Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!


Forgot your password?
Note: You can take 10% off all Slashdot Deals with coupon code "slashdot10off." ×

Comment Re:Mission accomplished (Score 1) 270

To generate enough power for the whole planet to live at US energy consumption levels (i.e., for everyone to have a good standard of living), you'll need to cover a significant percentage of the land area with solar panels. This is not completely impractical, though you'd need a panel with nothing rare in its construction and a very long lifespan, but it hardly seems ideal. It's also not going to work for industrial power (most of which doesn't even involve electricity today), because you need dense, reliable generation of thermal energy.

Fossil fuel use simply won't go away, at least for industrial needs, until we have small-industrial-scale nuclear plants of one kind or another, and fission doesn't seem promising for that. Orbital solar could work, but it seems farther out than fusion.

Comment Re:Hang on a minute... (Score 1) 316

Maybe mixing su with systemd is like mixing PCP and acid

Mixing Linux and systemd is like a remote control on a chainsaw: the idea may sound neat for 2 seconds, but then you realize nothing good can come of this.

"It's going to get out of control. It's going to get out of control and we'll be lucky to live through it."

Comment Re:Hang on a minute... (Score 1) 316

its the other way around. we used to have small, simple programs that did not take whole systems to build and gigs of mem to run in. things were easier to understand and concepts were not overdone a hundred times, just because 'reasons'.

now, we have software that can't be debugged well, people who are current software eng's have no attention span to fix bugs or do proper design, older guys who DO remember 'why' are no longer being hired and we can't seem to stand on our giants' shoulders anymore. again, because 'reasons'.

Comment Re:Because this will be unlike Biosphere 2 how? (Score 4, Informative) 53

To answer your question, smaller habitat, no experiment at maintaining atmospheric composition, outside excursions in "space suits" etc. Its not very much like Biosphere II.

As for why not under the sea or Antarctica I can give at least three reasons. (1) cost of building, transporting and maintaining the habitat; (2) all the support and research personnel live in Hawaii, above water; (3) the research objectives don't require putting the experiment in a dangerous or inaccessible place.

Now someday when we have an actual habitat design along with all the actual support systems we plan to send to Mars, a trial on top of a super high mountain would make sense as a kind of Mars analog. But we don't have such stuff to test so we don't need the Mars analog with all the expense and complication.

Comment Re:Furthermore, Saudi Arabia must be destroyed (Score 2) 270

Not everyone in Saudi Arabia are bedouin; in particular the ruling House of Saud is descended from town dwelling Arabs.

I'll go out on a limb and guess that not everyone in Saudi Arabia is worthless. Even people involved in managing their oil. And as for the elite they don't seem to be worse than anyone else who's inherited oil-based wealth; they've managed that for the long term benefit of themselves and their families. If they're ostentatious with their wealth, well they have a lot of it and it hasn't bankrupted them yet.

So there's no rational reason to want to destroy Saudi Arabia. But there's every reason not to want to be so dependent upon them.

Comment Re:Okay, if they think that will work (Score 2) 77

Yep, what made the movie work was that it was actually good Sci-Fi, as action movie Sci-Fi goes (which has little enough to do with written SF). Good character development, a bit of actual suspense, you cared about the characters, etc. Even without the parody stuff, it was better than the Star Wars prequels or half the Star Trek movies.

It was genre-savvy satire, more than simple parody, and it was good. Not sure how you could turn it into a series though, unless they're going to make the Galaxy Quest series that was the backstory to the movie, which could be fun for one season.

Comment Re:Wait, physics doesn't work either? (Score 1) 200

Everything in physics works in both time directions (you have to swap some signs +/- when you reverse time, but it all works). Causality as "a chain of related events over time" is a real thing, even if what you place in the chain may be somewhat arbitrary, but the direction, which is cause and which is effect, isn't so well defined. At the QM scale it's arbitrary. In human experience, a film played in one direction looks different than in the other because, ultimately, of the energy input from the Sun breaking the symmetry.

Comment I'm inclined to agree, but there is hope (Score 1) 77

I loved that movie.

However, it was about a bunch of actors thrown into a situation their characters on a long-canceled TV show should be in, who eventually figured out how to use their own abilities to win. You can't have character development like that in a typical TV show. The stupid parts of the ship that were created just to match things in bad episodes were fun, but that wouldn't last long before they'd either exhausted the possibilities or more than filled the ship with idiotic sets.

Unless they're going to do something like the Galaxy Quest TV show in the movie, which looked fairly mediocre.

The Galaxy Quest TV show reboot could be very awesome - there are tons and tons of Trek (hell, even B5) stuff that's great parody material. Super-powerful aliens (Q), weird alternate-realities that are too-much-like-reality, time travel... or things like how reboots and retcons are done.

And then there's sci-fi comedy like Red Dwarf which could lend some ideas. Or maybe pull stuff from Aliens or other scifi movies. There is a rich vein of material that awaits good parody.

I think there are dangers of being repetitive and derivative but there are opportunities out there too.

Comment Re:Wait, physics doesn't work either? (Score 1) 200

our "underlying state" seems equivalent to a "hidden variables" theory.

No, it's just the sloppiness of English trying to represent math, or perhaps my lack of facility with one of those in trying to craft a metaphor.

To extend my above metaphor: there's no hidden "observable" state. The underlying state is not "this one spin-up, that one spin-down" (which is forbidden), because there are not electron identities anyhow, but instead "exactly one of them is spin-up". As you measure one of them, there are now three entangled things: the two electrons and your detector, and there's a set of allowed observables given all that, when you add the second detector, now there are 4 entangled items. It's not non-local, it's just a constraining of the set of allowed states for the complete system.

Comment Re:Wait, physics doesn't work either? (Score 4, Interesting) 200

The real question is - exactly wtf is entanglement anyway? I can find lots to read about what it looks like and how it behaves... but what's the underlying mechanism? Is there even the most speculative explanation of it?

Here's the best answer I can give you - I think it's true, and not so over-simplified as to be wrong.

The universe has some underlying state. We don't have direct access to that state - not only is it not directly observable, it's not directly related in any intuitive way to the state we can observe. There's this arbirtary-seeming transform between underlying state and what we observe (it only seems odd or arbitrary because all our intuitions are based on human-scale observables, and are not at all directly informed by this underlying state). This underlying state seems to be well-defined and deterministic, forwards and backwards in time. The observable universe is not.

Entanglement is a feature of how observations relate to underlying state - a feature of the transform. In very simple experiments we can measure specific properties of, say, an electron. We can't measure all of them, for a given electron, because the transform just doesn't work that way, but we can measure some. However, that's deceptive, because you can't really track that property of that electron over time, in non-trivial cases. If e.g. two electrons interact, become entangled, your observations are now a function of both electrons' underlying state, and that's a different transform from 2 non-entangled electrons.

There are two key concepts here. The first is that the whole notion of "particle" is a handy but false oversimplification. It can lead you to all sorts of false intuitions about how particles behave. Fundamentally, individual e.g. electrons don't have unique identities. The underlying state is a single electron field, which other fields can interact with, in a way that can sometimes be simplified as "particle interactions", for a simpler mental model, but you can't go too deep with that model. An example: "two electrons collide in an accelerator, and two electrons leave, which is which?" That question is "not even wrong", it's just nonsense. Thinking of electrons as billiard balls colliding is simply not a helpful model, as it just misses the point of the interaction.

"Entanglement" happens just when the "particle" mental model fails: you can no longer pick two disjoint areas in the electron field and consider them as independent "electrons", but instead you have to reason about two areas which may be quite disconnected in space and time. E.g., you might know for sure that one electron is spin-up, and one spin-down, but have 0 information about which is which. None of that matters to the underlying state: there's just one electron field, and the only truly correct way to reason about it it to reason about the whole field all the time, and so this is only half of "WTF is entanglement".

The second concept gets too much into the math to explain well, but in a hand-wavy way it's this: "what is measurement?". There are older interpretations about measurement causing wavestate collapse and so on, but they're wrong because of that word "cause". Measurement is simply the observer becoming entangled with the observed. Measuring one entangled electron doesn't "cause" the other electron to do or become anything. The underlying state is unchanged, which is why there's no faster-than-light effect. In some cases, this is an overly pedantic distinction, but it matters when the difference between QM and intuition matters. In a two-slit experiment where you see an interference pattern at your detector, if you add a measuring device to one slit suddenly you don't see that interference pattern. Informally we might say the second observer "caused" this change, but formally that's wrong, it's just that a system with 2 slits and 2 detectors behaves differently from a system with 2 slits and one detector, and it doesn't matter which detector the electron passes first, because (see above) an "electron" as a discrete particle is fiction anyway, and both detectors are entangled with the electron field already, or they couldn't measure an electron anyhow.

Comment Re:A simple test is in order (Score 1) 410

Well, this is a bit like parents who take their kids to get vaccinated and a few hours later that kid exhibits the first signs of autism. It's an immensely compelling coincidence. You'd have to (a) know that autism symptoms often have a rapid onset and (b) realize that when they do they can follow any commonplace childhood event. Even if you did it'd still be hard to shake the suspicion if it happened to your kid.

Somebody points a IR remote at your friend; he gets up and has a brief moment of orthostatic hypotension -- also known as a "dizzy spell" brought on by a sudden drop in blood pressure -- just at the moment the guy pushes the button. Orthostatic hypotension can happen to anyone, but if your friend isn't otherwise prone to it that can be a very compelling coincidence; and many of the symptoms of hypotension can be reproduced by psychological stress.

If something like that happens to you people will say, "oh, it's all in your head," but the thing is that all suffering is inside peoples' heads. One of the worst kinds of pain you can have is passing a kidney stone, but if you happen to be in a coma at the time you won't feel a thing. Distress produced within the brain is indistinguishable to the subject from distress produced outside the brain. Having an external explanation for that distress can make someone feel like they have some control over what is a disturbing experience, and shooting holes in that explanation isn't going to help unless you can offer them a better handle on it.

Sometimes I think we'd be better off if we just brought back shamans and witch doctors.

Prototype designs always work. -- Don Vonada