95 posts • joined 3 Aug 2009
"You don’t want to find out that the fire alarm has lost its connection by having it fail to signal the fire brigade."
I am reminded of a story (from 30 years ago) of a factory that had a fire alarm system installed that would automatically phone the local fire station. However the station became a part time one and so one night when there was a fire, it called up the station and the system there replied with an answer phone message that the station was closed and to call the "Emergency Services". This exchange then repeated until the factory was raised to the ground.
"Pacifier transmits 3 milliseconds every 5 seconds, which means for over 99.99% of the time it is not transmitting at all."
According to my calculator 3ms every 5000 gives a 99.94% duty cycle.
...because they saw you coming.
Given a quick check of the boots website indicates that ordinary pacifiers cost about a fiver.
I wonder what happens to them when you put them through the steam steriliser (see icon)?
I'm always impressed with the Voyager craft. They have done such fantastic work, and produced such useful science.
I do have stuff that's older and still working, but they all require regular TLC. On the other hand they only cost a few tens or hundreds of pounds, rather than the many millions that the voyagers cost.
Ah, but think of the money you could make if you still charged them as if they had used the bandwidth!
Really, *really* don't do it.
I had to resurrect the VHS to play the tapes I had of D.M. for my kids, and they love it!
It doesn't need updating, just showing again!
"Once I've got the canards rigged, we be firing everything up..."
Given what's just happened, isn't that a poor choice of words?
Also the heat dissipation in thinner air is lower (that's how some vacuum gauges work), so it would have got hotter faster at high altitude.
The problem with a zener is that it'll dissipate heat too in a over voltage situation, and excess heat is not something you want in Vulture 2 at altitude. The Lithium cells can deliver a lot of current in to something if it fails (as your late and lamented servo appears to have discovered).
Are you logging the current consumption from the APM?
Have you dissected the servo yet, I presume it was the motor itself that let out the magic smoke?
or has it been airbrushed from history already?
But as an avid watcher of Tomorrow's World since the mid-70's, I have to agree with the principle of the article.
A lot of systems are regarded to be safe as they controlled by a Human that can be trained and tested and assessed. There is a vast amount of mistrust of automated systems controlling safety critical operations.
In theory railways ought to an ideal candidate for automation, but only a tiny number (usually urban mass transit systems) are, and only a small number of those are fully automatic without a human involved at all. All rest have an official present in some capacity to deal with failures and emergencies.
"Typesetting is very cheap nowadays"
Cheap != Free.
"..in standard publishing authors get *paid* to give publishers stuff.."
This is supply and demand in action. In science there are many more papers being submitted than being published. However there's only one Ian McEwan to write his books that the publishers know will allow them to ship a lot of copies.
It's an example of the controlled distribution world meeting the internet.
The ACSE make their money from having people subscribe to their journal. A researcher submits their manuscript, without having to pay a fee, and then the society have it peer reviewed, typeset and published (all of which cost them money). It's a valid model and has worked ok for some time, but has a few flaws.
One issue is that if your paper isn't in the journals area of interest it'll be rejected. This means that areas of research go in and out of fashion, so if you're doing good quality science outside those areas, then you can't get your paper published.
Another is that if your paper is a negative result, it'll be rejected. This means that other people are doomed then to keep repeating that bit of research, which is a waste of effort, as they don't know that someone else has looked in to the same idea.
A better model seem to be the Open Access one, such as PLOS ONE, where you pay to submit papers, and then the access to them is free. The fee isn't vast, and is generally factored in to the grant money that you get to do the research. The funding body in turn saves the money from not having to subscribe to yet another journal.
One of my very useful bits of RF analysis kit, made by Hewlett Packard in the days before they were HP, which is before they became Agilent, has a floppy drive as the only viable way to get data off it. So I have a small collection of floppies and USB-Floppy drive (as in Alistair's picture).
"Yesterday I saw Yes at the Royal Albert Hall and I struggled at times to follow the intricacies of Close To The Edge as they were drowned in an overall wall of sound."
That's largely due to the R.A.H. being an acoustically horrible place. It's the wrong shape (round) and too tall. I understand the baffles they have hung from the ceiling have made it less bad, but given the starting point they could barely make it worse!
There are lots of different tool for lots of different jobs. Using the tool in the wrong way or for the wrong job will result in a poor job or failure.
Bjarne Stroustrup did say ""C makes it easy to shoot yourself in the foot; C++ makes it harder, but when you do it blows your whole leg off" and adds the footnote that this really applies to all powerful languages.
The site for the Naval base is rented from the Cubans, so every year the US Govt. have to write out a cheque to the Cuban Govt.
Rumour has it that all the cheques for the last 50 odd years are in a desk drawer in F. Castro's office!
I have to agree.
The Doppler effect is 0.83ppm (not 830ppm) if the relative velocity is 250m/s.
From the article's link to the Malaysian Ministry of Transport report, there is a nice graph at the bottom of the measured shifts of the different pings. The maximum shift is 250Hz for the last ping. At 1GHz this is 0.25ppm indicating a relative velocity between the satellite and aircraft of 75m/s.
As the satellite isn't quite stationary relative to the earth, the Doppler effect going north would have been slightly different to that measured if it was going south. See the graph, again.
What exactly does this give us that WiFi and/or Bluetooth doesn't, both of which are established technologies, which can be implemented, with antenna, in about the area of a thumbnail?
On the plus side, perhaps someone will want the USB-UWB test gear I have here!
Obligatory xkcd cartoon: http://xkcd.com/927
"Great, you give him an F because his solution is too complex to implement yet you cannot come up with a better one ..."
He was just pointing out that complexity == cost, which doesn't go down well in a capitalist free market economy, so people will go with proprietary as it cheaper.
As Jim 48 said, there's no restriction on home brewing for personal consumption, which is in part the cause of these high alcohol yeasts that have been developed.
You do need a licence to run a still, which is in part a safety precaution as there is a significant risk of you taking the wrong fraction out of the process and giving yourself and your friends methanol poisoning.
In a helicopter, I trust?
It's an impressive video, but I am rather concerned he ought to have been wearing some ear protection in that sort of background noise level.
He did seem to have to shout quite loud just to be heard!
I'm quite impressed at getting the shot at all, 1.35ms isn't very long at all to take a snap!
Not the special water (although de-ionised water would be a good idea otherwise you print head might scale up!), but they'd just transfer the cost to the paper (which has to be specially preprepared) and they'd make sure that it was only their premium paper world work in their printer.
It's a sad reflection on human nature, unfortunately.
I have seen it occur a number of times in different organisations where volunteer labour is used. Someone volunteering there is doing it because they like it, and think it's a worthwhile cause, so the usual relationship between the company and employee doesn't exist.
Combined with some peoples tendencies to let a little power go to their head, and suddenly they think they are running ICI.
I'm sure they'll work it out, but I suspect the path will be littered with further incidents like this, which will help no-one at all, which is a pity as it wastes effort and demoralises others.
As opposed to the Ford Escort "Bent Coat Hanger Antenna"?
We had a similar setup connected to Middlesex Poly's DEC 10, It was fantastic. We lost the connection in the mid 80's when the Poly updated their systems and didn't support 110baud any more. There was a suggestion of upgrading the line to a Token K (300baud - ohh!), but that required money and there didn't seem to be much of that in education in the mid 80's.
I also recall seeing a computer science teacher get a near hernia from carrying the ASR-33 up the stairs!
I recall a review of a Citroen that enthused about the ride and road holding, with the caveat "... as long as you don't mind the noise and smell of children throwing up in back"!
I'm all for keeping leap seconds, and doing so until a significant fraction of the population aren't living on this planet. No matter how you define time, most people prefer to synchronise their day by the rising and setting of the sun.
They probably could, but it would have involved a lot of small children inside the the structure, holding the 'dolly' as someone outside riveted it with a steam hammer. "Loud" would not begin to describe the noise!
See also the films of building a riveted ship, where they throw the red hot rivet from one to another.
Look also at the Foxton Inclined Plane.
The impression from the film was what it was left in lunar orbit?
What's with the dreadful film score music? Some ballet music would have been better, given the process involved in celestial mechanics of large masses and small forces. Dance of the Sugar Plumb Fairy perhaps?
I didn't mention the quality of the train service they provide or the value for money of off peak tickets, both of which I will take you word for it are fantastic.
I was referring to the annual subsidies paid to Virgin for running the train service, and the complete fiasco that was the WCML upgrade that they negotiated and was part of the incentive for them to take the contract.
The upgrade was meant to cost £2billion and give us a 140MPH railway. Instead we spent £9billion and ended up with a railway that you could only do 125MPH, in parts and 110MPH on the rest.
Oh yes, as Virgin Trains, along with the West Coast Main Line Upgrade, was such value for money for the UK taxpayer.
Lincolnshire Poacher, anyone?
The "backup dam which had been built around the tanks" is generally called a bund. You'll find them around oil tanks and the like to catch the leak rather than letting it just soak in to the ground.
The bund is often open, which helps you see if there's anything in it, but this also means that they accumulate rainwater, which has to be drained off.
As an aside, I seem to recall that The Register you to sell little beta sources. Those glowing key fob things, which held phosphor coated vial of tritium.
Yes. Some NATO exercise in Europe in the mid eighties. I recall reading it on the EE Lighting stand at Duxford IWM.
"In 1984, during a major NATO exercise, Flt Lt Mike Hale intercepted a U-2 at a height which they had previously considered safe from interception (thought to be 66,000 feet). Records show that Hale also climbed to 88,000 ft (26,800 m) in his Lightning F.3"
Also, when did "massive novel civil engineering project" and "on-budget" come in the same sentence?
It one of the more silly ideas I have come across recently.
Mono-Rails (the Simpsons episode says it all)
Maglevs (Yes, i do know there are some in use, but they are just status symbols, whose function could be replaced much more cheaply, at only slightly lower performance, with conventional HSR)
Goerge Bennie's Rail-plane
The pump storage at Ffestiniog pre-dated this slightly (commissioned 1963), but it uses separate pumps and turbines. It was built to compliment the nuclear power at Trawsfynydd.
The one at Dinorwig (which uses reversible pump/tubines like Cruachan) is just huge though, and has some impressive stats: 0 to 1.3GW in 12seconds flat. Also It can also be used to "Black Start" the grid.
That's all I have to say.
For a long time the civilian GPS signals has a deliberate jitter which reduced the accuracy even further. This was turned off in the mid 90's, I think. Apparently the latest satellites don't have this feature in them.
As for hacking the Military signals (even by a Nation) is very difficult, as despite all their flaws, they do have some clever Boffins who are very good a crypto.
(Icon chosen for it's relevance to the application of GPS.)
Given the number of train tunnels in the area, I hope the builders are more careful than the ones building near Old Street:
Please don't think this will men you can use US "915 Band" equipment in the UK.
The FCC and IC 915 Band stretches from 902 to 928MHz, so is much wider than this new allocation.
The band is squashed in around the GSM900 Frequencies. Uplinks (phone to base station) are 876 to 915 and downlinks are 921 to 960, which is one of the reasons that the US use GSM850 instead.
Fantastic! A proper "Hot Line" phone phone.
There was a lot of research in to mechanisms for storing data, because it was a previously untackled problem before. Telephone and telegraph systems didn't store data, just transmitted it onwards to the next part of the system.
For fast access you need a pure electronic bistable circuit to record a binary state, but these use several valves each, and so you only used them on the internal registers of the CPU itself.
Another, a bit later, was to use a CRT with long persistence phosphor. You mounted a 2D array of photodiodes across the screen and implemented a refresh cycle circuit.
I seem to recall that some of the Canal Restoration projects in the UK have used inmates from HMPs.
The flicker at silent film rate of 18fps is just as likely to trigger photosensitive epilepsy, as at 24fps. The general sensitive range is 16 to 25Hz.
I'm still slightly unsure about the enthusiasm for higher def projection (tv or cinema). Cinemas are getting smaller and my TV is about the same size as it's always been. I put up with VHS for over twenty years!
It's not the picture itself that counts but what's in the picture.
Also, don't forget cinemas too.
Whilst there is more and more digital projection, there are still a very large number of theatres out there that only have equipment to project standard 35mm print.
At 90ft per minute a two hour feature print in 35mm is about 2 miles long. That's a lot of stock for all those prints.
"No, that would be infrared"
No, they were right. A rainbow has red on the outside of the curve (longest wavelength, so most refracted) and violet (shortest wavelength, so least refracted) in the inside.
So UV would appear inside that, and thus as the original A.C. said, under the rainbow.