C is a good choice where performance is critical for small or large programs. C++ used like C is comparable.

Perl or Python are good choices for short programs where ease of development and programming practices resilient to buffer-overflow style bugs are more important than performance.

Java is a good choice for large, complex programs where safe and secure programming practices are more important than micro-optimized performance.

See what's missing from that picture? Any role where C++ used with the low-performance safe practices abstractions is a better choice than something else.

No, you lose efficient code. For a simple example, the string abstractions in C++ and Java are much, much less computationally efficient than manipulating a C character array.

Once you're willing to take that hit for the sake of the things the abstractions gain you, Java's bytecode machine is a tiny additional hit versus the far superior design of the language itself.

And anyway, in case you didn't know it there are tools (like gcj) for compiling java straight to native code if that's what you really want. Only that usually isn't what you want because object code portability is damn useful.

Except we're not talking about off-grid systems, we're talking about Tesla's grid-tie application where power is stored from both off-peak grid delivery and adjunct DC systems and then supplements household usage during grid peak pricing.

When living completely off grid, you move most of the high-wattage equipment to propane. No electric stove or hot water heater. And you use an ammonia-cycle refrigerator. But that always will be a niche market, even if Tesla's dream comes true.

That's what C is for -- situations where low overhead is important. You retain that feature when you use C++ as if it was C but lose it when you employ Java-like abstractions instead.

The common buck converter circuit that reduces 12VDC to 5 VDC is as inefficient if not more inefficient than the common transform/rectify/smooth wall wart that drops 120VAC to 5 VDC. That's another problem with running a low voltage DC circuit through the house: whatever voltage we standardized on, every dang thing you plugged in to it will still need buck/boost circuits that are no better than the AC to DC circuits we're using now.

And it probably would be 12 volts (actually, 13.6). There's too much obvious value in matching what car electronics run on.

Seems premature to me. An awful lot of things have to work out just right for whole-home battery systems to make much sense.

Even then low-voltage DC plants don't make much sense. Your microwave oven consumes 1100+ watts. Know what amperage that is at 5 volts DC? You'd barely be able to wrap your hand around the power cord.

Even at 48 volts DC, the power plant in a telephone company central office is really something to behold.

Also, AC/DC conversion isn't as dire as stated. Sloppy cheap converters do indeed operate at around 75% effeciency with the remaining 25% lost as heat. But look at the "80+" computer power supply standards. The "80+ platinum" standard requires 95% efficiency. Those power cost twice as much but "pure science" does not prevent their operation. They work as promised.

If you're the sort of person who believes any and all business is merely a way to make profit and nobody who creates a company ever actually cares about the task they perform, then sure. Reality is more complex than that.

Re: China. iOS is in the minority in China. Even at the time of the iPhone 6 launch iOS market share was only 20%, but iOS market share always spikes around the time of a new iPhone launch, then falls back down in the other quarters. And China is a special case - Google isn't willing to play ball with the communist government so the services that make Android most useful are all blocked there. Apple cooperates so they can sell iOS as is, getting a built-in advantage. Despite this, Android still dominates.

From their perspective it'd be much worse than higher search rev shares. If Android did not exist, Google Maps would have been wiped out overnight on mobile when Apple decided to go it alone (against the wishes of their own userbase, no less). Android was never about making direct profit, it was always about ensuring Google was able to deliver their services directly to users. They were quite open about this from the start. And judged by this standard it has been an incredible, epic success.

iOS is on the way down anyway. Outside of English speaking countries and Japan it's in the minority everywhere. In some countries, especially European countries like Germany and Spain, the iPhone has been crushed.

Russia would like for us to continue gifting them with cash for 40-year-old missle motors, it's our own government that doesn't want them any longer. For good reason. That did not cause SpaceX to enter the competitive process, they want the U.S. military as a customer. But it probably did make it go faster.

Also, ULA is flying 1960 technology, stuff that Mercury astronauts used, and only recently came up with concept drawings for something new due to competitive pressure from SpaceX. So, I am sure that folks within the Air Force wished for a better vendor but had no choice.

These career govt employees feed info to the pres, make recommendations, and fight for their interests. Even if a new pres wants to turn on a dime, Washington DC is a large ship that turns slowly.

Bingo. The old UK comedy "Yes Prime Minister" was a rather cutting illustration of this phenomenon at work.

What happens to someone when they become the prez? Enormous numbers of apparently experienced people begin telling you all kinds of secret things. They stress the importance of secrecy. They tell you about this plot or that plot. They say it's vital they get new powers and they not-so-subtly imply that if you don't help them Women And Children will DIE! And although it's left unstated you know perfectly well that if you don't give them what they want, you will see leaks in the press from anonymous officials that paint you as a prevaricator, as weak, as unconcerned for the lives of Patriotic Heroes And Their Women And Children.

The problem any US President has, and I daresay many other countries presidents, is that they are immediately submerged into a fantasy world woven from the agendas of the people around them mixed with their own pre-existing views, and those people are themselves also in a slightly less extreme form of a personal fantasy world and so on all the way down. A toxic brew of patriotism, belief in American exceptionalism, militarism and most of all pervasive classification means that it's impossible for a prez to penetrate the fog of misinformation that surrounds them. They can be manipulated into believing nearly anything because it would take an incredibly strong willed personality to say directly to the senior bureaucrats feeding them classified intelligence, "I think you are bullshitting me and I am going to personally audit your shit and prosecute you if you're lying to me".

Obama is very much NOT a strong willed personality. He sees himself primarily as a reasonable man who finds compromise between different factions. This makes him easily manipulated: all it takes is for people who agree to present him two apparently opposed positions - one extreme and one very extreme - and Obama will reliably pick something that is quite extreme. And the officials around him know that.

In hindsight it should have been obvious. Obama has no real track record of achievement in politics. He supported no particularly controversial positions, or showed any particularly clear thinking. Compared to Bush he seemed like a genius of course but Bush was a fucking man child, so that wasn't hard.

For that reason, Rand Paul fans might be disappointed if he won. I don't expect he would be able to accomplish as much change as people would like.

Almost certainly not. But it looks like Rand Paul is made of stronger stuff than Obama. Paul consistently argues for positions that piss off most of his party. He seems able to come to conclusions about things himself regardless of what other people believe. He seems to have fairly strong principles. He doesn't come across as the sort of wishy-washy people person that Obama is. If there's any US politician that actually might tell the people in his secret briefings "stop bullshitting me or I fire you", it's probably Rand Paul.

That sort of logic holds true when moving between languages that are very similar. The transition between Python and Ruby or Java and C# spring to mind.

However if I need a C++ programmer and need one pronto, I'm not gonna hire a guy who has only JavaScript on his CV no matter what. Learning C++ is not merely learning a different way to create an array or slightly different syntax. To be effective in C++ you need to know how to do manual memory management and do it reliably, which takes not only domain knowledge but more importantly: practice and experience. You need to understand what inlining is. You very likely need to understand multi-threading and do it reliably, which takes practice and experience a pure JS guy is unlikely to have. You need to be comfortable with native toolchains and build systems: when the rtld craps its pants and prints a screenful of mangled symbols you need to be able to understand that you have an ABI mismatch, what that means and how to deal with it. Unfortunately that is mostly a matter of practice and experience. You might need to understand direct manipulation of binary data. There's just a ton of stuff beyond the minor details of the language.

Could the pure JS guy learn all this stuff? Of course! Will they do it quickly? No.

That's a bit of a problem, because when you program in C++ the same way you'd program in Java, you lose the efficiency and simplicity of C without gaining the clean design of Java. Java is superior to C++ in almost every reasonable use of C++ *except* the ones which call for programming in C but with, you know, a little bit plus.

I resemble that remark.