file `parser.mly` from [http://andrej.com/plzoo/html/miniml.html](http://andrej.com/plzoo/html/miniml.html) . See how it has it's own format for describing grammars. So does Yacc, so does X, Y, and Z. Is there an interchange format for parser generators?

<comment><USER2> There's BNF, and there's DFDL, and there's just plain lists of productions without the extra decorations in BNF, but basically no. The issue is that each parser generator in current wide use has its particular funky set of limitations that you have to hack around one way or another when you write the grammar for it: it can't handle left recursion, or right recursion, or ambiguity, except in certain special cases (maybe if it doesn't continue for more than one token, or two syntax-tree levels), or it can handle them but has potentially exponential runtime, or it just arbitrarily resolves them in a certain way which may be adequate for your needs or may require you to restructure the grammar, or whatever. And then there are lots of ways that our languages aren't quite context-free, and different parsing systems have different ways to shoehorn _that_ into a basically context-free framework.

I think it's maybe a solvable problem, but I haven't seen anyone try to solve it.

</comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER5> When I was in 9th grade, I frequented an IRC channel full of misfits and rejects from all over the world. One of them was a notorious drunkard whose inebriated jokes were all over the top of the quote tracker.

He was studying computer science at the University of Illinois, and at one point he asked me in private message if I was interested in OCaml. I said sure, I've been playing around with it. Then he said he was on a bender and asked if I wanted to do his homework for him... due in a few days...

The assignment was to implement the Hindley-Milner type inference algorithm in OCaml. And that's how I got started with learning about type theory and language implementation. Thanks, guy, whereever you are. Last I heard you were in the military.

</comment><comment><USER6> Oleg has a nice article on how to implement OCaml-style type inference. It's a more sophisticated approach than just Algorithm W: [http://okmij.org/ftp/ML/generalization.html](http://okmij.org/ftp/ML/generalization.html)

<comment><USER7> For me, this article was the one where it "clicked": [http://okmij.org/ftp/Haskell/AlgorithmsH.html#teval](http://okmij.org/ftp/Haskell/AlgorithmsH.html#teval). Summary: type inference is just "evaluating" the program/expression, but the result is a type instead of a value. Each time you evaluate a function call, use unification to bind the arguments rather than pattern matching. Another way to understand it: pattern matching only works "one way", whereas unification works "both ways" \- implying the caller's types as well as the callee's types. It also has a nice introduction of using a monad to simplify state management.

<comment><USER6> What OCaml's type checker do is a little bit fancier:

Damas-Milner type inference uses an "occurs check" to prevent the type equation solver from unifying a type variable with a compound type expression containing the same variable. The "obviously correct" way to perform this check is eagerly - as soon as possible.

However, performance-wise, delaying the occurs check can speed up the inference process - and this is exactly what OCaml does. The downside is that the resulting algorithm is quite involved, because the solver can now run into type expressions containing cycles, so naively recursively walking type expressions can cause an infinite loop.

<comment><USER7> oh right yes - I was replying to your comment because it was another article by Oleg, not because it was another article about OCaML type inference.

</comment></comment></comment></comment><comment><USER8> The nicest and clearest presentation of first-order unification I know of is in this book:

[https://www21.in.tum.de/~nipkow/TRaAT/](https://www21.in.tum.de/~nipkow/TRaAT/)

From there it is a simple means to form and solve the type equations needed for Hindley Milner.

</comment><comment><USER9> FWIW, I had previously bookmarked these related pages:

[http://smallshire.org.uk/sufficientlysmall/2010/04/11/a-hind...](http://smallshire.org.uk/sufficientlysmall/2010/04/11/a-hindley- milner-type-inference-implementation-in-python/)

[https://github.com/tomprimozic/type- systems](https://github.com/tomprimozic/type-systems)

</comment><comment><USER10> The paper "Typing Haskell in Haskell" is also very readable and informative.

</comment><comment><USER11> I actually did a school project that was very similar for a compilers class! It was also Hindley-Minler in Ocaml and we tried to basically stuff any random features of a programming language we could into one language, and just compile it to java (because you can do anything with java).

Here is the paper we did: [http://www1.cs.columbia.edu/~sedwards/classes/2013/w4115-fal...](http://www1.cs.columbia.edu/~sedwards/classes/2013/w4115-fall/reports/pubCrawl.pdf) and the full information is available here: [http://www1.cs.columbia.edu/~sedwards/classes/2013/w4115-fal...](http://www1.cs.columbia.edu/~sedwards/classes/2013/w4115-fall/index.html) our project was called "pubCrawl".

</comment><comment><USER12> I remember doing this in a practical exercice session with a teacher at university. We coded the algorithm, and i kept saying to myself that what i was coding didn't make any sense. I only understood many years later what i did that day, and how important it was.</comment>


How to pitch your startup: Michael Seibel - <AUTHOR> http://www.michaelseibel.com/blog/how-to-pitch-your-company <comment><USER2> In all honesty - I'd find this article really helpful IF I HAD ANY STARTUP TO PITCH!!!

Jokes aside, pretty helpful advice for anyone aspiring to startup their own business.

<comment><AUTHOR> Haha.. Totally.. I've been working on my startup's pitch ever since we started working on it with my team.. This post by Marc took it to another level in an instant..</comment></comment>