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Comment Re:Book misses major points (Score 0) 115

I don't think she sufficiently covered the HOW which is the problem.

They don't fund a charter school and see how the students there do.

They fund political campaigns to move money FROM the existing system TO their system.

When their system does not support their projections, they leave it. BUT THEY DO NOT PAY TO HAVE THE LAW REVERSED.

So the end result is a worse public school system.

Comment Re:Because the CIA is evil. (Score 1) 272

Don't be a fool.

Right back at you.

No one cared about Saddam's chemical weapons until it turned out he was never even close to having nuclear ones. The U.S. went into Iraq (for the second time) on the promise that Saddam Hussein had or would soon have a nuclear weapon and that he was likely to use it against the United States or one of it's allies. The information to justify this claim came from a single source, a drug-addicted Iraqi defector who basically said whatever his handlers wanted as long as kept him supplied with booze and drugs. This information was deliberately fed to intelligence agencies of several different countries to create the appearance of multiple sources.

The false pretences were nuclear, when the claims proved too absurdly wrong, the story changed to be chemical weapons, instead. Which Saddam didn't have either since he had long ago used the ones that the United States had provided to him.

Comment Re:Snowden unquestionably hurt the intel community (Score 1) 272

There is a book on the subject that details how Snowden negatively impacted US intelligence.

He certainly "negatively impacted" US intelligence, though it's a lot like how a police officer "negatively impacted" the criminal he just arrested. The US intelligence agencies did all the harm to themselves, and when you were made aware of their criminal activities, you chose to blame the messenger and the not the criminals.

Comment Re:Or just make the diesels hybrids (Score 2) 173

And even the best public transport system generally isnt going to start and stop *exactly* where you need it, so there still is going to be *some* walking. Which some people with disabilities or health problems simply can't manage. And to achieve a good public transport system - with frequent stops, densely placed stops, relatively direct routes and affordable prices - is entirely dependent on population density far more than it is on "will". In places with high density, it's a relatively straightforward process to have a good public transport system. In places with moderate to low density, it can be difficult to nearly impossible. And weaknesses in public transport system are a viscious cycle: the less frequent the stops, the further spaced out they are, the longer the transit times, and the more expensive the rides - the fewer people will ride them. The fewer that ride the less frequent you have to have the stops, the further apart they need to be, the less direct the routes, and the less affordable the prices.

Comment Re:systemD (Score 2) 98

Can someone explain why ALL THE MAJOR DISTROS have switched to systemd, when all I've seen is universal hate for it?

Either distro maintainers are masochists, or there's someone pulling strings somewhere to get this bullshit into every distribution.

We've slowed our move to newer versions of RHEL and Ubuntu at my workplace because of systemd. Eventually we're going to have to deal with it, but we're putting it off as long as we can. Everyone I know hates this thing. HOW did it become so pervasive?

Comment Re:Cost of access is key. (Score 1) 330

That was not my point. Ofc we can improve ISP. No idea how much that improves either 'performance' or drops price.

It improves performance a *lot*. As for price, it depends on how expensive that rocket system is. For first stages, an improvement in ISP's effect on the size of the rocket isn't that much greater than linear. But the further up the delta-V chain the engine is used, the more of an impact it has on everything that was used to get it there. An extra hundred sec ISP on a first stage might reduce the system mass by a third; on a second stage up to LEO, maybe cut it in half; on a kick stage for a Mars transfer orbit, maybe cut it by two thirds. On an ascent stage from the surface of Mars... well you get the idea. Shrinking down a rocket to a small fraction of its size - fuel, tankage, and engines - well, that's really significant. ISP is very, very important for upper stages. So you can afford to pay quite a bit for those top stages if it improves their performance. Just not an "unlimited" amount.

There is no way a high tech electrical engine will improve its performance by 10% regardless how much money or time you put into it: the efficiency is already between 98.5% - 99.5%, up to 99.9% in some cases.

This is getting a bit offtopic, but at least the electric engines in EVs don't usually run at nearly that high. Depending on the type they might average 85 to 94% on average. It varies over their load cycle.

Regarding rockets: there is simply not much margin anymore in changing the form of the exhaust tube, burn chamber etc

Actually you can. The general principles of how rocket engines work are fixed, of course - your exhaust will never exceed its local speed of sound in the throat, and then you want to expand it as close to ambient pressure as you want. But the details vary greatly. There's bell nozzles, linear nozzles, annular nozzles, aerospikes, throatless nozzles, atmospheric wake compression, and on and on. There's tons of different ways - developed, in development, and in theory - to pump and inject your propellants - where they need to be pumped at all. Even many propellants that are traditionally thought of as being in one state can be implemented in other states. There's various ways - developed, in development, and in theory - to prevent nozzle erosion. To improve regeneration. To reduce mass. And on and on and on. Rocket combustion is a rather complex thing and we're still trying to get a handle on it. Do you know that we still really don't know how aluminum burns in solid rocket propellant? There's something like five different competing theories. I mean, things like this are a Big Freaking Deal(TM), especially when such small improvements in upper stage ISP have such significance for lower stage mass. And even on your lower stages there's a lot of things that have a big effect on your system cost. For example, how to stop resonant shocks from ripping them up - a lot of people don't realize that one of the main benefits of adding aluminum first stage to propellant mixes is that the droplets of burning aluminum damp shocks. (yeah, it increases ISP too by raising the exhaust temperature, but it also has disadvantages, such as not contributing to expansion, slowing down gases (particularly near the nozzle), and impacting/eroding the throat (or even forming an accumulating slag)

Re, nuclear+chemical. There are proposals for this. The main issue isn't efficiency - the extra chemical energy doesn't make that much of a difference - but thrust. The downside to nuclear thermal is that the reactor is so heavy (fission is like that, unfortunately) that the mass ratio is only something like 3-4:1. That's really bad (you generally get 15-20:1 or even better for a chemical first stage). So the approach is to inject oxygen early in the ascent phase for added thrust, but only run on hydrogen higher up when gravity losses are lower. I'm really not that sanguine about nuclear thermal rockets getting a serious development program any time soon, though. The public overestimates the risk, of course - not only am I sure they'd well seal the fuel elements against whatever damage would be incurred by explosion or reentry, but there's the simple fact that the fuel is "fresh", not contaminated with the more hazardous actinides. But it's going to be a hard sell. And a really hard development project, if they ever did try again. Gigawatt-scale flying nuclear reactors that pose radiation hazards during assembly and test aren't exactly childs' play.

Comment Re:The guy aint no Sagan... (Score 1) 330

You forgot to exclude operational expenses.

Yes, people to run robots and comm time on the DSN. We're not talking about massive expenses here. The real expenses are the capital costs.

And also didn't mention that you can't just lob chunks of metal straight to Earth's surface,

Actually, you really just can. Even random rocks from space - not shaped for optimal entry shape, not cemented together by anything yet what nature chose to gie them - do this all the time. They have to be between a certain size range (too little and the whole thing ablates; too large and it explodes, either in the atmosphere or on impact), but the random creations of nature do it; delberately shaped and sintered projectiles should have no trouble with it, with (proportional to their mass) relatively little burnoff.

You would, of course, need a rather large area designated as the impact area; even with very precise aiming, by the time they get to Earth and undergo reentry the random variables will spread them out over a sizeable chunk of land. A large salar might be ideal, since they get resurfaced periodically so the impacts wouldn't be damaging the landscape.

By your same logic, the mining of minerals on Earth would be zero dollars per gram if the equipment was solar powered and automated

It's almost as if I didn't discuss capital and ongoing costs in my above post.

Launch costs really are key to the rate of development at the very least, in that they limit the rate in which funding can be raised for the necessary exploratory and test craft to be launched. Even if the economics for operating a mine on a NEO works out really well at present launch costs, you have to prove that you can do it before you can raise the billions to build it. And to prove that you can do it you have to launch a number of missions while you're still relatively poorly funded. They face the same problem that Bigelow has faced - a probably reasonable business plan but the early phases hinging around factors that they don't control.

It does nobody any good to pretend that the lack of a space economy is because investors are cowards and morons

I think you need to go back and read my last post again, particularly all of the "it's too early to say"/""we don't know"/"but time will tell"/etc lines. I'm not saying that at all. I'm saying that there very well could be a compelling case for asteroid mining even without any radical changes in space technologies. But there's a great deal of work to prove that before we can get to that point.

Comment Re: he should know better (Score 1) 288

The First Amendment to the ...


It is sad and sickening to see so called liberals ...

Also correct.

BUT ... it does not matter. In the end it is up to the business whether it will run X or not.

By way of example: if I paid you $10 to put a sign on your lawn saying X would it be wrong for you to refuse to put a sign saying Y on your lawn for $10?

And that's where we are at with this. The theatres refuse all religious / political ads. That way they do not endorse X or Y. Nor can they be seen as supporting Y.

Comment Re:seriously? (Score 1) 82

Are the other variants more dialectal? In addition to huoji ( / ) (fire chicken) what I read states that there's also qimianniao ( / ) (seven-faced bird), tujinji ( / ) (cough up a brocade chicken) and tushouji ( / ) (cough up a ribbon chicken)

(hope Slashdot doesn't mess up the characters)

Comment Re:seriously? (Score 1) 82

On the other hand I would want to talk to Archimedes

You speak ancient Greek and can communicate with the dead? Okay, I'm impressed. ;)

Thanksgiving trivia for the day: the word for "turkey" comes from extensive and long-running confusion about where the bird came from. For example, in English it's called Turkey. In Turkey it's called "hindi", referring to India. In India it's called Peru. In Peru it's called "pavo", referring to peacocks, which are native to south and southeast asia, such as India (cyclic there), Cambodia, Malaysia, etc. In Cambodia (Khmer) it's called "moan barang", meaning "French chicken", while in Malaysia it's referred to as "ayam belanda", meaning "Dutch chicken". Both of those in turn think it comes from India: in French it's called "dinde" (from "poulet d’Inde", aka "chicken of India"), while in Dutch it's "kalkoen", referring to a place in India. Greek has a number of local dialectal names, such as misírka, meaning "egyptian bird", while in Egypt it's called dk rm, meaning the Greek bird (even though the latter part of the name derives from Rome - the Italians, by the way, thinking it comes from India). One variant of Arabic even credits it to Ethiopia.

A couple languages deserve special credit for their words:

Best accuracy: Miami indian - nalaaohki pileewa, meaning "native fowl"
Worst accuracy: A tie between Albanian (gjel deti, "sea rooster"); Tamil (vaan kozhi, "sky chicken"); and Swahili (bata mzinga, "the great duck")
Most creative: Mandarin - many names with meanings such as "cough up a ribbon chicken" and "seven-faced bird"
Least creative: Blackfoot: ómahksipi'kssíí, meaning "big bird". Hmm...

Comment Re:The guy aint no Sagan... (Score 1) 330

Except that your cost examples are based around the price of rocks brought back as a "oh and we're going to do this too" mission add-on. It would be like as if I flew to America to visit my grandmother for Christmas via purchasing a $700 plane ticket and while I was there I bought a $15 sweater and brought it back, and you said, "See, she paid $715 to go to America and buy a sweater - American sweaters are unjustifiably expensive!" You simply cannot take the cost of the Apollo mission, divide by the mass of rocks returned, and pretend that that's anything even remotely close to the cost of retrieval per gram.

What's the actual cost of space mining? It's too early to say. But the mining of NEOs could be as little as *zero* dollars per gram (excluding capital costs and maintenance), insomuch as it would be possible to fire sintered minerals (using solar power) via a coilgun onto an aerocapture trajectory. You don't actually have to have a rocket to bring them back. What would the capital costs be like? That we don't know - again, it's too early to say. But it's normal for large mines on Earth to cost billions of dollars, and what one can do with a large mine on Earth one could do with a vastly smaller mine on a NEO due to the superb mineral concentrations on some of them. There are a number of peer-reviewed papers putting forth that it could work out to be economical (I was reading one from the USGS just the other day) as a result of this.

But time will tell. It's going to take a lot more basic research and engineering before we can get a good sense of just what it would cost to get what sort of throughput of what sort of minerals.

If you're not careful, you're going to catch something.