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Comment: Re:Ted Postol very bias opinion. (Score 1) 185

by Rei (#47440615) Attached to: A Skeptical View of Israel's Iron Dome Rocket Defense System

Actually, the key thing for them is "cheap". They need to keep costing sub-$1k missiles in the ballpark of these Iron dome systems - the more, the better. They might as well just omit the warheads to save money and increase range. Every $50k shot Israel fires with those systems costs 25 Israelis' annual tax contribution to the IDF. Every $55m system they deploy costs 27.500 Israelis' IDF tax contributions.

Palestinians are poor, but they're not *that* poor that they can't leverage those kind of lopsided financial ratios.

Comment: Re:Subject bait (Score 1) 184

by Rei (#47440537) Attached to: A Skeptical View of Israel's Iron Dome Rocket Defense System

No, in the case of Iron Dome, that's only PR too. They're shooting $50k+ missiles at $800 rockets. Even after factoring in that Israel's per-capita GDP is 20 times that of Palestine's, that's still a losing proposition, even *if* they had a 100% hit rate (which this article is suggesting it's anything-but) and assuming that you get the launcher, radar, etc for free instead of the actual $55 million per unit. It's in Palestine's best interests that Israel deploy as many of them as possible and try to shoot down every last rocket, because every shekel they spend on Iron Domes and missiles is a shekel they don't spend on jets, tanks, and bombs.

Comment: Re:because drinking water is so pristine (Score 2) 144

by fuzzyfuzzyfungus (#47439187) Attached to: Texas Town Turns To Treated Sewage For Drinking Water
The drugs are often exotic molecules we've cooked up for the purpose; but hormonal birth control exploits the same hormones that would naturally show up, since those are the ones that there are receptors for and that cause the desired changes. The quantity that a dense human population will put out is something quite different; but the chemistry won't be markedly different between humans and other placental mammals.

Comment: Re:Not new, and not shocking. (Score 1) 144

by fuzzyfuzzyfungus (#47439137) Attached to: Texas Town Turns To Treated Sewage For Drinking Water
There might be an RO system somewhere that uses gravity and an input reservoir at higher altitude than the output to supply some or all of the pressure; but I don't think that that is anything like the typical configuration. Cleaning up after a leak in zero gravity isn't going to be lots of fun; but everything else should work largely as planned.

Comment: Re:Subject bait (Score 4, Insightful) 185

by fuzzyfuzzyfungus (#47438915) Attached to: A Skeptical View of Israel's Iron Dome Rocket Defense System
In the case of SDI the PR might actually be worse than useless (playing mutually-assured-destruction isn't much fun to begin with; but if one or both sides come to believe the hype about a missile defense system things could really go downhill). In the case of 'iron dome', though, it might actually be helpful. Barring fairly substantial increases in rocket construction expertise, or acquisition of something particularly nasty to fill them with, the attacks it is supposed to defeat are only modestly dangerous; but extremely inflammatory.

Given how lousy the alternatives for appearing to be taking action against the rocket menace are (grovelling through every last hidy-hole in Gaza is militarily doable but a PR debacle and unlikely to turn up more than a few bits and pieces of impoverished machine tools, because low-end rockets just aren't that hard to build. Paying Hezbollah a visit might turn up somewhat more interesting stuff; but that hasn't turned out well in the past) a system that postpones or prevents somebody taking the bait and trying them might be quite helpful.

Comment: Re:USB DACs (Score 1) 477

Personally, I use built-in audio. It really IS good enough for most purposes - I have never been dissatisfied with the quality of my laptop DAC.

My original point was that cheap USB audio (those under $10) are crap, and most people who just want to improve the sound, and CAN tell the difference, don't need the fancy DSP stuff.

I want to Sweetwater's web site. They have a bunch of brands of USB audio interfaces in the $100 range from such brands as Alesis, PreSonus, Yamaha, and M-Audio. Behringer even makes $30 ones, but reviews are mixed. Still, if you need line-in on a laptop, that is the cheapest way. If you ARE into sound and music, you can get even mixers with audio interfaces built-in. Alesis even makes some rather nice studio monitors (speakers) with a USB interface.

Comment: That said... (Score 4, Informative) 54

by Rei (#47437451) Attached to: Sand-Based Anode Triples Lithium-Ion Battery Performance

... the greater your capacity, the less cycle life matters. If you want an EV that battery that will run a 250Wh/mi vehicle for an average 20 miles a day for 15 years, then you want it to cycle through about 30MWh. If you use a 100 mile (25kWh) battery pack, then that's 1100 cycles. If you use a 200 mile (50kWh) battery pack, then that's 550 cycles. If you use a 400 mile (100kWh) battery pack, then that's a mere 275 cycles. Actually, the improvement is even better than that in the real world, because the greater your capacity vs. how far you're actually driving, the more you can cycle the cells through a less destructive state of charge range rather than doing deep discharges.

A lot of people picture battery packs in EVs backwards, they think that things like hybrids stress the packs the least, PHEVs moderately, and EVs the worst. But it's reversed. If you look at how big hybrid packs are vs. how much electric range they hold, you'll see that they're disproportionately large, even after you factor in any differences in Wh/kg. The reason is that because hybrid packs get cycled so much, they have to keep the cycling in a very narrow state of charge range, only allowing shallow discharges. So if you only have a narrow discharge range, you have to make your pack bigger to make up for it. EVs can discharge through much more of their pack because they need fewer total cycles and only rarely go down toward the lower end of their allowable discharge range. Some EVs also let you limit the max that your pack charges up to to further extend lifespan (it's usually destructive both to use the very top end and the bottom end of the discharge range).

Comment: Re:Correct me if I'm wrong, but... (Score 4, Informative) 54

by Rei (#47437401) Attached to: Sand-Based Anode Triples Lithium-Ion Battery Performance

1024 mAhg1 is excellent capacity even vs. brand new graphite or amorphous carbon, about 3x as much as graphite's maximum. Silicon's theoretical max is 8-10x that of graphite, but the main problem with it is durability, it tends to tear itself apart on loading. There are silicon anodes in some newer li-ion cells on the market, but the tech is in its infancy.

That said, the real papers you want to be on the lookout for are cathode improvements, there's a lot more potential for volume/mass reduction there than in the anode. But it seems to be a more difficult challenge. Getting a 3x improvement in anode density is absolutely not the same a getting a 3x improvement in battery life.

Comment: Re:Little Bit of History Repeating. (Score 5, Insightful) 54

by Rei (#47437377) Attached to: Sand-Based Anode Triples Lithium-Ion Battery Performance

Commercial li-ion battery energy densities have continued to improve during that time period, including the commercial introduction of cells with silicon anodes. Of course, silicon anodes are a new tech, so there's a great deal of room for improvement, which probably won't come close to "maxing out" for a decade or more.

Of course, that said, this article is your typical fluff piece following the guidelines of fluff science reporting.

1. Present an oversimplified version of one technology challenge that may or may not address the biggest issue and certainly doesn't address all of them - but don't mention that.
2. Introduce an outside-the-establishment loner with a passion - or at least someone you can try to present as "outside the establishment" and glaze over anyone who helped him.
3. Loner gets a "vision" based on some everyday activity
4. Present their solution and make it out to be a huge revolution that will certainly solve all our problems - if they can only get corporate backing / funding!

I think these sort of articles hurt the image of science because people read them, think "OMG, all our problems are solved!", then when everything's not solved afterward, fail to trust science in the future. For example, in this case, the most important element to improve is the cathode, not the anode. And cathode improvements are less common and usually less major than anode improvements. There's also tons of different anode improvements out there in various stages of research. Pretty much all of the silicon ones get way better than graphite or amorphous carbon.

That doesn't mean that this isnt an important paper - actually, from looking at it, it looks pretty good. It's just not "all that".

BTW, anyone know how credible this journal is? I see it's hosted on Nature.com but not part of Nature, and I tried to find an impact rating for it but couldn't.

Comment: Re:Don't sweep it under the rug as collateral dama (Score 1) 148

Don't claim copyright on every video, this will make you guilty of perjury under the DMCA. Claim copyright on one video and then claim that every other video appears to be a derived work of that video. This is exactly the mechanism that the big studios use.

Comment: Re:Don't sweep it under the rug as collateral dama (Score 2) 148

The perjury clause doesn't say what you think it says. If I own the rights on work A, to file a notice on work B, I claim that work B infringes work A. The perjury clause kicks in only if I do not own the rights to work A (or represent the person who does). If work B doesn't infringe, then that's a matter for the courts. This is quite annoying, but it does make sense. It's clear cut if works A and B are the same, but not in the case that B is a derived work of A. A court has to decide whether the use of A in B counts under fair use or not.

The counterbalance for this is that the DMCA does indemnify YouTube if they respond to a counternotice and reinstate the work. If you, the owner of work B, think it does not infringe then you send such a notice to YouTube. I then have no further recourse against YouTube and must take you to court directly.

The problem here is that it's very easy to automate sending takedown notices, but very hard to automate sending counter-notices. Mass-sending of automated takedown notices was something that the authors of the DMCA didn't foresee and the act probably needs amending to require the notice to explicitly state (under penalty of perjury) the person who has compared the works and their reason for believing that they are infringing.

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