Pity nothing asked about ReRAM (Memristors). When do they see it becoming a competitor with Flash? Are they planning to manufacture it? Etc.
2567 posts • joined 10 Jun 2009
Pity nothing asked about ReRAM (Memristors). When do they see it becoming a competitor with Flash? Are they planning to manufacture it? Etc.
Leakage from a laser tube may be accelerated by the fact that the thing runs hot and the gas is ionised. Is it He2+ that gets into the glass? (He2+ a.k.a. alpha particles, helium nuclei). On the other hand, I'd expect glass to be an intrinsically better gas-container than a multi-part metal HDA.
The problem with head size is that they can't make it smaller while still passing enough current through a coil that small to generate an adequate magnetic field. Too much power in a very small volume = meltdown (and they still haven't found a room-temperature superconductor).
Which is where HAMR comes is. Shine a laser through the magnetic field created by the head, focussed on one track of the several under the head's "bubble" of magnetic field. That heats up the surface of the platter. Choose the magnetic medium right, and the head's magnetic field will flip only the bits in the heated track while leaving the cold tracks on either side unaffected.
To me HAMR feels like good physics and engineering, SMR feels like a kluge. Bits that can only change state when heated should be MORE stable than those stored conventionally.
Some SMR maths. A conventional disk doing small writes may manage 100-up IOPS (seek time ~8ms which dominates, half a rotation of latency 4ms, a bit of optimisation possible by doing out-of-order writes). If they shingle three tracks, the rotational latency of a write goes up to about six revolutions of the disk (three to read it and three to rewrite it after modification). That's about 50ms for a 7200rpm disk. SLOW except for large writes. (Reading will be no slower).
Magnetic media aren't worn out by repeatedly being written. (They can be adversely influenced by the read-write head lying at one particular location most of the time, whether active or not. The mechanism here is interaction between airflow and tiny amounts of contaminants within the sealed HDA. For this reason drive firmware periodically performs a random "elsewhere" seek on an idle disk)
The amount of power used in writing a track is a very tiny fraction of that used to keep the whole mechanical assembly spinning and to move the heads around.
So I wouldn't expect this aspect of SMR to reduce drive life expectancy.
However, there's a major qualitative change with SMR. In a conventional magnetic drive, once your track is written, it stays there on the disk without any maintenance being needed. With SMR, it will be read and rewritten whenever nearby data is updated. If something isn't working right, there is much greater potential for your pre-written data to become scrambled. In this respect, I'd expect SMR drives to "brick" themselves far more easily. More like an SSD (which also performs read-modify-rewrite cycles), less like the magnetic disks we're used to.
I hope that "old technology" drives remain on sale for a considerable overlap period!
Surely the authorities have their hands full with things more dangerous than pressure cookers. My list would have guns at the top, Ammonium Nitrate fertilizer second, and barbecue charcoal well above pressure cookers.
I guess they're lucky their son wasn't academically inclined and worried about future energy security. He might have wanted to find out the relative merits of conventional nuclear reactors (which create chemically separable Pu239 which can be made into A-bombs) and the mooted Thorium reactors (which breed chemically separable U233), and whether one can make an A-bomb from U233.
I never did find a definitive answer to that last one. I wonder what lists I volunteered myself onto?
You can cook rice in five minutes in a pressure cooker. Not sure who needs to save ten minutes of meal preparation, or why, but I guess it also works with quinoa!
Maybe easier in Europe for this one? Here in the EU one has an expectation of privacy in a lot of contexts. You employer should not be reading your e-mails without good reason.
In the USA, as far as I can tell you have no expectation of privacy unless you are talking to your priest, your doctor, or your lawyer.
911. He's in the USA. Some parts of the USA, he's not joking.
There are employers out there who regard using the company internet for private purposes as grounds for dismissal. I hope that they get the sort of employees they richly deserve (ones so incompetent that they can't get a job anywhere more enlightened, and "seagull" mercenaries in it just for the money).
Without knowing the content of the bosses call it's tough to say.
Me, I'm starting to wonder if the Laundry is just fiction?
I'm also wondering, if it's tethered, why not an electrically powered aeroplane for calm conditions, turning into a tethered glider whenever there's enough wind? (Electric power from the ground, via the tether).
What is the advantage of the "extra lift" from a kite design? Surely on a calm day, it either displaces enough air to keep its payload and the cable aloft, or it doesn't and sinks to the ground! Alternatively if it's trustably windy, why bother with the helium?
It's long been deduced that magma from very deep in the earth must occasionally come to the surface very quickly. Diamond is a stable form of Carbon only at very high pressure (>50km deep, ISTR). If magma containing diamond rises slowly, the heat and reducing pressure will decompose the diamond into graphite. It has to rise fast and cool fast, to freeze the Carbon as metastable diamond.
Diamond is associated with the igneous rock Kimberlite, and no Kimberlite erruption has taken place in recent geological history. This is possibly a good thing. They may be extremely violent events and/or happen unexpectedly at a location with no extant volcano.
Unless a Latin American country grants him assylum, I doubt we'll hear anything more from him. Russia has made it clear that they expect him to keep his mouth shut, and at present he doesn't have any other offers of a safe home. Sad. It appears that there is no longer anywhere even slightly civilised that allows one to say things that the USA government doesn't want you to say.
If Russia allows him freedom to travel and an exit visa, it is now at least possible for him to reach Latin America without passing through US allies' territory. (Travelling Eastwards through Russia and then across the Pacific).
Windows NT 3.1 was the biggest remake of the Windows family until Windows 8 came along
True, if you are looking "under the hood" i.e. at the kernel. (But note, the Win 8 kernel is still derived from NT). However, the kernel is not the first place most Windows users look. The other revolution was replacement of the Windows 3.1 GUI by the Windows 95 / 98 / 2000 / XP GUI, which pretty much defined a (small-w) windows desktop until Windows 8 was dumped on us.
NT 3.5 (at the time it shipped) was unbelievably stable, but still ran the 3.1 desktop. (It was basically NT 3.1 with most of the bugs fixed). NT 4.0 ran the newer desktop, which had required driving a coach and horses through the carefully designed VMS-like security model of NT 3.x. The system's architect, David Cutler, formerly architect of VMS at Digital, left Microsoft around the NT 4.0 release, possibly because of Microsoft putting image above security considerations. Microsoft has probably been paying the price ever since!
Ten dollars, or even fifteen, per smartphone, is hardly serious distortion of a market where customers pay twice that per month.
The far greater Microsoft monopoly abuse scandal is the way they have made it all but impossible, for very many years, to buy a PC and reclaim the full cost of the Microsoft Windows license which isn't wanted by people who run Linux. Yes, it' s possible to buy a PC without Windows in a few places, but it's hardly ever any cheaper, let alone as much cheaper as the known cost of a Windows OEM license! £50 per £400 PC is a far greater "tax" than $15 on a phone, and has far less justification.
Memristor rewrite-ability is effective infinity. It's targetted at replacing RAM, i.e. word addressable, with the added benefit of being non-volatile.
Price per Gbyte will start high and fall as the technology and semiconductor processes are prefected. It'll probably replace Flash within a decade unless there's some problem that hasn't yet surfaced in the labs. The more interesting thing is whether it'll ever be able to replace big disks. (i.e. multi-terabyte for under £100)
And you have eleven who think he deserves a fair trial. Or six. Or three. If as few as three won't convict, he's re-tried or acquitted.
One person who argues for an acquittal based on the evidence rather than prejudice is likely to be enough. Fiction, but a great classic movie: "Twelve Angry Men" has this plot.
Wouldn't the standard of critical thought on evidence here terrify you?
No, because it would have to be 10/12 of the jury like that before it made any difference. This case proves that the system works. The "bad apple" on the jury has ended up in the dock.
This is why you are tried by twelve jurors, not one or three. You'd have to be extremely unlucky to have ten out of twelve such idiots on your jury. Fewer means, at worst, a mis-trial. More likely, one good (wo)man and true on your jury will denounce the idiot(s) to the judge as soon as (s)he becomes aware of them.
There's a case to be made for ensuring that a minority of a jury are technically competent (for example, accountants in fraud trials; scientists where forensic evidence is complex). Maybe 4/12 of them. Never a majority, let alone all. Selecting such a group is likely to select for correlated prejudice.
Never buy a cheap ink-jet printer. With these it's true that they are made to sell expensive ink cartridges.
I have good experience of HP Officejets in the £80 - £120 bracket. I have several K550, K5400, 8000 models with 25,000 pages printed - some over 50,000 pages. Average print-out at time scrapped probably 35,000 pages.That's a per-page cost of 0.4p down to 0.2p, which is small compared to the ink cost, which in turn is lower than the running cost of any colour laser printer I know of. Plus colour quality is higher. Minus operating speed in duplex mode is slower, because of delay for ink to dry on one side of page before the other is printed. Latest HP8100 looks good though it'll be a couple of years before I can be sure.
Although not cheap ink-jets, they are cheap enough to treat as consumable when they do eventually fail. You can't say that of any colour laser printer that has comparable running costs.
No experience of other makes, so read nothing except their relative hostility to Linux into that omission.
And I've just finished recovering a server that crashed overnight when a WD RAID edition disk turned into a brick "just like that".
I don't hold this against WD. I do wonder whether Seagate are more honest in revealing SMART data that encourages one to replace a drive BEFORE it becomes a brick. Or maybe they are less reliable. Not enough data.
Unless one is Google with tens of thousands of drives to draw conclusions from, it's pure speculation. Also every drive one ever buys is in effect a prototype. By the time five years have passed and it's proven itself as reliable as you'd have wished, it's also long-obsolete, and I very much doubt whether the reliability performance of (say) WD1600AAJS drives tells you anything at all about the ones they are shipping today. I work on the assumption that every manufacturer is likely to ship bad batches from time to time, and to design "lemons" with poor endurance from time to time. Concentrate on the backups. It's data that's valuable, the disks are cheap in comparison.
I'll accept the literal meaning of translucent is light-specific. I thought extending it to how a whale's sensorium probably depicts a man was obvious. I was going to say "transparent" but that implies close to "invisible", which is completely wrong.
Whales and other cetaceans see by sonar, so they surely knew that the divers were there.
In sonar, you are translucent. So the whales can see your internal organs working. If they're intelligent enough, they probably have you pegged as a funny sort of dolphin with a hard thing on your back. If they have a sense of fun, they can see exactly how much they've startled / scared you by how much your heart speeds up.
My guess, those whales knew *exactly* what they were doing!
London Zoo had asked for a very large grave to bury a walrus in. The gravediggers didn't know what a walrus was, except one who said it "you know, grey skin, long tusks". So they dug an elephant-sized grave. Lots of space left when they found out what a walrus was, so they gave a day's worth of paupers a free burial at London zoo's expense. Man with hole in head? He'd fallen off a fourth floor scaffolding onto the cast-iron railings below.
I can't see any justification for the police recording *any* ANPR data long-term, whether they are recording all routes out of an area, or just one. (Short-term capture, to check against a database so un-taxed or un-insured drivers can be stopped a mile up the road, is fine by me. Longer than a day, is not! )
Bear in mind that a criminal with something to hide, can clone the plates of another car of the same make, model and colour. For the same reason, recorded ANPR data can't be used as evidence. It proves what letters were on a plate, not what car the plate was attached to.
Yes, they don't have a clue about the difference between correlation and causation. In the 1950s correlation famously "proved" (not!) that watching TV caused lung cancer. TV sets of that epoch gave out quite a lot of X-rays, percentage of households with a TV was rising fast, lung cancer was rising fast, so not a silly suggestion. But the real culprit was increasing affluence causing increasing cigarette consumption as well as increased TV sales.
With porn there is not even any correlation. The availability of porn has surely risen at least tenfold in the last decade. The incidence of ghastly assaults on children has not. Probably it has not increased at all, once one allows for increased reporting. The same is likely true of rape. So this appears to be evidence that perverts are NOT created by watching porn, and that the money which is about to be wasted by ISPs would be much better used to increase funding for child protection and victim support agencies.
Each meter costs £265. There are 53 million households according to the article which need to be fitted. so the total is £265 x 53,000,000 = £14 Billion.
How much electricity is this going to save?
Lots. You and I, the energy consumers, are going to be paying for the meters, through higher electricirty prices. Those who are having trouble paying their bills, will have to cut back on something, and that something may well include electricity usage. Also it gives them the ability to cut off anyone who is in arrears with their bills far more easily. Also it gives them the ability to inflict a power cut on most of us, without the opprobium that goes with inflicting one on those for whom a power cut might be life-threatening.
Probably not the answer you wanted? What, me, a cynic?
Mars is less massive than Earth. Mars has a negligible magnetic field compared to Earth. If the latter has been true for a long time, isn't that sufficient to explain how the sun's solar wind stripped all the water from Mars? Note, water vapour is the lightest gas in the atmosphere. Methane (a likely major component of Earth's early atmosphere) is even lighter.
So do they really need to postulate a catastrophe? (Other than the freezing of whatever liquid/magnetic core Mars might once have had, which would have been a catastrophe for Mars life when taking the long view).
Out of interest is there a simple proof that you couldn't make an achiral protein-building system? Is there a level of complexity of carbon chemistry at which chirality is unavoidable and below which there's an insufficient range of possible structures?
Sort of, and yes. A chiral molecule is any molecule with four non-identical sub-groups bonded to one Carbon atom. (There are also lots of other sources of chirality, but that one will do to start with). So, almost any complex carbon-based molecule will have a non-identical mirror-imaged form.
The more interesting question is whether mirror-life is likely to have evolved elsewhere in the universe. Life based on much the same building blocks as ours, but all components the mirror image of ours. Classical chemistry provides no reason why not. Quantum physics reveals that the weak nuclear force is itself chiral, and that there's a tiny difference in stability between Earthlife amino acids and their mirror-world alternatives. It's only about one part in 10^24, but there's a tipping-point in that L bonds stably with L, D bonds stably with D, and mixxed amino-acid polymers are much less stable than pure-L or pure-D ones. Ours is the mort stable. Evolutionary coin-toss, or inevitability?.
All speculation until we find some other instances of life. May be a long wait.
Trouble is that even if you are using open-source software, the hardware is closed. For a one-household linux router, maybe there's not enough space in the hardware to hide a backdoor. But in a corporate backbone hub, there's plenty.
Canadian oilfield workers can lose their fingerprints permanently. It's caused by repeatedly getting frostbitten fingertips, in turn caused by removing gloves in winter to do something fiddly, and accidentally touching a metal surface onto which one's finger-tip will instantly freeze.
Criminals have been known to attempt the same using a freezer. I suspect a freezer isn't as cold as outdoors in a Canadian winter.
did they have it stuffed and put it on a key fob?
Gruesome thought! Maybe some bad guys do just that. More likely they use the amputated digit to drive the car to the criminals garage, where the car is dismantled for spares.
Life is cheap in SA(*). People count themselves lucky if a carjacker leaves them alive, instead of shooting them dead for a more certain getaway.
Firearm-homicide rate UK 0.04 USA 3.6 SA 17.0
Mercedes briefly marketed a car that you unlocked with your fingers (in SA). That was until carjackers started amputating the driver's finger when they robbed him of his car ....
I am never going to allow a part of my body to be a key to an object of value!
Analog recording is very much working against that fundamental property of the media, not in harmony with it.
To the extent that analogue tape recorders are in fact very crude digital recorders. The record head is fed with an ultrasonic signal that generates a stream of 1 and 0 bits on the tape. The Analog signal modulates this signal so that the 1 bits become wider or narrower on the tape compared to the 0 bits. The read head averages out the magnetisation of a few "bits" worth of tape, to retrieve the audio. A filter in the subsequent amplifier removes what little remains of the ultrasonic carrier after averaging.
The very earliest magnetic tape recorders didn't use the ultrasonic carrier. The technique was discovered accidentally, whem a component failure caused a parasitic oscillation to develop in the recording amplifier, and the fidelity of the recording became spectacularly better as a result!
So if you really don't ever want to lose data, you have to write and read the entire medium before you use it for real.
Amen to that.
HDD systems typically fail from mechanical failures but the underlying data is maintained and you can usually get someone to haul the data off the platters for enough money.
If "spend enough money" is not an option, always give ddrescue a chance! In my experience many drives fail soft: they report so many errors to an operating system that they look dead, but a utility that tries and tries over and over again in an intelligent way (as ddrescue does) will eventually retrieve all the data, or all but a very small fraction of the data.
Of course, you need backup, for the times that the drive does turn into a brick, just like that.
Also always keep an eye on the drives' SMART counters. In my experience many failures are flagged a long time in advance by an exponentially increasing number of reallocated blocks. I pre-emptively replace such drives, long before the error count hits the SMART failure threshold. It's the rate of increase that's the give-away, not the absolute number. I have one drive with a few hundred reallocated blocks from the first time it was written to, but that number hasn't increased by as much as one since then.
This is why you put extra checksums in things that really matter.
ZFS, for example, does end-to-end checksumming, so it'll spot when a disk drive has corrupted data, and recover using redundantly recorded data where that is available (always, for metadata). Because the ZFS checksums are done at the CPU, it'll also spot errors between the disk drives and the CPU ( a failing disk drive controller, a flaky memory controller).
If your filestore can't be relied upon to protect you, store SHA256 sums of the data in your files. You can't correct using an SHA256, but the chances of a data error getting past it is truly infinitessimal.
I guess there may be some ingnoramuses out there that think the best place to find information is by guessing domain names. (Good luck to them, they need all they can get.) The rest of us type the key words into Google etc. and in instants find (for example) http://heylady.net/2010/08/06/why-i-hate-amazon-and-will-never-ever-ever-buy-from-them-again/
Except for one thing, the internet could easily dispense with names and go back to numeric addresses. That one thing is the extra level of indirection, the advantages of which I don't need to explain to technical readers. Heck, if domain names were just a dressed-up integer incremented by seven for each new one, domain-mistype-squatting would become impossible as a pleasant side-effect. Tinyurl.com proves (by existing) that many people actually prefer to use short if meaningless names.
Why on earth does amazon think a .amazon domain is even worth arguing about?
I type "amaz" into my browser and it auto-completes. (Like "ther" for this site, "goo" for google, etc.) And if I don't know a web address, "goo" will find it for me pdq.
And want to do SERIOUS serious work - get a desktop. (25 inch screen, or maybe two, proper full-depth keyboard).
There's nothing stopping Intel from taking out an ARM License. Their process technology would mean that Intel-fabbed Arm would be the best of class.
However, they'd regard that as losing because they'd have to split the profit with ARM. They'd rather keep 100% of the profit, if they can.
It's a VHS / Betamax battle on a far greater scale. I don't care to pick a winner at present.
No, they'd just give police cars a new number-plate on a weekly basis. Or give the police permission to clone someone else's plates, like they've been caught cloning dead babies' identities.
What's really stupid is the assumption that criminals will obey the rules. In this case, that they'll display the valid number plate for the car in which they are travelling.
Those with something to hide will clone a plate from another car of the same make, model and colour. Or they'll register the car to a fake identity at a fake address. Or they'll buy a hire-car company so that they can travel in a "borrowed" hire-car and create a false paper trail after the event should they need to.
So mining the data won't catch anyone that we really want caught, unless they're stupid, in which case it'll just be an "evolutionary" pressure to breed smarter criminals. Yet the data is still stored, waiting for a malign individual to use it for criminal purposes, or for a malign government to use it for genocide.
Plan B. Stop all intrusive advertizing. Work with Google so if I want to find out about your product, I can. Work on your product, so happy customers will recommend you to their friends. In particular, make sure that your post-sales sustomer support is A1. Nothing makes me more likely to buy than hearing from a trusted third party that when something went wrong, it was put right with an absolute minimum of hassle!
My philosophy is always to be a buyer, never to be a sellee. Any attempt to pressurize me into buying just annoys me. Charities that employ chuggers get written out of my will, if they were ever mentioned. Spam of any sort gets your organisation added to my buy-last list. And so on. You ought to be happy I can use Adblock-plus. If I had to mentally filter those adverts, a lot more of you would be on my mental do-not-touch-with-a-bargepole list!
I can think of an organisation that espouses most if not all of the above. It's called John Lewis. It's rather successful.
""anti-business value system". I rather think he means open-source. If Adblock-plus didn't exist, I'd have to write it. If Mozilla didn't support plug-ins, I'd have to fork it.
If someone pasted adverts on your garden wall, you'd be right to be annoyed and the fly-poster would be breaking the law. Why is pasting adverts all over my screen any different? (Apart from some of them being malware-insertion attempts ... akin to pasting with toxin-laced glue? )
Once, someone wrote an app to sign up a spammer's home address to every source of physical junk snail-mail the algorithm could find. About a hundredweight per day! Not sure about the legalities, but burying the bastard in his own effluent is a lovely thought.
Light isn't really so fast. Old electronic engineering approximation is a foot per nanosecond (or 30cm). So for a 100GHz clock, that's 0.3mm per clock.
In practice with things like this you don't normally measure the exact arrival time of a pulse, you measure the phase of a modulation of a carrier wave. As someone noted above, this scheme has a lot in common with GPS and might be a very interesting way to observe and test general relativity.
BTW is Mars the best place for such an experiment? I would have thought that the (cold) dark side of Mercury might be more useful, because it's deeper in the Sun's gravity well and moving a lot faster. Maybe Mercury next?
The other basic safety precaution that must have been lacking, was a mains supply wired though an RCCB!
Suggestion to the UK gomernment: that they scrap all the absurd PAT testing regulations for anything other than appliances that are ported on a frequent basis (vacuum cleaners etc). IF (and only if) all mains outlets in the area are wired through RCCBs. Or even make them compulsory, in exchange for scrapping the vastly more wasteful business of PAT testing every PC, printer, wall-wart PSU, charger, mains cable ....
I'm sure someone in Microsoft has Windows activation statistics. Although it does appear as if the top-level management is refusing to look at them.
In days of yore, the couriers drew straws to decide who would bring the latest bad news to the attention of the tyrant. It was a dangerous job. In those days the messenger might well be literally shot or otherwise executed. The worst that can happen these days is rather less, but losing your job for being accurate about the Emperor's new clothes is still a possibility under the worst sort of management. Safer to stay quiet until asked?
(Lu-Tze quote about leaders, which applies equally to managers. "The second-best leader is respected, and the third-best is feared. The worst is hated. When the best leader's job is done, the people say 'we did it ourselves' " ).