Posts by Martin Gregorie

GPS jamming rife, could PARALYSE Blighty, say usual suspects

Relying on just GPS for timing is stupid

Apart from GPS there are at least three alternative time sources:

- NTP. You DON'T need to connect your highly secure financial system to the net to use it. Run an NTP server on a 'net connected box and let it pretend to be a GPS receiver: every second it sends an NMEA GPRMC sentence to your secure network via a serial (RS-232) connection.

- MSF60 (UK) and DCF77 (German) low frequency time signals

- WWF and other short wave signals. The noticeable absence from this band is the UK

If accurate timing is critical for your application then you're an idiot to rely on just one, especially when receivers are relatively cheap (MSF60 receivers are cheap enough to fit in a 15 quid wall clock), so use at least two and plumb them into a local ntp time server - this way you won't be caught out by jammers or the big one if when a solar flare takes out GPS, Galileo *and* GLONASS.

Keeping LORAN alive as a GPS backup would be a smart move for shipping and airlines too.

LOHAN's flying truss: One orb or two?

Data! we need data!Martin Gregorie

Is there any reliable data on just how big one of the balloons can get? If not, are they so expensive that you couldn't slowly inflate one with air on the ground and track how big it gets before it bursts?

It seems to me that this is essential data because the beam length needs to be at least twice the burst size of a balloon. Three times would be better if LOHAN is to have a good chance at a vertical launch without hitting one of the balloons.

Re: How do JPA do it?

Just what I was going to say. So, ask them.

Worst thing that can happen: they won't tell you.

Met Office wants better supercomputer to predict extreme weather

'Idle' computer power isn't so idle these days

Now that modern CPUs can adjust their clock speed and number of active cores to match the load the situation with regard to 'free CPU cycles' has changed. Back in the day of P3 and P4 chips the CPU ran at the same speed and used the same amount of power regardless of whether it was working hard or twiddling its thumbs, so it made sense to donate the idle cycles to something like SETI@home or MalariaControl.

However, now there are no 'free CPU cycles' because the clock slows down and cores are stopped instead of being left to spin in idle.

I've just upgraded my old P3 box, which ran at a fixed speed, by replacing it with a dual core Athlon system, which does all that good frequency stepping and shuts down the second core when its not needed. I haven't measured its power consumption yet, but the effect is highly audible: once the OS had been installed and tweaked to match my workload it was pleasantly quiet - until I enabled BOINC, which masterminds the use of 'free cycles' to, in my case, run SETI@home and MalariaControl. The box promptly ramped up to full power, complete with howling fans that could be heard throughout the house. After three days of this I realised that I wasn't donating 'free cycles' at all, but instead I was paying for each one of the little buggers through the electricity meter and wear and tear on the PC. I've now deleted BOINC and the apps it managed. Result: peace, quiet and reduced running costs.

LOHAN flashes fantastical flying truss

Looks like a good design.

However, one or two suggestions:

- You'll have noticed that the JPL Aerospace airship required the pilot to destroy/release the second balloon when the first burst, so I trust you have a similar automatic mechanism in mind? If not, simply looping the end of each lift line round hooks on the ends of a V, which would be pivoted in the center, may do the trick. The first balloon to burst will let the second tilt the V towards it so its line slides off its hook. Launching would probably be easier if the V is fixed during launch and unlocked a few minutes later, when its above most of the turbulence. It may benefit from a spring that's to keep it centered in turbulence but weak enough to be overcome when the whole weight of the truss comes onto the remaining balloon.

- running the lift lines up inside tubes or along masts for, say, half the length of the truss sounds like a much better stabilizer that either equalizing the lift from the two balloons (tricky in a breeze) or using a suspended weight (which wastes lifting power).

- if you have a choice, go for larger diameter thin-walled tubes, such as fishing-rod sections, rather than kite rods for making the truss. The large, thin-walled tubes are lighter and more rigid that the rather small, thick-walled ones used to make kites. Rolled balsa tubes of around 30 mm diameter might be better yet, especially if covered with doped-on tissue paper or very light glass-cloth. However they'd take time to make.

Japanese robot mirrors master’s movements

That's no ROBOT...

... its a WALDO, as anybody who reads classic science fiction knows. The name comes from a story of that name written in 1942 by Robert A. Heinlein. The current term for it is telemanipulator: I prefer waldo because its shorter and more memorable.

The distinction is that a robot is capable of autonomous action while a waldo is not: its sole job is to do precisely what its operator causes it to do while providing real-time visual, audio and haptic feedback.

Oracle reels off one exabyte in tape storage

A proper price comparison could be interesting

That would be one that compares:

a) the cost of the online disk array plus a geographically remote disk array, data centre and rental for enough comms bandwidth between the two to guarantee no data loss if the online array goes bang. Don't forget that the comms bandwidth must be considerably more than the disk array's average data rate in order to handle resyncs after one of the arrays has gone down and been fixed and restarted.

b) the cost of the online disk array plus a local tape system, off site storage for backed-up tape set(s) and the cost of van+driver to shuttle tapes between sites.

When you add in the cost of the remote data centre, the power it uses and the bandwidth rental, you may find the cost difference is a lot less than you expect.

NASA study identifies the ‘low hanging fruit’ in climate change

@DaveMorris

"preventing emissions from landfills (what, a billion dollar dome over each one?"

Are you thick or what? Capping a landfill site with a plastic membrane doesn't cost even remotely what you think it does, but still manages to be rather an efficient methane trap. Add enough containerized motor generators to match the methane supply and connect them to the nearest electricity grid spur. Job done for a few million at most. This is known technology, so no development needed: its been in use in the more advanced nations since the early '90s. See:

http://www.envirowaste.co.nz/index.php?page=landfill-gas-to-power

Australia should head-hunt Michael Gove

That implies you have a spare keyboard and display. I bet most schools don't have the industrial quantities of them that would be needed to equip a programming class. Using Ethernet cables lets the RaspberryPis share the peripherals already attached to a roomful of working PCs and will certainly cost much less than buying the dedicated ones needed for direct attachment.

When I get hold of a RaspberryPi, I'm expecting to connect it to my local network, hide it in a corner somewhere and access it via ssh or telnet/Kermit. Apart from being able to access it from any other computer in the house, this will save both desk space and the cost of an extra keyboard and screen.

I agree

And better yet, it need cost no more than its face value plus a short Ethernet cable. Even the schools' current PC and the thing it calls an OS remain useful because the RaspberryPi needs a display and keyboard, but thats easy: use the cable to connect the two machines together and run PuTTY on the PC. Job done.

Rhino horn price spike drives record poaching

Hey, I've got a great idea

Sell licenses to hunt the poachers, thus killing two birds with one stone.

Besides, it makes the hunt a bit more even handed if the game can shoot back.

Boffins unimpressed by LOHAN's sizzling thruster

Agree about the altitude

I've seen the S8E guys flying and I'm certain they get a lot more than 80m. Besides, 500g is damn heavy: if I built a 2.2m span F1A glider that weighed more than 450g I'd want to pull my head off with blunt pliers. F1A gliders are strong. They routinely take 30+G launch loads for every launch and still last for years. So, if LOHAN weighs more than 200-250g its probably overweight.

S8E is an international competition class for radio controlled rocket boost gliders. They use a single 20-40 newton-second motor, must weigh less than 300g and have a minimum wingspan of 1100mm. The aim of the event is to make a flight of precisely 360 secs, landing so the model stops with its nose as close as possible to a designated point. One point is deducted for every second of deviation from the target flight time and 10 points are deducted for every meter between the nose of the model and the target point.

"These models can reach approximately 1000 feet in 10 seconds and then glide in dead air for about 7 minutes using an E6 (20-40 n/s) motor. Typical models weigh 200 grams or less after motor burnout and are 200 square inches wing area plus or minus about 25 square inches. The smaller the model is, the higher it will boost and longer it will stay up in dead air. However, the smaller it is and the higher it boosts, the harder it is to see and control. So, eyesight is the ultimate limiting factor. A clean 200g model will boost to about 1100 feet on an AeroTech E6 motor." - from an American S8 page.

UK-centric details are here: http://www.fairocketry.org.uk/S8_glider.html

You guys should put your design team in touch with the British S8E flyers: Mike Francies, the UK S8E champion, is currently the chairman of FAI Rocketry. Contact details are on the Contacts page linked from the URL given above.

HTH

Iran spy drone GPS hijack boasts: Rubbish, say experts

Flat spins have a lower descent rate than than a 'normal' spin, but I wouldn't know by how much. My gliding club requires that I spin a glider for recovery practise at least once a year, but I have never been in a flat spin and hope I never am: they are much more difficult to recover from.

The only aircraft I've seen in a flat spin, using only my Mk1 eyeball to observe it, has been an F1A class model glider, which are deliberately spun to get them down out of the thermal at the end of a flight. I've seen these go into a flat spin many times when the spin settings are not quite right. As it transitions from a 'normal' spin to a flat spin its descent rate is reduced a lot while the rotation rate increases dramatically. After a short while the flat spin destabilises and becomes a violent tumble which may, if you're lucky, transition back into a normal spin. The tumbling descent rate is a lot higher than during the initial spin, and if its tumbling when it hits the ground you get a lot of damage.

Flat spins, etc. may well do more damage on impact than normal spins because the rotation speed is so much higher.

Thw wind vector is easy enough to calculate

Holding a constant heading and airspeed for 20-30 seconds and comparing the result computed result with the GPS or an equivalently accurate inertial system, i.e. better than 5 metre accuracy, will also give a good enough windspeed to navigate by and is a method that can be fairly continuously updated. Alternatively, if either the inertial system or the GPS is working, you just fly 3-5 circles at a constant turn rate and measure the drift. Depending on turn rate, that need not take more than 5-10 minutes.

All sailplane navigation programs use the circling method to calculate wind. They update the wind vector every time you stop to circle in a thermal, and at least one of them uses the straight line method and can get an acceptable accuracy from 10 seconds of hand-flown straight, constant speed flight.

Don't forget the UAV will know its wind vector up to the point when the GPS signal gets jammed, so it should be able to get near enough to home to pick up an NDB or TACAN from its home field.

Nissan Leaf battery powered electric car

Don't be too sure about cheap driving

I track all my energy usage on the cost per kilowatt-hour, using a rate of 9.7 kWh/litre to convert litres of petrol into energy measured in kWh. This number comes from "Sustainable Energy - without the hot air" http://www.withouthotair.com/

Averaged over the last 12 months, I've paid 14.80 p/kWh for electricity and 13.74 p/kWh for petrol.

In other words, the cheapness or otherwise of running an electric car depends entirely on the relative efficiency of energy use by a petrol car vs. an electric one.

New account of Flight 447 disaster published

and also....

... the LOT pilot who did a superb job of putting a 767 down at Warsaw when its undercarriage failed to come down.

http://airpigz.com/blog/2011/11/2/2-videos-lot-767-lands-wheels-up-in-warsaw-poland-11-1-11.html

The second video, taken from outside the airfield, catches the touchdown perfectly. The pilot put it right on the threshold with the exact amount of flare to grease it on. Its hard to imagine how it could have been done better.

I hear that, like Sully, he is a glider pilot...

Groupon grotty grotto rage forces Santa's chief elf to quit

So, let me understand this...

"Ward said that the grotto did want to sell tickets through Groupon, but claimed that there were issues with the voucher and they had never signed the contract."

So, why in hell is the grotto out of pocket buying toys for Goupon punter's kids? No contract = no requirement to accept the Groupon voucher.

The unasked and unanswered question is "What are Groupon doing to sort the problem out?" Saying 'sorry' really doesn't begin to match the situation, but free entry to a grotto with a train for punters and paying for the grotto's losses and damage costs might.

Globe slowly warming, insists 'Hansen's Bulldog'

Error 404 revisited

Either the URL on the last line of your article, http://iopscience.iop.org/1748-9326/6/4/044022

is incorrect or that page has been moved recently.

PayPal founder helps steer super geek cruiser

A Born Again Freedom Ship ?

It certainly sounds like a bastard child of the Freedom Ship concept.

A late 90s idea, that was meant to be launched in 2001, but 10 years later they're still dicking about looking for finance and there's no sign of construction on the horizon.

LOHAN: Reader vacuum pump plans really suck

For your records

I found a US source of aspirators: http://www.capitolscientific.com

They sell a Brinkman pump with a 10litre tank of water that it recirculates with an electric pump for a mere $US1850, so far too expensive for the LOHAN test, but its the only one on their catalogue that can get down to an absolute pressure of 20mBar

At the other end of the scale are a couple of plastic ones that you can run from any water supply with enough pressure and capacity to squirt 12 litres/minute through the aspirator. These cost $12.50 to $14.50, so are affordable and can get down to 64mm Hg (85 mbar) and 37mm Hg (49 mbar) respectively.

So, the $12.50 aspirator is twice as good as a fridge compressor (lowest pressure around 100mbar) while the $15 one is three times as good. I'd say go for the fridge compressors but keep the $15 aspirator in mind if the compressor doesn't do the job for some reason.

Cold batteries won't start rockets

I could be entirely wrong, but I think the cold at 80,000 ft will provide more of an ignition problem than the low pressure and that, while freezing the rocket motor may be an issue, keeping the ignition battery warm enough to deliver enough amps may be the biggie.

Suggestion

Sacrifice an ignitor in order to measure the current it needs if the supplier can't tell you this, and then set up a second cold soak test to make sure you can keep the ignitor battery warm enough for long enough to deliver the required current after LOHAN reaches maximum altitude.

Size the battery to have enough capacity to keep itself warm inside its insulation for, say, twice the estimated time needed to get to 80,000 ft and still retain more than enough kick to goose the ignitor real good. I think you'll find that keeping itself warm needs more capacity than firing the ignitor and that you'll need a thermostat in the heating circuit to minimise power drain at lower altitudes. The PARIS time-to-altitude numbers should be a useful input to this capacity calculation.

Notes

Li-poly batteries don't work at all well below 25 degrees C and most other types get discouraged below zero.

Maybe a supercap, kept topped up by a lower current battery with chemistry that can deal better with lower temperatures, would work as well as a Li-poly kept at 25C. A look at the specs hints that you could charge it on the ground and forget about the top-up battery, though a top-up battery might be useful to counter any current leakage if you get condensation on the supercap and wiring as the rig gets cold. Supercaps may be lighter than Li-poly batteries (I can't find any weights), are certainly cheaper and are unlikely to be bigger.

They want an absolute pressure of 15mm Hg inside the chamber, not a 15mm reduction from atmospheric pressure.

Word and Excel creator: How Gates, Jobs and HAL shaped Office

"Please see Novell v Microsoft" - Why?

That was me reporting what I experienced at the time. IIRC we couldn't even persuade WPW to read a document we'd written a year or so previously with WP for DOS.

I cheered when Wordperfect finally sank without trace...

... because the DOS version had the least friendly UI of just about anything I've ever used. Yes, even worse than Wordstar with its collection of dot commands borrowed from nroff. On start up the Wordperfect screen was entirely blank apart from a cryptic indication in the corner that you were at line 1 page 1, it required you to use a template to sort out its tangled mess of 4 shifts on the function keys and its idea of WYSIWYG was to stick with the same font but use colours to indicate italic, bold, etc. Some will tell you that its Reveal Codes mode was wonderful: I disagree. Essential, yes. Wonderful, no. In truth Reveal Codes was nothing but a debugger and was essential because it was all too easy to create an unprintable mess of misused formatting codes that could only be fixed with careful editing in Reveal Codes. Last but not least, the only way it could produce our company standard documents was with a large collection of custom macros that somebody had to write in house.

Word 4.0 for DOS was 100% better: faster, fairly instinctive to use, and about as WYSIWYG as a 24x80 display could get. On-screen alignment etc was good, it could show italics, underlining and bold text on screen, and it was much faster than Wordperfect on the same PC. Company standard documents? Somebody took half a day to create a style sheet. Job done.

The company I worked for at the time used both Word and Wordperfect: I never used Wordperfect if I could possibly avoid doing so.

I disliked Win Word when it appeared because it was much slower than Word for DOS, but at least it worked reliably, which was far more than could be said for the Windows Wordperfect port.

Groupon stock dives below IPO value as Black Friday nears

Tech stock? Really?

Like hell Groupon is a tech stock. Its a coupon discount sales operation, pure and simple.

Keep up there.

Got a few minutes to help LOHAN suck?

Don'r forget the acetone

Get yourself a liter or two of acetone to pour into the dry ice chamber before adding the dry ice. Without it there will be almost no thermal conductivity between the dry ice and the steel tube and cooling down will take forever. The advice to get things cooled down before pulling vacuum is good too, but you should also think about packing steel wool into the space between the chamber wall and the rocket motor for better thermal conductivity and faster cooling.

However, two things to watch with acetone:

(1) it dissolves styrofoam instantly, so don't use any styro insulation round the acetone jacket. Wrapping the dry ice container with 2-3 layers of corrugated cardboard, gluing on a ring of cardboard top and bottom and finishing with a coat of acrylic or enamel paint to keep the acetone out (both are immune to acetone) will provide plenty of insulation for the fairly short time you need to keep things cold.

Its possible that you could get away without any exterior insulation. Things will get cold enough inside the chamber without the insulation - you'll just use rather more dry ice, but its fairly cheap at around $US 2 - $US 4 a kilo and, as it sublimes at the rate of around 5 Kg / day if kept in a chilly bin, you'll probably need to buy 10 Kg or so in any case. When I used it in the lab, we always bought it as 5 lb or 10 lb chunks first thing on the day we needed it and didn't have much left at the end of the day.

(2) Acetone is very flammable, so drain it out before hitting the GO button on the rocket motor: fit a pluggable drain hole in the bottom of the dry ice compartment.

What to expect from a fridge compressor

According to this site: http://www.paragoncode.com/shop/vacuum_pump/

a fridge compressor maxes out at 100mb, or about 75 mm of mercury, so its probably not good enough.

@PC Paul: if you sucked down to 15mm Hg (0.98 bar) when vac-bagging a foam wing you'd end up with a very thin wing. I have an AutoVac II system I bought from ASP which was set to pull 5" (128mm) of mercury when I got it (0.16 bar): that's plenty for vac-bagging wings. I vac-form carbon shells on Dow blue foam male moulds and pull about 11" (0.36 bar) but this is much stiffer foam than anything you'd make a wing out of: its sold for under-floor insulation and is rated to support something like 260kG/m^2 load with a hard floor surface on top of it to spread the load.

Apple requires Mac App Store candidates to be sandboxed

Clearly the Secunia guy(s) had no clue

..or they'd have known that DEP is irrelevant to the Java JVM. The JVM works by interpreting bytecode (and for all I know single-steps JIT output since that would still be a lot faster than bytecode interpretation) which means that:

(1) the bytecode generated by javac is just data to the host OS since it can't be run by the OS. All that can happen to it is to get read as data and interpreted by the JVM, which IS a binary executable within the meaning of the act. The OS neither knows not cares that bytecode is going to be interpreted by the JVM. Since the JVM reads the byte code as data and will apply its own rules to prevent access outside the memory regions the JVM has allocated as stack and heap data space, DEP is simply irrelevant.

(2) the JVM allocates and manages all access to memory containing byte code, the stack and heap, ASLR rules also become somewhat irrelevant since the JVM interpreter will use ASLR in OSes that support the facility and, anyway, applies its own sanity checks first, so it will spot an out of limits data reference before it gets bounced off the ASLR gatekeeper.

(2) the JVM is a normal executable that happens to do a number of things as the result of reading the bytecode - WHICH DOESN'T MAKE THE BYTECODE EXECUTABLE TO THE OS

Cameron is right too: implementing DEP and ASLR checks over the head of any program (user-land or not) is entirely OS business: any OS that leaves these checks to a program its running is shockingly badly designed.

This isn't exactly recent news either, boys and girls: mainframes have done this since 1964. No, I don't mean the IBM S/360 schlock, but the ICL 1900 series, which always used zero-based addressing within a program regardless of the address a program was loaded at: the OS knew the datum and limit values for every program and restricted all program addressing (for both data and instructions) to that range - and yes, even in the 60s a running program could be and typically was moved in memory while it was running and could also be stopped, swapped out to disk and back in to (probably) a different memory region without knowing that it had been stopped or moved.

India uncloaks new thorium nuke plants

+1 signers

Thanks for the heads-up about this petition.

CERN boffins re-running neutrino speed test

Because a neutrino beam can't be bent.

Photons can be made to follow an optical fibre if the angle they make with the sides of the fibre is low enough for them to all be reflected back into the cable.

However, neutrinos are particles that barely interact with other particles enough to be detected, which is why they can travel 732 km through solid rock. The chances of reliably deflecting such a beam in a circle are approximately zero. Similarly, they carry no electric charge so magnets won't deflect them either.

To show how unreactive neutrinos are, Its been calculated that a neutrino beam can penetrate a lightyear of solid lead without loosing more than a few percent of its brightness and they can whistle through the sun almost without noticing that it was there.

So, as collisions don't deflect them, they can't be reflected by anything, and magnets or electric fields don't affect them, you have no choice except to design the experiment around measuring a straight beam on neutrinos.

Disk drive crisis: Economists are terrible weathermen

A good summary of the situation. Many thanks for writing it.

There's just one thing I'd like to know: why was this flood so much worse that others in previous years? I know that the area around Bankok is like a billiards table but I wonder what has been happening upstream that may have made those floods more severe.

BTW, I remember the semiconductor manufacture problems after Kyoto, but I thought the factory was the source of the casting resin used to make plastic-encapsulated chip packages.

Google leads shoppers into pay-by-wave future

OK, so tell me how I know

"millions of credit cards already have the technology embedded, but very few people use them or even know they're there" .

Obvious question: how do you know if a card is NFC-enabled?

Is there some sort of logo, hologram, or what?

RIM: 'Faulty switch took out faulty-switch-proof network'

When fault tolerant isn't

Some time ago I was developing on a Stratus box that shared a server room and mains connection with a Tandem Non-Stop box. Both are fault tolerant machines.

We came in one Monday to find that our Stratus was dead. It turned out that the Tandem PSU had shorted during the weekend which tripped out the mains, shutting down the 2nd half of the Tandem PSU and leaving the Stratus to run on its backup battery until that went flat after 3 hours or so.

Exactly the same thing happened again a month later, proving it was no fluke.

Moral: if the backup(s) aren't in different buildings which are connected to different substations and standby generators the system can't be considered fault tolerant - and still may not be due to other circumstances.

NHS orgs not keen on UK gov's mega-intranet

Privacy is paramount

If NHS use of N3 keeps J.Random Civil-Servant's hands off my data, which I assume it does, but use of PSN or merging N3 into PSN can't guarantee the same level of protection, then I'm totally against any use of PSN by the NHS.

Pampernaut love-rat space shuttle pilot prangs plane

Thats not exactly true

Plain to see you haven't flown much. Stalls are pretty benign apart from the height loss, never involve a tumble, and are always recoverable[1] given enough altitude to do it in. In a glider all you do is reduce back pressure on the stick and recovery is almost instant.

Spinning is a Much Worse Thing because its a stable state that requires positive action to stop the rotation. Some aircraft are placarded against spinning, but the rest are recoverable given enough height and the appropriate pilot skills[2].

[1] unless you're flying something like a BAC 111 or a Gloster Javelin, where the design allows the wing to blank out the tail entirely in a deep stall.

[2] All gliders will spin and so all glider pilots have spin training. In my club we do a pre-season refresher every year that involves, amongst other things, aero towing to 3000 ft or so followed by stalls and spins. Fun! However, many powered trainers are placarded against spinning and I believe that spin recovery is no longer part of PPL and NPPL training.

Email and compliance: How not to blow the storage budget?

Use a Mail Archive

There were no automatic, essentially no-maintenance mail archives available when I got serious about mail storage, so I wrote my own. Its portable, being written entirely in Java and using PostgreSQL for storage. It has equally portable enquiry and database weeding tools. The benefits of this approach are:

Automatic: an 'always_bcc' Postfix directive sends copies of all incoming and outgoing mail to the archive. Postfix needs no maintenance, since all its tuning and index maintenance is automatic.

Fast: I can find almost any e-mail in under 30 seconds in a 120,000 message archive. The search tool can search on address, subject, body text, date range or any combination of these.

Convenient: regular mail folders can be kept small since its generally faster to retrieve a message from the archive than it is to hunt for it in my mail reader's folders

Automatic whitelisting: I also run Spamassassin. A plugin for it whitelists anybody who I've sent mail to and is in the archive.

If you keep mail for more than a month or two, this is the way to go.

Check your machines for malware, Linux developers told

Many thanks for the tip: found it in the F15 repository, downloaded and installed.

Run: says system is clean.

chkrootkit is now toast.

What's all this trust in chkrootkit?

The current release of chkrootkit (0.49) is quite old as it was released some time in 2009. The developers aren't answering e-mails, so I'm wondering if its now abandonware.

I reported the following to them at the beginning of last month to a deafening silence:

chkrootkit has periodically false alarmed over SuckIT using a sig. pattern against /sbin/init. I also use a behavioral test that says I'm not infected. chkrootkit has periodically done this after kernel updates to Fedora 13 and 14 during the last 12-18 months. Currently it thinks Fedora 15's systemd management package, which replaced the old Sys V init, is infected with SuckIT ever since I first installed it, but again the behavioral test says no.

If there's a replacement for chkrootkit that's better maintained and has more responsive developers I WANT TO KNOW ABOUT IT.

Steelie Neelie calls for copper price cuts to drive fibre

Telcos vs. tealeafs

As copper prices rise a really switched-on telco would realise that replacing stolen copper is a mugs game. A better idea would be to flog off their copper *before* it gets nicked and use the proceeds to finance the fibre that replaces it.

Profits? They'd result from not having to pay the costs and overtime that occur each time their copper is stolen.

Faustian descent into backup hell: A play in two acts

One word: rsync

There are rsync versions for Linux, Windows and unices in general.

IME its the best backup solution I know because, once the initial copy has been done, subsequent copies only do the minimum amount of work to bring the backup inline with the filing system being backed up. In my case this takes somewhere between 8 - 15 minutes.

LibDems call for gov 'IT skills' office

Government IT disasters aren't new

I agree that the Civil Service IT people at the coalface know what they're doing and are no less competent that any other IT staff. However, their management are both incompetent and could care less about results.

I was part of the crew that rescued the Naval Dockyard Project back in the mid-70s. The original project was planned on 'Magnificant Men In Their Flying Machines' lines: zer is nuzzing an HEO cannot do. The result was that in 7 years the original project got nowhere - and was fixed in 18 months when the management were replaced by good ICL project managers aided by a number of outside programmers and system designers.

In the early 90s I was also involved in the 3rd attempt at an HMCE project - all three attempts failed to deliver anything due to HMCE management being more interested in scoring points off each other than delivering anything.

Sacking everybody above HEO is the best way of reforming the Civil Service.

Internet fails to dethrone TV news (so far)

If you've ever watched American news on TV...

...you'll not be surprised that its losing out to every other source of news.

Judging by the newscasts I've seen, US TV news reporting is the worst in the world. It seems carefully designed to keep the voters ignorant rather than seeking to inform.

I remember watching the prime ABC evening newscast in LA a while back, because there had been a significant political upset here that I thought they might cover. Fat chance. This was a full hour's news program and it broke down this way:

- in the first 10 minutes they covered four breaking stories. Three were the sort of thing that might have made the local news here on a slow day. One was about a row of three shops in Ventura that had caught fire and the other two were even more forgettable.

- the fourth story was about some fairly minor Washington politics and was covered in much the same way as the BBC might cover East European politics.

- the remaining 50 minutes was sport(!).

Celebrating the 55th anniversary of the hard disk

Technical correction

'Winchester" was the code name of a sealed removable cassette containing both platters and a set of heads, and the heads weren't in contact with the platters - they flew on an air layer that was dragged round with the disk.

The RAMAC head, OTOH, didn't fly. The rotation speed was low - similar to a floppy (another contact device) and was loaded onto the disk and unloaded very similarly to a floppy disk. The head traveled up the stack to the platter it needed, swung in to the required track and was then loaded onto the surface to read or write a block of data. I've never used a RAMAC but have seen one. In the mid '70s IBM used to have fantastic displays in the street-level window of their 6th Ave, NYC building. One of them showed all their disk tech from the RAMAC up to their latest and greatest DASD of the day.

OTT, they built the flight computers for the Gemini and Apollo capsules. I remember seeing them in that window too, but I digress....

I came into the business by programming ICL mainframes in 1968. We too had disk drives - 10 surfaces in a removable 8 MB cartridge. The heads flew on these disks, which spun at 2800 rpm and had an average access speed of around 135 mS.

Unlike the Winchester, these cartridges weren't in sealed cassettes and the heads were a permanent part of the drive. To swap disk packs, you opened the drive's cover, dropped a transparent cylindrical cover over the disk pack, turned a handle and lifted, put a flat cover on the bottom to seal the disk from dust, and carted it away. Putting one on was the opposite: turning the handle locked the disk onto its spindle and detached it from the cover.

LOHAN deluged with Reg readers' interjections in REHAB

Re: Perspex top cover

You'll need to make a few perspex top covers then, because the top plate will be damaged by the exhaust and, unlike a metal plate, a perspex one won't be easy to clean up. If you expect a camera to look through it, then it will almost certainly be a single use item.

Re photography: if the spacing between motor and top plate is small, say 1-2cm, a camera mounted as much as 45 degrees off axis should get a good view. Just make sure that the light sources are behind the camera to avoid reflections. What about using a key fob camera? They give adequate resolution and are very cheap, so it doesn't matter it gets damaged, though a small piece of clean glass in front of it should do no harm optically. I don't know if the frame rate would be high enough, but that would apply to any domestic video camera too.

LOHAN to suck mighty thruster as it goes off, in a shed

Suggested mods

I have one main suggestion: reverse the metals.

Use an inner steel tube because its easier to weld than alloy and welding on the lower end cap would be a good idea. I'd also suggest that you weld a 10 mm wide flat lip on round the top and grind it fairly accurately flat. This way you can get rid of the rubber seal: put a fairly thick layer of low temperature grease on the lip, drop on a flat steel top cap and you should get a good enough seal. Laboratory glass vacuum rigs typically use grease on ground glass mating surfaces and have few sealing problems.

Your biggest problem is likely to be connected with the temperature probe. You may end up having to use flexible epoxy round a length of wire through the inner tube and fit a connector to each end of it. Mounting the sensor on the motor support near the cartridge would be sensible since its probable there will be a big temperature gradient within the tube: hence the internal connector so you can take the innards right out if needed. It will be important not to strain the cable vacuum seal, so gluing the internal connector to the inside of the tube and binding the cable to the outside with Dacron line or linen thread and epoxy would be good.

The rocket motor support can be made of anything, e.g. assembled from alloy disks and steel threaded studding and simply slid into the inner tube. If its a reasonably loose fit there's no need to perforate the plates since vacuum pumps are fairly slow and a 0.5mm gap, or just 3 or 4 3mm semicircles filed in the edge of each plate will be plenty.

Using a tether on the top cap sounds like a very good idea.

Vacuum connection: screw a brass nipple into the inner tube or through one of the end caps and use a rubber vacuum hose to connect it to the pump. Suitable nipples ands hose is readily available from laboratory supply houses. Alternatively the bits and bobs used for vacuum bagging glass/carbon mouldings should be good, and if you're going to build parts of LOHAN from carbon composites you'll need vacuum bagging kit anyway. You could do a lot worse that talk to ASP http://www.acp-composites.com/ or CST http://www.cstsales.com/ about this. Both are good places to deal with and very knowledgeable about their products.

Vacuum pumps: don't immediately rush out and buy one: they can be expensive if you're going to get down to 7.6 mm of mercury (that's 0.01 bar, approximately the air pressure at 100,000 ft) If I was doing it, I'd start by trying a 2nd hand fridge compressor: cheap as chips (often free) and may do the job. They are commonly using them for vac bagging composites at between 0.5 - 0.75 bar and I know they'll go down to 0.1 Bar but may take their time toward the end.

Final hint: you may find that the thermal contact between the dry ice and inner tube isn't all that good and that the dry ice doesn't sublime fast enough to really suck heat out of the system, so make sure that the dry ice compartment is water proof. This will let you use a slurry of dry ice and acetone, which will get you down to -100C, plenty good enough. Acetone is the usual solvent used for a dry ice freezing mixture in the lab because its freezing point is below anything you can reach with the mixture. An ice/salt/water mix won't go below -25C. Of course, using a low boiling organic solvent has implications:

- you can't use styrofoam insulation because acetone dissolves it (but fibreglass loft insulation will do the trick)

- make sure you run the ignition tests outdoors and have a fire extinguisher on hand because, if the rocket ignites it will almost certainly set off the acetone too.

LOHAN eyes hardcore partner's impressive girth

This sounds like a very good idea, though if you use a water column, something impermeable on the top, such as a loose-fitting polystyrene cylinder might be good: I just wonder how much the water vapour in the low pressure chamber may affect the ignition sequence - especially with the motor at -60C.

On second thoughts, water vapour in the chamber is probably a good idea because things could well ice up while LOHAN is on the way up under the balloon, specially if its a bit cloudy that day. If it ignites under icing conditions in the test chamber it should be OK on the day and less likely to fizzle when lit for real.

BTW, I agree that the rocket powered altitude gain will be much less than that under the balloon. I've seen the RC rocketry boys flying S8E boost gliders (typically 200g, 200 sq.in wing) using cartridges with similar thrust and burn time as Lester is considering. These models are capable of getting to 1100 ft on an Aerotech E6 cartridge. Here are some launches and an idea of the size and shape of these models:

http://www.youtube.com/watch?v=t52Ii55kgt4

They'll obviously get higher in the thin air at 80-90,000 ft but possibly not more than double the height.

Diebold demos cloud-based ATM

...no, but the answer is 'not much'.

The mechanical features of an ATM (the card reader, keyboard, screen, safe, banknote hoppers, banknote handling kit and the printer will, by and large, remain the same because they have to.

The computing element in an ATM won't change much either. It still has to drive the mechanical bits, handle its end of the comms line to the server and drive the cardreader, keyboard, screen and printer. About all it no longer needs to do is run the finite state machine (FSM) that forms the heart of virtually all ATMs.

There should be little effect on ATM reliability since the servers are generally fault tolerant and have been for almost two decades. The effect of comms line failures and ATM breakdowns should be the same as at present.

AFAICT the only effect of this redesign is to move the FSM from ATM to server. The sole benefit will be that the (fairly infrequent) changes to the sets of screens and actions will be applied to a single local copy of the FSM state table rather than being sent over the lines to every ATM. Against this the volume of data sent between ATM and server, and hence the required bandwidth, will be hugely increased because screen images and keypresses will have to be exchanged for every user action.

I can't see any significant benefit to the ATM operator in this, while Diebold gets to replace whole bank-fulls of ATMs and the server manufacturers may need to upgrade their boxes to support the FSMs.

World ostracizes firm that issued bogus Google credential

Same here.

There are no DigiNotar certificates in my copy of Opera 11.50

Supercomputer and superboffins spot rare baby supernova

Actually....

...that 'line of code' may be part of the job's run control script.

Its not unusual for jobs run on systems bigger than a bog standard server to require the run control script to tell the OS what resources this run requires: not doing so is an excellent way of wasting computer power. The number of cores the job needs is an obvious candidate for such a request.