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Comment: Re:Ted Postol very bias opinion. (Score 2) 216

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) 216

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) 55

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) 55

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) 55

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.

+ - Maldives Denies Russian Claims That Secret Service Kidnapped A Politician's Son

Submitted by Rei
Rei (128717) writes "As was previously reported here, the Russian government has accused the US Secret Service of kidnapping the son of ultranationalist LDPR MP Valery Seleznev in the Maldives. The son, Roman Seleznev, stands accused of running one of the world's largest carding operations, with others charged in the affair having already been convicted; however, Roman had until recently been considered out of reach in Russia. Now the Maldives has struck back against these claims, insisting that they arrested him on an Interpol Red Notice and transferred him to the US, as they are legally required as an Interpol member state to do. “No outsider came here to conduct an operation,” president Abdulla Yameen stated. “No officials from another country can come here to arrest anyone. The government has the necessary documentation to prove it.”"

Comment: Re: (Score 2) 420

by Rei (#47423005) Attached to: Climate Change Skeptic Group Must Pay Damages To UVA, Michael Mann

He said ice sheet. So we're supposed to ignore what he actually said and assume he meant something completely different? Um, no.

"I am not well read in this department" - wait a minute, you can give exact cites for research papers on sea ice, but don't even have a *general* conception of what percentage of the Antarctic ice sheet is gaining versus what is losing? Something tells me you're just grabbing cites you've never even read from denier websites.

Let me help you out with ice sheet. Pretty much all of the East Antarctic ice sheet is gaining, while pretty much the only area losing is the Antarctic peninsula and surrounding areas in West Antarctica. Now, they're losing *mass* a lot faster per unit area than the east is gaining mass, but in terms of area, the overwhelming majority of Antarctica is gaining ice. Because it almost never gets above freezing there, even in a warming world.

The 2010 paper was evaluating the failed CMIP5 predictions

If you'd actually read the paper, which you clearly haven't, you'd know that they themselves did the CMIP5 runs, it's not CMIP5 runs that had been done earlier. Do you even have a clue what CMIP5 stands for? Coupled Model Intercomparison Project Phase 5. As in, "there were four freaking phases that came before this one". CMIP5 is comprised of all of the latest models from all over the world. They didn't even start planning CMIP5 unitl September 2008. Your notion that this is some sort of review of old climate predictions just shows how terrible your understanding is of what you're talking about and how you don't actually read the papers that you cite, that you're just simply grabbing them from whatever denialist trash websites you read.

Comment: Re: (Score 1) 420

by Rei (#47422677) Attached to: Climate Change Skeptic Group Must Pay Damages To UVA, Michael Mann

First, that's a paper from 2010. How was a paper from 2010 supposed to be "predicting" anything about what scientists in the past thought?

Secondly, and more importantly, I had been responding to Archangel Michael, who was talking about the thickness of the Antarctic ice sheet, not Antarctic sea ice. So your link about pack ice is totally irrelevant.

But hey, let's switch topics totally and talk about sea ice, since you seem to want to. Here's how the IPCC sums up all papers on the modelling of antarctic sea ice, including this one:

Whereas sea ice extent in the Arctic has decreased, sea ice extent in the Antarctic has very likely increased. Sea ice extent across the Southern Hemisphere over the year as a whole increased by 1.3– 1.67% per decade from 1979–2012 with the largest increase in the Ross Sea during the autumn, while sea ice extent decreased in the Amundsen-Bellingshausen Sea. The observed upward trend in Antarctic sea ice extent is found to be inconsistent with internal variability based on the residuals from a linear trend fitted to the observations, though this approach could underestimate multi-decadal variability. The CMIP5 simulations on average simulate a decrease in Antarctic sea ice extent , though Turner et al. (2013) find that approximately 10% of CMIP5 simulations exhibit an increasing trend in Antarctic sea ice extent larger than observed over the 1979-2005 period. However, Antarctic sea ice extent variability appears on average to be too large in the CMIP5 models . Overall, the shortness of the observed record and differences in simulated and observed variability preclude an assessment of whether or not the observed increase in Antarctic sea ice extent is inconsistent with internal variability. Based on Figure 10.16b and (Meehl et al., 2007b), the trend of Antarctic sea ice loss in simulations due to changes in forcing is weak (relative to the Arctic) and the internal variability is high, and thus the time necessary for detection is longer than in the Arctic.

Weak trend, short observed record, and high internal variability in the simulations. Which shouldn't be surprising, sea ice is a lot harder to model than ice sheet thickness, which really only has three main parameters - snowfall, melt/sublimation, and outflow, and the short observed record is due to how few people historically have navigated antarctic waters vs. arctic.

But again, to reiterate the primary point: the conversation you jumped into was about ice sheet thickness, not sea ice.

Comment: Re: (Score 1) 420

by Rei (#47421159) Attached to: Climate Change Skeptic Group Must Pay Damages To UVA, Michael Mann

I'm sorry, I just read through that paper, and nowhere in it does it say that a decline in Antarctic ice is a forecast of AGW. That's one of the worst examples of "proof by ghost reference" I've ever seen. Not to mention that the paper is mainly focused on the Antarctic Peninsula, the one place that actually gets melt on more than super-rare occasions and juts into a different climate zone.

Comment: Re: (Score 3, Insightful) 420

by Rei (#47418485) Attached to: Climate Change Skeptic Group Must Pay Damages To UVA, Michael Mann

Go right ahead and point me to where a decline in Antarctic ice was a forecast of AGW.

You do know that - below freezing - there's an inverse correlation between temperature and snowfall, don't you? And I really hope you know that it's very rare that temperatures rise above freezing in the vast majority of Antarctica, whether you add a couple degrees to the temperature or not, right? Or did you not know / ever consider that?

Just because you didn't realize something that should have been really bloody obvious to you doesn't mean it was a scientific prediction by your straw-man scientists.

Comment: Re:Not just Obama. (Score 1) 78

by Rei (#47415799) Attached to: Buzz Aldrin Pressures Obama For New Space Exploration Initiative

Corr: That should read "doesn't lose much IR transmission as a consequence of neutron bombardment like happens in higher frequency bands" - accidentally lost that middle part. Fused silica and fused quartz (especially the latter, but also the former) blacken under neutron exposure, losing transparency; it's even done intentionally to make jewelry. But the papers I ran into when researching the topic showed that this effect isn't very pronounced in the IR band.

Comment: Re:Not just Obama. (Score 3, Interesting) 78

by Rei (#47414883) Attached to: Buzz Aldrin Pressures Obama For New Space Exploration Initiative

Agreed. But that doesn't mean it doesn't make sense to embark on big projects. Rather than a "Hey, we're going to walk somewhere new" sort of thing, I'd like to see work on one of any number of space-related megaprojects - for example, a launch loop and/or fallout-free nuclear rockets**. Something that could actually lower the cost of access to space to the point that it doesn't take a vast effort to go walk on another celestial body.

** - There's so many competing designs it's hard to know where to start. My personal concept I've mulled over is a variant of the nuclear lightbulb concept, but instead of the fused-silica bulb containig a gas or plasma core reactor which requires some unknown containment method, the concept calls for a dusty fission core (akin to a dusty fission fragment rocket), which can be electrostatically contained. The energy would be released in the infrared, not visible or ultraviolet (as in a conventional lightbulb concept), but that's fine - fused silica is also transparent to infrared, and moreover doesn't lose much IR transmission as like happens in higher frequency bands; the lower radiation rate of infrared would be compensated for by the huge surface area of the dust radiating it. The simultaneous huge amounts of electric output (from fission fragment deceleration in a grid) could be used in part to run a microwave beam, creating a plasma sheath in ducted atmospheric air surrounding the bulb (airbreathing mode) or injected gas surrounding it (rocket mode) to aid in IR absorption and keep as much of the heat away from the (reflective) walls as possible. A VASIMR-ish mode is possible if you use low gas injection rates and a magnetic nozzle. In space, gas injection could be terminated altogether and the core could be opened up to run in dusty fission fragment mode and get Isp figures in the lower hundreds of thousands. To make up for the problems with using the standard dusty fission fragment rocket proposal's (heavy) moderator in such a high power environment, my thoughts were to have it operate as a subcritical reactor with a spallation neutron source as the driver - after all, there's no shortage of electricity to run an accelerator if you're decelerating a good chunk of the fragments; you don't even have to deal with Carnot losses.

I am not now, nor have I ever been, a member of the demigodic party. -- Dennis Ritchie

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