FlyKly Smart Wheel - <AUTHOR> http://www.kickstarter.com/projects/flykly/flykly-smart-wheel <comment><USER3> FlyKly guys: Welcome to HN. I know that a lot of this thread is going to look like we're hating on your product. (Personally I think that if you deliver it with the level of finish you're aiming for, it will be pretty cool). Mostly we're not, this is how we roll. For geeks, we've got x-ray vision when it comes to most new technologies so we see right down to the basic principles (which are almost always simple) right away. These are almost never the most interesting parts of new product releases but will elicit the predictable _" pfft, Thomas Edison did it in 1913..."_. Water off a duck.

What we will do is pour our thoughts like water through your product and ideas. Anything that's not perfectly thought through is going to leak. I hope you'll take the criticism in the (mostly good) spirit in which its offered and use it to build a better product.

<comment><USER4> We're also going to read one sentence of your copy and assume that we know everything about how it works. We're going to draw a quick conclusion despite have never developed anything in that space and assert that your product has fundamental flaws without understanding your research, your market, or your funding model. We're going to compare your product to previous market failures despite fundamental differences that actually go so far as the previous product never having been produced.

But hopefully you'll still be able to get something useful out of this crowd :D

<comment><USER3> Heh. Some of us might. There's no shortage of cynicism to go around, here and everywhere.

On the other hand, what does the HN crowd say about technologies they really do find uninteresting and unimportant? Absolutely nothing. They drop right off the bottom of "NEW" without a single comment.

Edit: And to be fair, most market-speak is so vapid that we often only get one meaningful line of copy stating the purpose of a thing and a picture showing us its general physical shape to go on. We have to deduce everything else from that. In short, we've gotten used to disappointment.

<comment><USER5> "On the other hand, what does the HN crowd say about technologies they really do find uninteresting and unimportant? Absolutely nothing."

This also encourages us in a way, as weird as it sounds. It probably means we're at least doing _something_ right if everyone is paying so much attention to it. Thanks!

</comment></comment></comment></comment><comment><USER6> I was going to join everyone else in this thread in bashing elements of the design and product, the specifications, etc. But I won't do that.

Instead I'll do the opposite.

I'll point out upfront, I own 5 bikes, I run one of the largest cycling forums in the world, and I run one of the largest cycling clubs in the UK. I get cycling.

I like it. The FlyKly.

I like it because it allows a rider to keep their existing bike, and yet to retrofit for a really reasonable price an electric motor.

I like it because the vast majority of the weight within the wheel isn't a moving thing, the batteries are fixed.

I like it because the 30 mile range, whilst not suiting my 18 mile commute for a daily charge, actually does suit the vast majority of cyclists that I know who only commute fewer than 10 miles.

I like the 1,000 cycles, which is probably 900 in reality, is actually a few years of use for the average cyclist. Even most cycle commuters don't actually cycle 7 days a week, and those do diligently do so on all work days only do so for 220 > 250 days per year.

It hits all of the sweet spots:

1) Can I keep my existing bicycle?

2) Can I just get the electric bit and not pay to replace all of the other bits I have?

3) Will it just work and be easy to install?

4) Will it help me on my commute?

5) Will it realistically last a couple of years?

6) Is it priced such that I can afford it?

For the majority of cyclists I know, the answer is yes to all of the above.

I think it's got a good chance, which doesn't mean I'll be buying one but then I'm not your average cyclist.

PS: FlyKly, you show several times the use of the wheel on a brakeless fixed- gear bike. That's just for the aesthetics right? Or is the wheel fixed compatible such that you're fine with people skid/skip stopping?

<comment><USER7> > I like it because the 30 mile range, whilst not suiting my 18 mile commute > for a daily charge, actually does suit the vast majority of cyclists that I > know who only commute fewer than 10 miles.

If you can easily remove the wheel, then this isn't much of a problem, they say it charges in 2-3 hours from a normal socket so you could probably get to work, plug the wheel in under the desk and have it charged well before you're going home.

<comment><USER8> yup, this is what I do with my homemade ebike [http://farm3.staticflickr.com/2841/10328825565_ef951c4367_b....](http://farm3.staticflickr.com/2841/10328825565_ef951c4367_b.jpg)

fwiw, as a designer I think this team is solving some of the biggest issues with current ebike design that is holding back wider adoption in the US/UK markets. Kudos to them, hope they hit a home run.

</comment></comment></comment><comment><USER9> You need to differentiate from the long-existing BionX hub motors[0] which do regen braking at user-selectable levels AND allow proper 7, 8 or 9-speed clusters, unlike the single gear your pictures show.

[0] [http://www.bionxinternational.com/bionx-international- north-...](http://www.bionxinternational.com/bionx-international-north- america/products/bike-retrofit-systems/motors/)

Edit: the big differences would be (a) this has the battery integral to the hub, where the BionX uses a separate battery pack; and (b) that this communicates to its controller -- your phone -- wirelessly, where the BionX console[1] connects with a wire.

IMO as owner of a BionX-equipped bike, I'm dubious about whether either difference is a positive one. For (a), the in-hub battery is clearly size- limited, can't be removed from the bike for charging indoors, and would be harder to replace.

As for (b), is it really a good idea to require a smartphone to be attached to your handlebars whenever you ride? That's not an easy environment, it has a lot of vibration as well as exposure to water, dust, and sweat. A minor point, the BionX dedicated controller has an optional thumb operated throttle lever for proportional control when you don't want to pedal, and it's hard to see how that could work with a smartphone.

[1][http://www.bionxinternational.com/bionx-international- north-...](http://www.bionxinternational.com/bionx-international-north- america/products/bionx-e-bike-systems/consoles/)

<comment><USER10> It also seems to be four times the price? That's what's listed here[1]. Either way, could you describe your experience? What do you use it for, and is it worth the expense? I'm wary of electric bikes because they are expensive, heavy, and let you exercise less.

[1][http://electricbikereview.com/bionx/sl-350/](http://electricbikereview.com/bionx/sl-350/)

</comment></comment><comment><USER11> "it can quickly be located and tracked via GPS" but the only radio in it is Bluetooth, so I guess you can track it if you're in the same room...

"36V Lithium" battery, but no spec about how many kWh it stores.

"Top Speed 20mph". Given that it only operates when the human puts in some effort, what does that even mean? I'm guessing this is written down because US Law says if it goes faster than 20, it's no longer a bike.

"In 2011 Niko Klansek introduced the first line of electric bicycles to the USA market." Nope; ebikes have been available in the US for far longer than that.

GAH. There are lots of conversion kits you can buy today. The kickstarter gives no way for you to figure out if this is anything better.

<comment><USER5> A GPS module is of course also located on the Smart Wheel itself so it sends a signal on its own once the motion sensors (that turn on only after you lock it) notice it's moving without your knowledge.

The top speed means exactly that - because the Smart Wheel is a pedal assist this means it helps you accelerate until you reach 20 mph and no further. You're correct in stating that the top speed is also set in accordance to the US Law (or European Law, which allows for speeds up to 25 km/h).

We're sorry about the confusion about "the first line of electric bicycles" \- this was of course meant to inform the reader about the first line of e-bikes that we're introduced by FlyKly, not the first e-bikes EVER.

<comment><USER12> _...the motion sensors (that turn on only after you lock it) notice it 's moving without your knowledge._

Is there any reason that "locking" doesn't render the device immobile? I realize someone could still carry it off, but most thieves would be more reluctant to steal a device they have to take apart and hack before using, than one they can literally just ride away.

<comment><USER13> I assumed they meant the bike is being geographically displaced and that yes the wheel mechanism would be locked. For example if you pick up the back wheel and push the cycle on the front one only.

</comment></comment></comment></comment><comment><USER14> Niko (the CEO) is real deal - he used to work across my cubicle at Projective Space in SoHo. He first introduced FlyKly electric bikes in NYC (he did manage to sell a lot in the area). His personal story is full of inspiring entrepreneurial journey! He is now back with smart wheel! Good luck man!

</comment><comment><USER15> Here's why I like this design.

5 kg is light for a battery/motor module, but it still adds about 50% to the weight of a decent bike. The added thickness also means it's probably not practical to put a multi-gear cassette on it. End result, this will _cripple_ most bikes once the battery runs out. More weight and poor gear ratios = hell for the cyclist. However, most smart-bikes are crippled anyways once they run out of juice.

The great thing is that you can use the same bike for commuting that you use for your sweatier, long-haul weekend trips. All you have to do is swap the original dumb-wheel back in. If you buy a dumb-bike and a smart-wheel you almost get two bikes for the price of one.

Tip for the makers: Stress the ease of hot-swapping that wheel in even more than you are now. This is a _major_ selling point.

P.S. I don't see a quick-release clamp on this sucker in your pictures or video. This is a no-brainier and absolutely needs to be on there.

<comment><USER16> The weight of the bike doesn't matter. A 20 pound bike plus a 200 pound rider is about the same as a 30 pound bike plus a 200 pound rider. You're the heavy part, not the bike. (People complain about citibikes being too heavy, but I rarely get passed even on a citibike, so my guess is the problem's the rider, not the bike.)

Also, I don't think a quick release will work for this. The motor needs to push against the bike in order to move the wheel relative to the bike. A quick release will slip.

<comment><USER17> Not necessarily. QR systems such as Maxle are sturdy enough for competitive downhill use.

Also 10 pounds is a huge difference not just in the effort needed to propel the bike forward but also in terms of maneuverability, especially as it is rotating weight. And in city usage you often have to carry the bike down stairs etc. where again 5 kg and a messed up center of gravity is a big deal.

<comment><USER16> I bike about 5000 miles a year in the city and have never needed to carry my bike down stairs while riding. Once you get it home, you might need to lug it up to your apartment, but it's well within the realm of possibilities for a healthy adult to carry a 40 pound bike up a few flights of stairs. (Then again, it's also rather easy to pedal the bike around without a motor. But I digress.)

<comment><USER17> Most European cities will make you carry your bike from time to time or make huge detours. But, like you, I'm not the target customer for this so maybe people in general are more careful with route planning.

</comment></comment></comment></comment></comment><comment><USER18> KERS for a bicycle. Cool.

Given that old Lotus bike, Im surprised one for the F1 teams hasn't rustled something up. I'd have a chat with one of them and see if they would like to partner up. Especially as they are trying to be all green these days.

Can you harvest from the front wheel too?

<comment><USER19> If you slow the bike from either the front wheel or the back wheel, energy is removed from the whole bike. There's little to no benefit from harvesting from both wheels.

<comment><USER18> All the resistance is from only the rear wheel. So its like rear wheel breaking, and potential lock ups in the wet. Surely its better to spread the load. Also means twice the surface contact. Wouldn't that be better, perhaps safer, to ride? Especially in the wet.

<comment><USER20> But the extra cost and complexity, even weirder look, extra wires. For emergency braking, keep the regular front brake. For minor speed adjustments the rear brake will get the job done.

</comment></comment></comment></comment><comment><USER21> My wheelchair-using family and friends have been rocking Alber e-motion wheels[1] for some time, and would highly recommend them. Those don't recharge from motion (or as fast), or support bluetooth, but work in a similar way.

[1] [http://www.alber.de/en/products/wheelchair-drive/mobility- wh...](http://www.alber.de/en/products/wheelchair-drive/mobility-wheelchair- emotion.html)

<comment><USER22> Cool! Do you know if they have any issues with it making the wheelchair wider and therefore causing problems with doors/turning? I guess I'd have to give up my 2 degree camber with those wheels but it might be worth it.

<comment><USER21> From what I can tell (having not used one properly myself), they fit the components within the push rim, so there's no real issues with doors or turning. Just done some research for you, and looks like they can actually support camber, too!

<comment><USER22> Thank you! Much appreciated. The last time I looked at these kind of wheels they were big enough to require some modifications to the chair itself - <USER2> like even wheelchair technology gets a boost from time to time.

</comment></comment></comment></comment><comment><USER12> IANAMechanicalEngineer, but do we need to worry about additional stress on the left dropout? The forces to which this component is typically subjected are the weight of the system and the tension of the chain. This device would seem to add an additional torque associated with driving the wheel via the pill- shaped peg that slides into the dropout.

This probably wouldn't be an issue for most bikes, but it seems like it's outside the design specs for any existing bike.

<comment><USER23> Having done e-bike mods in the past, rear-dropouts tend to be stronger than front-dropouts, and on any steel bike you can put a lot of torque on the front dropouts.

Only problem with rear-dropouts is accommodating the gearset, which they cleverly handled by eliminating the gearset; that will _suck_ if you run out of power downhill from your destination, but will otherwise work fine.

<comment><USER12> That would indeed suck! I can see why they didn't incorporate a cassette body (and the chain clearance issues that would entail: basically everything they have on the right side now would have to be moved to the left side) but it does make the final product seem less like a _bicycle_. (I know, this is sacrilege to the fixie folks. Meh.)

</comment></comment></comment><comment><USER24> This is less efficient than putting all the batteries and other gear on the frame, right? Spinning all that mass around will take energy. I don't see an advantage unless you expect to swap wheels out often.

<comment><USER5> The Smart Wheel actually consists of two halves one of which is fixed (it doesn't turn). The battery is therefore stationary and doesn't require any kinetic energy to be spinned around the axis.

<comment><USER24> Oh, I guess I didn't pick up on that. Thanks for the clarification.

</comment></comment></comment><comment><USER25> It doesn't appear to support bicycles with gears. Is that something planned for a future model? Or do gears somehow become unnecessary with electric assist? Could you even retrofit this to a standard cheap 15-gear bike, or is it strictly fixed-gear only?

<comment><USER26> I think it supports bikes with gears where the pedals are( in the middle not on the last wheel ). If you look in the video at about 3:58 you will see some bikes with gears. This does limit you to two to four gears but that should be enough. Just have two low gears and one high one.

</comment></comment><comment><USER27> "It goes up to 20 mph (25 km/h) for a 30 miles (50 km) range."

The speed conversion is way off. But the distance conversion is pretty good. Wonder why that is.

<comment><USER28> I mentioned that on Twitter. It turns out that those are the limits according to the laws in US (20 mph) and EU (25 km/h), so it's top speed is limited accordingly depending on the country it's in. It's also an amazingly confusing way of putting it.

<comment><USER27> Uh...yeah...20mph isn't 25km/h even if you are in the EU. They could use an additional sentence there.

And worse...where does that leave Canada? Or any other of the 98.5% of countries that use the metric system?

</comment></comment></comment><comment><USER29> The chances of me sticky-taping my phone to the front of my bike are non- existent.

...but also, won't charging this be a complete pain? I'm just imaging a bicycle sitting next to all the other USB charge devices on my desk. Awkward...

</comment><comment><USER30> Considering the acceleration of the motor is controlled wirelessly, I wonder if you could attack it so it e.g. accelerates uncontrollably.

<comment><USER13> I imagine there's hardware limitation of the maximum current flow from the batteries (above and beyond the natural limitation).

Perhaps less catastrophically but similarly you might attack the lock, engaging the lock would most likely produce a skid and loss of control. With a solenoid engaged by a control circuit might that be possible simply by blasting the circuit with radio waves to induce a current? Thus you'd bypass having to gain access to any software controls and such.

Much easier to just nudge the back wheel with your car or shove a stick in the spokes if you're in to knocking people of their bikes though?

</comment></comment><comment><USER31> I like the concept very much, but they're being a bit dishonest about the "fits practically any bicycle frame". Even in their own video, they show the wheel mounted on bikes where it absolutely does not fit with the brakes: see [http://imgur.com/lZZ2ABg](http://imgur.com/lZZ2ABg)

</comment><comment><USER32> Could you fit it the front wheel instead? Less work with the chain, and you can keep all your old gears. Not sure how it would affect the "drivability" though.

<comment><USER13> I was wondering about having a trike with both back wheels motorised (or a wheelchair?). Weight at the front does make it easier to fall off though I feel.

</comment></comment><comment><USER33> It's an interesting idea. But there are some big obstacles:

1\. I question the need for a retrofit product. There are many mature e-bike designs on the market. I doubt it would be hard to find an ODM or CM that could sell you a good design off the shelf.

2\. Many e-bikes have removable batteries. You can charge them at work. This doesn't look like it could.

3\. Maybe the e-bike isn't the sweet spot. Maybe a slightly larger electric scooter is it. Or maybe an even bigger three-wheeler like Toyota has shown.

4\. Outside of China, where gas scooters are prohibited in many (all?) cities, e-bike have not caught on (though I see quite a lot of them in Manhattan, still not enough to be mainstream)

<comment><USER34> Retrofitting avoids the problem of needless waste and cost when it comes to the _vast_ quantity of existing bikes out there. I don't want to buy a new bike if I can avoid it so replacing a wheel is quite a bit more appealing. I can't imagine that I'm alone in this.

In fact, I'd argue most people would be willing to try this if only because it only involves replacing a wheel. It probably won't cost nearly as much as a new bike either so folks who couldn't otherwise afford it can purchase.

<comment><USER35> Plus, the target market doesn't likely have storage space for both their existing bike and a pedal assist model. If I'm a city-dwelling hacker, I'd prefer buying a wheel over a scooter. I just pulled up listings on Amazon for inexpensive e-bike pedal assists, and they're mostly largish scooter-types that take a significant footprint to store compared to a bike which I can hang on my wall.

Plus, having a wheel allows me to continue using my tires, frame, accessories and everything I love about my current commuter bike.

<comment><USER36> Also, I would use the e-wheel during the week for my commute to work and come the weekend I could fairly quickly switch the wheel over to my regular one and exercise properly. One bike, two purposes.

</comment></comment></comment></comment><comment><USER37> If you don't mind having to position a battery on your bike, for $399 you can already get an electric wheel.

[http://www.electric-bike-kit.com/hill-topper.aspx](http://www.electric-bike- kit.com/hill-topper.aspx)

Otherwise I've been using a wheel and battery from [http://www.leafmotor.com/hub-motors/16r-electric-hub- motor.h...](http://www.leafmotor.com/hub-motors/16r-electric-hub-motor.html)

If you're more into plugging stuff together yourself. They also offer more wheel sizes, like 700c.

<comment><USER23> While we're plugging ones we've used, I like [http://www.ampedbikes.com/](http://www.ampedbikes.com/) I have an old ugly battery; they now have a shiny frame battery that I can't justify buying.

</comment></comment><comment><USER38> These guys made an electric bike/scooter hybrid a few years back that had some buzz here in NYC before release, but just seems to have fizzled. I'd be curious to know what happened.

</comment><comment><USER39> What's to stop someone from just taking the wheel when it's locked? Or removing the wheel and taking the rest of the bike?

<comment> r-s It looks like this wheel is using a standard quick release. If that's the case it would be fairly easy to take out. Couple of options though:

\- When locking the bike, run the lock through the wheel. Yes, someone could still cut the spokes and steal the main hub, but this is going to take q fair amount of effort.

\- Have a bolt on version, lots of older bikes, or bikes which use a horizontal dropout design already have this. Typically they use 15mm wrenches, but there are some alternative sizes (some even use hex keys).

Looks like a pretty cool concept. I personally would prefer a model which only gained energy from the rider when coasting down hills or braking, then could release the energy at the riders discretion. Plugging a bike into an external power source isn't something that interests me.

<comment><USER40> > I personally would prefer a model which only gained energy from the rider > when coasting down hills or braking

But then you gain nothing, on average.

<comment><USER41> Of course you gain, since that energy would otherwise be wasted as heat.

</comment></comment></comment></comment><comment><USER42> Most bikes I see in cities in Europe have hub gears in the rear wheel's axle. I think this won't work with these because if you put that wheel in, you loose the hub gear? [https://en.wikipedia.org/wiki/Hub_gear](https://en.wikipedia.org/wiki/Hub_gear)

<comment><USER26> Can you have hub gears in the pedal section?

<comment><USER42> No, the gear is in the axle. My bike has this too. I'd love to have something like the FlyKly but as it is, it won't work.

<comment><USER26> I did some research and pedal section( bottom bracket) gears exist, but aren't very common.

[http://bicycles.stackexchange.com/questions/8872/bottom- brac...](http://bicycles.stackexchange.com/questions/8872/bottom-bracket-with- built-in-internal-hub-does-this-exist)

[http://www.haberstock-mobility.com/en/products/schlumpf- driv...](http://www.haberstock-mobility.com/en/products/schlumpf-drive.html)

[http://bicycles.stackexchange.com/questions/5274/why-not- hav...](http://bicycles.stackexchange.com/questions/5274/why-not-have-the- gears-inside-the-bottom-bracket)

</comment></comment></comment></comment><comment><USER43> Im curious how does the (normal) braking system work? If the motors helps push against hills it pushes against resistance like the rubber brakes too? Surely its not always regenerative braking? I guess you always have to stop pedaling for that to kick in.. It is nice though to go down a hill or even flat land on free without feeling the resistance of regenerative braking or something slowing you down.. Do we get control over this?

The second was how does it talk to the phone without a SIM card or some kind of internet connection if you're a couple of storeys up in a building where Bluetooth? doesn't have any range?

Otherwise this is pretty awesome, although I do like getting a bit of a workout when going around I like when you want you can move around stressless it would be awesome for 'those days' and not have to use a car.

</comment><comment><USER44> If this project is like the other Kickstarter projects I've backed, it will meet its funding goal then be delayed by months and months, if not years, with letters of apology sent every month or so. It's a shame because Kickstarter is one of the best things to ever happen to capitalism.

</comment><comment><USER45> I thought electric bikes are illegal in New York??? [http://nymag.com/daily/intelligencer/2013/04/electric- bikes-...](http://nymag.com/daily/intelligencer/2013/04/electric-bikes-to- become-even-more-illegal.html)

<comment><USER16> They are illegal to ride on the street, not to possess. So you can build them in NYC and ship them to somewhere legal, and everything is fine.

</comment></comment><comment><USER35> Battery life of 1000 cycles? Isn't that a bit low considering it'll only take you about 30mi/50km per charge cycle?

If they had some way of restoring the batteries without replacing/repurchasing the wheel, I'd be less concerned.

<comment><USER5> 1000 cycles of 30 miles is in average way more than an average commuter spends riding over a course of a year. We believe this distance is acceptable for a product with a one year warranty.

Of course the battery pack will also be easily replacable.

<comment><USER46> So your view is that the expected lifetime of the product is identical to your one year warranty? I think that's the sort of thing you're supposed to let your disappointed customers discover after they've purchased.

<comment><USER47> Interesting interpretation of that comment. I read it as "30,000 miles is WAY WAY WAY more than the average commuting distance in a year." Not "is equal to". Do you think the average bike commuter lives 50 miles from work?

<comment><USER36> Not unrealistic if you happen to 25 miles away (journey each way) but definitely not your "average commuter". (I used to cycle 20 miles each way, I knew someone that cycled 35 miles, but for different reasons than _just_ commuting).

</comment></comment></comment></comment></comment><comment><USER48> What I'm not clear here is whether this does regenerative braking, or only charges at home. If it's regenerative, it's awesome and I want it. I've actually wanted to do a DIY regenerative braking project for a bike for a long time (impracticality and net-loss-due-to-added-weight would not really bother me as long as it worked). Somehow, if it's only charged at home, I feel like it's kind of silly, like a way to make biking lazier.

Still, in any case it would be awesome in that it would make biking practical in hilly areas where it is otherwise a horrible mode of transportation.

<comment><USER49> From the Kickstarter page:

"The battery also charges when you're going above the desired speed, riding downhill or pedaling with the motor off."

</comment></comment><comment><USER50> I'm disappointed it doesn't (seem to) do regenerative braking... so elegant, don't waste that power, reuse it! But I don't think this is a big selling point, and you can always add it later.

I think your marketing approach is what will make or break it: "non-sweaty to dates/interviews" and the phone-charger could be the killer app (perhaps look into what segment actually experiences this pain most? Many of today's phones have adequate battery life for some people's usage; target those phones + usages that _don 't_).

<comment><USER51> Regenerative braking often doesn't pay off. Note that you don't need a whole lot of energy to put your bike into motion, while you need quite some energy to keep it moving due to friction. Putting in numbers, if you go 5m/s=18km/h=12mph, your kinetic energy is 100kg*(5 m/s)²/2 = 1.25kJ, which at 125W can power you for ten seconds.

You can cast longer than ten seconds in front of a red light in most situations. And keep in mind that for regenerative braking to work, you must walk twice through the whole efficiency chain, which is generator -> electronics -> battery -> battery -> electronics -> motor), giving you an efficiency of about 0.85^6=37%. So 3.7 seconds.

</comment></comment><comment><USER52> It only comes in 26 and 29 inches size. Good luck then selling to one of the biggest market of Bikes (and electrical bikes), Europe, where the common size for Urban bikes is 28 inches.

</comment><comment><USER36> Will this only work with single speed bikes? What about bikes with gears in the front and/or back, they will need to be converted to single speed I presume?

</comment><comment><USER53> I absolutely want one of these. They've thought of everything. As I went to pledge my money for it, I found that the starting pledge that actually gets me a wheel was $550 and that's all gone. So to get one will run me $590 and presumably more in retail. This is where "more accessible" as one of their goals falls short.

It looks great, but I'll have to pass at the price.

</comment><comment><USER54> Sweet product. But am I the only one who has noticed that the "locking" feature is an absolute joke? Esp. in NYC, where the most burly bike locks money can buy keep you a mere step ahead of only the least-committed thieves.

Also, can this thing run without a smartphone? If it's raining, you certainly don't want to keep your phone on the bars.

</comment><comment><USER55> I was trying to figure out if this same type of thing would be possible to build into a car tire. I haven't been able to figure out braking yet?

Is there any work being done to simple regen braking systems that could easily be added to cars?

</comment><comment><USER56> Will it come in black? 700c?

<comment><USER57> I'm pretty sure when they say "29 inch" they mean "700c". It's the same bead seat diameter.

</comment></comment><comment><USER58> I do hope this will work even if I don't have a smartphone.

It's ridiculous how a lot of mechanical things today are bound to the digital world when they don't need to be.

</comment><comment><USER59> This has been done before, not sure why it warrants a kickstarter.

The Copenhagen wheel has been around for around ~5 years and looks identical to this, sans the GPS.

[http://www.engadget.com/2009/12/16/mits-copenhagen-wheel- tur...](http://www.engadget.com/2009/12/16/mits-copenhagen-wheel-turns-your- bike-into-a-hybrid-personal-t/) [http://www.soullessmachine.com/2013/01/the- copenhagen-wheel-...](http://www.soullessmachine.com/2013/01/the-copenhagen- wheel-is-real-as-seen-in.html)

<comment><USER5> We're aware of the many similarities people will want to draw with Copenhagen Wheel but allow me to introduce some important differences as well:

1) Smart Wheel introduces a brand new electric motor that is thinner and lighter (and more efficient) than any other before it. Copenhagen Wheel uses regular rotary motor that's heavy and cumbersome, not to mention it's not a replaceable wheel - it comes together with the whole bicycle.

2) The GPS module might seems like the only thing that separates the Smart Wheel from the Copenhagen Wheel (it's not) but it's the difference of how they use this data that makes all the difference. Smart Wheel uses GPS data to learn about your cycling habits and routines and then suggests on how to improve them. This data can also be used to help improving the cycling experiences of other people. Copenhagen Wheel measures noise and air pollution levels and uses them for statistical purposes only.

3) Smart Wheel is opensource which means our users will be available to develop their own apps and other tools to find new innovations to using the Smart Wheel. We're already working closely with Pebble Watch and other similar devices are in the works, too.

4) Last but not least, despite being around for ~5 years, Copenhagen Wheel is still only a prototype with no sign of ever being available to the market. Smart Wheel is becoming available in May 2014.

<comment><USER36> _...not to mention it 's not a replaceable wheel - it comes together with the whole bicycle._

Are you sure about that? [http://senseable.mit.edu/copenhagenwheel/wheel.html](http://senseable.mit.edu/copenhagenwheel/wheel.html)

> The Copenhagen Wheel turns the bike you already own, quickly and easily into > an electric bike with regeneration and real-time environmental sensing > capabilities.

Albeit, the big caveat being point 4 you mention of course! :)

<comment><USER60> The copenhagen wheel looks pretty cool. Too bad nobody can buy it. I guess those copenhagen people can put whatever they want on their press release since they will probably never turn it into an actual product.

</comment></comment></comment></comment><comment><USER61> Will it be waterproof? ipx7? What about vibrations? The housing for a Di2 battery case are enormous compared to the battery it contains.

</comment><comment><USER62> This is the Copenhagen Wheel from Andy in Weeds!

</comment><comment> Ono-Sendai spelling mistake: "and it weights only 9 lbs (4 kg)"

</comment><comment><USER63> Unsprung mass

<comment><USER64> Many bikes don't have any suspension springs. What is your point?

<comment><USER12> Possibly that the device won't stand up well to the rigors of regular riding? Potholes, curbs, railroad tracks, stairs, etc.? With all those different batteries, if any particular solder connection fails say once a year on average, this would be totally unusable after a few months.

</comment></comment></comment><comment><USER65> Unless you're disabled, why do people want an electric bicycle? I figured most people cycle because they love cycling and the exercise of it. Including hills. Is this product meant to attract more automobilist?

<comment><USER66> Electric bicycles are pretty big in Japan - a lot of mothers and housewives use them to get around all the time as they don't tire you as much as normal bikes.

Also, there's a few bicycles these days with two childseats, so that's a lot of weight to cart around.

A bit of info here: [http://www.japantimes.co.jp/life/2008/08/17/travel/electric-...](http://www.japantimes.co.jp/life/2008/08/17/travel/electric- bikes-charge-the-market/)

<comment><USER67> Maybe in Tokyo, but I have never seen them in Sapporo. That must be why everyone is so fit :)</comment></comment></comment>


Months Before Reddit Purge, The_Donald Users Created a New Home - <AUTHOR> https://onezero.medium.com/months-before-reddit-purge-the-donald-users-created-a-new-home-a732f79e4f04 <comment><USER2> I've become a bit disillusioned by grassroots organising given how easy it seems to be to fake. This place claims to be self-funded, but I wonder. It's exactly the sort of thing a foreign adversary would fund just to cause trouble in the U.S.

I feel like the internet has caused a sort of problem of how easily the public can be pushed to vote against their own interests. It's a cheap way for foreign countries to "attack" a democracy without ever risking serious retaliation, and I haven't seen an answer to it. Or even corporations to protect their interests at the cost of having people vote against their own interests.

Off the top of my head I can think of two answers: walled garden(I think of this as the Chinese approach) and high education levels(I think of this as the Swiss approach, but I have no idea how effective it is).

Thoughts on how to solve this problem?</comment>


What.CD Nukes Data After Servers Seized - <AUTHOR> https://torrentfreak.com/what-cd-shuts-down-following-reported-raids-in-france-161117/ <comment><USER2> This war on sharing is quite insane.</comment>


Game SHENZHEN I/O: Build Circuits. Write Code. RTFM - <AUTHOR> http://store.steampowered.com/app/504210/ <comment><USER2> I must also recommend Human Resource Machine from Tomorrow corporation</comment>


How to Explain Bitcoin to Your Grandmother - <AUTHOR> http://suitpossum.blogspot.com/2013/04/how-to-explain-bitcoin-to-your.html <comment><USER2> Bitcoin is digital money, Grandma. Say that you want to send me money for my birthday, Instead of paying for postage and an envelope, and instead of going to the bank or ATM to cash a check, you just send it from your computer to my computer.

And it's a lot safer than using social security numbers and mailboxes and cash. You know how sometimes the mailman or the neighborhood kid will steal cash from an envelope? As long as you keep your computer secure, that wont happen with bitcoin</comment>


10 tips on not getting screwed by a client (from a developer) - <AUTHOR> https://medium.com/how-i-learned-ruby-rails/how-not-to-get-screwed-by-your-client-when-youre-contracting-21c95eef0c4a <comment><USER2> some sour grapes here.

I realize you feel jaded, but airing your business openly does not endear you to future clients.

Overall your tips are good.

About your estimates: ALWAYS estimate the time to deliver. As humans we tend to underestimate because in our heads we (generally) want to please people. So we give an underestimate, or a partial estimate.

I recommend this:

        * break the project down into logical phases
        * estimate the minimum time it would take if everything goes well
        * estimate the maximum time it would take if things go badly
        * add up the mins and the maxes
        * add a pad
        (what if I get sick for a couple of days,
        what if the customer isn't able to be contacted,
        etc)

Give the min and max estimate to the customer. They may end up going with someone else. But you don't get stuck with an impossible task either.

It also helps quantify the unknowns. When the customer looks at it and says "it may take between 1 hour and 2 weeks????" That is when you state that there are too many unknowns to give a more accurate estimate. Then guide them towards a path of more concrete understanding and tighter estimates.

Also, deliver in and bill in phases. Let your customer know they are able to walk away at any phase, but they will owe for each phase that will be accomplished.

Thus, the "scoping deliverables" phase may take 1-4 hours of BILLABLE work. But if they don't like what they see then they can walk away.</comment>


FBI Announces Post-Election Attack on Encryption - <AUTHOR> http://thedashtimes.com/2016/09/06/fbi-announces-post-election-attack-encryption/ <comment><USER2> This appears to be an extraordinarily misleading reframing of a story AP ran last week:

[http://bigstory.ap.org/article/7d57f576e3f74b6ca4cd3436fbebf...](http://bigstory.ap.org/article/7d57f576e3f74b6ca4cd3436fbebf160/comey- fbi-wants-adult-conversation-device-encryption)

In particular: Comey was _lamenting_ (albeit weakly) that the conversation had "dipped below public consciousness", and his plans where to return it there.

Heavily editorialized pieces can be fine when they do their own reporting. But "The Dash Times" doesn't seem to have done that; rather, they seem to be refocusing other pieces --- and not entirely honestly --- in order to generate rageviews.

(I am, of course, foursquare against key escrow).

<comment><USER3> That article seemed so suspect that I came and checked the comments.

<comment><USER4> There should be an app to blacklist people with misleading headlines.

</comment></comment></comment><comment><USER5> Any bets that the FBI has traded some discretion on the Clinton email scandal now for total support on surveillance and crypto when she gets in? Even if they haven't, if Clinton does get it they have a huge lever to hold over her if she is elected, and will likely become the FBI President. The republican nominee doesn't seem like much a civil liberties guy either.

The big winner of the U.S. presidential election will be police.

</comment><comment><USER6> "Back doors to encryption"? IIRC, Zimmerman and his Pretty Good Privacy (PGP) based on Rivest-Shamir-Adleman (RSA) public key encryption is open source without back doors.

And the RSA paper is no doubt still on the shelves of the libraries. And it is in various books, e.g., IIRC one by B. Schneier. IIRC, the main number theory is just Fermat's little theorem in even elementary books on number theory.

IIRC, breaking RSA is equivalent to being able to factor a large integer into a product of prime numbers. As soon as some mathematician finds how to do that quickly enough to be practical, likely we will hear about it via an Abel Prize of just the front page of the NYT. I haven't heard yet.

Comey: Good luck on getting your _back doors_ in DIY, roll your own, open source PGP RSA encryption! The open source part? That is much of why Zimmerman did his work.

<comment><USER7> > Comey: Good luck on getting your back doors in DIY, roll your own, open > source PGP RSA encryption!

He doesn't have to. He just has to compromise the main commercial systems, which 99.99% of the world population uses.

At that point, the very fact that you're one of 0.01% of the population using decent crypto makes you a target.

</comment></comment><comment><USER8> > The wait to address encryption until 2017 comes because "next year we can > have an adult conversation in this country" about it.

Which means: we won't have a conversation about it, and simply start issuing warrants and orders to companies demanding they comply anyway. If you want to challenge it, here's a Kafkaesque process for you.</comment>


Facebook Reminds Publishers That It Is in Complete Control of Their Livelihood - <AUTHOR> http://babylonbee.com/news/facebook-sends-warm-reminder-publishers-complete-control-livelihood/ <comment><USER2> For some context, Babylon Bee is a satire site, best described as the Onion for Evangelicals.

The publisher of the Bee has tweeted a warning from Facebook, threatening to throttle traffic to the site, because Snopes.com says obvious satire isn't true.

[https://twitter.com/Adam4d/status/969405110324523008](https://twitter.com/Adam4d/status/969405110324523008)

</comment><comment><USER3> Thank god this is Satire.

But that said, I've worked on/at many (many, many, many) projects/companies that are dependent on someone else's ecosystem to be viable. Sometimes it's about traffic. Sometimes it's about behavior (e.g. they change an API without giving you a heads up). There's money to be made in those ecosystems and often times the owners of that ecosystem care a lot about their partner network...until they don't.

Worst of all, they _really_ aren't beholden to keeping your lights on and you should realize that when entering a (often implicit) relationship with them. It's just the way it works.

<comment><USER4> > Thank god this is Satire.

The best satire has a grain of truth to it.

See also:

[http://www.businessinsider.com/littlethings-online- publisher...](http://www.businessinsider.com/littlethings-online-publisher- shuts-down-and-blames-facebook-algorithm-2018-2)

</comment></comment><comment><USER5> On the plus side, Babylon Bee has at least _one_ new reader because of this. The CNN story was a little lame, but they grabbed me with "Calvinist Dog Corrects Owner: 'No One Is A Good Boy'".

On the downside, really, Facebook? You sending warnings to The Onion, too?

</comment><comment><USER6> I worry that next Amazon is going to start denying affiliate links to political opponents and many blogs will be faced with a desperate existential threat. The politics of Google, Facebook, Amazon, and Twitter are so narrow and similar and yet they by themselves can choke any video maker or writer to death.

<comment><USER7> The social media bigs aren't attacking political opponents, they're attacking hate groups.

If your political ideology is hate, then you should expect to be increasingly ostracized and driven away into the shadows.

<comment><USER8> > The social media bigs aren't attacking political opponents, they're > attacking hate groups.

Who defines what is a hate group? So if saudi arabia labels atheist groups as hate groups, should social media ban atheists? If china labels democracy groups as hate groups, should social media ban democracy groups?

[https://news.ycombinator.com/item?id=16506887](https://news.ycombinator.com/item?id=16506887)

What about political groups who hate trump? Should they be banned from social media? What about socialists who hate capitalism? When russia labeled lgbt groups as hate groups, you agree with them banning lgbt groups from social media?

> If your political ideology is hate, then you should expect to be > increasingly ostracized and driven away into the shadows.

Wouldn't you want to shine the light on hate groups? Isn't that the last thing you want to do? To push hate groups into the shadows where they can fester?

What happened to liberalism? It's something every college student learned about when I went to school. Free speech and why it is fundamental to defend "hate speech" or ideology/speech you find offensive or disgusting in order to protect free speech. It's philosophy 101. Is logic and philosophy no longer taught in schools anymore? This is basic stuff.

<comment><USER9> > Wouldn't you want to shine the light on hate groups? Isn't that the last > thing you want to do? To push hate groups into the shadows where they can > fester?

thank you for saying this, as it seems to be often forgotten these days. you want "bad" sites to be out in the open like trash collectors so law enforcement can use them as honeypots.

</comment></comment></comment></comment><comment><USER10> "When done right, satire is virtually indistinguishable from truth" \- erikig

</comment><comment><USER11> Satire

<comment><USER12> [https://youtu.be/ntICHMV-WMA](https://youtu.be/ntICHMV-WMA)</comment></comment>


Rats on vacation - <AUTHOR> http://www.jasonmendelson.com/wp/archives/2011/01/vrbos-questionable-review-policy-shame-on-vrbo.php

<comment><USER2> Raise your hand if you've used VRBO.com, brainstomed on how you could build-a- better-version, and promptly chucked it into the pile of other projects collecting dust on your hard drive.</comment>


Hermitage: Testing the "I" in ACID - <AUTHOR> http://martin.kleppmann.com/2014/11/25/hermitage-testing-the-i-in-acid.html <comment><USER2> A key concept here is that real databases have transactions, there's some concurrency between transactions, and that in the more efficient modes, transactions can deadlock, fail, and be rolled back.

In MySQL, a statement within a transaction can return "ERROR 1213 (40001): Deadlock found when trying to get lock; try restarting transaction". This can be forced by the following sequence of events. (This assumes an InnoDB table in Repeatable Read mode.)

        Process A does a START TRANSACTION.
        Process B does a START TRANSACTION.
        Process A does a SELECT which reads row X.
        Process B does a SELECT which reads row X.
        Process A does an UPDATE which writes row X.
        Process B does an UPDATE which writes row X.  - Deadlock error.

Process B gets a report that the transaction failed, and everything done in B's transaction is rolled back. The entire transaction has to be retried. Transactions are atomic if they commit, but can fail in a deadlock situation.

A SELECT does lock parts of the database. "Repeatable read" means that if you read the same data item twice within the same transaction, you get the same result, even if someone else is changing the data. This requires locking. If you try to update the data in conflict with another process, you'll get a deadlock error, but if you COMMIT a select-only transaction, you won't. You do have to COMMIT select-only transactions, or you'll fill memory with locks and stall out updates.

Ref: [http://dev.mysql.com/doc/refman/5.1/en/innodb-lock- modes.htm...](http://dev.mysql.com/doc/refman/5.1/en/innodb-lock-modes.html)

<comment><AUTHOR> What you describe is the Lost Update (P4) anomaly. It's in the test suite: [https://github.com/ept/hermitage/blob/master/mysql.md#lost-u...](https://github.com/ept/hermitage/blob/master/mysql.md#lost- update-p4)

MySQL in repeatable read mode actually doesn't prevent this anomaly (it doesn't deadlock). You need to be in serializable mode to get the deadlock.

<comment><USER2> You're right. MS SQL Server does reject that on repeatable read, but MySQL does not.

Should MySQL have the same behavior? It detects the problem and blocks, but then does the update when the other transaction finishes, losing one update. I tried this for different values of "value" in each process, and it still fails. (The test sets the same value from each process, so you can't see who wins the race or if the database treated the update as a no-change transaction.)

<comment><AUTHOR> I don't know what behavior it "should" have. IMHO there's scope for different databases to implement things differently — otherwise there would be no room for innovation. The important thing is just that we understand precisely which guarantees we're getting and which we're not, so that we can write applications which behave correctly under a given isolation level. And that's the whole point of Hermitage.

<comment><USER2> That's not "implementing differently" or "innovation". That's very differing semantics for the same named mode of operation.

Since you have a test suite, try getting that to the SQL committee for the next revision of the standard.

</comment></comment></comment></comment></comment><comment><USER3> "...able withdraw more money than they had in their account...Most so-called ACID databases — for example Postgres, MySQL, Oracle or MS SQL Server — would not have prevented this race condition in their default configuration."

The author didn't really show that this was true. He obviously understands isolation well, so I would tend to believe him, but it would be nice to see an example.

In a simple case (not sure that it matches the exchange's case), postgresql in any configuration will prevent this problem:

        CREATE TABLE account(
          id int8,
          balance numeric, check (balance >= 0)
        );

No matter what concurrent activity you have going on, it's impossible (as far as I know) to end up seeing a balance less than 0. That's actually true in _any_ isolation mode that postgres supports (read committed, snapshot isolation, and truly serializable).

Does someone have a counterexample, or more details about the case at the exchange that would not be solved by postgres?

I'd also like to point out that the postgres's implementation of true serializability performs quite well and there isn't much of a cost to using it over snapshot isolation.

<comment><USER4> The key phrase is the line quoted is "default configuration". According to PostgreSQL docs, the default isolation level is "READ COMMITTED".

Your example check constraint indeed appears to work as advertised. Trying

        UPDATE account SET balance = -1.00 where id = 1;

gives an ERROR message re: new row for relation "account" violates check constraint ...

Still it's not clear exactly what the author sees re: where postgres fails. I'll have to read the article again. With any luck someone more knowledgeable than I am will shed light on the question.

<comment><USER5> In short: prior to version 9.2, postgres's "serializable" level still allowed some transaction patterns that would be rejected by a strictly serial execution. Later versions prevent it.

This paper: [http://dl.acm.org/citation.cfm?id=1376690](http://dl.acm.org/citation.cfm?id=1376690) outlines the general issue. This paper discusses Postgres's solution: [http://drkp.net/papers/ssi-vldb12.pdf](http://drkp.net/papers/ssi-vldb12.pdf)

</comment></comment></comment><comment><USER6> Very cool - would love to see tests of FoundationDB!

FYI I'm an engineer at FDB, happy to help.

<comment><AUTHOR> Awesome, I'd love a pull request! I've been looking at FoundationDB, but haven't had time to test it. Porting the tests to another database is (hopefully) a mostly mechanical exercise.

<comment><USER7> Here's one way you could run this test vs. FoundationDB:

[https://gist.github.com/MMcM/f00108c5943e919f73d1](https://gist.github.com/MMcM/f00108c5943e919f73d1)

</comment></comment></comment><comment><USER8> Interesting! One minor quibble:

> The idea of isolation is that we want our database to be able to process > several transactions at the same time (otherwise it would be terribly slow)

Not necessarily true. Things like Prevayler and LMAX provide isolation by processing transactions one at a time, and they're very fast. They manage this by keeping everything relevant hot in RAM. LMAX, for example, can do 6 million TPS for a financial trading platform. You can read Martin Fowler writing about LMAX here: [http://martinfowler.com/articles/lmax.html](http://martinfowler.com/articles/lmax.html)

</comment><comment> a-priori In case it's interesting to people, here's a blog post I made earlier this year on the topic of what exactly transaction isolation means:

[http://www.michaelmelanson.net/2014/03/20/transactions/](http://www.michaelmelanson.net/2014/03/20/transactions/)

<comment><AUTHOR> Nice example of a bug caused by weak isolation. FWIW, Postgres has an interesting implementation of "serializable" which takes far fewer locks than MySQL, so may give you better performance while retaining the same isolation level.

<comment><USER9> Yes: it is the relatively new approach by Cahill et al in 2008, known as SSI: [https://courses.cs.washington.edu/courses/cse444/08au/544M/R...](https://courses.cs.washington.edu/courses/cse444/08au/544M/READING- LIST/fekete-sigmod2008.pdf)

Which, as far as production-common database implementations go, is lightspeed for implementing new academic work (9.1, the first version with the feature, was released in 2011).

</comment></comment></comment><comment><USER10> I wonder what approach you could use for global safe timestamp snapshot transaction checking.

[https://static.googleusercontent.com/media/research.google.c...](https://static.googleusercontent.com/media/research.google.com/en/us/pubs/archive/41344.pdf)

</comment><comment><USER3> I strongly rebut the following claim, which is central to the article:

"Internet commenters, in their infinite wisdom, were quick to point out that if you're dealing with money, you had better use an ACID database. But there was a major flaw in their argument. Most so-called ACID databases — for example Postgres, MySQL, Oracle or MS SQL Server — would not have prevented this race condition in their default configuration."

I hesitate because I don't really understand the details of the situation the exchange faced. But, going by the linked references here:

[https://bitcointalk.org/index.php?topic=499580](https://bitcointalk.org/index.php?topic=499580) [http://www.reddit.com/r/Bitcoin/comments/1wtbiu/how_i_stole_...](http://www.reddit.com/r/Bitcoin/comments/1wtbiu/how_i_stole_roughly_100_btc_from_an_exchange_and/)

it appears that the pattern in question, if translated very unnaturally to SQL, is something like:

        CREATE TABLE account(id int8, balance numeric);
        ...
        BEGIN;
        SELECT balance FROM account WHERE id = 123;
        -- application sees 100, subtracts 90, sees that
        -- it's still positive and does:
        UPDATE account SET balance = 10 WHERE id = 123;
        COMMIT;

Technically speaking, running that in postgres in the default configuration (read committed) is prone to a race, and you'd need to use repeatable read or serializable mode to protect you.

But that's ridiculous. Anyone using SQL would instead do:

        CREATE TABLE account(id int8, balance numeric, check(balance >= 0));
        ...
        UPDATE account SET balance = balance - 90 WHERE id = 123;

And that is _not_ prone to a race. Try it in any version of postgres, in any configuration. You can't get double withdrawls (where only one takes effect), and you can't get it to go below zero.

So, the author is _technically_ right: (a) if you translate the NoSQL-isms into SQL in an unnatural way; _and_ (b) don't bother to use SERIALIZABLE mode, which costs very little in most situations.

I agree with the author that isolation is tricky, and developers should not be expected to understand the nuances. And I applaud the development of a testing framework to really understand the various kinds of isolation and how they apply to different products. But the example is a bad one, because it actually does work just fine in postgres, and probably many other systems.

<comment><AUTHOR> Your first ("very unnatural") example is what I had in mind. And since read committed is the default isolation level in most RDBMS, it is prone to the lost update anomaly. (In MySQL, repeatable read is the default, but its implementation of repeatable read doesn't prevent lost updates.) Note I did point out that I'm referring to the default configuration, not the strongest supported isolation level.

Although your second example is probably what a human would write, an ORM framework would very likely generate a transaction looking like your first example.

Another example would be inserting a transaction into a table, and summing the transactions in the account in order to calculate the account balance. Making that safe requires preventing phantom reads, which means requiring serializability.

You say serializable costs very little in most situations. I can't claim to know what most situations are like, but all I know is that I've seen many people who have tried serializable and found it too slow for them. User a-priori gives an example elsewhere on this thread: [http://www.michaelmelanson.net/2014/03/20/transactions/](http://www.michaelmelanson.net/2014/03/20/transactions/)

My point is that weak isolation is very subtle, easy to get wrong, and you don't know that you got it wrong until it's too late. We need better understanding and better tools so that concurrency is less easy to screw up.

<comment><USER3> Your example of poor SERIALIZABLE performance is from a MySQL user. Have you tried SERIALIZABLE in PostgreSQL? The implementation is based on fairly recent research, and performs quite well for a lot more use cases.

And the point about ORMs is valid, but still not enough to back up your unqualified claim that using postgres would not have solve the problem. It _might_ not have, but postgres offers a lot of tools to solve this problem (we didn't even discuss SELECT ... FOR UPDATE), and even inexperienced users are at least _more likely_ to have stumbled into one of those solutions.

I very much agree that isolation issues are subtle traps for many users, even in SQL. I would like to see SERIALIZABLE become more common, and eventually the default, in postgres. I also like the fact that you're writing real tools to check up on these in a formal way.

But please be a little careful when making statements like that, because it can turn people away from the systems most likely to help them.

</comment></comment></comment><comment><USER11> There's been so much drugs articles in HN lately that I literally expected some LSD story here...

</comment><comment><USER12> Nice ! Very interesting.

</comment><comment><USER13> An interesting read.</comment>


Australian Alps Walking Track - <AUTHOR> https://markoates.exposure.co/australian-alps-walking-track <comment> saiya-jin Glad to see even down there they use modern low-tech ski touring bindings. Never understood why people would take big heavy ones (apart from price, but basic Dynafit low tech ones that guys have are actually among the best and widely used in Europe).

Have been on Kosciuszko but it was cca May, reminded me of some lower mountain ranges back home in central Europe. Met a guy finishing his 2 week hike up there, in fierce winds and clouds, very nice encounter.

It looked like they get their share of snow up there, but these pictures bring much more - never thought you can actually die in avalanche in Australia! Couldn't find any victims by quick googling so hopefully noone yet.

Good to remind me to start packing for the weekend snow camping in similar conditions, forecasts say up to 60cm of fresh snow so better be careful.

<comment><AUTHOR> I use the similar AT bindings in Australia for all types of skiing. Pattern base skis work very well in Australian conditions too.

There is occasional avalanche incidents in Australia and sadly there were a couple of deaths on Mt Bogong a few years ago. Since then there has been a lot more awareness of the danger here.

</comment></comment><comment><USER2> For anyone in the same boat with me - these are Austr-AL-ian Alps.

<comment><USER3> I didn't even know they existed. [https://en.wikipedia.org/wiki/Australian_Alps](https://en.wikipedia.org/wiki/Australian_Alps)

<comment><USER4> They are quintessentially Australian. Barren, dry, low (Alps is a very generous description), spread out.

A few years ago very hot dry and windy conditions created by north westerly desert air precipitated major bush fires ripping through the area, killing a few people. Fire fighting in these area is very hard, so they were essentially unstoppable.

They were stopped though - by a snow dump from an Antarctic blizzard coming in from the south.

</comment></comment></comment><comment><USER5> Wow I knew there was a bit of snow in Australia but I didn't expect that! Definitely on my list to visit one day.

Calling them "Alps" is a stretch though, an upward stretch.

<comment><USER6> As a Swiss, I'd say that the Australians are grading their mountains on a bit of a curve there.

But other than altitude, this seems to be pretty serious wilderness.

<comment><USER7> Don't worry, I'm Australian and I had to look at the wikipedia page to find out what they were talking about. We normally call the area the Victorian High Country, a far more accurate description.

</comment></comment></comment><comment><USER8> Not something I would expect to be an Australian landscape: [https://markoates.exposure.co/australian-alps-walking- track/...](https://markoates.exposure.co/australian-alps-walking- track/photos/5695892)

<comment><USER9> People forget Australia's the size of the continental US, with basically the same sort of climate and ecosystem variance as you'd see between Maine and Florida.

<comment><USER10> The parent links to a snowy mountain ridge. The tallest mountain in Australia is 7,300 feet (2,200 m), which is lower than foothills of the Rocky Mountains for a thousand-mile stretch. Snowy mountain vistas really are much rarer in Australia than the US, despite the similar land area.

I'd also guess that, due to the extreme arid interior, Australia has less climate and ecological variation overall than the continental US, but I don't know how to quantify that to check.

<comment><USER9> If you're going "variation per square mile", the Outback is gonna throw things way off. Travel from Darwin to Hobart - especially in the winter - and you'll get quite a bit of difference in climate, wildlife, views etc.

The Adirondacks in the US get plenty of snow, incidentally, only being in the 4000s of feet. Height isn't the only parameter. I learned to ski at the "Big D" at Mt. Hotham. :-D

<comment><USER10> Hobart as in Tazmania, more than 2,000 miles away from Darwin? I'm willing to bet I can pick a 2k-mile straight line through the continental US that has more variation, but we would need a way to quantify it.

</comment></comment></comment></comment></comment><comment><USER11> I am half Swiss, half Australian and am always amused that we call what are glorified hills, "Alps".

That's[1] not an Alp, that's[2] an Alp... [3]

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

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

[3] [https://youtu.be/WWl8EbNN8NM](https://youtu.be/WWl8EbNN8NM)

<comment><USER9> Yeah, my parents took me up Mount Kosciuszko as a kid in a stroller. It's a little bump on a plateau.

Australia has more mountain-y mountains, of course, but nothing like Switzerland.

My favorites are the Hazards, down in Tasmania. They ([https://www.flickr.com/photos/ceejayoz/44492848854/](https://www.flickr.com/photos/ceejayoz/44492848854/)) and the surrounding Freycinet National Park are absolutely stunning.

</comment></comment><comment><USER12> Interestingly, there are flush toilets and septic systems installed along the entire length of the walking track.

<comment><USER13> Source? I doubt they're flush toilets; many national parks in Australia have composting toilets though (I haven't walked these particular areas for a long time). The remoteness and freezing conditions mean plumbing is just too prone to failure.

<comment><USER12> There are quite comfortable warm-seated Western flush toilets roughly every 10 to 15 meters along the entire trail. These are powered by wind generators, solar panels, and Australian poop-eating mountain gnomes stationed approximately every 1500 meters or so. As you say, it has been some time since you have walked the trail.</comment></comment></comment>


How Antarctic bases went from wooden huts to sci-fi chic - <AUTHOR> http://www.bbc.com/news/magazine-38574003 <comment><USER2> It's a daydream of mine to work in Antarctica for a season. I don't really know how it works and I doubt it's something I could do, I'm not a scientist. Seems like it would be an awesome experience though.

<comment><USER3> > Seems like it would be an awesome experience though.

Unless you're there doing research that you enjoy doing, I can tell you that it will not be an awesome experience. For a few days, OK, but beyond that, you probably will be bored to death.

I once spent 30 days in the middle of nowhere doing research. Just a few guys, no females.

When we got back to civilization, everything looked super colorful. The green leaves of plants I first saw, and it remained like that for a few days, after we got back looked absolutely beautiful. I thought I'd never seen green colors that bright.

And the sight of women, omg!

<comment><USER4> Even if there are members of whatever sex you're interested in, I think that there is a general rule (official or unofficial) against getting involved (romantically/sexually) with others when you're in that sort of environment.

<comment><USER5> Antarctic Winterer here. Hahahahahaha! Erm, yeah, suuuuuuuure.

<comment><USER4> I remember there being an Reddit AMA from someone that was going to winter in Antarctica and that's where I got that from. So maybe that's the 'official word' or people doing different jobs have different amounts of care for that "rule." I dunno. It seemed to make sense to me that getting involved with each other could have fallout when it comes to getting actual things done if there are hard feelings, etc.

</comment></comment></comment></comment></comment><comment><USER6> This tour of Amundsen-Scott Station makes it seem like they're not "roughing it" so much anymore. Sure the sun may not set, pull the blind. Plenty of indoor light for the long nights, as well. Too cold to go outside? Go do a myriad of indoor activities with a whole contingent of other people or get away in the vast indoor spaces.

Great walk-through, 30 minutes flew by in interesting fashion.

[https://www.youtube.com/watch?v=P5lQ9DCXIbs](https://www.youtube.com/watch?v=P5lQ9DCXIbs)

<comment><USER7> Herzog's Encounters at the End of the World is also amazing. Looks like they have the whole thing on youtube.

[https://www.youtube.com/watch?v=7edsEUQB-J8](https://www.youtube.com/watch?v=7edsEUQB-J8)

</comment></comment><comment><USER8> It says McMurdo was powered by a nuclear reactor for 10 years (ending in 1972). Anybody know why they got rid of it?

Edit: Wikipedia to the rescue: [https://en.wikipedia.org/wiki/McMurdo_Station#Nuclear_power_...](https://en.wikipedia.org/wiki/McMurdo_Station#Nuclear_power_1962.E2.80.931972) "As a result of continuing safety issues (hairline cracks in the reactor and water leaks), the U.S. Navy Nuclear Power Program decommissioned the plant in 1972."

Still seems cheaper to run another better one than bringing in 8 million gallons of fuel every year?

<comment><USER9> There were other issues as well.

Decommissioning[1]

With a total of 438 malfunctions during its operational lifetime from 1964 to 1972, the reactor at McMurdo proved to be an unreliable source of power generation, available only 72% of the time. Because of this, in May of 1972, it was determined by an independent assessment from the Bechtel Corporation that the PM-3A was not cost effective and that replacement with modern diesel- electric generators would require less staff and would also be more reliable.

1\. [http://large.stanford.edu/courses/2014/ph241/reid2/](http://large.stanford.edu/courses/2014/ph241/reid2/)

<comment><USER10> It's really a shame there's so little innovation going on for these sorts of devices. There's nothing inherent about a nuclear device that will make in unreliable.

<comment><USER11> Eh, I'd take a mass produced object over a hand made version any day. Even more important if reliability is an issue.

Ferraris are nice and all, but a boring old camery will get you where you need to go for hundreds of thousands of miles.

It makes a lot of sense to me to just use what hospitals and data centers and military bases use. Also, if one breaks, you can probably use it for parts for the rest.

<comment><USER12> That ideas was actually proposed to revive nuclear reactors: instead of building them on site, come up with some energy-generating components to be mass produced in a central factory and shipped out.

(You can make those parts inert and safe to handle. Even the fuel rods of current reactors are safe to touch before they are spent.)

<comment><USER13> > Even the fuel rods of current reactors are safe to touch before they are > spent

What? Fuel rods consist of uranium, which alpha-decays into thorium (a sheet of paper is enough to shield the alpha particles), but the next decay step is beta-decay to thorium, and that needs more shielding. No way one can touch a fuel rod without getting a load of radiation.

<comment><USER11> Yeah, maybe there's some other model, but there would be no reason for a Spent Fuel Pool [1] if you could handle the things.

There's also an interesting anecdote about spent fuel here [2]. You can get pretty close, if it's under water... but it gets very dangerous very fast.

[1] [https://en.wikipedia.org/wiki/Spent_fuel_pool](https://en.wikipedia.org/wiki/Spent_fuel_pool) [2] [https://what-if.xkcd.com/29/](https://what-if.xkcd.com/29/)

<comment><USER12> Spent fuel is dangerous to handle. That's why I specifically mentioned the unspent fuel.

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER14> I very much like the German station which keeps stepping up on top of the packed snow. Buildings as really very slow vehicles seems a particularly successful way to build in an environment with a high degree of uncertainty.

<comment><USER15> Coincidentally, a couple of weeks ago I visited a talk by Dr. Lochte from the Alfred-Wegener Institute that runs the station.

Interesting tidbit: The ice shelf it stands on rest upon the open sea, so for legal purposes, it's a ship ;)

</comment></comment><comment><USER16> Maciej has a great post about his visit to McMurdo: [http://idlewords.com/2016/05/shuffleboard_at_mcmurdo.htm](http://idlewords.com/2016/05/shuffleboard_at_mcmurdo.htm)

<comment><USER17> I loved this footnote from that one:

[http://idlewords.com/2016/05/shuffleboard_at_mcmurdo.htm#ped...](http://idlewords.com/2016/05/shuffleboard_at_mcmurdo.htm#pedantic)

</comment></comment><comment><USER18> The plans for the future of McMurdo ( [https://www.usap.gov/news/documents/McMurdoMasterPlan_2.1.pd...](https://www.usap.gov/news/documents/McMurdoMasterPlan_2.1.pdf) ) are quite exciting, but unfortunately, if it comes to fruition, it means less science for some number of seasons as the construction project happens.

I'm sure there are vastly more experienced folks here, but I was just McMurdo for a ~month in November-December. I've also spent some time at Summit Station in Greenland, which is a much smaller (but newer! with some buildings on stilts!) station.

<comment><USER19> Are the building stilts for some kind of insulation from the ice or for some other reason?

<comment><USER20> They talk about this near the end of the article: Snow blows all over the place, and if you build a structure on the ground, it will eventually be enveloped with snow. These stilts help prevent that.

</comment></comment></comment><comment><USER21> For those wanting to read about McMurdo, Big Dead Place [http://feralhouse.com/big-dead-place/](http://feralhouse.com/big-dead-place/) is the best book to read. Apparently it was due to be made into a TV series....

<comment><USER22> A documentary that seems like it was made from that book is "Antarctica: A Year on Ice." It was on Netflix but isn't any longer.

[http://www.imdb.com/title/tt2361700/](http://www.imdb.com/title/tt2361700/)

</comment></comment><comment><USER23> "For years afterwards...nothing much fancier than wooden huts went up on the white continent."

I think that in 1903, that wooden hut would be thought of as pretty fancy and state of the art. Only in retrospect 114 years later would it seem quaint.

<comment><USER24> The Eiffel Tower was built for the 1889 World's Fair. A wooden hut was not state of the art in 1903.

<comment><USER23> For what _could_ be built in Antarctica in 1903, I bet it was state of the art. In 2015, the Shanghai Tower was built...it doesn't make what they're building in Antarctica today any less state of the art just because it's relatively less ambitious in scale.

</comment></comment></comment><comment><USER25> I remember reading a lot about staying during the winter in Antarctica from this: [http://www.funraniumlabs.com/category/antarctica/](http://www.funraniumlabs.com/category/antarctica/)

Alcohol, lot of alcohol.

</comment><comment><USER26> This guy's site has a great history of the pole station: [http://www.southpolestation.com/trivia/trivia.html](http://www.southpolestation.com/trivia/trivia.html)

</comment><comment><USER27> I can't help but think about Helix' snow station here.

</comment><comment><USER28> Interesting to see the architectural race kicked off by India's Bharati. The race is to find mineral deposits as Antarctic is the new Africa.

</comment><comment><USER29> Wouldn't these structures be more energy efficient via less surface area if they built them higher?

<comment><USER30> I wondered about that as well. There is one example of a pair of cylindrical buildings, which seems pretty efficient. Maybe the use of good insulating materials reduces the trade-off, and with more surface area you get more rooms with windows.

</comment></comment><comment><USER31> I want to stay for a winter _so_ bad.</comment>


Ask HN: Three jobs in eight months...am I justified? - <AUTHOR> Long story short, I'm a statistician in the automotive industry who has had a colorful history over the past eight months. Here's a brief review.
a. Laid off from job b. Started two businesses c. Got an interesting job offer and accepted it. One month later, I realized that I couldn't juggle all three things. Furthermore, my venture was doing fairly well d. Fast forward five months, and I'd poured tens of thousands into my two businesses and things had turned for the worse. e. I accepted the first job offer I had and moved to another state. f. Another company offered me a job one month into job two, and it seemed better, so I accepted. g. Have been at job three for one month. It's acceptable, even though they mis-characterized the work responsibilities and I don't think I'll get much out of this job. h. Have sent out my resume just to test the waters and have had some great responses.
For the future, I won't be putting the two one month stints on my resume. But if a company does a background check and finds the job hopping, how do I explain it?
So here is my justification for my behavior. I have a degenerative neurological disorder that impact my walking, stability, and will eventually leave me bed ridden. I have about 6 to 10 years until that happens. Due to these circumstances, I have little patience for staying at jobs that I don't feel are benefiting me or are as advertised. Look, I'm trying to cram a fourty year career into about fifteen years.  If a company isn't delivering, I'm going to jump ship. So....am I justified? If I'm not justified, what can I do to counter-act my job hopping.
Also, before to these eight months, I've had two stints at companies for two + years. I'd also note that if I found a good company, I'd stay for as long as I'm able  to <comment><USER2> I would avoid talking about your disorder if I were you; you may feel like it explains your actions, but no-one else gives a shit. I would just say you felt like the role was falsely advertised to you, and be prepared to explain the specifics, people will want to know how big a difference there was that made you leave, especially considering the fact that some amount of drift is expected.

Most importantly though, I would ask if you've tried to talk to your management about the discrepancy and your dissatisfaction. If you haven't, this seems like a problem to me. No-one wants to work with someone whose first instinct to be to walk away rather than try and work things out.

Beyond anything else, I feel like the lesson here is to make sure that you actually want the job you are accepting. Be very specific in what you expect; if you figure out there is a discrepancy you can walk away before you both get burned.

Personally, I've started having bringing up what I want much earlier in the interview process, rather than getting to the end of the whole process to find there is a mismatch between what I want and the company wants so that we don't waste each others' time.

</comment><comment><USER3> I feel you are justified, but I also suspect you could do yourself a favour by remembering that the interview process is a two-way street.

Are you asking enough, or good enough questions before accepting offers? For the right company be up-front about your reason for leaving, as long as both parties know the role is sufficiently rewarding I doubt you would be classed a flight risk.

</comment><comment><USER4> I just wanted to make sure this didn't sink into oblivion with no comment. I suspect that few of us will feel qualified to comment on your situation. I know I don't. I hope you can find someone who can help you talk your way through this.</comment>


Taking Up Animation as a Hobby - <AUTHOR> http://yosefk.com/blog/a-better-future-animated-post.html <comment><USER2> Quarantine Time has really made me value a few extra hours a day more, I never realized how much that affected my average day to day before then.

<comment><USER3> I've found during quarantine that the elimination of my commute and the ability to do chores during time I'd otherwise spend on a mid-work mental break has really helped me feel happier with the work I'm doing. Laundry and dishes and home maintenance don't feel like I'm digging into my free time. If I need to get away from my desk, I take my dog on a walk.

</comment></comment><comment><USER4> I love it. As someone who is putting more and more energy into making music this resonates with me strongly. I need to figure out a way to get to part time work.

One piece of advice about creative hobbies - set it up so you have a feedback loop. Maybe I'm just an insecure jerk, but I really found that getting feedback and encouragement motivates me to keep trying. Oh, and try to get that feedback from your peers, not friends and family. They mean well but you'll never get honest criticism.

<comment><USER5> I think it depends on your family.

Once when I was a child, my father found a stack of my drawings and proceeded to tell me which ones were the weakest and what was wrong with each of them. Another time, I can remember showing my sister a drawing I'd made that I was extremely proud of. Her response? "The arms are too long".

Funnily enough, I ended up devoting years of my life to artistic pursuits.

</comment></comment><comment><USER6> If you are interested in learning animation as a hobby, and would like a community to contribute to and learn from - consider joining Anim8 ([https://anim8.io](https://anim8.io)).

We are the largest group of hobby animators on the web, and host collaborations, competitions, etc. on an ongoing basis.

We use some of our funding to build free educational content as well which can be found at ([https://blog.anim8.io](https://blog.anim8.io)).

We also have a great Discord full of beginner animators as well as pros

</comment><comment><USER7> Personal value systems.

Today's god money is, in my humble opinion, such a poor substitute for the other wealths of this planet, time being possibly the most valuable thing we have.

It is possible, and, for me, completely logical to wish to find some way out of the modern work trap. The HN crowd being startup minded is focused on one way: make a bunch of money in order to trade it for time somewhere down the road. A risky path, to say the least.

There is another path -- To figure out a way to provide for your needs without a dependence on state backed currency. This entials an entirely different line of work, but one that can be immensely beneficial, both to sanity and to resilancy. If you had your core needs of housing, food, and transportation met, would you be able to curtail your manufactured "need" for consumerism and enter a life of spending the rest of your life figuring out what to do with your time, hopefully leaving a postive legacy?

</comment><comment><USER8> I really like how the article phrases money as options. It's really like a heart and mind question, and that I think is the biggest chasm to cross. At the end are we happier if we follow our hearts?

<comment><USER9> >At the end are we happier if we follow our hearts?

Yes. Absolutely. I wholeheartedly agree with the author's conclusion.

Money is not the only thing which provides options; time does too. As you age, you tend to have fewer and fewer options.

People usually think that freeing up time at the expense of a cushy salary is an enormous opportunity cost.

But it is much rarer for us to think of freeing up money at the expense of time as a huge opportunity cost, even among people who make enough that they don't need to work 2000+ hours every year.

I wonder why. After all, how often do we say things like "time is money" to each other?

<comment><USER10> "Time is money" is far from the truth. You can get money back, but time can't be replenished. For me at least, time is much more valuable than money.

But then again, most middle-aged people have a family that needs to be feed etc. You simply don't have that many options. Best thing that can happen thus is that your passion becomes profitable.

<comment><USER11> > For me at least, time is much more valuable than money

yes, but 'for you' being the operative word. Your time is worthless to me. Your time, if you used it to do something _I_ wanted done, would be worth something to me. Therefore, it is true for people to say time is money.

</comment></comment></comment></comment><comment><USER12> I love the animation you used to get in say Mythbusters - where it would explain fairly complex "what's going on" with what looked like quick and simple animation.

I don't want to learn that cos it's my love but because it looks a useful tool.

But ... what animation tools did they use? How hard is it actually? how does one start at that simple levels?

<comment><USER5> The software was most likely Adobe After Effects. Like anything worth learning, it's a little bit challenging. Fortunately, there are many tutorials on YouTube to help you. I'd suggest you start with the basics (moving an object around the screen) and go from there.

</comment></comment><comment><USER13> Yossi's C++ FQA (rebuttals to each of the C++ FAQ) is worth checking out if you enjoyed this. His Twitter is pretty fun too.

</comment><comment><USER14> This is from 2014. I wonder, how much did he move in the last 6 years?

</comment><comment><USER15> Blew past my expectations. Excellent (first) animation.

</comment><comment><USER16> (2014)

</comment><comment><USER17> Beautiful

</comment><comment><USER18> No Money?

Yossi Kreinin

Vice President and General Manager, Platform & Application Software, MobilEye

<comment><USER19> Where does he say he has no money?

He is expressing he'd like to do more art, but he has to weigh giving up his salary to do that, and weighing the pros and cons.</comment></comment>


Snapchat responds to the Change.org petition complaining about app's redesign - <AUTHOR> https://techcrunch.com/2018/02/21/snapchat-responds-to-the-change-org-petition-complaining-about-the-apps-redesign/ <comment><USER2> ...and says, in essence, "yeah, yeah, whatever. Our way or the highway, get used to it."</comment>