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Comment Re:Mission accomplished (Score 1) 390

"Fossil fuel use simply won't go away, at least for industrial needs, until we have small-industrial-scale nuclear plants of one kind or another, and fission doesn't seem promising for that. "

Water-based nukes aren't hot enough for the most part, however there are proposals for Thorium MSR systems which are small enough to fit in a 40 foot shipping container and put out 8-20MW of heat at 800-1200C.

If you need a source of concentrated heat and carbon gets too expensive then other heat sources will be put into action.

Comment Re:Mission accomplished (Score 1) 390

1: The sahara desert is a complex ecosystem. Panels will damage it.

2: large parts are warzones.

3: It has mountains and other geography which get in the way.

4: There's this pesky stuff called "sand" which keeps moving around and burying anything that isn't mobile or wet.

5: "Generate power for the entire planet" is a major exaggeration. The Californian solar-thermal plant can't even generate enough power to feed more than 10% of houses _IN ITS AREA_. If African society increases its energy consumption to "western levels" it will account for every Joule generated and then some.

6: Exporting what it does generate will make Africa collectively even more pissed off about colonial expliotation than they already are

7: Even if that was to happen, you're talking about an infrastructure project a dozen times larger than anything ever built in the past, simply for electricity transmission, let along the panels - and losses over long-distance lines are substantial even with HVDC

8: If "we" are to reduce carbon emissions then that means not only converting existing carbon-fired systems to non-carbon sources, but also:

  i: doubling it (at least) to take over from carbon-driven heating systems in cold climates (ground heat pumps and suchlike can only do so much) - heating accounts for as much carbon emission as electricity production and people won't stand for conventional nuke plants nearby so they can act as district heating.cooling systems too.

  ii: doubling that result and then some, to account for transportation going more-electric (75% of carbon emissions are in transport)

Solar PV and wind simply don't have the energy density needed.

Comment Re:Mission accomplished (Score 1) 390

You missed "except when you have to put up with the chmical wastes from solar PV production."

http://news.nationalgeographic...

http://www.science20.com/scien...

http://spectrum.ieee.org/green...

"The reporters found that the company was dumping silicon tetrachloride waste on neighboring fields instead of investing in equipment that could reprocess it, rendering those fields useless for growing crops and inflaming the eyes and throats of nearby residents. And the article suggested that the company was not alone in this practice."

" In August 2011, a factory in China’s Zhejiang province owned by Jinko Solar Holding Co., one of the largest photovoltaic companies in the world, spilled hydrofluoric acid into the nearby Mujiaqiao River, killing hundreds of fish. And farmers working adjacent lands, who used the contaminated water to clean their animals, accidently killed dozens of pigs."

[ you really don't want to go anywhere near hydrofluric acid. One drop on your hand can easily result in the entire arm being amputated.]

etc etc

Seriously: the energy cost of making solar panels is only at or just past breakeven over the life of the panels. Windfarms are in a similar situation, because the big turbines have a nasty habit of eating gearboxes (they're only profitable when stopped, but collecting subsidies)

Fusion would be nice, but I doubt we'll see it in my grandchildrens' lifespans.

In the meantime we need fission _now_ (PWR/BWR systems for the moment and LFTR-style system as soon as they're mature enough to be rolled out as civil systems). Continuing to dump carbon into the atmosphere at uncontrolled rates is likely to kill us far faster than any global warming scaremonger might realise: https://en.wikipedia.org/wiki/...

Comment Re:Summary sucks (Score 1) 345

"A good few of those more recent 747 sales were the -8 Freighter. These are very popular with cargo lines."

There's good reason for this. The Big Twins are efficient at hauling Pax but that comes at cost of payload mass.

People will point out that a 777 has a lot more cubic feet of cargo capacity available than a fully-laden-with-pax A380 (or 747), but they neglect to mention that the A380 or 747 can actually haul more cargo mass in the same situation on long-haul flights (ie: the 777 is great if you're freighting fluffy pillows transoceanic)

4 engine aircraft simply have greater lifting muscle. That's not necessary on a long-thin passenger route but it's important if you're DHL and friends.

Comment Re: Meet the new guy (Score 1) 393

"Making fraud hard at the exclusion of 0.001% of the population is better than making voting fraud easy."

The incidence of voting fraud in the USA _before_ photo ID requirements went into place was vanishingly low (single/double digits in each state) and unless it's organised (therefore detectable), it makes no statistical difference to the outcome.

The real way to throw elections is systematic disenfranchisment, which is a policy the USA has been pursuing for decades.

Comment Re:Can the enemy actually shoot down the F35? (Score 1) 732

"It gets worse for stealth though"

F22 and F35 stealth is _only_ valid nose-on and up to 30 degrees off that axis.

At any other angle (including over-the-horizon radar) it's useless. As soon as you have networked radar stations the game is over.

The original combat design was for the (expensive) F22 to establish air superiority and take out radar stations, leaving the (cheap) F35 to fly unopposed in a primarily ground-attack role or long-distance stand-off missile launch.

Because the F22 got too expensive, everything got concentrated on the F35 - which is now more expensive than the F22.

It's a tubby thing with stubby wings. It wasn't designed for dogfighting, nor was it designed to avoid SAMs. In either situation it will lose. It should be designated the A35, but that wouldn't be acceptable to many.

Last time around this multirole stuff was tried, it got dropped (F-111 family) and replaced with F14/15/16 - this time it's too deeply entrenched in pork. This could be the weapon that sank the US military.

Comment Re:Can the enemy actually shoot down the F35? (Score 1) 732

"Service members actually get a huge pay raise when they get married."

And yet, the largest single group of food stamp recipients in the USA happens to be serving military personnell who are married.

Whilst the overall USA military budget is stupidly large (larger than the next 10 countries combined), the amount it pays its staff is pititful - and the way it treats its veterans is beneath contempt.

If you're going to put people through a meat grinder the very least you can do is pay for their upkeep when they come back broken.

Comment Re:in the UK it would be fibre (Score 1) 135

"To be fair, it sounds as if they are running more fibre"

They've been running fibre in distribution for decades. This is fibre to the street cabinets.

Unfortunately the circuit is a bastard hybrid of fibre to a street DSLAM coupled with a voice pair back to the central office. There's no good reason why DSLAM/concentrators couldn't have been used, making the entire copper loop the distance of the cabnet to the customer premises.

As it is, copper loop problems between the cabinet and the central office can seriously screw up VDSL delivery and debugging them takes _months_ (personal experience with a wet trunk run back to the CO)

Comment Re:ADSL is for apps (Score 1) 135

GPON gear is cheaper than G.max. Fibre is cheaper than copper to lay.

The difference is that western telcos can pretty much charge the entire cost of equipment to go on the end of existing copper up front, whilst laying fibre needs to be amortised over a 20 year period. Because they're focussed on the next 3 months, this screws up any long-term planning objectives traditional telcos may have had.

Comment Re:DC power? (Score 1) 239

Here are two reasons why AC is generally better than DC at consumer level:

1: AC arcs are self-extinguishing every half cycle.

Anecedotally: Back in the days when Sydney Australia had 250VDC distributed in industrial areas as well as AC, a DC-powered lamp in a factory blew (filament failure) and started arcing internally. That arc eroded away the glass stem of the bulb, its base, the ceramic bulbholder and most of the flex leading back to the ceiling rose before someone managed to kill the power.

2: Human safety:

DC is more deadly than AC, for pragmatic reasons: If you get attached to a DC power line for any reason, continual muscle contraction will ensure you cannot free yourself. With AC, the pulsating nature of the beast has a greater chance of making you kick yourself free.

I've known people who've been bitten by high voltage DC, AC and RF feeds. The DC guys came off worse than AC, but RF can cook you.

#1 means that every single piece of switching equipment in a DC circuit needs to be derated over its AC counterpart. Take a look at any switch you can lay your hands on and you'll notice that there are AC and DC ratings. This is down to arc resistance, not current carrying capability.

Comment Depends how its done. (Score 1) 307

Led lighting can be dimmed down to 30% (or less) and snap up to full brightness when someone walks underneath it. The better luminaires all communicate with each other, so that a car will cause them to light up several poles ahead whilst a walker will only light things up 1 or 2 ahead.

This system is being used extensively in the Netherlands and in _some_ UK areas. The initial cost is far outweighed by power reductions and labour costs (lamp changes) being eliminated - the cost of changing a lamp far outweighs the cost of the lamp itself.

Unfortunately, the UK is the home of the most amazing amounts of Jobsworthian behaviour. Council bureaucrats are deliberately electing to switch off lamps despite safety warnings and justifying this to councillors (who are mostly non-technical) by claiming that it's the only way possible, deliberately withholding knowledge of these systems from those decisionmakers.

I have pointed a few councillors at these systems. They're generally angry about not being informed of their existence.

These are the same UK councils who repeatedly raise parking charges in shopping areas and then wonder why small businesses are suffering as drivers go to retail parks or malls instead - they keep justifying the raises on the basis of "parking income is falling".

System going down at 1:45 this afternoon for disk crashing.

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