Become a fan of Slashdot on Facebook


Forgot your password?
Check out the new SourceForge HTML5 internet speed test! No Flash necessary and runs on all devices. ×

Comment Re:I say BS (Score 2) 109


And I'm telling you that lithium-ion batteries are not a "single tech", that they've dramatically improved in power and energy density (both volumetric and gravimetric) over time. And if you doubt this, I repeat: go find and older lithium-ion battery and compare it to a new one.

As for li-air, yes, the maximum energy density of li-air is about 10x of the maximum of li-ion. Namely because it works by direct oxidation rather than intercalation, so you don't need the mass of the matrix into which the ions get intercalated. It is not a "magical tech". It exists. Like all technologies in all fields, however, you have to reach production specs. This means not only maintaining a combination of safety, reliability, longevity, efficiency, temperature range, power density (charge and discharge) and energy density, but also affordability in mass production. And to be able to guarantee that you can do all of these things to a high enough level for investors to take the risk.

As with all technologies, you start out with promise in one or two fields, but serious problems in many others that you have to deal with. With time you refine them, until all of refined to a state where the product is commercialized. Li-air has actually been advancing quite well. In the early days one of its biggest problems were efficiency and longevity, but they've made huge strides in both in recent years. Lithium sulfur still looks nearer term, but commercialization of Li-air appears to have gone from "possible" to "quite probable".

Comment Re:Halfway There (Score 2) 373

Right. Out of the 330 million people in the US (not counting the broader market, there's "nobody" who wants a gun that can't be accidentally picked up and used by their young children or an intruder. Literally "nobody". Yeah, totally believe you.

They have a niche. You want to prevent them from filling it.

Comment Re:Progress! (Score 4, Interesting) 109

Actually, that is a concern. Li-ion batteries don't have lithium metal in them unless something goes wrong. Lithium-air batteries always have lithium metal in them, by design.

In practice, you'll probably see a bit of the energy density given up in order to beef up the casing to prevent rupture/fire.

Thankfully, lithium-sulfur batteries don't use lithium metal, just lithium polysulfides. The max energy density isn't as high, but it's still quite good. They're already on the market, albeit in small quantities for applications that require the absolute highest rechargeable energy density (mainly aerospace).

Comment Re:I say BS (Score 2) 109

Yes, cue the standard "Batteries haven't advanced!" stuff from people carrying around cell phones with significantly more amp hours in a smaller battery profile than the last generation phones that they owned.

News flash: every time a new tech advance makes it into a product, they don't mail a letter about it to everybody who read an article about it years earlier. Example: hey, remember all of that stuff about breakthroughs in silicon anodes several years back? Yeah, they're in batteries now. Even Tesla is starting to use it in their higher-end packs.

Comment Re:67% is not that good (Score 2) 116

It's good for the NAO. When you're pushing the boundaries, anything over 50% is good.

For long-term climate models, things like the NAO average out across many years. For short-term weather forecasting, you have a week or more before the system diverges enough to cease to be useful. But it's tougher working on those in-between scales.

Comment Re:No it can't (Score 1) 116

Should be well worth it in terms of things like planning for agricultural products, natural gas supplies, etc.

The real issue however is that they've validated it with hindcasting. Which is certainly something, but isn't as ideal as you'd want. It's trivially easy to fit any arbitrary past dataset to a statistical model if you have enough parameters that can be tweaked, but that doesn't mean that you're actually capturing the underlying dynamics. That said, from the sound of it it's built around a physical model, so that increases the odds that it actually is, rather than just fitting to some arbitrary curve.

Comment Re: Were the users randomized? (Score 1) 492

You forgot installing weird things like asset management software and anti-virus, on top of being based on an enterprise distro with poor desktop support to start with, and *then* holding back updates on top of that.

Funny thing was, the anti-virus software at the time *only* supported detection of signatures of Windows viruses. They supported linux with the use case of a Samba file server to protect Windows clients, but they put it on all the linux desktops and sucked down tons of resources and brought things to a crawl.

It was the moment that I got a 'blessed' configuration of Linux to run on my laptop that I finally had some sympathy for Microsoft and how their platform is treated by vendors and IT departments and how much of MS 'badness' is due to preloads and IT department loads being very stupid. Of course Microsoft hasn't done any favors with poor QA on updates causing that mindset in the first place, but the avoidance is worse than taking the updates.

Comment Re:We Were Attacked! (Score 2) 66

The problem is this philosophy tends to create targets of great value by putting so much infrastructure into so few places.

It's been a curious development in the internet. In the 90s, there was a trend from walled gardens and centralized resources to more federated approaches. In the last decade, the trend has reversed.

We have increasingly powerful endpoint devices, even as their form factors have shrunk. This *should* have led to the reduction of the importance of 'datacenters', but now they are more important than ever *and* so much function has been consolidated into 3 or so companies, and a handful of physical locations.

Now it's not as bad if everyone at least had their infrastructure to bank on a couple of providers as you do (so long as they all don't bank on the *same* two, but generally there's only a couple of companies people go to.for services)..

In a decentralized case, a random entity is doubtlessly unlikely to withstand such an attack, but also they are far less likely to be the target of such an attack (being a bonus effect of taking down a target versus *being* the target).

Slashdot Top Deals

Nature, to be commanded, must be obeyed. -- Francis Bacon