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.

I can't help but picture a sign on the door at the exit of an airport in Israel. It reads "Thank-you for not stirring up ancient inter-tribal conflict".

Now I can't help but think of this excellent video :)

Using a nuclear device at high altitude? You do know what happens if you do that, right? That one test bomb knocked out street lights and long distance phone service nearly 1000 miles away and took out a third of all satellites in orbit around Earth at that point in time.

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.

Goliath is stomping ten Davids every time one David throws a rock, and a hundred if it's a credible throw (e.g. a rocket).

It seem more that they will blame "David" every time a rock gets thrown. Some of these rockets are being fired from Lebanon yet Hamas, rather than Hezbollah, being blamed. Co-operation between Shia and Sunni not being likely either. Those launcing the rockets are also being refered to as "Hamas supporters". Rather implying "With friends like these who needs enemies".

After reading the article, his reasoning is that the Iron Dome is mostly chasing the rockets from behind, and therefore cannot be effective, because a rocket cannot effectively be caught from behind, or from the side.

Without knowing the actual flight characteristics of both the rockets and the missiles you can't really say if "tail chasing" is a viable interception approach or not.

Furthermore, previous anti-missile systems (the patriot) have had their success rate exaggerated.

It's likely to be harder hit an unstable missile than one which stable. IIRC this was one of the issues with Scuds. Ironically "proper" rockets might be easier to intercept than something scratch built from whatever materials might be to hand.

Applying the "sewage' attribute to pure water molecules would be superstitio

Or "homeopathy".

unless you assumed the sewage was somehow radioactive.

Unless it's been kept isolated for a few hundred years it probably will be slightly radioactive :)

Actually, I've been calling for someone to graft the THC-production complex into kudzu. That way, either we get government help to wipe it out, or the government finally gives up; either way, kudzu becomes useful for something.

Anyway you could call it "superweed".

If we ever learn to design new genes and proteins quickly, there are a bunch of starter projects:

Give mold the ability to synthesize CBD and THC. It would motivate you to wash your dishes- so you can use a razor blade to scrape off a gooey film of cannabinoids from the slimy ceramic in your sink, puff away, develop the munchies again, refill the sink with dirty dishes, and complete the cycle.

Insert a couple genes into E Coli that can synthesize cannabinoids in your intestines, so you can get a buzz after eating regular brownies.

Give cows a few genes for synthesis of cannabinoids during lactation. THC milk would also go great with regular brownies.

Design a virus that invades the human nervous system and inserts genes into white matter cells to induce synthesis of Adderall.

Engineer mosquitos that have the ability to synthesize heroin.

Make puncturevines that synthesize injectable human vaccines for measles, mumps, pertussis, polio, flu, rubella. and accumulate them in those tack-shaped goathead seeds. Plant them near people who think vaccines cause autism. Also include genes for synthesizing tire sealant, so their needles stop blowing out my bike tires when they reach the curb.

Give chili peppers the ability to synthesize and retain methamphetamine. Pulverize them and you can get meth with that "Chili P signature" like Jesse was selling in the first episode of Breaking Bad.

Create bees that can successfully avoid any areas tainted with anything manufactured by Bayer.

Resurrect DNA from extinct giant bird Palagornis sandersi but modify the legs a little so that the birds can hold bombs and chemical weapons.

Design trees that grow both apples and oranges, so we can finally compare them.

They should insert the THC gene into mold spores. It would motivate you to empty the sink so you can scrape the scum off the ceramic with a razor blade and roll it into a joint.

I'm not going to bother with genetic engineering. I'm going to get a 3D printer, download THC.sdl and CBD.sdl, and print my own cannabinoids.

Which reminds me I also have to print a new bong because this one is starting to smell like yeast.

... 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).

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.

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.

If there's one thing Mars doesn't have enough of, it's Legos.