NiFe batteries self discharge at a rate of 20-30% per month. If they're fully charged, during the day, they'll lose under 0.5% of their charge by the time you start charging them again, which seems a pretty adequate loss - you'll lose more than that in the charging and discharging of pretty much any battery type. Remember, we're talking about very short-term energy storage here.

That is not backing. Backing requires responsibility. If all of the people who accept bitcoin today suddenly stop tomorrow, who will enforce their guarantee? No one has made legally binding promises to exchange Bitcoins for anything in the future.

The US Dollar is backed by two guarantees in US law, deriving from Constitution. One is that the US Government will accept them in payment for taxes. The other is that the US Government will, via its legal apparatus, allow any debts held between US citizens to be settled by US Dollars.

This is what gives the US Dollar its value. A large organisation (a government, with a big military) promises to accept them as payment. They can print more, but the rate at which they can do this is limited because they need to maintain the value of new treasury bonds. Since 1960, the rate of inflation of US Dollars has mostly stayed in the 3-5% range (two big peaks over 10%, in the mid '70s and early '80s) and so someone accepting US dollars can be fairly confident that if they spend them again in a few weeks they'll have approximately the same value and even if they keep them for a year or two without investing them they won't lose much.

In contrast, bitcoins can gain or lose 50% of their value overnight. This makes them irrelevant as a currency. How do I price my goods or services in bitcoins when the value is totally unpredictable? It's popular among speculators, because they can make a lot of money if they make good guesses, and the increasing number of speculators keeps driving the price up. If a better game comes out, the value of bitcoins will plummet. And the lower limit on their value is 0, because there is nothing backing them.

You appear not to understand the concept of backing a currency.

Precious metal-based currencies are also backed by the promise that the person storing the metal for you will exchange the currency for some quantity of the metal.

Scarcity does not imply value. There are lots of things that are scarce, but have low value because no one wants them. You don't create value just because you have something that is scarce. Pieces of paper on which I have drawn a picture of a cock are scarce, but that doesn't make them valuable. I don't intend to create any more, and so now by your logic they should be more valuable than BitCoins. Want to give me $100 for one?

Efficiency matters a lot when you're in the burn-fuel-for-power model, because you can always just burn the fuel tomorrow if you need to have the power tomorrow instead of today. For wind and solar power, the power is available when it's available, and you can either consume it, store it, or waste it. Ideally you'd have a proper smart grid (not the kind that's being marketed, which is just a power meter with WiFi) so that you could have things like fridges and freezers run their compressors during supply spikes and leave washing machines and so on programmed to run whenever there is surplus power. In the absence of being able to trigger demand when you have supply, storing it inefficiently is probably better than wasting it.

That said, the majority of my electricity consumption when there is no solar power available is lighting. It would be great to have a DC main with a relatively small battery that could power LED lights overnight. It would probably also let me charge electronic devices more efficiently than going via DC.

Volatility is exactly the opposite of what you want in a currency. When you sell something, you want to know that the money that you get in return will have a certain approximate value when you spend it. If there's a small but predictable amount of inflation or deflation, then you can factor that in to the purchase. It's much harder to make rational purchasing decisions if the money in your pocket may be worth 50% more or 50% less tomorrow.

The smooth scrolling on the iPhone is implemented by the scroll view instructing every view inside one to draw a larger region than is actually composited into the final image. It looks smoother because it's just compositing already-drawn data into the exposed region, rather than having to do all of the rendering on demand. It's a pretty neat trick, but this trick comes at the expense of making the CPU do more work to render bits of a page that may never be seen, and used-CPU means used battery life. I don't know what the total cost is, but Apple has obviously decided that it's worth it and you apparently agree, but it's not a question of CPU speed it's a question of what the widget set does with it.

No, it's not a phone. It's a pocket-sized computer that can also make phone calls. We call it a smartphone for historical reasons. Do you also complain that we say 'computer' as shorthand for 'electronic computer', when we all know that a computer is a person who prepares logarithm tables?

The surprise isn't that Google would push G+, it's that other companies are stupid enough to fall for it, although they seem to be doing the same with Facebook, so I guess it shouldn't be a surprise. I wonder at what goes on in the heads of management at these companies though.

For a medium sized Internet business like this, the biggest threat is that a company with a lot more budget than them will roll out a similar service and take all of their customers. The two companies most likely to do this are Google and Facebook. Microsoft might also try, but they don't seem to have had much success lately. So why on earth would you think that the best way of protecting yourself is to require that your customers already have an account with your potential competitor? If Google decides to add RSS aggregation to G+ (actually, I thought G+ could do that already?), then Feedly's business model is gone: all of their customers would have a G+ account that they need to log in to Feedly, and now they've got everything they wanted without using Feedly.

My only guess is that they think that Google will decide that they want to replace Reader and will buy Feedly instead of reimplementing it. Given that they still have the Google Reader code, and they're not short of people with experience developing web apps, this seems unlikely. The only reason that they'd want to buy Feedly would be to get the customer base but if Feedly makes all of their users get G+ accounts even this reason evaporates. Since their users would really be G+ users, there's also less reason for anyone else to buy the company.

Real money is something that has a guarantee that it can be turned into goods or services in the future, backed by something that most people will trust. Examples of the guarantee include a bank that owns a lot of assets making a promise, a guarantee that a government will accept it in payment for taxes or will enforce your right to settle debts with it, or some commodity (historical examples include grain and precious metals) that is stored somewhere in an amount that makes a convincing argument that people who want the commodity can go to the backer and exchange their tokens for the commodity.

Bitcoin is backed by nothing. There is no large organisation (government or private) guaranteeing that they will accept it in exchange for goods, services, or relief from debt. There is no commodity store that you can go to and exchange bitcoins for some guaranteed amount of the commodity.

There are markets, but they are unlike traditional commodity markets because commodity markets have a mixture of traders (who either produce or consume the commodity being traded) and speculators (who bet that the value of the commodity will go up or down and make money when they guess right, and who provide extra liquidity that helps the market function). Bitcoin markets solely contain speculators and so are extremely volatile.

Depends on the entry requirements. If anyone who can get, say, 500 signatures from a district is eligible for the same funding, then there isn't much of a barrier to entry for any candidate who stands even the vaguest chance of winning. In the UK, candidates must pay a deposit (£500, I think) and they get it returned if they get more than a certain (small, but nontrivial) percentage of the vote. The amount is small enough that if you start with any support it's easy to raise - the Pirate Party managed in a few places, although they lost the deposit in places where they only got a handful of votes.

There's probably a lot of truth in what you say. Banks tend to be incredibly conservative in their upgrades. I know of a couple that are just finishing their migration from FreeBSD 2.x to FreeBSD 6.x. They didn't even manage to start the upgrade to 6.x until after it was no longer supported upstream, but they pay people to backport security fixes. I know of a couple of others that still do a lot of processing on VMS on VAX, although they do have some Alpha and Itanium boxes. Outside of HFT, performance doesn't matter that much to them, but they really don't like surprises. This is why they tend to be a lot more positive about open source than you might expect from such a conservative industry: they like the idea that you can keep running an ancient platform long after the original vendor goes out of business. Transaction processing volumes grow a lot more slowly than Moore's Law, and unless they need new features they'd much rather keep using the system that they know works with occasional bug fixes when it doesn't than have to switch to something newer.

Microsoft was the first (I think, certainly one of the first) company to sell an OS as a commodity off-the-shelf product. Previously, operating systems had been sold to computer manufacturers, tailored specifically to their system, and developed in-house with the computer. IBM was the first company to develop an OS (OS/360) that ran on multiple computers and allowed userspace software to be trivially ported between them. Microsoft recognised this trend (almost 20 years later) and realised that the OS, not the hardware, was what defined the computer and that this was the right monopoly to aim for.

I was actually thinking of Number of the Beast and Time Enough for Love (which could have been more accurately titled Time Enough for Eugenics). I forgot about All you Zombies, although at least in that case it's not the character's goal and motivation.

If it were something capable of crossing interstellar space, then the thruster exhaust (even if they had some exotic drive for travelling very long distances) would likely be invisible in the visible spectrum and very, very bright in the IR. It would also likely be travelling significantly faster than anything naturally occurring and so would be quite distinctive in several ways.

The one thing that the left and right appear to agree on in the US is that most of the population is too stupid to survive without their lives being micromanaged by the state. The predominant difference seems to be that they disagree on whether a cull is a good idea...