Lyft's revenues double, losses quintuple and prospects darken - <AUTHOR> https://www.economist.com/business/2019/05/11/lyfts-revenues-double-losses-quintuple-and-prospects-darken <comment><USER2> When Lyft was doing their road show there were a few analysts who had price targets of $45 as Lyfts fair value at IPO with an acknowledgement that the amount of shares available would double, and possibly triple when all shares were off restriction, meaning that the $45 price target was a best case and we would probably see far lower once people can sell.

This is a company that has maybe 33 million shares outstanding now with about 27 million of them being sold short. So they have an enormous short bet against them. We see borrow rates as high as 30% for borrowing shares to short with no real stable borrow available.

However, due to the enormous amount of those short shares being rehypothicated(relent), Lyft is vulnerable to a quick upwards price run if those long sellers ask for their shares back. That would cause a run on those shares as they may be lent out multiple times by the same bank.

So whenever someone ask why you don't short an individual stock its always valid to answer that you believe you are right in the long term but the short term could wipe you out if you shorted.

As a quick edit, uber is now indicating its opening at a range of 45.50-46.50, given that the IPO price was $45, it looks like the underwriters will have some work to do and will almost certainly exercise their green shoe option.

So maybe wallstreet is wising up to money losing companies or Uber learned from Lyft that a slow and steady approach to their share price would be better long term for them?

<comment><USER3> Could you please tell me how do you find out what the borrow rates are for short shares and how many are being shorted?

<comment><USER2> Bloomberg terminal will give you a lagging number for SI(Short interest).

If you want a current indicator you have to pay for it from companies like Markit that poll hedge funds. The idea being that if you want to know the number you pay by including your own data that they can then show to other funds in aggregate.

For the borrow rate you ask your prime brokerage(like a bank but for holding equities/derivatives/etc). They'll go find you shares and figure out what rate to charge you, while adding their own rate on top.

<comment><USER3> finviz mentions, the short float to be 7% and Short ratio is 1.05 which says it's much conservative than the numbers posted. How to explain the difference?

<comment><USER2> Lyft's float can be viewed one of two ways

1) Total Shares of 273Million this is what finviz is using. This includes locked up shares that can't trade right now

2) the Currently tradable float, this is 32 Million and what I, Bloomberg, Markit, and any non budget site will use as these are the only shares that currently matter.

<comment><USER4> Sorry, trying to reconcile the comments.

LifeOfPi mentioned the short float to = 7%. Chollida1 mentioned the 7% figure was using 273mil shares as a base.

So wouldn't the total shorted shares equal 19mil? (19mil = 273mil X 7%). However, Chollidal mentioned in the first post that 27mil shares are shorted. Trying to figure out how to bridge the gap between 19mil and 27mil...

PS. Not trying to nit-pick. The comments are very useful. Maybe I'm missing something....

<comment><USER3> Time of reporting matters here. Some report every 15 days. others with a different time frame. Probably that's the reason for discrepancy?

</comment></comment></comment></comment></comment></comment></comment><comment><USER5> Very interesting process going on right now with Lyft & Uber both losing money and some of their drivers trying to stage protests and strikes. The drivers appear to rely on the company as their primary source of income and want more money yet at the same time the companies are operating at a loss. Were they to increase wages (as % of every ride) it stands to reason the losses would widen. If they get to wide the company goes out of business and the drivers lose their jobs. I understand that this same standard can be applied at any company but this is a gig / 'work only when you want' job so it is different.

The strikes were small so the effects on both companies were negligible. I would be curious to understand what changes the drivers (who work only when they want) expect and how they think a company running deep in the red could meet them. Not trying to pass judgement on the strikers just trying to understand.

<comment><USER6> Right now, Uber keeps 22 cents on each dollar paid by passengers, as its fee for creating the app, keeping it working, etc. That's cheap relative to the iTunes store, which keeps 30%. It's preposterous compared to the 3% that real- estate agents get for buying or selling a home.

We really don't know what the "fair" rate is for running a ride-hailing business. We know what's been collected to date in a venture-funded duopoly with limited public disclosure.

But my guess is that 22% is not the long-term equilibrium. Lots of outside pressures (regulators; new competitors) could drive Uber's share down. It's hard to see any forces that would cause it to expand.

<comment><USER7> 22% is really high for what's effectively a dispatch fee.

If you factor in the way Uber can dictate price, you may actually be "paying" a higher fee versus what you could've made on your own. If they force you to accept a 40% discount that's got to be factored in, too.

Apple takes 30% but they don't tell you what price you can charge.

<comment><USER8> Would be very interested to see the economics if drivers could set their own pricing.

<comment><USER9> I don't think it would work. This works for AirBnB but for Uber you need ride flow in order to keep drivers on the road and riders bothering.

</comment></comment></comment></comment></comment><comment><USER10> Fundamentals question: Can somebody explain how these ridesharing companies expect to turn a profit, eventually?

If you lose 50 cents on every ride, how do you make it up in volume? Every ride is subsidized by the Sand Hill Road crowd. They're a great deal. I took a 40-min ride yesterday for US$12.50 in a high-cost-of-living traffic-clogged city. How can that make sense? A ride in a sketchy 1970s-era New York City gypsy (no-medallion) cab would have cost more. And, without all the magic and overhead of some app.

Oh, I get it. They're going to scale up using autonomous vehicles. But, that's also a problem. Right now their business model relies on independent owner- drivers. In other words, from the front office's point of view, their fleets fuel, maintain, garage, and insure themselves. How's that going to work when they replace the drivers' cars with their own capital equipment?

Why should I invest for the long term in these companies?

<comment><USER11> The idea (urban myth?) I've heard for discussion's sake:

The long term bet is on them becoming THE way to get around and monopolizing the market (or a chunk of it at least) and THEN jacking up prices.

If you undercut cabs and public transit long enough, they'll have to react to lower ridership and reduce availability. Sorry, no late night buses, most people are taking a very inexpensive and convenient Lyft home. Now that there's no late night buses, we can charge 3X the cost.

<comment><USER12> Aside from NYC most cities do not have late night public transport past like midnight in most cases, maybe if you are lucky 2am. On top of that outside of NYC and maybe people commuting to DC, public transport ridership is pretty abysmal.

Plus all the cabbies have to do is either assign drivers to third shift or not, it can be done on a whim as demand dictates.

</comment></comment></comment><comment><USER13> "...and prospects darken"

It doesn't actually sound like that from the body of the article.

I have no idea if this is true or not, but the story says most of the $1.14B loss was due to booking employee stock based compensation of $894M. I'm assuming that's come out of the IPO and is not a recurring cost.

With revenues of $776M, which perhaps are mostly recurring, doesn't that seem to bode well for the future?

Of course, I'm not sure what we can expect their actual on-going costs or revenues to be. I'm just not seeing any reason for concern in this article fter the headline.

<comment><USER14> >With revenues of $776M, which perhaps are mostly recurring, doesn't that seem to bode well for the future?

Isn't the majority of that going to drivers which gives them a lot less room to maneuver financially?

<comment><USER13> Well, sure, maybe.

It would just be nice if the article backed up the headline rather than leaving us to speculate.

</comment></comment></comment><comment><USER15> I don't know what the end game for these companies is. Most average people would never use uber or lyft for transportation on even a semi regular basis if those companies didn't heavily subsidize the rides.

<comment><USER16> doesn't the ride cost go down substantially if they ever get autonomous vehicles on the road? I believe that is the end goal.

<comment><USER17> In short, no.

I read this in literally every HN discussion of ride sharing, but there's literally no reason to think that ride sharing companies will have any special role to play with autonomous vehicles if they materialize (which seems extremely doubtful in the short or medium term) and there's even less evidence that it will be cheaper.

I still can't figure out why people don't realize that low income humans are _cheap_. An autonomous car, if such a thing is ever in the real world, will at least for a long time be a complicated technically advanced computerized machine.

Like here's a pretty straightforward machine that rents for $125 a day: [https://www.adoramarentals.com/p-~nkd4skit/NIKON-D4S-KIT](https://www.adoramarentals.com/p-~nkd4skit/NIKON-D4S-KIT)

For reference that's about the same price as the cost of hiring a minimum wage employee for an entire work day.

Now tell me if the guts of a self-driving car are going to be cheaper or more expensive than a standard DSLR camera.

<comment><USER18> There are a ton of factors that make your DSLR to Autonomous Car comparison flawed.

The utilization rate of the camera is going to be far lower than the rate of the car. The camera may sit on a shelf for weeks before being rented for a single day, so the per-rental price must be relatively high. The market is small. Also, cameras are comparatively easy to break, and the technology goes out of date extremely quickly as compared to a car.

I think the greatest fiscal advantage to autonomous car fleets is the likely high utilization rate.

<comment><USER17> > There are a ton of factors that make your DSLR to Autonomous Car comparison > flawed.

Indeed. The biggest one of course being that there's no such thing as an autonomous car.

<comment><USER19> Snarky but inaccurate reply. They do if you're a resident of Phoenix. Prices are equivalent to Uber but it's still too early to conclude what's behind those prices. Are they sustainable at scale? Is it just to avoid having the price floor drop out from them if they're viewed as purely a discount option? Is it to dissuade having too many users on the system all at once?

<comment><USER17> The way you can tell if you're looking at a driverless car is to check and see if there's a driver in it.

</comment></comment></comment></comment></comment></comment></comment><comment><USER20> > Most of that was down to booking stock-based compensation plans for > employees, who earned $894m from Lyft's initial public offering

Could someone help me understand what this means? Is this compensation above and beyond employee stock options? If not, that means employees own ~5% of Lyft, which is much less than I would expect.

As an employee of a pre-IPO startup, I'd love to get a better handle on the realistic value of my stock if we do reach an IPO.

<comment><USER21> 0\. It's a lottery ticket. To be realistic. Esp with the DOW down 300 today.

<comment><USER20> Yeah, I've always considered it a lottery ticket, but I'd love to get a sense of whether I'm holding a $10k or $10mm lottery ticket.

FWIW, I've done the math based on my percentage ownership, expected valuations, timeline to IPO, etc. The big unknown for me is dilution. I don't yet have a good sense of how much dilution I should expect as we move through rounds of funding into an IPO.

<comment><USER22> Dilution is a red herring. It doesn't change the value of your shares (theoretically). What will matter is how the company spends the funds that it raises, and whether it does so in a way that generates a positive or negative return on investment.

<comment><USER20> Here's how I'm thinking about it with example numbers: I own 0.1% of the company. Based on our market and performance and valuation of peers I expect us to be worth $10b.

With no dilution my stock is worth $10mm (minus taxes, strike price, etc.)

With 10% dilution per round and 4 more funding rounds, it's now worth $6.5mm.

<comment><USER22> You expect the company to be worth $10b at some point in the future, but the question to be answered is how much you think the company is worth today. Let's say you think the company is worth $10m now, which makes your stock worth $10k. Suppose the company then raises $90m in funding and gives the investors a 90% stake. Now your shares are only 0.01% of the company, and you think "Oh no, I got screwed by dilution!" But the company is now worth $100m, because it has its previous $10m worth of assets plus $90m in cash. So your 0.01% is still worth $10k.

What matters now is how the company spends the money. Hopefully they spend it smartly and the value of the company increases 10x. Now your stock is worth $100k. You didn't get screwed by dilution, you got a $90k bonanza because the company was successful.

</comment></comment></comment></comment></comment></comment><comment><USER23> I don't know what the bull case for Lyft is at all. They haven't expanded into other products or markets outside of pure U.S. ridesharing, which had already been plateauing for some time. Uber, OTOH, has years of experience operating and expanding internationally, has built UberEats into it's own mult-bil vertical on it's own, and owns substantial shares of dominant ridesharing cos in other markets like Grab, DiDi, now Careem, etc.

</comment><comment><USER24> Once the ride-sharing matures, 5-10 years from now, Uber, Lyft and new competitors are not going to take 20 to 25 percent per cent of drivers' fare. If I had to guess, 10 years from now they take just 1-3% per ride and maybe ask few $100s upfront for each registered driver to cover fixed cost of handling new drivers.

These valuation include hopes for fully autonomous cars and the fear of missing out.

<comment><USER25> It won't get that low. That wouldn't cover cc processing.

They also need to cover insurance and several other costs. But I could definitely see it settling around 10-15%

</comment></comment><comment><USER26> I previously submitted 'Uber's enormous, vague IPO prospectus is an outrage (ft.com)' Well worth reading and quite ominous in light of Lyft performance IMO

[https://www.ft.com/content/60ab80e2-6a8b-11e9-9ff9-8c855179f...](https://www.ft.com/content/60ab80e2-6a8b-11e9-9ff9-8c855179f1c4)

<comment><USER27> From the summary in the child twitter link:

>We hope in the future there will be driverless cars and that we can then make money because no drivers but other people are developing them too.

Nice! It's common to think that self-driving cars will be Uber's salvation, but even then, they'll have to come with other SDC providers, so there's no moat. They'd have lower costs, but so would everyone else, and so they'd have to cut fares proportionally.

In theory, they can have such a lead time on a workable SDC that they get a great moat until everyone catches up. But that would be ~2 years at the absurdly optimistic end; not enough to pay back the costs of the program and throw off the huge returns investors demand. And in reality, Uber is lagging on this.

<comment><USER28> The self driving car idea won't help Uber or Lyft for two reasons. First, neither company has the tech experience to build one. Second, and more importantly, both companies would have to _buy and maintain_ the cars which isn't financially viable.

<comment><USER29> They're hoping you'll buy a self-driving car and then let them pay you a minimal fee to use it when you're not.

The problem is that self-driving cars will change car ownership needs, and that there could be entirely different companies in the space when it does finally come around.

<comment><USER30> I'm not sure I buy that scenario...

Is there any other market where random consumers are basically acting as financiers for a commercial fleet of equipment? What's the reason for the fleet operator to involve those customer-owners at all?

In terms of immediate cost, it will be cheaper as a customer just to use the ride sharing service yourself, since you won't have to pay car payments you'll just pay the rideshare fee. Especially if the self driving software gets priced in the $10,000+ range as Tesla has suggested it will end up.

So anyone in the "budget" category will just be buying rides not vehicles. They'll have to wait 5 minutes for a vehicle, and they won't get to have their vehicle of choice, but they also won't have to deal with the hassle of running a mini carshare business, whatever that will entail.

Most people in the "premium" category isn't going to want random drunk people fingerblasting each other in the back seat of their nice car, so that cuts out the top of the market.

That leaves what... people who want to save some money but also really want to own their own car, but also are comfortable sharing it with random people?

Seems like a weird segment. Why wouldn't the fleet operator just buy cars and own them? They're going to be burning through these vehicles every 5 years anyway, what's the point of parking them in a random owner-operator's garage and having them taking it out of the fleet when they feel like it?

<comment><USER28> Indeed. And surprisingly, no one[#] has brought up that there is no such thing as as a national (or even regional) taxi service. And why is that? It's because the economics of fleet ownership don't scale to that size. If they did, we'd have a single nationwide taxi service already. In 100 years of taxis, no one has done that.

[#] Except Hubert Horan who destroyed all their BS with his series, "Can Uber Ever Deliver?"

<comment><USER27> Yeah, but arguably smartphone technology reduced admin costs and raised the size of the economically optimal taxi provider. _That_ has been around for less than a hundred years.

Edit: Dangit, I thought my reply got eaten, but I was looking at a different branch. See the rephrasing here: [https://news.ycombinator.com/item?id=19880565](https://news.ycombinator.com/item?id=19880565)

<comment><USER28> Smartphones didn't reduce the cost of dispatch. Look what Uber spends on app development! The big costs in taxis are maintaining the fleet, a cost which Uber externalizes to its drivers, some of whom now have to sleep in their cars.

<comment><USER27> They most certainly did. As expensive as that software is, it's very little when amortized over the rides. It eliminates the overhead of finding a location and transmitting the info, and delivers higher value in that it gives real time data about where the car is, and lets you pay more conveniently.

Also: while the drivers have _physically_ taken over maintenance, Uber can't push the economic cost on to them, because they have to pay enough that drivers want to continue to work even given those costs. If anything, maintenance is cheaper when handled by a big org.

To the extent they realize a savings, it's because they're using the spare hours of existing vehicles and don't have to take on all the dead ours they'd have from owning the cars _not_ because they're getting maintenance free in any meaningful sense.

</comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER8> Is the plan for the original investors to sell their stock to regular investors before the whole thing tanks? They make their money and whoever followed is left holding the cheque. Seems like a Ponzi scheme as it's been clear for years these companies are not going to be profitable any time soon.

</comment><comment><USER31> The problem with Lyft is that they are in a poorly understood market, in second place and burning cash at neck-breaking speed. Even if they manage to start making progress towards profitability, they might need more than that.

The reality is that ride-sharing probably needs another lustrum or so to solidify and that seems excessively long for Lyft in its current state.

Uber faces the same challenges but its way more diversified and can scale down from certain markets and verticals. Lyft on the other hand has only one market (N.America) and only one vertical (ride-sharing).

Doesn't take a genius to understand that scenario looks risky as hell. Especially when you're in a business with nominal differentiation.

<comment><USER32> Uber's multiple markets maybe an advantage. If they're all equally unprofitable, perhaps not, but at least that's plausible.

Uber's multiple verticals are dogs, and reek of money madness. Eats is small time and loses money. I don't know it's financials, but I find it hard that this ancillary business is in a healthier state than a competitor who has it as their core buisness.

Uber ATG is as bad off as any other autonomous car program. There's a growing realization that technology won't be ready anytime soon. (See Andrew Ng's comments about just redesigning cities to limit autonomous vehicles' interactions)

Uber Freight is a ghost town.[0]

The of course there's the buisness if renting and then discarding Xiaomi scooters. (Or is that not a thing anymore? I honestly don't remember.)

Sure, I understand the logic behind all of these. Once you have a system to tell a person "Go here, and take this here," then you can plug pretty much anything into those slots. However. No one has shown that the way they're doing it is a sustainable business model, and it looks like it's not.

[0] [https://www.forbes.com/sites/stevebanker/2018/04/10/is- uber-...](https://www.forbes.com/sites/stevebanker/2018/04/10/is-uber-freight- on-the-verge-of-going-out-of-business/)

<comment><USER33> Uber Eats is making money... the financials are clearly listed in its S-1, [https://www.sec.gov/Archives/edgar/data/1543151/000119312519...](https://www.sec.gov/Archives/edgar/data/1543151/000119312519103850/d647752ds1.htm)

Uber Eats is currently 2nd/3rd place in market share for food delivery at around 20%, [https://qz.com/1549084/doordash-overtook-uber-eats-in-us- onl...](https://qz.com/1549084/doordash-overtook-uber-eats-in-us-online-food- delivery-second-measure-finds/)

There is a lot more out there on Eats financials as listed in the S-1 and in previous "leaks". Definitely seems like a healthy business where I agree its revenue is much smaller than the overall ride-sharing business, but from a technology standpoint they are likely better than their competitors BECAUSE of having a core ride-sharing business with which it overlaps a lot of ideas like pricing, dispatch, ETA predictions.

<comment><USER32> Thanks for the qualification about Eats. However, I don't think the issue in food delivery is a technical. I think it's financial.

</comment></comment></comment></comment><comment><USER34> All these ride sharing companies are here to carry us seamlessly into the driverless future. Unless they're capable of pivoting to driverless technology they are mostly matching services for riders and drivers and Honestly, I dont think it should be uber or lyft's responsibility to build driverless technology - they should just focus on making the experience of getting a ride as excellent as possible. Leave driverless technology to other experts.

<comment><USER12> And what happens to uber/lyft when the experts make their own rideshare app? Why license your tech to them? These apps can be cloned.

</comment></comment><comment><USER35> They should charge a service fee to the rider, for however much they need to be profitable; and let the drivers charge whatever they want (baseline auction). Now the customer knows how much they are paying to whom.

Imho, Taking a cut of earnings is borderline unethical for a automated services, whether its lyft, upwork, or patreon. Charge a fee, know your numbers, give both sides of your service's users confidence in the service's stability.

</comment><comment><USER36> They just went public at $80b but are raising $8b, so per the chart in the article, quite a few recent investors are getting a haircut? Pre-money $72b valuation?

<comment><USER37> The investors from the last funding round paid about the same share price as the IPO price, so they haven't really made or lost any money. It certainly wasn't a good investment for them (0% return), but I don't think they have taken a haircut yet. It will ultimately depend on where the stock price goes.

<comment><USER36> What's he hold period? 45 days? Seems like the $79b investor got a 10% haircut.

</comment></comment></comment><comment><USER38> Uber and lyft look like a charity set up by VCs to provide people with cheaper transportation. Who knows what will happen once they increase fares as they promise to investors

<comment><USER39> As soon as one of them increase prices to generate profit ill just move on to the next ride sharing app, then the next, then the next.

You'd need a price fixing scheme worthy of British Airways make this work.

<comment><USER40> It doesn't actually work that way in reality. If it did, there would already be another massive Uber undercutting Uber in eg the US market and raising $10+ billion in VC money to do it. Because hey, a $75 billion valuation is sitting right there, so it's really easy: just put $10 or $20 billion into the company, undercut Uber, IPO, easy return. Everbody can do it, just add $20 billion.

What's actually the case, is the next clone will need $20 or $30 billion to fight and undercut Uber's entrenched brand, functioning system and scaled up position. And even in that case, the odds of winning against the large incumbents is low. It will cost even more to beat Uber via the undercut game than what Uber has already spent, because you have to take the market away from them - always a dramatically more expensive and difficult proposition.

VCs are not going to continue to burn massive amounts of capital trying to fund the next loss-making ride hailing company. The next $10 or $20 billion to put into an Uber clone in its major markets, does not exist and it will never exist.

Few things would scare a VC more than having the pitch that your plan is to destroy twice as much capital as what Uber did, to unseat Uber's entreched position, with nothing to differentiate you other than the speed at which you destroy capital.

That's why nobody is doing it right now. There isn't another Lyft, much less another Uber. Softbank isn't looking to drop $20 billion to fund the next Uber, to fight with Uber, in the US and similar markets that Uber dominates now.

<comment><USER41> The company that delivers fully autonomous vehicles would have no trouble securing funding to not have to operate within Uber's walled garden and give Uber a 22% cut of profits, and make their own app. Remember, when the independent contractors go away, you don't need offices in every city to onboard drivers, you don't need a big legal team to fight the ongoing "are they contractors or employees" debate, etc.

In other words, the company that delivers autonomous won't need $10B to make a cloned Uber app. Since the driver is the biggest cost for Uber, riders will gleefully switch to the clone at even cheaper prices.

<comment><USER42> Someone is going to have to put up the money to buy the fleet of autonomous vehicles.

</comment></comment></comment></comment></comment><comment><USER43> now you need a new side gig to support your old side gig (main gig)

</comment><comment><USER44> It's fun watching these "smart" economists trying to tell you what's going to happen, with Lyft and with the upcoming Uber.

The reality is that many people will feel they're able to "beat the market", and they will try to get a chunk of the glory, mostly losing in the effort.

<comment><USER28> Indeed. A few at the top will get rich from both companies with lots of regular middle-income folks taking the fall. Reminds me of Enron.</comment></comment>


Categories for the Working Hacker [video] - <AUTHOR> https://www.youtube.com/watch?v=gui_SE8rJUM <comment><USER2> Some background for the uninitiated, this is Lambda Man, or Philip Wadler. One of the core contributors to Haskell. He also introduced monads to Haskell, which has had a huge impact on functional programming in general ([https://ncatlab.org/nlab/files/WadlerMonads.pdf](https://ncatlab.org/nlab/files/WadlerMonads.pdf)). His home page has so many functional programming treasures: [http://homepages.inf.ed.ac.uk/wadler/](http://homepages.inf.ed.ac.uk/wadler/). His most recent book is "Programming Language Foundations in Agda", which is available for free: [https://plfa.github.io/](https://plfa.github.io/). I have no affiliation, just a fan.

<comment><USER3> Thanks for sharing that book! Super cool!

</comment></comment><comment><USER4> Here are slides of an earlier version of the talk given at QConSF 2017: [http://homepages.inf.ed.ac.uk/wadler/papers/categories/qcon-...](http://homepages.inf.ed.ac.uk/wadler/papers/categories/qcon- sf.pdf)

</comment><comment><USER5> This is the first time I've seen someone casually use "f;g" as notation for (reversed) function composition. I'm glad for it, but does anyone know how widespread this notation is?

</comment><comment><USER6> I thought it would be an old talk but it's from Strange Loop 2018

* plays _</comment>


Metrics Lead to Effective Sprint Retrospectives - <AUTHOR> https://sourcelevel.io/blog/how-metrics-lead-to-effective-sprint-retrospectives <comment><USER3> I have come to the conclusion that the number of MR's during a sprint is not a insightful metric.

Primarily because the functionality targeted for being completed by the MR can vary so greatly.

Regarding time MR's take to merge? I don't think trying to get the number "lower" is the goal. Probably best to say, we've agreed to an SLA of x days. Anything over Y days is a big red flag.

Thanks for sharing- not trying to come across as negative. I totally agree metrics should be included in retro's ... it's adjacent to what I'm working on.

I'm just convinced that a lot of product/project management metrics have "no meat on the bones" or aren't really concrete at the end of the day - <USER2> metrics.</comment>


The Tethered Uni-Rotor Network: Eternal Flight UAV - <AUTHOR> https://turnuav.com/ <comment> gene-h Another interesting idea in this domain is to use wind power rather than solar power. Wind gradients can be harnessed through dynamic soaring although this can be a bit limiting. One way we might get around this is by flying two airplanes connected by a long tether.[0][1] One airplane flying at a different altitude where the wind is significantly different can be used like a kite sail to pull the other airplane. Although it has been shown to be a pretty nasty control problem at least for a human[2].

[0][https://www.nasa.gov/feature/flight-demonstration-of- novel-a...](https://www.nasa.gov/feature/flight-demonstration-of-novel- atmospheric-satellite-concept) [1][https://www.nasa.gov/sites/default/files/atoms/files/14-2015...](https://www.nasa.gov/sites/default/files/atoms/files/14-2015_phase_i_william_englom_virtual_flight_demostration_stratospheric_dual_aircraft_platform.pdf) [2][https://arc.aiaa.org/doi/10.2514/6.2018-1492](https://arc.aiaa.org/doi/10.2514/6.2018-1492)

</comment><comment><USER2> I'm the originator of the TURN concept, and owner of the company. I can answer any questions you guys have about the vehicle.

<comment><USER3> How would it respond to gusts?

How strictly does it need to maintain angular velocity as it goes around?

What would the maximum speed in still air be? Some fraction of the rotor tip speed?

Does the tilt-wing configuration (presumably for landing and perhaps takeoff) set the constraint on payload mass fraction, as that will require more structure than the tension-stabilized rotary mode? Or is the payload mass fraction relatively insignificant compared to the battery and solar cell mass?

Safety: is there a way for it to gracefully fail? Transition from 4 blades to 3, and let the failed one dangle down as you descend? Would this be even remotely possible?

<comment><USER2> In steady wind, it needs to spin faster to maintain its wind robustness, which does consume more power... but that's common to all aircraft. Generally speaking, the it is robust to wind gust velocity about 25-30% of the wing speed.

It's more important that each wing maintain equal spacing between one another. But the angular rate of the entire system can be adjusted to accommodate the current operating condition.

I've evaluated models that can travel at 68 knots. Not terribly fast, but the intended application is to stay in one spot for as long as possible.

The tilt-wing configuration is actually dated. The L/D ratios of the wing would require the motors to be excessively oversized for takeoff and landing only. The design has been revised to have a single motor on the outboard section, and the system begins its rotation while on the ground prior to takeoff.

With three rotors it is still possible to stabilize the central hub, assuming the three can support the additional weight of the lost rotor arm. And with my controls background, I can't wait until I have more time to investigate this failure mode mitigation option!

</comment></comment></comment><comment><USER4> Not sure I understand the images. The cables seem to be connected to the end of the wing units. A wing can't normally generate force longitudinally. So how is the wing generating cable tension?

Added: OK, it is all generated by the centripetal force caused by the mass of the wing units. So fast spinning and lots of cable/parasitic drag to get the wings reasonably level. Seems like a lot of wing area for a small payload. How is this better than just a wing large enough to support the payload with cables to distribute the load across the wing length?

Added2: This scheme still has the problem that the downwash from each wing will affect the other wings, just like in the helicopter case.

<comment><USER5> Seems that the four wings rotate around the central unit creating centrifugal force that will keep the cables tight.

<comment><USER6> Wouldnt a single wing being buffetted by a downdraft or sudden turbulence cause catastrophic loss of tension between all wing tethers and the whole thing collapse?

What if instead of teathers, you just had two large circles of composit, as a hub and a rim, that were stiff enough to keep all wing positions but stiffer than a flimsy string - and thus keeping formation?

<comment><USER7> I'm a paraglider pilot, not an aerospace engineer, so take this with a lot of salt... but:

Paragliders can have asymmetric collapses of the airfoil due to turbulence, but usually it's no big deal (other than being a little scary). Catastrophic loss of tension is avoided because there's still airflow over the rest of the glider, which remains pressurized. All the pilot needs to do is maintain safe directional control until the full wing re-pressurizes. You feel a sudden loss of pressure and then an abrupt surge of pressure, then things normalize.

My _guess_ is that something if similar happens here, it'll happen asymmetrically, and the props might keep airflow over the other 3 wings, which are still flying. They maintain stability while the wing that went floppy drops, regains its tension, and then resumes normal flight.

Last: I'd wager that they plan on deploying these in stable air, at very high altitude.

</comment></comment></comment></comment><comment><USER8> This is very interesting. I'm a little confused though. The page talks at length about eternal flight, and how the turn system is supposed to enable them. Then, in the "Smaller Scale Commercial Drone" section (which I imagine is a smaller scale version of TURN), it states that the endurance is only 4.5-7.5 hours. What does scale do, which enables eternal flight? Is it just a matter of having more power on board?

In addition, what are these eternal flight numbers based on in terms of latitude, and season? In the video, he states that they were looking at internal combustion @ 30 days. What about the solar approach? Would 18 hours a day of light be enough? 12? 6?

Can anyone here call out whether or not this looks like a viable thing?

<comment><USER2> The research is using a spiral development process, where flight data from small scale prototypes are used to validate existing simulation and dynamic models, and then those models are used as design tools for the next largest embodiment. So right now, there are three different scale systems which serve different demographics.

The smallest scale system is purely battery power, but offers flight endurance well beyond what conventional fixed-wing can achieve. Traditional 10-ft wingspan drones carry 5-pounds for about 90 min. A comparable weight/payload TURN system can fly closer to 7 hours. This prototype is being used as a minimum viable product for an upcoming product launch.

The company was awarded an SBIR research grant from the Air Force which considered an internal combustion engine TURN embodiment. While not eternal fight, it again offers significantly extended flight endurance. The best research aircraft can fly a 250 pound payload, drawing 2000 watts of power for about five days. My research shows that an IC TURN system could remain aloft for over 30 days.

Finally, the largest scale system is striving for eternal flight while operating within the stratosphere. At 65k feet, the system is above most weather and commercial airliner traffic, and the air is thin enough to warrant a large wing fitted with solar panels. By getting the power requirements low enough, the energy collected during the day is enough to remain aloft throughout the night, thereby eliminating the need to land and refuel.

<comment><USER9> This is a really neat project. I noted in the discussion that by rotating with end tip motive power you eliminate the need for stiffening the wing, however doesn't this increase the need for better tensile strength along the wing? (in order to prevent it from pulling itself apart, something "regular" wings don't get a lot of stress on).

Also, in typical rotor craft the lift is highest on the outer edge of the rotor and least in the center where the airfoil speed is slowest. Does that affect where you put the payload? Is it on the edges of the wing or still in the center? At the center, if the wing is supported by the centripetal force of the wingtip motor's angular momentum, there is a huge torque in the middle if you pull it down. (much like pulling down on a suspended cable). How much deflection before you have the same problem as the stiffened wings of current efforts?

<comment><USER10> Increasing tensile strength is super easy compared to improving bending and twist resistance, especially when the aerodynamics not only constrains the thickness of the wing but also rewards high aspect ratios (the tip-to-tip length of a wing compared to its front/back dimension).

Imagine a wing that's 20+ times longer than it is deep, and is only 5% as thick is it is deep (so, for example, a 20m wide wing, that's 1m deep front- to-back, and 5cm thick top-to-bottom) - that's really hard to get stiff in bending along it's long axis, and in twisting stiffness around that long axis. This is why - as the article mentions, a sailplanes long thin wings account for 40+% of the airframe weight, when a stubby-winged but less aerodynamically efficient wing (like, say a Cessna 172) the wing might only account for 10-20%$ of the total airframe weight.

This TURN design minimises bending/twisting forces by replacing the load bearing and alignment forces with mostly end-to-end tension ones - which are much easier to resist (just load the structure up with "axial" carbon fibre...).

</comment></comment></comment></comment><comment><USER11> Very exciting project! Love the idea, and can't wait to see some proof of concepts eventually. It obviously has the potential to be revolutionary in the aerospace industry, though time will tell if it's as effective as claimed of course.

They compare the TURN concept to satellites in the beginning, mentioning only positives by comparison - of which there are indeed many (cheaper, better comms). One thing I didn't see mentioned was the failure mode between the two. A satellite that ceases to function will stay in orbit, until this orbit decays enough for it to burns in the upper atmosphere. If one of the rotors on this device fails, it will just come crashing down to earth.

And also, in typical neo-luddite fashion, I'm fearful for the surveillance applications of this device. Even if staying airborne isn't eventually completely free (eternal flight) with this system, the ability to stay up for 9 hours at a time on a few Li-Ion cells opens up a world of possibilities, not all of which are great. If NOAA can afford to put a number of these out in the Atlantic to get better atmospheric readings, surely cities, states, city- states, and others can afford to put a number of these above their populace.

However, progress is inevitable, and the technology can't always be blamed for it's potentially negative applications. I think this is an amazing project - but it will require some self-control to not let this push us further into a surveillance state.

<comment><USER12> Regarding your second point: [https://www.airbus.com/defence/uav/zephyr.html](https://www.airbus.com/defence/uav/zephyr.html)

"The first unmanned aircraft of its kind to fly in the stratosphere, Zephyr harnesses the sun's rays, running exclusively on solar power, above the weather and conventional air traffic. It is a HAPS: a High Altitude Pseudo Satellite, able to fly for months at a time, combining the persistence of a satellite with the flexibility of a UAV."

This isn't a new idea, at all. You have to go back to the late 1780's to find a time before the use of balloons as recon platforms: [https://en.wikipedia.org/wiki/History_of_military_ballooning](https://en.wikipedia.org/wiki/History_of_military_ballooning)

<comment><USER13> You'd have to go back before humans to find a time before facial recognition was used to track individuals, yet people get upset about when facial recognition is used to automatically track and record all of your movements through ubiquitous cameras.

There's a big difference between a person going up in a balloons for a few hour to scout a military locations and a swarm of drones constantly monitoring a city in peacetime.

<comment><USER12> I was not making a judgement about whether or not there's a difference between a single balloon and a drone swarm (there is), but addressing the comment:

> And also, in typical neo-luddite fashion, I'm fearful for the surveillance > applications of this device. Even if staying airborne isn't eventually > completely free (eternal flight) with this system, the ability to stay up > for 9 hours at a time on a few Li-Ion cells opens up a world of > possibilities, not all of which are great.

<comment><USER13> It looks a lot like you were saying these are similar. I'm not sure what else your comment could mean. What was your intended meaning?

</comment></comment></comment></comment></comment><comment><USER14> Perhaps I just didn't understand the web page, but this seems unnecessarily complicated.

The Department of Customs and Border Protection already operates a fleet of tethered airships. These seem to be a much simpler solution to "eternal flight."

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

<comment><USER15> It probably wasn't a good choice for them to use the word "tethered" in the name.

It might not be incorrect, but tethered means you are connected to something. In this case, that something is the aircraft itself. Self is not the first thing most people are going to think of when they hear the word tethered. Especially since, as you point out, there are already aircraft that are tethered to the ground.

</comment></comment><comment><USER8> What's the current longest endurance, COTS (commercial off the shelf) flight platform?

<comment><USER16> It's not at all COTS, but the Rutan Voyager [1] spent 9 days in the air on it's round-the-world flight.

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

<comment><USER17> Similarly not-COTS, but a series of UAVs, a Zephyr "7" made a record 336 hour flight - 14 days, with an unofficial runs of three minutes (!!) short of 26 days aloft for a recent Zephyr S.

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

<comment><USER16> The Zephyr is using Lithium-Sulfur batteries, which have a better energy-to- weight ratio ("Currently the best Li–S batteries offer specific energies on the order of 500 W·h/kg" according to Wikipedia [1]).

These aren't commercially available though. Twice the performance of currently available automotive batteries is a major advantage for aircraft applications.

Pretty cool.

[1] [https://en.wikipedia.org/wiki/Lithium%E2%80%93sulfur_battery](https://en.wikipedia.org/wiki/Lithium%E2%80%93sulfur_battery)

</comment></comment></comment></comment><comment><USER18> I wonder if the development of thinner, flexible solar panels and batteries would make a lighter than air UAV a better choice for eternal flight. That way it only needs to power rotors for positioning instead of maintaining flight.

<comment><USER2> DARPA already looked at that through ISIS. The problem is the massive volume of gas within the airship. Even the lightest winds require a substantial amount of power to travel or station-keep. Google is using weather balloons, but they don't have any active controls, so they drift aimlessly away from the equator, and then need to be manually picked up after about a month.

</comment></comment><comment><USER19> I have to wonder what the maximum translational velocity would be for these hovering platforms. How well could they deal with high winds? Gusts? How quickly could they change their position?

To make a comms network you'd need them relatively evenly spaced out to maintain coverage over a wide area. You'd also need them to have beefy and power hungry broadcast/receiver systems. How well can they scale with the solar energy?

Overall a very cool idea though!

<comment><USER20> The use-cases discussed in TFA all seem pretty low-power, mostly recon-type stuff. That said, it'd be interesting to contemplate what the right proportions would be to actually run a hungrier payload.

At a certain point, "perpetual" also starts to run into problems of mechanical failure. Then again, if these things are cheap enough and/or able to limp home in the case of a snapped cable or failed prop motor, maybe it still works out.

<comment><USER19> Seems like the video talked about wanting to make it into an internet communication network, which just doesn't seam feasible to me.

Then again, I'm just a programmer. I recognize I have no grasp of the power requirements for that kind of project.

The inexpensive nature of them seems a major draw. I wonder if they can detach cables and have the wings fly home on their own while having the center parachute down?

</comment></comment></comment><comment><USER21> This seems like a really cool idea. What I can't figure out is the bootstrap process. How do you launch/start the wings rotating?

<comment><USER22> There's an image. [https://static1.squarespace.com/static/5901f9f12994ca40051ae...](https://static1.squarespace.com/static/5901f9f12994ca40051ae59d/t/590346c9f5e2316bee3d0122/1493387276592/TURN.jpeg?format=2500w)

Basically, the whole thing takes off like a helicopter, before turning the wings on their sides.

</comment></comment><comment><USER23> I think there is merit for the last idea in the article - some kind tethered drone array as a windmill using something like autorotation:

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

Similar ideas have been suggested using balloons:

[http://latesttechnology-world.blogspot.com/2013/07/magenn- ai...](http://latesttechnology-world.blogspot.com/2013/07/magenn-air-rotor- system-mars_18.html)

[https://www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=134023](https://www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=134023)

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

An array of wind-powered drones could scale well beyond what's possible with a traditional wind turbine, since most of the torque gets applied at the wingtips. There might be advantages with inconsistent wind gusts too, since the rotor could wind up in strong wind and unwind in weak wind. Startup costs would be negligible since a few drones could start the rotor and more could be added as needed. It might even by safer for birds if a drone array turns slower than a fixed rotor.

<comment><AUTHOR> Not really sure how those ideas are all that similar to the TURN here. Those are long flying and involve tethering, but the flight systems are quite different and they're tethered to the ground.

</comment></comment><comment><USER24> Utterly Brilliant!

Something like this is sorely needed for bringing broadband to other parts of the world. Best of luck to Justin in this endeavor. I hope he succeeds wildly!

</comment><comment><USER25> Is the cable portion essential? I'd think a semi-rigid structure (like they talk about with helicopter blades or glider wings) when under load would survive longer.

<comment><USER26> it'll be really interesting to see how this performs in extreme weather. i wonder if the cables would result in a much higher tolerance for shear, etc.

<comment><USER27> There's not much weather up at the planned operating altitude.

</comment></comment></comment><comment><USER28> Er, use the Magnus effect. (Cf. "Magenn Power, Inc." company, now apparently defunct.)

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

I've been playing with geodesic cellular kites, and "eternal" flight is certainly possible. If the ratio of surface area to mass is great enough it's actually hard to stay on the ground. Cellular kites scale. I would like to eventually make flying buildings, etc...

<comment><USER29> Lol I just asked the same question without seeing your response. I was thinking hollow canvas tubes radiating out from a central hub, slowly unspooled in flight. Some mechanism would use the mechanism of rotation to draw air outward along the tubes to keep them inflated, combined with rotation induced from the central hub. No idea if that would work...

<comment><USER28> Sorry for the delay. I don't know if that would work either, but it sounds good. ;-)

Check out "Tensairity" [https://en.wikipedia.org/wiki/Tensairity](https://en.wikipedia.org/wiki/Tensairity)

</comment></comment></comment><comment><USER30> clever design, but that video was awful. It came across as either ill-informed or misleading - and the beige - oh my, the beige.

<comment><USER2> Sorry about that. It's all I had to work with. The TURN concept recently won a local business pitch competition, with a video posted on their website. Slightly (just slightly) better production quality.

[https://757pitch.org](https://757pitch.org)

</comment></comment><comment><USER31> Why not use a balloon? or dirigible or something like that?

</comment><comment><USER32> Balloons?

</comment><comment><USER33> Is this "solar freaking roadways", but for UAVs ?

<comment><USER34> I don't think that building (maybe) better solar glider UAVs falls in that category.

They basically combine the existing principles of control-surface based helicopter blade pitch control (e.g. Kaman K-Max) and blade tip propulsion, then drive them to the UAV-exclusive extreme where the individual blades gain complexity until they are a coordinated team of autonomous planes while the "body" of the helicopter along with all the complicated mechanical linkages to the blades is reduced to simple tethers between the blades and a central connection point where a stationary payload could be attached.

I suspect that they are overestimating the structural savings relative to something like the helios glider (where mass was already distributed along the wing) and underestimate tether drag.

The big difference is that a new type of aircraft won't fly at all if it's as bad an idea as solar roadways, whereas the latter could be built mile after mile until the world runs out of stupid money, no matter how bad it really is. If nothing else, the idea of "tethered uni-rotors" deserves a place in the canon of cool sci-to technologies that could theoretically work. They would fit in quite nicely in the future segment of Seveneves for example.</comment></comment>


Ask HN: Protecting HTML5 video and audio - <AUTHOR>

I know HTML5 doesn't allow DRM in video and audio files (which would be a pain anyway), but is there anyway to stop a user downloading the file?<p>Can you forbid downloading, but not playing? Can you hide the URL from "view source," "inspect element," and the activity window? <comment><USER2> No more than you can protect an image in a page from being downloaded. e.g. you could escape the URL or check referrers, but that's not really going to stop anybody.</comment>


Guess What Percent Of Black Friday Online Sales Came From Twitter Referrals? - <AUTHOR> http://www.businessinsider.com/black-friday-online-sales-from-twitter-referrals-2012-11 What are the implications for Facebook/ Twitter valuations ? <comment><USER2> pretty funny answer....</comment>


Ask HN: Why is Heroku affected by single zone outages? - <AUTHOR>

I would have thought they would be multi-zone, at least for app serving if not database services. Am I missing something? <comment><USER2> Multi-AZ is so hard, even people whose job it is to handle this stuff can't do it.</comment>


Paypal Freezes ProtonMail Campaign Funds  - <AUTHOR> https://protonmail.ch/blog/paypal-freezes-protonmail-campaign-funds/ <comment><USER2>
      "Like many others, we have all heard the PayPal horror stories, but didn't actually think it would happen to us on our campaign since PayPal promised, very recently, to improve their policies."

The naivety is strong here.

<comment><USER3> Glad I donated in BTC.

Does Paypal own a lot of Bitcoins? They sure make an effort out of highlighting bitcoin's advantages.

</comment></comment><comment><USER4> Could this have anything to do with Operation Choke Point? [http://www.washingtonpost.com/news/volokh- conspiracy/wp/2014...](http://www.washingtonpost.com/news/volokh- conspiracy/wp/2014/05/24/operation-choke-point/)

</comment><comment><USER5> PayPal does it again. It had previously done it "again", on many occasions. I just don't understand how people keep going back to an organisation like PayPal, or GoDaddy which practically mean "horror stories".

</comment><comment><USER6> Its Anuj from PayPal here. We made a mistake. I just spoke with one of the guys at ProtonMail and apologized on behalf of the company. We fixed it as soon as we were made aware.

</comment><comment><USER7> The second meeting took place in October 1988 at a summer resort in Western Virginia, sad and grey this particular autumn. The Americans turned up in force. Bill Bostwick, from the Department of Energy was the Chairman, Barry Leiner from the Department of Defense and Vint Cerf were present. The European representatives were thin on the ground: a German and British representative plus Francois Flückiger.

In 1991, 80% of the internet capacity in Europe for international traffic was installed at CERN, in building 513.

</comment><comment><USER8> An excerpt from a Softpedia article on his topic: "the payment processor questioned the legality of ProtonMail and inquired about having government approval to encrypt emails."

OK. So now I'm 100% convinced this company is a slave to the US government and it's probably ran by money-hungry apes.</comment>


Why are all the 'good' restaurants starting to look the same? - <AUTHOR> https://medium.com/gone/why-are-all-good-restaurants-around-the-world-starting-to-look-the-same-d03f454c137d

<comment><USER2> What a weird article. Modern culinary arts are at their most inventive right now, with boundaries constantly being pushed, with the trickle down reaching more and more places due to globalization, resulting in more and more people being able to have exciting dishes at affordable prices.

At the same time, more and more attention is being paid to preserve authentic food, while elevating it to more haute cuisine levels.

The author claims they're not trying to begrudge locals good food, but basically the entire article reads "I want to travel to places and have TRADITIONAL!!! cuisine, not this fancy bullshit!"

There's never been a better time to be alive for foodies and even food tourists than now.

<comment><USER3> > TRADITIONAL!!! cuisine

Which is no more than a few decades old at most, a century at the outside.

People live, people die, and new people do the "same" food differently; people move, new people come, and there's a new influence in both locations.

A static view of tradition is a Victorian invention, a reaction to the increasing pace of industrialization, and nothing more than nostalgia. Mix that with the idiotic notion that the Medieval period was a stagnant "dark age" and you have the modern notion of "traditional" "organic" food which was the same for ever until Evil Modernity Literally GMO Monsatan moved in and made a Mordor out of our little Shire.

<comment><USER4> > _A static view of tradition is a Victorian invention, a reaction to the > increasing pace of industrialization_

You understand that those two notions are contradictory, right?

If industrialization "increased the pace", then indeed "static tradition" was what existed before it, as food and other aspects of tradition changed with a much slower pace -- even if not totally static (which is a strawman anyway, no Victorian thought food at 20 A.D was exactly the same as food in 1700 A.D)

</comment></comment></comment><comment><USER5> Everything around the world shows influence from everywhere else in the world. As people travel back and forth, they bring ideas back and forth, until eventually a sort of equilibrium is reached.

As for restaurants, I'm not sure I agree entirely. A few generations ago, every 'top' restaurant was a French restaurant. Serving the same classic dishes. Now you have places serving 'Nordic Cuisine' (Noma, Faviken), Spanish cuisine has had a resurgence in a major way (Arzak, Etxebarri), South American cuisine is becoming recognized at the highest levels (D.O.M., Central), as is Asian cuisine (too many to list), there's 'avant garde' (El Bulli and the Adria brothers' other ventures, Alinea), and then you've got the chefs who break all the rules and just create whatever they want at the time (Pierre Gagnaire comes to mind). Not to mention the trends of gastronomic bistros, brasseries and pubs, cheap tasting menus, haute fast food and street food, etc...

While I think it's somewhat true that the 'style' of a restaurant is becoming less location specific, I think there's more variety and innovation than ever before, more restaurants in general than ever before, and I would argue that food itself is getting more interesting.

As for the article, it seems more like the writer just doesn't like the fact that Buenos Aires isn't as they remember it (almost a colonialist attitude IMO, that Buenos Aires should stand still for them). However this attitude also ignores history - people have always migrated, adopted new ideas, cultures, cuisines, etc... 'Traditional' European ingredients like the Potato and Tomato, for instance, both came from the New World.

Nothing stands still.

</comment><comment><USER6> Perhaps for the identical reason that all articles on the internet are starting to look the same.

<comment><USER7> Brought to you by Marriott. "Stay inside your comfort zone" -Most Interesting Man in the World

</comment></comment><comment><USER8> Are we seeing Medium's monetization strategy come into play here?

</comment><comment><USER9> Native consumer anthropology advertising, yay.

</comment><comment><USER10> It's disappointing to me that restaurants always tend to serve the same tired dishes with slight variations on recipe or style.

The best and most exciting food and mixes of ingredients / obscure cooking techniques seem to come from hole in the wall restaurants with chefs who just really love food and know what tools/ingredients/techniques are available to them and like a brilliant mad scientist they serve up and share their successful experiments.

<comment><USER11> Basically, everyone in the world agrees on what ingredients they'd _like_ to cook with, and how they'd _like_ to prepare things. When you give a chef unlimited time and money to make a dish, they make mostly the same stuff, which is what we tend to call "fine cuisine." There might be variation due to local consumer tastes, but a French chef and a Japanese chef and an American chef will basically agree on, say, who makes the best beef in the world, and then will (if allowed) all import that same beef.

So, you only get originality and inventiveness and "ethnic flair", under resource constraints. Every "local dish" is a local resource optimization, making food tasty using ingredients or techniques that happen to cost less to apply (or, at least, used to, traditionally) in the local area. And hole-in- the-wall restaurants, running under the heaviest resource constraints, tend to thus produce food at its "most ethnic."

<comment><USER5> While I agree that constraints can lead to creativity, there's not nearly as much 'consensus' when it comes to cooking as you think. Someone from France and someone from India will have very different ideas on how to cook something, even if they both live in Canada and have the same ingredients and cooking apparatus.

<comment><USER11> Note that I'm mostly talking about the five-star chefs who do global competitions, as far as "cooking alike" goes. Like the best singers have a "vocal range" so wide that it overlaps with a lot of the other best singers, the best chefs have a "culinary range" so wide that it overlaps with a lot of the other best chefs. Basically, a thousand-dollar meal in America doesn't look a lot different than a thousand-dollar meal in Pakistan or one in Norway, because if you're paying a thousand dollars for your meal, you're getting a chef who could make _anything_ , and who has ordered their ingredients from _everywhere_.

That doesn't seem to be a very widely-applicable point, I admit. But my real argument is that this a point on a spectrum. Hole-in-the-wall short-order cooks are on one end, inventing new ethnic foods out of necessity. "Globally- ranked" chefs are on the other end, synthesizing together every style in the world and thus ending up with their own "cosmopolitan fusion cuisine" culture that doesn't really _belong_ anywhere except within the space of a fancy lounge.

 _Between_ those points, most real chefs lie—not quite constrained to only cook with what's grown locally, but not quite free enough to bring together fresh ingredients from opposite ends of the earth on a whim. Western "home cooking" is precisely in the middle, in fact: a cuisine that sits on one end of the incentive-structure of the global shipping industry, cooking with whatever can cheaply be brought from wherever it was grown to a local chain grocery store.

<comment><USER5> Still though, just thinking back to the cuisine in my wife's home country (a thoroughly 3rd world country), even with something as basic as a fish you get from a fisherman on the road, we'd eat fried fish, fish curry, fish stew, fish sautéed with various starchy vegetables or greens then eaten with flatbread or rice, and so on...

Even in a culture where the only cooking implement is a fire in the backyard (and a clay oven similar to a tandoor), all the vegetables come from no further than the next village over, and starchy vegetables are dug up from behind the house, the variety was staggering.

Fusion cuisine exists everywhere BTW. African cuisine has Arab and Indian influence, Caribbean cuisine has African, Indian and Amerindian influence, Asian food has Western and Indian influence, and the various Asian cuisines all borrow from one another.

Heck a great example of fusion cuisine is the Kebab - seen from Germany to Turkey to Iran, Pakistan, all the way to Vietnam and elsewhere. All have regional variations, yet all can trace some sort of middle-eastern (likely Iranian) origin.

The fusing of cuisines has happened since the beginning of time, ever since nomads encountered agriculturalists, since Egyptians traded with Sumerians, since Greeks journeyed to Babylon and India, when merchants travelled along the silk road (all Western cuisines use Black Pepper, which is certainly not indigenous to Europe), etc...

</comment></comment></comment></comment></comment><comment><USER12> Well that was a bait and switch...</comment>


Safe Native Code - <AUTHOR> http://joeduffyblog.com/2015/12/19/safe-native-code/ <comment><USER2> > You need a great inliner. You want common subexpression elimination (CSE), > constant propagation and folding, strength reduction, and an excellent loop > optimizer. These days, you probably want to use static single assignment > form (SSA), and some unique SSA optimizations like global value numbering > (although you need to be careful about working set and compiler throughput > when using SSA everywhere)…I hate to say it, but doing great at all of these > things is "table stakes."

I'm not sure. It depends on the audience you're aiming for. Go has done very well with a compiler that essentially performs no compiler optimizations (by modern standards; certainly it doesn't do most of the above) by positioning itself appropriately.

> For example, there are ways to write the earlier loop that can easily > "trick" the more basic techniques discussed earlier:

Yeah, bounds check elimination ends up nightmarish quickly. I think I prefer an approach that fixes the problem at its source, by just encouraging programmers to stop using for loops (which are bad for non-performance-related reasons as well). Note that all of the examples given use for loops; if they were rewritten using iterators, there wouldn't be a problem. C# has iterators, so the machinery is there; they just need to make it more painful to use a for loop than the iterator alternative. :)

> Imagine you have a diamond. Library A exports a List<T> type, and libraries > B and C both instantiate List<int>. A program D then consumes both B and C > and maybe even passes List<T> objects returned from one to the other. How do > we ensure that the versions of List<int> are compatible?

I don't understand why this is a problem. Both separately compiled implementations of List<int> should monomorphize to bit-identical runtime value representations. Does the problem have to do with quirks of the compiler's RTTI implementation (e.g. making sure "foo instanceof List<int>" in package A works even if "foo" came from package B)?

> First, Go generates the interface tables on the fly, because interfaces are > duck typed.

Does it really? That's interesting and seems extremely inefficient. I would have assumed that the Golang compiler would just statically determine the set of vtables that need to be used by the program and write them up front into rodata. Am I missing something?

<comment><USER3> > I would have assumed that the Golang compiler would just statically > determine the set of vtables that need to be used by the program and write > them up front into rodata. Am I missing something?

IIRC the Go compiler will generate the itables that it can determine are needed at compile time, but because you can dynamically request an interface conformance for a type there is also a runtime fallback.

Swift does something similar; the compiler tries to generate protocol conformances as much as possible, but because there may be an unbounded number of types at runtime, clearly it can't generate all of them.

<comment><USER2> > IIRC the Go compiler will generate the itables that it can determine are > needed at compile time, but because you can dynamically request an interface > conformance for a type there is also a runtime fallback.

That would make more sense. But [http://research.swtch.com/interfaces](http://research.swtch.com/interfaces) claims it's all runtime-based (though that document may well be out of date).

<comment><USER3> It looks like the optimization I remember was implemented in gccgo, but maybe they never added it to the main compiler: [http://www.airs.com/blog/archives/277](http://www.airs.com/blog/archives/277)

</comment></comment></comment></comment><comment> vive-la-liberte >Thankfully, these days you can get an awesome off-the-shell optimizing compiler like LLVM that has most of these things already battle tested, ready to go, and ready for you to help improve.

I wonder if "off-the-shell" is a typo or a pun.

</comment><comment><USER4> So what exactly was Midori? He says they benchmarked "booting all of Windows" \- what's that mean in context? And why are they back pushing and focusing on C++?

Really good series of posts. Always good to see sufficiently smart compilers and such.

<comment><USER5> One of the earlier posts in the series explained Midori in more detail. Apparently it was a research operating system built at Microsoft to explore using safe/managed code for building the entire OS while also aiming for the same kind of performance you get with raw C/C++.

<comment><USER4> So what does "booting Windows" mean? Did they port some sort of Win32 compat thing or was that supposed to be a general term for their UI?

<comment><USER6> In addition to backend compilation for managed code, Phoenix could continue to be used to compile C/C++ code. One of the things the team did was continue to compile the Windows codebase to compare Phoenix and UTC (for both functional and performance reasons, IIRC).

Disclaimer: I was on the Midori team for a few years but did not work on Phoenix itself.

</comment></comment></comment></comment><comment><USER7> How much of this tech has been published in academic papers? Microsoft's normal MO seems to be to just patent it then publish and/or use it like they did with a lot of other stuff (incl VerveOS). I'd love to read the technical reports on how they handled each problem and what specific results came from it. Meanwhile, Joe's write-ups are great substitute.

<comment><USER8> Joe explains this on the first blog entry, almost nothing, hence why he decided to write these posts, so that the information doesn't get lost and the world outside MSR gets to learn a bit about what Midori was all about.

</comment></comment><comment><USER9> Looking forward to CoreRT being usable for non-trivial applications. But I wonder why CoreRT is still in early development, while .NET Native is ready for universal apps on the Windows Store. Why wouldn't the runtime from .NET Native be suitable for desktop and server apps today?

<comment><USER8> As I understand it, it doesn't cover all possible MSIL opcodes or .NET APIs.

Only libraries that can run on top of CoreCLR can be AOT compiled with .NET Native. For example the F# team is currently making possible to target CoreCLR.

Then there are possibly the political issues where Microsoft wants to drive .NET Native.

</comment></comment><comment><USER10> Great article series. Very easy to understand, and brings a lot of inner works of a managed runtime out.

</comment><comment><USER11> How does this compare to native client?

</comment><comment><USER12> Admins, how did this dupe [https://news.ycombinator.com/item?id=10764870](https://news.ycombinator.com/item?id=10764870) (11 hours ago)?

<comment><USER13> (I'm not an admin. You probably want to email HN because they won't see the question otherwise.)

In the past HN had a fairly strict dupe-detection filter.

That meant that a lot of good stories that didn't get attention on the first posting didn't get reposted.

Currently the dupe-detection is much weaker than it used to be. A story that didn't get much attention on the first post can be reposted easily now.

HN tried an experiment where they'd email people and ask them to repost submissions, and give those reposts a small bump. That was a lot of work, so they only do that for "Show HNs". Now they do something like an auto-repost which resets the timestamp.

This means that sometimes you'll post something, and it won't get much attention, and a few hours later someone else will post the same thing and it'll get upvotes.

This isn't going to stay like it is. They're working on a better system.

[https://news.ycombinator.com/item?id=10754760](https://news.ycombinator.com/item?id=10754760)

>> We've recently started doing things to make the original submitter get the front-page slot more often

[https://news.ycombinator.com/item?id=10753401](https://news.ycombinator.com/item?id=10753401)

>> Invited reposts are mostly deprecated now in favor of re-ups [1], but when it looks like the submitter might also be the author (as e.g. with Show HNs), we still send them. It's nice for an author to know that their post may still get discussed, and it's good for HN when an author jumps into the thread.

[https://news.ycombinator.com/item?id=10705926](https://news.ycombinator.com/item?id=10705926)

(A meta post, with links to previous discussion).

<comment><USER12> Thanks for that! I knew they'd loosened de-duce up a bit, but this was ~10 hours.

</comment></comment></comment><comment><USER14> It's sad that such otherwise smart people choose to stay at Microsoft. Microsoft doesn't yet realize it, but the would really would be a better place if it were to die. They did a lot of interesting things over the years, but their view of the world is so fundamentally out of touch with what the world is today, that they can't help but lose mindshare. They're still quite strong, as there's no alternative to them on the desktop (for most people), but they never quite gained dominance on the server (and continue to further fuck it up by introducing more and more bizarre licensing arrangements), their development environments and APIs look like a bad joke, and most decent engineers would rather have their balls/ovaries removed than code for the Microsoft platform. Nearly a decade ago, when I actually did develop for Windows, I asked a fellow engineer who coded for Linux why he refused to admit how superior C# was to Java. He basically said that he is not interested in chaining himself to any given platform. In the years that followed, I saw just how right he was.

So my message to Joe and other solid folks like him: there are tons of opportunities outside MS campus. I know large companies tend to make you believe it's a barren desert out there, but it's simply not true, and it's especially not true now, when job market is starved for good talent. Go out there, make the world a better place. Let Microsoft ride into the sunset.

<comment><USER15> > their development environments and APIs look like a bad joke

I agree, cmd.exe is bad. Everything that doesn't require the command line is better in Windows land though. Visual Studio has nothing coming even close to it (CLion is getting there for C/C++ though), .NET has an amazing set of APIs and I wouldn't trade them for any other language's, Direct3D is actually a good API compared to the pile of crap that is OpenGL. Win32 is actually not that bad compared to the crap you have to deal with on Linux.

For certain things, Windows is the superior alternative. However, if your job requires you to do JS/ruby/python/etc. then by all means, go with Linux/OSX, it is clearly better. But the integration of some tools and languages on Windows beats any other OS.

<comment><USER14> Huh? For the past several years I've been doing C++ development in Vim, with YouCompleteMe providing excellent code completion. Eclipse works pretty great for C++ too, especially for browsing code. Seems to me you haven't seriously worked in Linux. The only thing that's lacking is the debugger. Everything else is either the same (for eg Java) or an order of magnitude better. All non-ms programming languages are UNIX-first. They feel bolted-on when ported. And let us also not forget the complete freedom you have on UNIX systems. Want to spin up a VM or a dozen? Go right ahead, for free. Want your server to serve five hundred people? Go ahead, no need for extra licensing. Want dev setup for nearly any language under the sun? It's a one liner. And so on and so forth.

Another benefit is, the lower level APIs are the same they were two decades ago, some are even older. And that API surface is much smaller. You basically learn them once, and they're good for life. Same with much of the tooling such as text editors, build systems, command line tools, and so on.

Once you grok all this, there's _really_ no going back to ball and chain that is Windows.

<comment><USER16> > All non-ms programming languages are UNIX-first. They feel bolted-on when > ported.

This is not an argument against Windows, but against these programming languages and their maintainers.

> And let us also not forget the complete freedom you have on UNIX systems.

There are lots of commercial UNIX systems that have much more restrictive licensing terms than Windows.

> Another benefit is, the lower level APIs are the same they were two decades > ago, some are even older. And that API surface is much smaller. You > basically learn them once, and they're good for life.

The same holds for WinAPI etc.

<comment><USER14> 1\. Be that as it may, no one is idiot enough to create their life's work on a proprietary platform. 2\. Which is why commercial unixes are being supplanted by FOSS. And it far easier to do than, eg porting anything from Windows to anything else. 3\. WinAPI is a verbose, poorly designed turd, so that doesn't really help your argument any.

<comment><USER17> I'm primarily a Linux user, and only use Windows at work, and don't consider POSIX precisely the pinnacle of tasteful API design.

<comment><USER14> It doesn't have to run faster than the bear. It only has to run faster than the other guy.

<comment><USER17> It isn't clear to me that POSIX is strictly better than the Windows API in all respects. For instance, synchronizing processes manipulating a common file is _very_ awkward in POSIX.</comment></comment></comment></comment></comment></comment></comment></comment>


Apple to stop using intel chips in laptops - <AUTHOR> http://www.reghardware.com/2011/05/06/apple_arm_laptops/

<comment><USER2> Headline is missing the key word "Reportedly" and is seen quoting "SemiAccurate".</comment>


Ruthless enough for a startup? "...these startups did things that I probably would not have been willing to do." - <AUTHOR> http://glinden.blogspot.com/2006/11/ruthless-enough-for-startup.html <comment><USER2> Perhaps the lesson from this blog is that if you want to be a successful startup, you can't get on a moralistic high horse and tell people what they're allowed to see, say, or do.

This dude's definitions of "ruthless" stretch credulity. HotOrNot is ruthless because they allow people to engage in the very-human activity of scoping? Skype is ruthless because they take advantage of the net to remove a market? YouTube is ruthless because they trade in "soft porn"? (And the fact he calls YouTube content soft porn tells me he probably doesn't get cable.)

The sites that didn't apply some arbitrary filter of self righteousness to their content succeeded. Surprise! That's not ruthlessness, it's glorious, beautiful freedom. The fact that jokers like this continue to lament the passing of censor bureaus and Manuals of Acceptable Content should only reinforce how precious and incredible the net is.

<comment><USER3> I would say not enforcing the so-called self righteousness is at least a faster way to market a startup, if not making it more successful. It's the ruthlessness of youtube, not soft porn, made its way through.

I am not sure about the very first motivation of all business around me. However, apart from possibly ruthless objectives those business are trying to achieve, what is really important is that how iterations of those business ideas can fulfill the (other) needs of everybody else (like me).

</comment></comment><comment><USER4> What is it about youtube's one-click emailing feature that put it in the same list as myspace spamming 10M addresses?

</comment><comment><USER5> This guy seems to have a bit of a problem with lust. He picks on Bittorrent, Hotornot and Youtube for using porn and near-porn to attract users. I think the way all three services handle sexual content is entirely appropriate for their intended audience and social interface.

</comment><comment><USER6> why is this so surprising? and why considered ruthless?

it's not random that the richest companies in the world are those involved in telecommunications and transportation. People live to communicate.

<comment><USER7> Perhaps the curiosity is about the "dirty tricks" department.

Companies here in Italy are all about dirty tricks, for instance - I don't think anyone would believe an entrepreneur here if he said he was completely clean. That's why a lot of the country voted for Berlusconi even if he was accused of various nefarious dealings.

Sorry, that's going rapidly off topic... perhaps what's most interesting to people is wondering how much they have to be ready to do to make a go of things.

For instance, PG talks about adding fake workstations in their offices, in his founders at work interview. That's pretty innocuous, and certainly not illegal. Some of the things mentioned in this link though, are of dubious morality, and I can understand not wanting to go that far to win.

<comment><USER6> even campionato sufferred from this 'dirty tricks'! I wasn't really surprised when I heard about it..everybody knew it I guess...

..i mean all these are common secrets nobody wants to talk about..

maybe in his examples these 'dirty secrets' are more obvious but come on everybody knows that they occur and what triggers the boost of the acceptance of technology...

...kissing for instance in cinema movies was unacceptable 4-5 decades ago...in 10 years what may come us a surpise today that may have caused torrent or youtube's broad initial use, as the writer implies, will be so innocent unfortunately or not, that people will be surprised to hear that it actually helped these services to take off..

i suppose this is more like a society problem or truth that is in the nature of humans.

even the "reason" for Trojan war was a beautiful woman. But today, now that barriers and nations are a reality, wars for dominance had to move into a new field, and hopefully or not, internet came along...

this web 2.0 startup wave, is more a part of a new revolution, thats why is not a bubble...

</comment></comment></comment><comment><USER8> Sites that depend upon users to somehow benefit other users (most web2.0), can be faced with a chicken-or-egg situation when starting up.

Where do these first users come from? These tricks aren't "ruthless" at all. Often, it is necessary to use unconventional means to get the ball rolling.

</comment><comment><USER9> Are you kidding? Moral gray areas are part of the fun of startups!</comment>


Ask HN: Unbreakable Crypto How to Market - <AUTHOR> I was talking to this tech person today who was telling me about his unbreakable crypto technology. He was wondering how to market the idea as it didn't get any tracktion in the market.
I was wondering if a social network type of approach where you offer an incentive (1000$) to break a technology, yet you have to pay 10$ to enter which get added to the amount offered. Is that something that could interest people to try to hack your crypto? Is that too cheap? Like bounty hunter on a bug?
Are there contest and other avenues to prove your working concept? <comment><USER2> This is like asking _I was talking to this medicine person today who was telling me about his perfectly effective zero-cost therapy. He was wondering how to market the idea as it didn 't get any tracktion_ [sic] _in the market._

* Firstly, "tech person" is strange considering this place is Hacker News, and possibly insulting.

* "Unbreakable" is unbelievable.

* "Crypto" is not specific enough. (Is it a symmetric cipher, asymmetric crypto, a secure hash?)

There are cryptological competitions like this [0] one (it is too late to contest now in that one). I am not an expert, but I think if you were doing your own "crypto contest" thing, you would need to ensure the winners get at least on the order of 50000$ (consider that people get thousands of dollars just on bug bounties, the money may need to replace tenure, attackers may be better funded, etc.)

[0] [https://csrc.nist.gov/Projects/Lightweight- Cryptography/Roun...](https://csrc.nist.gov/Projects/Lightweight- Cryptography/Round-1-Candidates)</comment>


Help virtually restore the Mosul Museum - <AUTHOR> http://projectmosul.itn-dch.net/

<comment><USER2> How practical would it be to automatically search the web for images of the Mosul Museum? Has anyone calculated SIFT descriptors for all of Flickr or Picasa? Seems like with enough computing and bandwidth, and a set of seed images of objects in the Museum, someone could search the entire web automatically for the needed images.

<comment><AUTHOR> It isn't impractical, but our cursory searches revealed few images of the museum. Unfortunately it has been closed for over a decade, meaning very few people with digital cameras have been in there in recent years. But, we can use scanned slides and frames from videos too.

</comment></comment><comment><USER3> Why not use Photosynth

<comment><AUTHOR> We are using similar software. In fact, we will use a suite of tools to generate the models. Agisoft's PhotoScan, VisualSFM, SURE... just to name a few.</comment></comment>


Playdom Engineers Shocked They're Still Not Rich After $763 Million Disney Buy - <AUTHOR> http://www.businessinsider.com/playdom-engineers-shocked-theyre-still-not-rich-after-763-million-disney-buy-2010-8 <comment><USER2> My husband was an early employee in a privately-held games company that was purchased for a similar amount. Only the founders and a couple of employees from day one were made rich, in the "FU money" sense. OTOH, it was a games company so no one went in expecting a payoff. The retention bonuses were also extremely generous.

The reality in almost every startup is that only the founders are going to see a payoff, no matter how big the acquisition is. Calibrate your behavior accordingly.

</comment><comment><USER3> The original link is down, "We're down for some scheduled maintenance. We'll be back up again shortly." and there is no google cache so here is the bing cache:

[http://cc.bingj.com/cache.aspx?q=http%3a%2f%2fwww.businessin...](http://cc.bingj.com/cache.aspx?q=http%3a%2f%2fwww.businessinsider.com%2fplaydom- engineers-shocked-theyre-still-not-rich-after-763-million-disney- buy-2010-8&d=769956906591&mkt=en-US&setlang=en-US&w=3e623a43,ebfbeef8)</comment>