Follow Slashdot blog updates by subscribing to our blog RSS feed


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

Comment Re:Set up correct secondary DNS servers (Score 1) 211

Wouldn't it be subject to the same weaknesses of cryptocurrencies -- namely that an enormous amount of energy has to go into otherwise useless computation, that anyone with sufficient computing power can assert that they have the correct blockchain, and that the blockchain quickly becomes large and unwieldy?

Comment Re:I say BS (Score 2) 151

the improvements have been minor in battery tech... the main improvement has been in lowering energy use in the chips (shrinking mainly)

Flatly contradicted by comparing old batteries with new, amp hours vs. volume and mass. For the past couple decades, batteries have doubled in energy density once every 8 years or so. Do you perchance have an old cell phone lying around at home? Check out its amp-hour rating and see how big/heavy it is compared to the amp hour rating and size/mass of your current cell phone's battery.

and the article say's nothing about 10x, so yes this is bullshit..

No, it is not. The maximum theoretical energy density of li-air is about 10x that of the maximum theoretical for LCO/graphite li-ion.

The problem is chemistry, no matter how much you want to believe it's possible to make a battery that is anywhere near as energy dense as gasoline, the chemistry say's no!!

Once again, false. The maximum gravimetric energy density for li-air is comparable to gasoline (12kWh/kg vs. 13kWh/kg) in the charged state, and significantly better in the discharged state. Now, you don't ever achieve the maximum for a particular chemistry, or even close to it. But then again, for a given amount of EV range, you don't have to, as electric drivetrains are 3-5x more efficient than ICE drivetrains.

Of course, neither of these are actual impediments to EV adoption; nobody gives a rat's arse whether a battery pack is physically larger or heavier than a gas tank (partially or completely offset by the reduced drivetrain mass). The real impediment is price. That said, if cost per unit mass/volume remains the same and energy density improves, then cost per watt hour improves as well.

Comment Re:I say BS (Score 1) 151

Wow, unreferenced rant someone added at the bottom - clearly you've got me there!

Try googling those quotes. The first one is only people quoting Wikipedia. The second one, I downloaded the paper and the conclusion says just the opposite ("A huge interest expressed by the scientific community in the development of Li-air battery is the demand of modern automotive industry. We have identified four major areas. If properly addressed, this technology may enter the commercial phase in the near future." (immediately after going into a wide range of papers on dealing with each of these four topics))

Comment Re:Make up your mind (Score 1) 124

Do you have any idea what conditions are like under occupation? Here's a hint: go ask the Palestinians what occupation is like.

Not every occupier runs a Naziesque genocidal regime. Why don't you look at the American occupation of Iraq instead? We instituted curfews, and desegregated populations that were living next to one another in relative peace, causing them to come into conflict and fomenting terrorism. That's pretty close to what American occupation of America is like, except instead of desegregating a segregated populace, our laws seek to segregate it further by demonizing and subsequently ghettoizing some races.

Comment Re:Copseye (Score 1) 124

Alas, our police aren't as benevolent as those Niven depicts. Ours would take umbrage at rocks being thrown at their copseye-equivalents.

Are you kidding? Ours takes umbrage if you cross the street in the "wrong" place (even with no cars coming) or burn a spliff in the top of a tree where nobody can smell it. There's not going to be any benevolent anarchy. Just a boot stomping a human face if it doesn't assemble those doodads correctly, forever.

Comment Re: autism is preferable? (Score 1) 601

Not so fast. If I, in a developed country with good health care, had a child to be vaccinated with the MMR, I would realise that getting the measles is not by far as bad as making him autistic by trying to prevent him from getting the measles. I would never be able to forgive myself if such thing happened.

So you could forgive yourself if they got neural damage from measles, and acted as a vector to give it to other children making you a total shitbag of a parent, but not if they became autistic?

In the USA nowadays 1 in 25 children becomes autistic

Who told you that? It's 1 in 68.

and I'm sure that even if everybody got the measles, only 1 in 1,000 or so would be severely damaged by it.

Measles causes the most vaccine-preventable deaths of any disease. You're a colossal dumbass.

Comment Even IPv6 completely fails to address this (Score 0) 211

So we're going to have to handle it at the routing level. We're going to need a web of trust routing system and when some provider goes full retard and fails to block malicious traffic originating from their network, their peers null-route and refuse to carry their traffic until they fix it.

Comment Re:progressive thinking (Score 1) 72

Some of the land was taken by force, other land was simply unoccupied.

There was no land which was simply unoccupied. Some of it was very sparsely populated, but the natives had over ten thousand years to figure out what the population densities should look like.

Are you trying to get at something?

It's the government's land, because they took it by force! But wait, it's wrong to take land by force. So... give your land back to the natives and fuck off.

Comment Re:I say BS (Score 5, Informative) 151


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:progressive thinking (Score 1) 72

as owners of the land that the pipeline runs over, the government is naturally the institution demanding safety. What makes government "evil" is that it usually acquires property by force, gives it away to powerful special interests, and does a piss poor job managing and preserving it.

That is, if this land (and the Indian territory) actually was private property and managed as private property, then there would be nothing to riot and protest about.

Wait, is it evil to acquire property by force, or not? Because... how do you think the government got the land this nation is based upon?

Comment Re:Halfway There (Score 2) 385

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) 151

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).

Slashdot Top Deals

You know, Callahan's is a peaceable bar, but if you ask that dog what his favorite formatter is, and he says "roff! roff!", well, I'll just have to...