Another vacuum tube technology with current applications and substantial advantages over semiconductor approaches to the same problems is the Thermionic Converter. This is a vacuum-tube technology heat engine that turns temperature differences into electric power - by boiling electrons off a hot electrode and collecting them, at a somewhat more negative voltage (like 0.5 to 1 volt), at a cooler electrode.
Semiconductor approaches such as the Peltier Cell tend to be limited in operating temperature due to the materials involved, and lose a major fraction of the available power to non-power-producing heat conduction from the hot to the cold side of the device. Thermionic converters, by contrast are vacuum devices, and inherently insulating (with the heat conducted almost entirely by the working electrons, where it is doing the generation, or parasitic infrared radiation, which can be reflected rater than absorbed at the cold side.) They work very well at temperatures of a couple thousand degrees, a good match to combustion, point-focused solar, and nuclear thermal sources.
Thermionic converters have been the subject to recent improvements, such as graphine electrodes. The power density limitation of space charge has been solved, by using a "control grid" to encourage to charge to move along from the emitter to the collector and magnetic fields to guide it (so it doesn't discharge the control grid and waste the power used to charge it).
Current thermionic technology can convert better than 30% of the available thermal energy to electrical power and achieves power densities in the ballpark of a kilowatt per 100 square cm (i.e. a disk about 4 1/2 inches in diameter). That's a reasonably respectable carnot engine. This makes it very useful for things like topping cycles in steam plants: You run it with the flame against the hot side so it is at the combustion temperature, and the "cold" side at the temperature of the superheated steam for your steam cycle. Rather than wasting the energy of that temperature drop (as you would with a pure steam cycle) you collect about a third of it as electricity.
It also beats the efficiency of currently available solar cell technology (and the 33.4% Shockleyâ"Queisser theoretical limit for single-junction cells), if you don't mind mounting it on a sun-tracker. Not only that, but you can capture the "waste heat" at a useful temperature without substantial impairment to the electrical generation or heat collection, and thus use the same surface area for both generation and solar heating. (Doing this with semiconductor solar cells doesn't work well, because they become far less efficient when running a couple tens of degrees above room temparature.)
I think you missed the simple fact that everything was working fine before, without cramming everything in the init process.
Has everything been crammed into the init process? In what may have been a bad PR move, the systemd people use "systemd" both to refer to the init process and to their whole suite of daemons, most of which run as processes separate from process 1, so "systemd does XXX" doesn't necessarily mean "XXX has been crammed into the init process".
I would like BMG to sue the atmosphere, because just yesterday I heard pirated music being played on somebody's stereo. Let's drag that piracy-helping fucker Yahweh into court!!!!!
... every schematic drawn by every semiconductor engineer got the arrow backwards.
As I heard it, The arrow is "backward" because Benjamin Franklin, when doing his work unifying "vitreous" and "resinous" electricity as surplus and deficit of a single charge carrier (and identifying the "electrical pressure" later named "voltage"), took a guess at which corresponded to a surplus of a movable charge carrier. He had a 50% chance to assign "positive" to the TYPICAL moving charge carrier in the situations being experimented with (charge transfer by friction between different substances, currents in metallic conductors, and high voltage discharges in air and water-in-air aerosols) and happened to guess "wrong".
Thus we say electrons have a negative charge, "classical current" corresponds to the sum of the flow of moving positive charge minus the flow of negative charge (i.e. the negative of the electron current, which is all there is in normal-matter metallic conductors), the arrowhead on diodes (and junction transistors) points in the direction of classical current across a junction, and so on.
But though it's the charge carrier in metallic conduction and (hard) vacuum tubes, the electron ISN'T the only charge carrier. Even in the above list of phenomena, positive ion flow is a substantial part of electrical discharge currents in air - static sparks and lightning. Positive moving charge carriers are substantial contributors to current as you get to other plasma phenomena and technologies - gas-filled "vacuum" tubes (such as thyratons), gas an LIQUID filled "vacuum" tubes (ignatrons), gas discharge lighting, arc lighting, arc welding, prototype nuclear fusion reactors,
Move on to electrochemistry and ALL the charge carriers are ions - atoms or molecular groups with an unequal electron and proton count, and thus a net charge - which may be either positive or negative (and you're usually working wit a mix of both).
And then there's semiconductors, where you have both electrons and "holes" participating in metallic conduction. Yes, you can argue that hole propagation is actually electron movement. But holes act like a coherent physical entity in SO many ways that it's easier to treat them as charge carriers in their own right, with their own properties, than to drill down to the electron hops that underlie them. For starters, they're the only entity in "hole current" that maintains a long-term association with the movement of a bit of charge - any given electron is only involved in a single hop, while the hole exists from its creation (by an electron being ejected from a place in the semiconductor that an electron should be, by doping or excitation, leaving a hole) to their destruction (by a free electron falling into them and releasing the energy of electron-hole-pair separation). They move around - like a charge carrier with a very short (like usually just to the next atom of the solid material) mean free path.
For me the big tell is that they participate in the Hall Effect just as if they were a positive charge carrier being deflected by a magnetic field. The hall voltage tells you the difference between the fraction of the current carried by electrons excited into a conduction band and that carried by holes - whether you think of them as actual moving positive charge carriers or a coordinated hopping phenomenon among electrons that are still in a lower energy state. Further, much of interesting semiconductor behavior is mediated by whether electrons or holes are the "majority carrier" in a given region - exactly what the hall effect tells you about it.
So, as with many engineering phenomena, the sign for charge and current is arbitrary, and there are both real and virtual current carriers with positive charge. Saying "they got it wrong" when classical current is the reverse of electron current is just metallic/thermionic conduction chauvinism. B
Except when it doesn't and since it swallows stderr
A sane background/daemon process launcher sends stdout and stderr somewhere where it gets logged. Are you saying systemd just sends the standard output and error of stuff it launches to
If as a result the Linux community grows closer together and focuses more on consistency I'm all for the move to systemd - even if that moves Linux away from the rest of the unixes due to loss of posix compliance.
Not that systemd affects POSIX compliance (and not that Linux is certified as POSIX-compliant; I haven't found it to be significantly worse than any other UN*X in terms of "annoyingly different from everybody else" - frankly, if there isn't at least one thing your UN*X-family OS does annoyingly differently from all the other UN*X-family OSes, it can't really call itself a UN*X
"No point progressing since the bombs are gonna fall any day now. Then where will your fancy silicon highways and databases be?"
Given that the Internet Protocol and much of the rest of the networking technology that still underpins the Internet were developed as part of a cold-war program to create a communication system that could survive a nuclear attack that destroyed most of it, and still reorganize itself to pass messages quickly, efficiently, and automatically among any nodes that still had SOME path between them, your post seems to come from some alternate universe to the one I inhabit.
The ability to legally install it on any hardware I want.
And their colony failed. The Spanish, Portuguese, English and French colonies in the New World succeeded because the governments that ran those colonies backed them financially and militarily. At least in the case of the English, owners/shareholders of colonials often received economic monopolies, giving them substantial impetus to make colonies economically viable in fairly short order.
And even though colonies could obviously become self-sustaining in pretty short order, they still required a significant amount of protection from the colonial power, and the colonial powers served as the route to accessing markets.
The Vikings experiments in colonization as private endeavors were mixed successes at best, and ultimately only Iceland survived as a successful colonial enterprise by the early Modern era, with the North American and Greenland colonies failing (though the Greenland colony did manage to hang on for several centuries).
There are probably any number of reasons; less than hospitable sites for colonization that were vulnerable to climactic changes at the top, but also the more limited means of making such colonies economically viable. At least in the North American attempts, the native peoples may have played a roll as well. The Norse simply didn't have the resources at their disposal that the Colonial Powers could bring to bear when they started seizing the New World. The Norse were hardly better equipped than the Inuit and Native Americans they encountered, whereas the Spaniards, French and English had firearms and much larger numbers.
A whole helluva lot of money. But if gravity is your enemy, why fight it?
But no one says it doesn't exist locally. Quite the opposite, everyone thinks it does. It's just fucking hard to see.
It's not that cosmologists aren't willing to look at GR, and certainly are, but no potential quantum theory of gravity suggests an alternative to dark matter. And considering we all know there is physics beyond the Standard Model, and the potential for currently only hypothetical or even unpredicted particles, the idea that we should just toss out one of the most successful scientific theories in history because we're confronted with what looks like a lot of extra mass seems absurd.
But I get it. There is a certain type of person, underachievers mainly, whose only contribution to any discussion is to find the gaps in our knowledge and then proclaim researchers in those fields retards. It's pathetic, and contributes absolutely nothing.
In the very long run, probably. But I think there's probably a route to increasing space exploration and utilization by explicitly avoiding the cost of Earth-to-orbit transport costs. The plan I've seen that has some promise goes as follows:
1. Find some metal-rich and volatiles-rich asteroids and comets (not exactly rare in the Asteroid Belt). Tow these asteroids into a near-Earth orbit and begin extraction and smelting.
2. Set up manufacturing facilities in Earth orbit to build spacecraft and satellites.
2a. We could even "grow" plastics with bacteria or genetically-engineered plants.
In all seriousness, if you created a parallel space-based economy whose sole purpose is to make transporting anything but humans into space, then the whole question of how to make Earth-to-orbit transport cheaper ceases to be an issue. Obviously the startup costs and R&D for such a project are monumental, but in the long run, the rewards would be huge. The whole point of commercial spaceflight is to find a way to make it economically feasible, and this is about actually creating a space-based economy.