Follow Slashdot blog updates by subscribing to our blog RSS feed


Forgot your password?

Comment Re:Pseudoparticles (Score 3, Interesting) 156

They're like magnetic monopoles in almost all ways...

Correct. The ways they don't behave like magnetic monopoles are scale-dependent. At sufficiently large distances they are indistinguishable from point-like monopoles (monopole equivalents of electrons.) At short distances they aren't anything like monopoles.

The theory they are based on, curiously, predicts that they are free in the medium they exist in, which was something of a surprise. That is, in an infinite BEC, they would be free to move anywhere, making them much more like "true" monopoles than expected.

Whether or not you call these "real" monopoles is a matter of taste. The reality is that at sufficiently large distances no experiment you could perform would be able to distinguish them from a monopole particle, making them extremely practical mechanisms for investigating the physics of monopoles.

One interesting thing is that Dirac showed the existence of a single monopole anywhere in the universe could explain why the electron charge was quantized, because for a given monopole strength there is only one value of electron charge that can interact with it consistently (any other value requires the electron wavefunction to have multiple values at same point in space-time, which would imply a breakdown of quantum mechanics.) I don't know if these pseudo-monopoles are sufficient to impose that condition.

Comment Re:Wow (Score 5, Informative) 31

From context, I believe they mean "asteroids closer to the sun having surface temperatures *at the time of their formation* that are warmer than those located further away."

The volatile fraction in asteroid surfaces goes down as they get closer to the sun, indicating they out-gassed at the time they were formed. The "early warmth correlates with current orbits" indicates relatively little orbital resorting over time.

The new data on smaller bodies suggest this is not the case in general, only for the largest bodies. This is quite important to theories of asteroid formation, which in recent decades have been dominated by the assumption that the asteroid formed "in place".

Comment Re:Space or Lack of Gravity? (Score 1) 267

That is a good idea in theory, but artificial gravity by rotation has a rather big problem involved: We're not 1 inch tall.

The data suggest a 100 m wheel would be adequate to deal with much of this issue, but I'm going to argue that even that is unrealistically large. I'm a sailor, and anyone who has spent a few days at sea knows that the ground has a tendency to move a bit when you get back on land, and that the first day on the water is often a bit nauseating even for those of us who aren't much affected by sea-sickness.

So I have to ask: how many days were the centrifuge experiments carried out over? And what cross-section of the population did they test? I know people who can't go below on a relatively calm day without turning green and losing their lunch, and I know people who have cast-iron stomachs. There are enough of the latter about that it is unlikely we'll need to build truly huge structures for long-term space flight.

Furthermore, the differential forces in a wheel that is 10 m in radius with, 1 g at the outer edge would have 0.8 g at the head of a 2 m tall human. It is not uncommon on a boat to be subject to more than 0.2 g accelerations, and sailors adapt to this. We move differently, and our vestibular systems get used to the disruptions.

So I'm expecting in a decade or two to see an article that says, "Humans adapt far better to centrifugal gravity than land-lubber scientists expected!"

Comment Re:The undersides of rocks... (Score 1) 140

Can you think of a terrestrial example of a rock whose underside has a significantly different chemical composition than its topside? I can't.

You've never actually looked at a rock, have you? Or you live someplace really geologically boring?

Where I live we have sandstones with embedded basalts, basalts with quartz inclusions, and so on. It is extremely common for rocks to have multiple compositions, and this rock appears to be a fairly pedestrian example of that.

Comment Re:Stupidity... (Score 1) 175

Of course it's not really real, but for a real world analogy look at escorts. It's all bullshit and because of the money but people like to pretend they're dating and pretend she wants to have sex. Same with prostitues, customers don't want to hear it's a rent-a-hole service and the meter is running they want sweet, sweet lies. If people can "forget" such little details they'll have no problems "forgetting" that this AI girl is nothing but a bunch of circuits. Particularly if it comes with a "fully functional" android body.

The incredible thing about this whole thread and the story itself is that no one seems aware of just how easy it is for people to do this.

Here's news: "Some users developed an emotional attachment to ELIZA and some psychiatrists went so far as to suggest that such programs could replace psychotherapists altogether." That was forty years ago.

Of course humans are going to form emotional attachments to machines that mimic the most rudimentary forms of human behaviour. We've been doing so for decades, and your example of escorts is dead-on: this kind of emotional gaming isn't even remotely new, and it doesn't even require very good fakery to bring it into play.

Comment Re:Water=life (Score 4, Interesting) 66

Water plumes or not, I suspect...

I suspect that suspicion is a code-word for ignorance.

Water is an incredibly weird substance. It's a near-universal solvent and has constituent molecules that are fantastically reactive. Both properties make it uniquely well-suited to supporting the chemistry that imperfectly-reproducing molecular machines depend on.

It's not too much to say that once you add water to the sorts of chemicals we know are relatively common throughout the universe, it's difficult not to get life, if you're willing to wait long enough.

As for energy: the last time I looked Ceres was not at absolute zero, nor was it chemically inert nor free from radioactivity. While it almost certainly doesn't have a molten core, if it has a composition similar to Earth's crust it's generating about a nano-joule per kilogram from radioactive decay (mostly 40K) which sounds small until you realize the total mass is almost 10^21 kg, so it's getting on for 10 TW in radioactive energy alone. It has a warm interior, with a thermal gradient near the surface that might well power molecular machines.

Also, Ceres orbits at just under 3 AU, so the solar flux on its surface is about 10% of what we get on Earth, which would make the integrated solar flux comparable to what is seen on Earth at about 55 degrees latitude in winter, well below the (ant)arctic circle. This region includes permafrost-free zones in Northern Canada.

Enough energy for life? Maybe, maybe not. But certainly a far stronger argument for the presence of life than anyone's "suspicions" against it, which only include information about the person in question and tell us exactly nothing about the world at large.

Posting "I suspect X (therefore, at least implicitly, you should believe X)" is exactly like saying, "I had toast for breakfast, therefore you should believe X". You have posted a fact about yourself (your suspicions, your feelings, what you had for breakfast) as if were in some way germane to a conclusion about a part of the world that is not you.

Comment Re:Guy is foolish. (Score 2) 188

I've so far been online dating for about 9 months, I've dated only 6 women.

Dating is a long game. In my early 40's I dated for years, including a couple of relationships (which lasted a few months to a year) before finding someone really compatible, and who I've been with for almost a decade now. Like me, she had by that time dated virtually everyone in our age group in the city we lived in, so it was optimization by exhaustive search for both of us.

I've used OKC, PoF and a couple of paid services (LavaLife is the one I remember.) They all suck. OKC and PoF suck less.

OKC routinely matched me with people who were ludicrously unsuitable, mostly anti-science alternative-types who were frequently much younger, and I've dated enough younger women to know that doesn't work for me even with basic values in common. I can understand why that happened, but although the algorithms clearly think I'm "young at heart" my brain is still as old as the hills, to say nothing of my body.

PoF was better for demographic reasons, I think, so it's worth shopping around to find a site that has more of your kind of people on it.

That said: everyone is bad at online communication, and most people shade the truth on their profile at least a bit. Weirdly, the most honest people sound the least real, in my experience (my partner and I had seen each other's profiles off-and-on for several years on different sites and never contacted each other because we thought it was impossible we were what we seemed.)

So keep at it, fail often, and be utterly up-front about who you are. You'll be surprised at how rapidly you filter out the dross and how well you connect with people who are really on the same wavelength, once you find them. But finding them can take a long time.

Comment Re:In other words ... (Score 1) 265

Because it means not only has Chris Christie lied and continues to lie about this, Chris Christie's lies were transparently stupid lies. So not only is Chris Christie a petty, vindictive liar, he is an incompetent petty vindictive liar.

Alternatively, he's a terrible manager who surrounded himself with incompetent petty vindictive liars who he failed to communicate with effectively over a period of years.

Really, this story is about how stupid and incompetent Chris Christie is, which is a little different form how dishonest and vindictive he is.

Comment Re:So what? (Score 1) 534

Japan is rejecting its existing CO2 commitments...

Because it shut down nuclear power generation after Fukushima, because clearly the problems with a technology aren't to do better, but to quit.

Quitting is made easier by the political unpopularity of nuclear power created purely by decades of hysterical agitation by "environmentalists" who are far more interested in imposing known-failed "abstinence only" "solutions" than actually solving problems.

Comment Re:Double down (Score 1) 534

Had we investing in moderate, completely reasonable solution 60+ years ago when the scientists first agreed that we had a serious problem on our hands we could have nipped this problem in the bud at very little expense.

We tried to. It was called nuclear power. Some bunch of hysterics shut it down and made it politically impossible to improve on the early, relatively crude systems that were in place in the 60's and early 70's.

Today, those same people are telling us what we should do about climate change, which amounts to "anything but nuclear power or even doing research into geo-engineering, because when we pretend to be in a panic about the future of the climate we're lying: if we weren't lying we'd really be interested in any solution whatsoever, not just ones that we happen to find politically palatable."

I mean seriously, isn't it interesting that so many "environmentalists" let their politics over-ride their supposed concern for the environment?

The risks of AGW are real. I'm not convinced they are potentially civilization-ending, but if I was, I'd be screaming from the rooftops to build more nukes and investigate geo-engineering. Anyone who claims to think AGW could be civilization-ending but isn't doing those things is a liar or a fool, or both.

Comment Re:Double down (Score 1) 534

I guess for me it boils down to this: if there is a nonzero probability X that future generations will suffer devastating consequences of our pollution, we should do everything we can to mitigate that. This is true even for small X because the scale of consequences are potentially very large.

By "everything we can" are you including the standard proviso, "except invest in nuclear power or even do research in geo-engineering, because when I say 'everything we can' I only mean 'everything we can to control other people's lives, because I'm a control freak, not an environmentalist'?"

Comment Re:I wish they'd stop calling it that. (Score 1) 71

After that, maybe they could try writing a remotely accurate summary, too! The summary is borderline gibberish, as it is impossible (in linear materials) for EM fields to "deflect" each other.

This "cloak" is interference-based, using active dipoles to generate a field that cancels the scattered field in the forward (0 degree) and backward (180 degree) directions. It's a clever piece of work, but there are fairly hard limits to the how wide an angle such techniques can cover, and moving from an essentially 2D scenario to full 3D increases the complexity enormously, although I'd love to see them try it.

Comment Re:Orson Scott Card (Score 3, Insightful) 732

then introduced a what-if scenario where the rules failed.

...and thus turned the movie into yet another remake of RUR, the primordial "robots go nuts and kill people" story that is precisely what Asimov was reacting against and trying to avoid when he created the 'three laws", whose whole purpose was to write off the very possibility of such a plot from the word "go", so he could concentrate on the interesting questions.

So yeah, they took the title and slapped in on something that was antithetical to the original in every respect. Other than that it was a good movie (except that RUR is a fairly pedestrian play, and doesn't need any more remakes, even though every single movie about robots ends up as a remake of it.)

It's as if someone took "Starship Troopers" and made a film where humans settle their differences with aliens by peaceful negotiation. It might be a good film (it probably would be better than the film that was made of that name) but it would be diametrically opposed to the theme of the original book, just like the movie "I, Robot" is.

Comment Amazing (Score 0, Troll) 43

Monkeys and every other living creature with a brain uses their mind to control all kinds of things. Why is this remotely interesting to anyone?

Show me one example of anyone anywhere controlling anything without using their mind.

I'm typing this grouchy rant right now... using my mind! Is that worth getting written up on /. for?

Or could the headline actually mean, "Monkey controls something using millions of dollars of custom hardware that replaces the functions of some of its nervous system and musculature"? If that's too long, then why not: "Monkeys Move Avatar Arms With Expensive EEG Hardware"?

Comment Re:Ask Doctors ... (Score 5, Interesting) 786

You should talk to Doctors. They seem to have a quite different opinion of Medicare

You should also look at world-wide comparisons. Medicare and other public healthcare programs in the US account for more dollars per capita spent than all or almost all universal health-care systems in other countries, and deliver lousy results comparatively.

Canada--with our nominally single-tier, public, single-payer health care system--has longer life expectancy, lower infant mortality, and better outcomes by any number of other measures. Critics (sometimes justly) focus on input measures like wait-times, but at the end of the day what matters is that we are getting health care and getting good outcomes. We aren't even the best in the world--just middling-decent as these things go.

So the real question is not "why can't government launch a website" but "why can't the US Federal government, alone amongst all governments in all developed nations, provide a reasonable level of basic, universal health care at costs comparable to those in every other developed nation on Earth?"

This isn't a "government" problem. It is a uniquely American problem, and the solution does not lie in any general ideological fix, but in the detailed structure of the specifically American, particularly broken, Federal government.

Slashdot Top Deals

I judge a religion as being good or bad based on whether its adherents become better people as a result of practicing it. - Joe Mullally, computer salesman