Posts by Alan Brown

Re-light my diode: Trio of boffins scoop physics Nobel for BLUE LEDs

Re: Reducing Electricity Consumption???

"So as well as being more efficient in the first place, LED street lights can be on motion sensors, allowing them to remain off most of the night without a safety implication."

People don't like dark streets. The current incarnations of these things run at 10-30% brightness until there's motion under them - and they signal adjacent lamps to brighten up too.

There are some quite interesting youtube videos about this stuff if it floats your boat - and bear in mind that a 90% reduction in lumens is only a subjective halving of brightness thanks to the human eye being logarithmic in sensitivity.

The real win in leds vs traditional luminaires in streetlighting isn't the reduced power consumption. The saving in energy costs are utterly dwarfed by the cost savings associated with getting a bloke in a bucket up the pole to change the lamp - theres a 5:1 reduction in labour costs.

Re: What IS the physics then?

"That part I know, jumps between energy levels. It doesn't sound terribly revolutionary, more like trial and error."

The concept is easy, Making it happen is more difficult.

In the same way that rocket science is easy, but rocket engineering is _hard_.

Re: Curious

The physics of lasers is well-known too.

But so far noone's managed to produce a green semiconductor one (current green lasers are infrared lasers with output passed through a doubling crystal)

What's more remarkable than the prize is the fact that Nakamura was ordered to cease his research into blue leds as he wasn't making progress and his employers didn't see a market. He was so determined to create the device that he continued on his own time and expense, which has made him a very, _very_ wealthy man.

Re: Curious

"He nicked the idea from Joseph Swan......."

Yes, but he did spend quite a number of years making it last more than 2-3 hours.

His adventures stealing the Lumiere Brothers' invention and output essentially created Hollywood - the filmmakers of the time were trying to get as far away from Edison and his control-freakery as possible.

Oi, lobbyists. Cough up your details – EU's new first vice-president

only a few million?

That would put lobbying in the EU at 0.2% of the expense of lobbying in the USA.

Inflatables in SPAAACE! ISS 'nauts to enjoy bouncy castle spaceship

Re: TSSSSSssssss.........

In theory it's also self-sealing if there is a puncture.

The ability to "give" a little on impact should make the thing a lot more robust than the metal sections of the station, when it comes to getting punctured in the first place.

Re: This long and nobody has gone there?

"Interesting idea in a microgravity environment allowing free floating fluids. Ewww...."

Astronaughties.

Re: "Inflatables in spaaace"

One could argue that if there's enough atmosphere to sustain a balloon, it's not spaace. :)

One can also argue that ISS isn't _quite_ outside the atmosphere, given that it's air friction which causes it to require periodic reboosting.

Re: TOP TIPS

Floating it up would be one thing (or sending up on Virgin Spaceship Two), hooking onto ISS as it whizzes by at a jillion miles per hour is somewhat harder....

As we all know from Hollywood, everything is accessible inside the life support time of a spacesuit, no matter how much the orbits differ.

Official: Turing's Bombe better than a Concorde plane

Re: countless?

"Hypothetical question - after the nukes were dropped on japan, would germany really kept fighting for another 2 years? What if the 3rd nuke was dropped on berlin?"

If Germany hadn't surrendered, there wouldn't have been enough uranium available for the USA to make nukes for another couple of years - and a good chance the germans/japanese might have had a chance of developing their own nukes.

See https://en.wikipedia.org/wiki/German_submarine_U-234

Be nice to the public, PC Plod. Especially if you're trying to stop terrorists

Re: I would hazard a guess I'm more likely to be shot by a cop

"How many people are killed each year by members of their own family rather than criminals or loons? I suspect a lot."

The vast majority of murders are intra-family, so the answer is "most of them"

Marriott fined $600k for deliberate JAMMING of guests' Wi-Fi hotspots

The "jamming equipment"

Is the hotel access points themselves. it's part of the "rogue detection/mitigation" facility - however deauthing is _never_ turned on by default.

All the enterprise systems offer this facility - and they're also all capable of detecting and dynamically avoiding frequencies used by portable hotspots anyway.

The FCC could have impounded the hotel's entire wireless network, should Mariott have argued - and I'm pretty sure that point got raised.

Air-slurping solar battery will slice energy costs – boffins

Re: Fantastic!

"I wonder how much area there is just using roof spaces? "

I wonder how many people will die falling off roofs, whilst installing the damned things?

http://motherboard.vice.com/blog/whats-the-deadliest-power-source

Apple blacklists tech journo following explicit BENDY iPhone vid

Re: If you can't say anything nice

" believe they also had another episode where something similar happened, iirc they were driving through russia or romania... some eastern europian country. "

It was the USA - and Hammond quite liked it in the end too, especially after the performance at Bonneville.

Want to see the back of fossil fuels? Calm down, hippies. CAPITALISM has an answer

Re: Clean energy NOW

"No, it's not because nuclear is horribly dangerous and produces very, very nasty waste products."

Many of those "very nasty waste products" have remarkably short lives. The danger of commercial scale water-based reactors stems from the intrinsic dangers of using water to cool a process which if uncontrolled can get hot enough to split water molecules and thus create an explosive atmosphere without external assistance. It's that explosive atmosphere (and the results of such) which ends up causing short-lived crap to be sprayed into the atmosphere, not helped by the fact that the casing of nuclear fuel rods (zirconium alloy) melts at too low a temperature(*) - which is why all that crap is in the water and able to to be sprayed around in the first place.

(*) That's what melts in a "meltdown". The uranium itself doesn't.

Boiling-water reactors are 1940s-50s technology designed for small-scale use on submarines (where water and overheating isn't an issue) and then scaled up by a factor of at least 100 for land-based use. Better technology has already been developed and discarded - because it didn't easily produce plutonium for bombs.

That "better technology" uses a cooling system which happily works right up to the maximum possible temperature of a nuclear reaction (they're self-limiting at around 1500C) and because it can run far hotter, it results in more efficient power generation on the steam turbine side. (Yup, nuclear reactor power is simply changing the "fire" on a steam engine.)

Yes nuclear fission is dangerous, but every other method of power generation has higher death/injury rates (including wind/solar/hydro) and if nuclear safety standards were applied everywhere, almost every coal plant in existance would be shut down tomorrow.

Re: Clean energy NOW

Hydrogen gas is extremely reactive.

To put that energy density into perspective - there's over twice as much hydrogen in a litre of diesel as there is in a litre of liquid hydrogen.

If you treat carbon as the scaffold which allows you to fit hydrogen into smaller spaces and keep its reactivity down, then you have a better way of handling the stuff.

One problem there is that whilst it's possible to comvert H2 to CH4 and onwards to heavier molecules, it's highly inefficient, so you need a dirt cheap energy source to start with. Something much cheaper than even Nuclear energy promised to be.

Re: Dear reader

"Use your photovoltarics to power your heat pump during the day?"

Believe it or not, it's still an overall win, but a heat engine or Electrolux cycle pump (solarfrost.com) would be a better overall strategy and less fiddly to implement.

Heat engines can also do things like driving water pumps (which generally don't need to run 24*7 if sized correctly)

Re: The problem with this article...

" Oil is transported in massive supertankers because you get economy of scale benefits even though those tankers can be pretty expensive to build and run. Double the size of a normal big tanker, but not double the costs sort of thing. "

There is such a thing as "too big" - contemporary oil tankers are significantly smaller than their 1970s-80s predecessors, so I think we've already arrived at the optimum size.

Re: The problem with this article...

"Not really. You make fertiliser from natural gas (Haber Process)."

If you have a cheap and plentiful source of process heat you can use water and atmospheric carbon (or any other carbon you can get your hands on) Natural gas is just a convenient carbon source.

Re: The problem with this article...

"Some people argue this would be a good thing, go back to getting your fruit and veg in biodegradeable paper bags instead of landfill plastics for example."

For what it's worth, paper isn't a poster child for environmental friendliness. Recycling costs significantly more than making from new stock and as the fibres get chopped each time, paper can only be recycled so many times. Glossy paper is usually varnished and can't be recycled OR composted (most paper is difficult to compost)

Plastics are easy to recyle - once paper contamination is removed. Disposable plastics - bags/bottles/6-pack rings/film can (and should) be made of starch-based plastics which are more biodegradable than paper. These will break down at a known rate and won't accumulate in the guts of animals unfortunate enough to eat them (stomach acids are enough to see to that).

Re: The problem with this article...

"Aside the the obvious uses (plastics, fertilizer), any industry which uses chemicals (pharmaceutical, cosmetics, etc) need them..."

"Energy" is by far the highest consumer of fossil fuels. Nailing that down would leave a virtually infinite supply of raw materials for manufacturing.

An article I read (dated 1964) once said - "One day our great(^n) grandchildren will say to each other 'Did you know in the old days they _burned_ coal and oil for heating?' " - the context there was the value of the stocks for manufacturing.

Re: How much power?

"And as most of the world's carbon dioxide comes from volcanoes under the ocean, our use of petrol makes no significant difference."

Natural sources of carbon dioxide are fairly outmatched by natural sinks of carbon dioxide.

A good chunk of the anthrogenic CO2 is also taken up by natural CO2 sinks and those natural sinks were able to keep up until the industrial revolution really got into high gear.

The problem is that man-made CO2 production is well above the level which natural sinks can absorb, so levels are climbing.

Man-made CO2 emissions account for less than 10% of all CO2 emissions on the planet and volcanoes are a tiny fraction of that, as someone else has already pointed out.

http://www.skepticalscience.com/human-co2-smaller-than-natural-emissions-intermediate.htm

The issue isn't the level of emissions, it's the DIFFERENCE between total emissions and total absorption.

One analogy is filling a water tank with the drain valve open - If your inflow rate can exceed the outflow rate, you'll overfill the tank eventually (or make it so heavy that the structure supporting it will collapse.)

You can achieve that endpoint by increasing the inflow rate (fossil fuel burning), pinching off the outflow rate (chopping down forests, etc) or a combination of the two.

Re: @ledswinger

"Similar sums suggest that there might be something to be gained from heating houses using nuclear electricity with a heat pump."

In an epoch of higher gas prices, this would make more sense _and_ be signifiicantly less complex (AC systems are long lived and self contained, but micro-CHP Stirling engines need regular maintenance.)

Re: @ Anonymous Blowhard

"At a representative 100 kWh per square metre per year for a PV panel in the real world you'd need 8,600 square kilometres of solar PV, an area about the same as Gloucestershire, Staffordshire, and West Sussex put together."

If you added the rooftop area of the uk together you'd probably come close.

A more practical measurement would be "Can the average UK house supply 100% of its annual electricty and heating needs from a roof-mounted solar installation." - the answer being "no, of course not"

"I'd heard they were looking at algae, which doesn't need farmland. Although I'm guessing it might have a negative effect on marine ecosystems."

That depends where you grow it. There is a lot of "unproductive land" which has water resources (pollluted or not doesn't matter for this use), the right climate (warm to hot, with lots of sun) and can be used for the purpose.

Hydrogen has a number of nasty issues

" If you can get enough H2 and electricity from solar to be able to completely replace your current energy providers, it becomes a complete solution. Home gas appliances can all be replaced by electric appliances (electric cookers and heating), and transport can be run on H2, it's just less energy dense than petrol. "

Hydrogen at any significant pressure has a nasty habit of embrittling metals, especially if there's any carbon content in them. It is even worse for things like flexible hoses, which will go brittle even at atmospheric pressure or the extremely low pressures used by household delivery systems.

That's quite apart from the issue of throwing more than 50% of the input energy overboard when electrolysing water to make hydrogen (on top of the max ~20% efficiency of solar PV.), compared with what you get when you burn it or pass it through a fuell cell.

Re: (Way past) Time for an ordered priority list

"Coal is only useful for two things that I am aware of: smelting iron and burning for heat."

Other than the (minimal) carbon requirement to make steel (and coal isn't consistent enough quality/contaminant-free to do that anyway), you can get the necessary heat from a LFTR reactor.

As far as using solar PV to store energy, to then use to generate heat: with an overall efficiency of less than 5% (PV efficiency, electrolysis efficiency, etc) you'd be better off putting the solar heat directly into hot water or molten salts and extracting that heat for warmth or to drive a stirling motor for AC/power.

EU probes Google’s Android omerta again: Talk now, or else

Re: All or nothing

" hiding your spare key under the doormat is security through really poor obscurity. Hiding your door key up the arse of model pelican you keep by the front door is also security through obscurity but far more likely to be effective."

Hiding a trojan key under the doormat, rigged so that if it's used, it will set off an alarm is an example of security via apparently poor obscurity which not only catches villains, but allows intent to be shown.

See "Honey Trap".

SMASH the Bash bug! Apple and Red Hat scramble for patch batches

Re: Bash patches and the flack.

"Long and short - the issue was discovered, and about 4 days later a set of suggested fixes were discussed, and the first set of fixes was put in place, those were tested and one tester found an additional unique path that had a similar flaw."

It's worth noting that similar holes have been picked up in sh and ksh (at least), as people start poking round to see if other shells have problems.

The problem with "legacy code" is that because it's legacy everyone assumes that it's safe to run and audited (this is a constant refrain raised here against updating things). The last few days (and the X bug last year) is a clear example of why such a stance is a logical fallacy and that ALL legacy code should be considered dangerous unless there's a recent auditing statement for it.

Note that in all cases, holes in legacy software have generally been discovered within minutes of people going looking for them. The implication is that the vast majority of such code is a minefield of undiscovered issues.

Re: Bullet dodged

"Note the use of the work 'logged'. The bug has been around for decades. Do your logs go back as far the server build time?"

Mine do (about 8 years). The first attempts to exploit this hole started coming in on Thursday afternoon.

Renault Twingo: Small, sporty(ish), safe ... and it's a BACK-ENDER

"Most of the inside is taken up with 500 airbags, impact protection zones, automated emergency callout, tyre pressure warning automatic wiper/light gizmos that add almost nothing to the driving experience other than addin weight."

And ensure that you don't get squished like a bug when some goit in a SUV runs into you whilst checking her phone, swilling hot coffee and touching up her makeup at 40mph.

Re: R5 Turbo I & II's

"I would suggest removing "In the snow" from the last sentence for appropriate context."

Cortinas were shit everywhere - especially Mk4/5 - The 4 litre straight 6 Australian version and the 5 litre V8 South African versions just took the shitiness to new lows.

Re: Reanult has a problem, called 'marketing'

Couple that engine with a hybrid setup to provide peak power and urban stop-start operation and it'd work without being overstrained in a Mondeo. That's a topic for another forum, though.

I'm still mourning the loss of the AU V8 Falcons

Inateck BP2001 Bluetooth speaker: The metalhead sysadmin's choice? Not exactly

Re: AKA Tecevo S100

Don't knock Bose too much. The original designs were based around psychoacoustic modelling and being able to produce high transients without excess power wastage.

They sound good for particular environments and particular music, which happens to cover about 80% of the scenarios. In that respect they work better than 95% of the items which masquerade as "speakers" or "sound systems" out there (anything which advertises output as "PMPO" is best avoided in my experience)

Mines the one with B&W801Ms in the pockets.

Re: my favourite is the Sony SRS-X2

"...most of my mates worked at Philips where they had a big "SONY IS OUR ENEMY" poster in their factory"

My experience a lot of the time is that Philips can produce good products but often choose not to (by design, not by build quality) especially in the consumer ranges(*). That said, they do tend to be reliable.

That poster explains a lot of the apparent philips mentality.

(*) Just about every item Philips sell has some form of "crippled" in one area or another. It's as if Philips don't want to produce a good "allrounder" most of the time. Often you'll find that regional variants of the same product have the "crippled" part enabled, but another section is dutifully nobbled instead.

BT claims almost-gigabit connections over COPPER WIRE

"Yeah, the thieving bastards have all moved to France."

Most of 'em. the rest have figured out that they can take a van full of stolen copper to France and sell the scrap there.

" But to get it to my house you'd have to micro trench my driveway which is more costly because that run of cable is not in a duct. "

Overhead fibre has been around for more than 20 years. It's just as ugly as overhead copper but less susceptable to lightning damage.

Re: I wish they would give me something anywhere near that...

Don't you know how to solve that?

Setup a broadband company, chase EU funding for community broadband - you're eligible for it if BT says "not viable".

Get everyone signed into it, etc etc

Announce a launch date and do a but of groundwork.

Watch as BT magically change their tune and drop everything to install DSL to the area they once deemed "not viable"

Anticompetitive activities? Nosirree, just that the market conditions have changed.

Re: WHY WHY WHY WHY !!!!!!

"WHY WHY WHY WHY !!!!!!"

Money:

If BT pays fibre to every house as a general infrastructure upgrade it has to pay for it and recover the costs over 20 years.

If it puts whizzy bits of kit on the existing copper it can charge the ISPs the full cost of kit (and then some!) for one end and the enduser has to stump up the all the costs for the other.

Heatmiser digital thermostat users: For pity's sake, DON'T SWITCH ON the WI-FI

Re: Old school hacking ...

Mine insists on turning lights off even if out of the room for 30 seconds - and if you know anything much about CFLs you'll know that being turned on and off all the time shortens their lifespan.

Hackers thrash Bash Shellshock bug: World races to cover hole

Re: criminals != hackers

"But sometimes hackers will do."

instead of "crackers" or "skiddies" ?

Re: Eyes on the code? Not.

The question is why CGIs would be running bash instead of a much more restrictive shell.

Or why CGI is used at all. It's always been regarded as ragingly insecure.

Seagate's BUMPER State of the Storage Nation announcement

One fly in the ointment

This: https://www.backblaze.com/blog/hard-drive-reliability-update-september-2014/

Man's future in space ... Barack Obama: Mars. Narendra Modi: Mars. Vladimir Putin: Er, Moon

"Nobody has done that yet. We've had people spending a fairly long time in space, but not on another body. "

There were a number of years between Abel Tasman's trip to New Zealand and another bunch of Europeans heading out that way, etc.

Not that I think Putin can do it. This is mainly about grandstanding.

Re: Oh?

"The way things are going, it is hard to say, do you recall the hysteria following the Russian's launching Sputnik?"

Something to do with having a ICBM flying overhead with a radio on its nose instead of a nuke - a good demonstration of what could happen if they changed their minds.

Re: Moon is a harsh mistress

linear mass accelerators (rail guns) work quite well for getting out of gravity wells where there's no atmosphere to slow them down. All you need to do is get the launch angle and velocity "just so"

Supercapacitors have the power to save you from data loss

Re: Huh,

"Seriously, the hyped up "supercapacitors" tech articles love to refer to in the vaguest terms these days are actually boring old "Tants" as used on just about every board you might care to pick up from the last 20 years? Never seen on explode that wasn't backwards."

I've seen non-backwards tants explode but they did have 5 times the rated voltage applied in one case and in the other case the tant was getting a nasty EMF back-kick.

Disk buffers

"The DRAM buffers cannot be set to read only: they are on or they are off."

Bzzt, WRONG.

Write buffering can be disabled on spinning HDDs (hdparm -W0), but read caching generally can't be as it would devastate performance. Switching off write buffering is bad enough.

NASA's MAVEN enters Mars orbit to sniff its gas

Re: Fantastic stuff

s/through/amongst/ and I'd be a lot happier (and somewhat less crispy).

Ten years on, TEN PER CENT of retailers aren't obeying CAN-SPAM

Re: So...

" I don't have a f*cking LinkedIn account, and I sure as hell aren't creating one just to stop receiving your bloody sign up requests. Cnuts."

In order to test things, I went through their signup process and oprted out of everything.

They still kept spamming that account and have done to this day.