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Comment: Re:Ted Postol very bias opinion. (Score 2) 222

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 2) 222

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: That said... (Score 4, Informative) 56

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) 56

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) 56

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.

Mars

Mars (One) Needs Payloads 74

Posted by timothy
from the ok-but-nothing-too-heavy dept.
mbone (558574) writes Mars One has announced that their first, unmanned, lander, targeted for 2018, needs payloads. Along with their 4 experiments, and a University experiment, they have two payloads for hire: "Mars One offers two payload opportunities for paying mission contributors. Proposals can take the form of scientific experiments, technology demonstrations, marketing and publicity campaigns, or any other suggested payload. 'Previously, the only payloads that have landed on Mars are those which NASA has selected,' said Bas Lansdorp, 'We want to open up the opportunity to the entire world to participate in our mission to Mars by sending a certain payload to the surface of Mars.'" The formal Request for Proposals for all of this is out now as well.

+ - Mars (One) Needs Payloads->

Submitted by mbone
mbone (558574) writes "Mars One has announced that their first, unmanned, lander, targeted for 2018, needs payloads. Along with their 4 experiments, and a University experiment, they have two payloads for hire :

Mars One offers two payload opportunities for paying mission contributors. Proposals can take the form of scientific experiments, technology demonstrations, marketing and publicity campaigns, or any other suggested payload. “Previously, the only payloads that have landed on Mars are those which NASA has selected,” said Bas Lansdorp, “We want to open up the opportunity to the entire world to participate in our mission to Mars by sending a certain payload to the surface of Mars.”

The formal Request for Proposals for all of this is out now as well."
Link to Original Source

Comment: Re:What is life? What is a virus? (Score 5, Insightful) 156

by radtea (#47428331) Attached to: Hints of Life's Start Found In a Giant Virus

Then, in that case, what separates pithovius from the prokaryotes?

Structure, from the sound of it, although mostly this is people committing various fallacies of reification and making false claims of "natural kinds".

Everything is a continuum. Humans divide the continuum up using acts of selective attention. The only infinitely sharp edge is the edge of our attention (because we scale the edge to match the scale we are attending to, so whatever scale we are attending to seems to have a sharp division between the things we are selecting out.)

"Species" do not have particularly crisp boundaries in the general case: they fade into each other, and we draw edges around them in more-or-less arbitrary ways. When we find new varieties we can either create new categories (by drawing new edges) or lump them into old categories (by moving old edges). Which move is to be preferred depends on the purposes of the knowing subject.

Comment: Re:Repercussions? (Score 2) 107

They have shown that they can not be trusted. They must lose the power to do this.

Pull someones certificates or kill some CA. Someone needs to suffer because of this.

What happens now is that there's an investigation. Depending on the outcome the CA may be revoked for good, or merely forced to reissue lots of certificates. The deciding factor is the reason for the screwup - for instance they may have got hacked, rather than been actively corrupt. In that case Microsoft will have to decide if they have patched things up enough to continue as part of their root store program or whether to pull the plug. I doubt many people have certs issued by this CA so the damage would be relatively minimal.

Unfortunately you can't just kill any CA that screws up. For one, if the CA was widely used it'd be disrupted. For another, nothing is unhackable, especially when you get the NSA involved. Expecting CA's to be able to reliably fight off professional hackers from dozens of governments and never ever fail is likely an impossible standard to ever meet.

Hard decisions ahead for browser and OS makers for sure ...

If you're not part of the solution, you're part of the precipitate.

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