Slashdot stories can be listened to in audio form via an RSS feed, as read by our own robotic overlord.


Forgot your password?

Comment: Re:Dark matter and the sniff test (Score 5, Informative) 85

by Baloroth (#48589511) Attached to: Deflating Claims That ESA Craft Has Spotted Dark Matter

However, for some reason unknown to me, the visible matter in our solar system perfectly describes how the planets orbit the sun, how the moon orbits the earth, and how hard I hit the ground when I try to fly. So where is this dark matter, all this extra gravity? Shouldn't I hit the ground a lot harder than we can explain just based on the mass of our planet?

It's because dark matter only interacts gravitationally. See, normal matter clumps up into planets and stars because it sticks to other particles, and loses energy from collisions, causing it to collapse over time into locally dense spheres (planets, stars, black holes, etc.). But dark matter doesn't: it just passes through itself (mostly: it may interact through the weak force, but only very very very rarely if so, not enough to clump up). That means it doesn't form local regions of high density. On the other hand, an object immersed in a more or less uniform sea of matter (of any kind) won't notice any gravitational effects, because it's being pulled in all directions equally (for example: you'd be weightless at the center of the Earth. Dead from the pressure/heat/lack of air, but weightless). So, we can float through a sea, even a fairly dense one, of dark matter and notice nothing at all. Now, there is an non-uniformity in this dark matter "sea": there is more on the side of us towards the center of the galaxy than there is on the other side, but that pulls the entire solar system uniformly, accelerating it in it's galactic orbit, and that effect we do in fact see.

Comment: Re:Entrapment is lazy policing (Score 1) 388

by Baloroth (#48541201) Attached to: Man Caught Trying To Sell Plans For New Aircraft Carrier

It's arguably entrapment, and whether or not the guy will end up with a criminal conviction I don't know (IANAL, certainly not on matters of treason), but this has nothing to do with "policing". They aren't looking for criminals at all. It's essentially a penetration test: they generally try to only give out security clearances to more or less trustworthy folks, but some people with clearances are going to be willing to give up classified information for money. The way to find those people is to offer them money. This sort of thing is routine practice in many different areas. It's quite common, for example, for companies to send out fake phishing emails so they can identify people who might fall for them. Usually, this sort of "entrapment" results in firing or training, but when you're dealing with classified information, criminal prosecution is a pretty obvious step.

Generally, being stupid and greedy isn't a crime, but when you work in a field where being stupid and greedy like this can easily get people killed, and you know that, and signed a document to that effect, well, then when you act stupid and greedy, you won't get much sympathy from me if the government tries to throw you in jail.

Comment: Re:Drake is Obtuse (Score 4, Interesting) 334

by Baloroth (#48527853) Attached to: Aliens Are Probably Everywhere, Just Not Anywhere Nearby

Unfortunately the Drake equation is worthless even for that purposes, as several terms in it cannot be estimated with any accuracy at all, and may in fact never be able to. You can't for example, extrapolate the probability of life evolving on a given planet when you only know of a single example of life evolving (extrapolation requires at least two instances). That leaves 4 terms in the Drake equation (fraction of planets that develop life, fraction of living planets that develop intelligence, fraction of those that end up sending signals into space (though those latter two should probably be condensed into a single term), and length they send out said signals) that cannot be estimated with any accuracy until we discover some instance of them. Which, rather ironically, means the Drake equation is worthless for any kinds of actual predictions unless we actually discover intelligent life, at which point the entire problem it was meant to illustrate becomes kind of moot (because we'll then know the answer that yes, there definitely is other intelligent life in the universe).

You can sort-of put weak upper bounds on (at least some of) those terms, but we're a long way from being able to do that.

Comment: Re:You will not go to wormhole today. (Score 4, Insightful) 289

by Baloroth (#48492951) Attached to: Physicist Kip Thorne On the Physics of "Interstellar"

Humor aside, relativity and thermodynamics have been proven at both the largest and smallest scales that humans have been able to observe, and at every level in between.

This is half completely wrong. Thermodynamics by definition does not apply to small scales, only to bulk systems. Hell, a small system of particles can (and in fact quite often will) easily violate the laws of thermodynamics. They're almost meaningless at small (i.e. a few dozen atoms) scales, because they're purely statistical laws. Even a large system can, in principle, violate the laws of thermodynamics, but only for extremely brief periods of time, and with a likelihood that approaches zero for macroscopic (order of 10^23 particles) systems.

Secondly, the behavior of relativity at very small scales is currently unknown. Reconciling general relativity with quantum mechanics requires quantized gravity, and all current attempts to describe that mathematically have failed. This is a problem in either very small scales (i.e. Planck lengths, which to be fair haven't been observed and probably won't for quite some time), or in extremely large gravitational fields, such as that created by black holes, which we have (indirectly) observed. Both relativity and thermodynamics work great in their relative domains, but both of them have known domains where they collapse. For thermodynamics that doesn't really matter (it's constructed to only be true for bulk systems), but it's a pretty big issue for relativity, and suggests there is a significant gap in our knowledge.

Comment: Re:Lightsaber crossguard wtf (Score 1) 390

by Baloroth (#48481107) Attached to: First Star War Episode 7 Trailer Released

Of you would pay more attention to the actually used fighting style you had realized that the choreographers are aware of the problem and use a fighting style that avoids losing hands. Your idea of sliding along the 'blade' is easy countered ... if you know how to handle a light sword, floret or katana.

In reality, fights using conventional blades don't slam the blades against each other like duels in Star Wars always do. That's a very quick way to ruin a sword (sharp metal on sharp metal quickly ends up with an edge more suitable to a hacksaw). In fact, duels with something like a katana are usually ended in a stroke or two, conventionally. Real sword fighters would usually use a shield, buckler, or some other variety of off-hand blocking device (or the flat of the sword, if absolutely necessary) if the combat style emphasizes blocking.

Star Wars duels are pure Hollywood looks-good-on-screen-but-totally-impractical (mind you, the lightsaber itself is a totally impractical weapon in a world where ranged weapons are common: it's like people in that universe haven't even heard of shotguns). Even then, no less than 3 people end up losing a hand in a duel (Mace Windu, Anakin (twice), and Luke). The fighting style in Star Wars only avoids losing hands during the duel because it's written that way (there are many times when the fighters clash blades inches away from the hilt).

Comment: Re:Lightsaber crossguard wtf (Score 5, Interesting) 390

by Baloroth (#48480307) Attached to: First Star War Episode 7 Trailer Released

That's not something you can do to a lightsaber goddammit.

Ahem. Actually, it makes a kind of sense: it always bothered me how Star Wars lightsabers didn't have any kind of hilt/crossguard, which should have made it almost trivially easy for their opponent's to simply slide their lightsaber down the blade and slice off their opponents hand. Maybe someone in the universe finally realized that with a crossguard every lightsaber duel wouldn't end with someone loosing a hand?

Comment: Re:ENIAC wasn't the first (Score 2) 126

by Baloroth (#48464149) Attached to: How the World's First Computer Was Rescued From the Scrap Heap

Fail. The Z1 was the first programmable computer, finished in 1938 by Zuse himself, on private funding.

Yes, but he didn't fail, because that's not what he said. He said first electronic programmable computer. The Z1 (and successors) were electromechanical. Still impressive in their own right, true, but nothing like the electronic computers that were invented later.

Comment: Re:Except... (Score 4, Insightful) 126

by Baloroth (#48464097) Attached to: How the World's First Computer Was Rescued From the Scrap Heap

Colossus absolutely was general purpose - it just wasn't stored program. You had to set it up fresh for each program.

No, it wasn't general purpose. It was designed from the ground up to solve a very specific class of problems. It would have been possible (as the linked article states) to put a bunch of them together to form a Universal Turing computer, but it itself was not general purpose nor Turing complete.

Comment: Re:Armchair cognitive scientist (Score 2, Interesting) 455

Watson is actually way "smarter" than any human in certain ways.

That has *always* been true of computers. That is, in fact, exactly why we built computers in the first place: to do things faster than humans can. Saying that something is "smarter than any human in certain ways" is meaningless. Hell, in a way, rocks are smarter than humans. After all, if I throw a rock, it "knows" exactly what path it should take (minimizing energy, interacting with the air, etc.) Sure, it'll be nearly a parabola, but it will be perturbed from a parabola by tiny air currents, minute fluctuations in the gravitational field, et alia. And it will follow the resulting path perfectly. Humans cannot calculate, and will never be able to calculate, this trajectory with perfect precision. No one would ever say the rock is smarter than a human, however, because obviously, it isn't. It has absolutely no intelligence whatsoever.

Watson is, fundamentally, no different from that rock. Sure, it follows a very complex "path" indeed (though laid down by humans), but the only difference between the rock and Watson is the *kind* of path. In fact, Watson's path is less complex than the path of the rock (which isn't entirely a fair comparison, since the rock's path is practically infinitely complex). There is intelligence in Watson, sure, but it's our intelligence, in the same way a thrown rock can make a deadly weapon if well-aimed. This is not to say that it's impossible for humans to design an intelligence that can supersede our own, but the kind of intelligence required for the "singularity" is entirely and almost completely different from anything we've come up with so far. We might do it one day, but it'll require an invention of an entirely new kind of artificial intelligence, and we don't even know what that kind of intelligence would look like, beyond possibly running a simulation of a human mind (which is, quite possibly, one way of doing it).

I certainly wouldn't listen to the "it's coming in 2040" predictions for the singularity: I mean, people seriously thought we'd have fusion power, flying cars, and regular moon trips by now 50 years ago, and none of that happened. On the other hand, we did get the Internet and ubiquitous wireless communication, which few people predicted. The future of technology that far away is unpredictable, because it relies on new discoveries, and by definition we don't know what we haven't discovered yet.

Comment: Re:Tentative summary (Score 2) 150

by Baloroth (#48264747) Attached to: Researchers At Brown University Shattered a Quantum Wave Function

I don't see that this experiment is any different from a photon reflecting between parallel partially-silvered mirrors. You see a range of arrival times at the detector, despite the wavefunction being "fragmented" by multiple reflections.

I only got a chance to scan the paper, but my impression is this. The difference is that the split electron wavefunction is creating a bubble in the liquid helium. Splitting a quantum wavefunction is rather boring: it's pretty easy, all you need is a finite barrier to produce tunneling, or a double-slit to produce separate paths, or a bunch of other ways. What this experiment does, though (if they're correct about the cause) is show that the split wavefunction actually affects the matter through which it travels (creating a bubble), proportional to the amount of wavefunction that splits off, without counting as a "measurement" which would collapse the wavefunction and place the electron definitely inside one bubble or another.

Or, to put it another way, it shows that matter not only behaves like a wave when traveling (which was very well known in quantum mechanics), but can do so even when interacting with matter. That is fairly novel (AFAIK) in QM, since usually such interactions either cannot be measured or collapse the wavefunction into a particle-like behavior. It's a lot closer to directly measuring the wavefunction (or it's amplitude, anyways) itself than most QM experiments allow.

Comment: Re:Shash-job-vertisement (Score 3, Insightful) 205

by Baloroth (#48176249) Attached to: The One App You Need On Your Resume If You Want a Job At Google

Ugh, this reads like a job ad.

When I moved from Matlab to Python three years ago, I saw a massive speed increase of my methods. Also I no longer have to decide whether or not to shell out more cash for the statistics package, it's all there!

Looking back at my old Matlab code also makes me cringe a bit about the syntax of that language.

Reads more like an ad for Matlab (with 2 links to Mathworks and 1 to the Wikipedia Matlab page in TFA) than a job ad. Though I suspect what actually happened was the reporter heard Jonathan Rosenberg mention Matlab (which the reporter hadn't heard of before) and got all excited over his "discovery" when anyone who's likely to get any kind of data analysis/statistics job for, well, anyone, already knows what Matlab is.

Comment: Re:Easter egg hunt (Score 1) 622

by Baloroth (#48134519) Attached to: The Correct Response To Photo Hack Victim-Blamers

If it were April I would say that huge mount of boring text has a point hidden somewhere inside it. Let's hope there's a piece of chocolate attached to it as well.

Although if anyone does find something dark brown and gooey in that text, I'd advise them not to try eating it, as it's probably not chocolate.

Comment: Re:Yes, because everyone is burning their smartpho (Score 1) 238

Relativity and Quantum Mechanics are both about 100 years old now (really!). Why aren't they taught in high school? High schools mostly teach science that was the state of the art around the time of the US civil war (really!).

Kant is even older than that, and yet you don't see him being taught in high school either. The age of an idea has little to do with the complexity of the idea, and quantum mechanics is quite complicated, if you want to really understand it. Shakespeare is only widely taught because, due to cultural influences, he is considered something that everyone should know, and his plays aren't really all that hard to understand. Quantum mechanics, orbital dynamics, E&M, etc., not so much. It's not simply because they're hard, either, though those subjects are: it's simply because, unless you're going into a field that requires it, you really don't need to know them, just as the physicist doesn't need to know Kant.

Comment: Re:Alibaba (Score 4, Interesting) 192

by Baloroth (#48009405) Attached to: NVIDIA Begins Requiring Signed GPU Firmware Images

They are selling nvidia cards with a modded firmware? Why? Nvidia is going to change their hardware, and hardware will only accept signed firmware. Fake cards, can choose to simply not do any signature checks on their hardware. Unless the fake cards are real nvidia cards, which for some reason run a modded firmware instead of nvidia singed firmwares, this will have no effect on them.

That's exactly what they are. It's pretty trivial to take, say, GTX 440, and reflash the firmware to report that it's a GTX660. It's extremely difficult to make a fake nvidia card that isn't actually an nvidia card that actually works as a video card and isn't completely obviously a fake. The story was even on slashdot.

"Text processing has made it possible to right-justify any idea, even one which cannot be justified on any other grounds." -- J. Finnegan, USC.