Follow Slashdot stories on Twitter


Forgot your password?

Comment Re:ZFS is nice... (Score 1) 243

Uh, that doesn't work. The problem is that doing exactly what you've written down is contriving to avoid your copyright responsibility by deliberately creating a structure in someone else's work which you believe would be a copyright insulator. If you went ahead and did this (I'm not saying that you personally would be the one at Ubuntu to do so), I'd love to be there when you are deposed. Part of my business is to feed attorneys questions when they cross-examine you. I have in a similar situation made a programmer look really bad, and the parties settled as soon as they saw the deposition and my expert report. See also my comment regarding how Oracle v. Google has changed this issue. You can't count on an API to be a copyright insulator in any context any longer.

Comment Re:ZFS is nice... (Score 1) 243

I think you need to look at this in the context of the appeal of Oracle v. Google. We had a concept of an API being a boundary of copyright based on 17 CFR 102(b) and elucidated by Judge Walker's finding in CAI v. Altai. That stood for a long time. But Oracle v. Google essentially overturned it and we're still waiting to see what the lower court does in response.

Comment Re:Not the total cost! (Score 2) 252

You also have to include the cost to maintain the fossil fuel plants that back up the fossil fuel plants, in the fossil fuel analysis.

The UK National Grid maintains a "spinning reserve". This has to be big enough to cope with a couple of large fossil fuel or nuclear plants going offline suddenly, which does happen from time to time (and there have been blackouts when there was not enough spinning reserve when two power stations went offline - for unrelated reasons - within minutes of each other). From the point of the UK National Grid, nuclear, coal and gas are seen as "intermittent power sources". Sizewell B, one of the largest generators in the country, could go from full capacity to zero in an instant, without any warning, if a problem occurs - and suddenly you're without a terawatt of generating capacity. Wind power on the other hand doesn't suffer this problem, wind generators are small and numerous and the loss of one of them doesn't have that kind of impact since at most they are only about 2MW each. Over the period of the next hour or two, wind is also extremely predictable. The wind doesn't just unexpectedly stop blowing. Also in the UK, it tends to be windiest when power demand is highest, those dull winter days when it's doing horizontal rain and everyone's got the lights on.

Of course you still need an alternative for when the whole country is under a high pressure system and there's not much wind at all. But any power generation system alone isn't a silver bullet, that's why we don't just have solely nuclear, or solely gas, or solely coal, or solely oil - we have a mix of different fuelled generation.

Comment CDDL and GPL don't mix (Score 3, Informative) 243

Regardless of what Ubuntu has convinced themselves of, in this context the ZFS filesystem driver would be an unlicensed derivative work. If they don't want it to be so, it needs to be in user-mode instead of loaded into the kernel address space and using unexported APIs of the kernel.

A lot of people try to deceive themselves (and you) that they can do silly things, like putting an API between software under two licenses, and that such an API becomes a "computer condom" that protects you from the GPL. This rationale was never true and was overturned by the court in the appeal of Oracle v. Google.

Comment Re:If the black cabs have a legal monopoly... (Score 1) 215

But London has had minicabs too for years (these are cabs you can't just hail in the street, you have to phone them to get one) and these are regulated under less onerous regulations than the black cabs. What makes Uber different to any other minicab service that's currently up and running in London? Nothing really, other than you press buttons on your mobile phone's touch screen to order one, instead of talking into your mobile phone's microphone.

Comment Re: They demanded my ID and power bill (Score 1) 230

What is a "real name" in Facebook's definition, anyway? I know many people who are not known by the name printed in their passport. There's two people at the place I work who are not known by the first name their parents gave them and that is printed in their passport. I'd argue the name we know them by is still their "real name" (more so in fact) than the name printed in their passport.

In any case I'd just photoshop mine if they asked.

Comment Re:What applications? (Score 3, Interesting) 176

In other words, virtual reality. The problem with the current VR headsets like the DK2, is you have effectively a 1080p display that fills most of your field of vision, in other words, yes - you can see the pixels and they are pretty big. The screen door effect is also pretty bad. Text is very difficult to read using the Rift DK2 unless the text is very large.

Developing very high PPI displays will be a real benefit for VR headsets. Tne next crop (the Vive/SteamVR and Oculus CV1) have better resolution (IIRC it's something like 1200 pixels vertical) and probably will have much less of a screen door effect, but the resolution really needs doubling at least for a VR headset to truly feel HD.

Comment Re:What about cars? (Score 1) 147

The charging cables would have to be enormous, though, to fill (say) to a 400 mile range in less than 3 minutes. The currents and voltages required would be absurdly high. Let's say we have a 180kWh battery/capacitor we want to fill in 3 minutes (0.05 hours). The power coupling would be running to the car at 3.6 megawatts during the charge cycle. With a 11kV coupling you'd need a current of almost 330 amps, so big, thick and heavy conductors. Even if the charger was 99% efficient, you'd need to dissipate 36kW of heat energy during charging (about equivalent to the power output of a small car at wide open throttle).

Having quick charging capacitors/batteries isn't even half the challenge of making an electric car charge rapidly.

Be careful when a loop exits to the same place from side and bottom.