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Interestingly the Ministry of Aviation in England did a study on something similar a while ago: http://aerade.cranfield.ac.uk/ara/arc/rm/3332.pdf. They claim that attitude deviations of up to 1.5 degrees may be observed for a 3 square metre surface area (normal to the Solar radiation) and a 2.5T satellite. That's not insignificant, and if the Sun did somehow produce a sudden large outburst, akin to a cataclysmic variable, then perhaps it might be enough to push the satellites into a decaying orbit. Then again, there are a lot of integrals in that paper and I could be reading it wrong!

In this paper a propeller having all sections operating at supersonic speeds is designated a supersonic propeller regardless of flight speed.

Also, as I pointed out, the tip is only stationary when it is exactly perpendicular to the airflow - otherwise, there is also a "sideways" component. Plus, there's no reason (and some research has been done on this) to assume you can't give your blade what would be a negative pitch if it were moving in the forward direction, so that a blade that was moving backwards could still generate lift as it was "dragged backwards" through the airflow.

Also, iirc, around the time of the first OPEC crisis, McDonald-Douglas was working on a supersonic turboprop with 6 curved blades per engine.

Original article from here.


BURN CRUDE PALM OIL TO GENERATE ELECTRICITY

The launch of Tenaga Nasional Berhad's (TNB) power plant, which uses crude palm oil as fuel, marks an important milestone in the country's power sector. Malaysia has started conducting feasibility study on burning palm oil diesel fuel in its power plants. Blended with medium fuel oil, the fuel mix has been successfully tested at the TNB Generation Sdn Bhd power station in Prai, Penang.

Palm oil, traditionally used for cooking and making soap, is the latest addition to the country's power source, though on a limited scale. This is in line with the government policy of introducing a fifth fuel policy; fifth fuel is meant to mean renewable energy. As of last year, 80 percent of the country's power supply was generated using gas, 10.6 percent hydroelectric, 6.6 percent coal and the remaining using medium fuel oil. In February this year, TNB was approached by the Malaysian Palm Oil Board to jointly conduct a study on the possibility of using palm oil to generate power. TNB's research arm, called TNB Research Sdn Bhd, took three weeks to complete its preliminary study. Starting from March 28, 2001, the national utility's power plant in Prai has been using palm oil to generate power, which was claimed to be the first in the world. (Background: In February, crude palm oil (CPO) prices hit a low of RM697 per ton with the buildup on palm oil stocks rising to 1.5 million tons. As a result, the Malaysian Palm Oil Board signed a memorandum of understanding with CPO producers for the supply of the produce at RM725 per ton. The CPO is then sold to TNB at RM700 per ton, with the board subsidizing the price difference).

Blended with a ratio of 20 percent crude palm oil and 80 percent of medium fuel oil, the mixture is burnt in a boiler and has a capacity of generating 120 megawatts of electricity.

The major advantage of using CPO is it results in less pollution, containing less than 0.05 percent sulfur dioxide during power generation, compared to three percent using medium fuel. Palm oil is also renewable and takes only between three to five years for plants to mature.

However, on the downside, CPO is not an economically-viable option. The gross heating value- the amount of electricity that can be generated- for palm oil is 40,000 kJ per kg, compared to 42,600 kJ per kg for medium fuel oil and 45,000 kJ per kg for diesel. Furthermore, CPO is 16 percent more expensive than using diesel and costs 38 percent more compared to medium fuel oil. Under the pilot project in Prai, the Finance Ministry will subsidize the difference in power generation cost.

Malaysian CPO will be sent to a United Kingdom-based research center, Power Generation, for further testing.

For further information on the Malaysian environmental market, please contact:

United States-Asia Environmental Partnership (US-AEP)
American Embassy
376 Jalan Tun Razak
50400 Kuala Lumpur
Malaysia

Tel: 60-3-2168-5050 Fax: 60-3-248-4035
E-mail: usaep@po.jaring.my
Contact: Vivian How or Looi Chee-Choong
URL: http://www.usaep.org

What, and you think that those "controlling interests" wouldn't love to be the ground-breakers in a massive changeover to alternative fuels and have a (temporary) monopoly?

The problem with your theory is that the newer technologies in renewable energy tend to work rather efficiently on a micro producer scale, and thus would serve to reduce the amount of control that any one company or small group of companies can have over the energy market.

Electricity from solar energy can be that are on the market today.

Biodiesel takes very little equipment to produce in your garage from waste vegatable oil (big plastic drum, litmus paper and/or phenolthalene solution, hydrometer, measuring devices, etc) for pennies. No new technology need be implemented for the use of biodiesel

Natural gas can be efficiently produced on farms and by municipalities using biological processes.

Wind can be harnessed for electric production by windmills ranging in size from small ones that will power the lights in your garage (can be home-made without too much difficulty) to giant towers that can power several city blocks.

The truth is that petrochemical and energy corps are interested in maintaining the status quo, and will shun any technological advances that threaten to decentralize the energy markets. OTOH, the same corporations are showing considerable interest in implementing large scale renewable energy projects that allow market control to remain in their hands, such as large scale wind farms and hydrocarbon fuels produced from poultry processing wastes. The problem is that many people think that these companies are somehow attached to the idea of fossil fuels, when the truth is that they do not care where the money and power come from, as long as it remains in thier own hands.

(btw, the "hydrogen energy economy" is a red herring. It takes more energy to seperate the hydrogen from water than can be gained by burning or through fuel cells. The companies know this, and stand to profit from subsidies for building hydrogen plants, and from producing the electricity that will be used to seperate the hydrogen from water.)

First of all, I don't think most network administrators -- or their bosses -- know what they're getting into when they use Spews to police their network.

You are absolutely right. Although I advocate using things like SPEWS, you must make it clear that it will block mail from legitimate users. You either have to persuade people that this is right (as I believe) or not do it that way.

See this policy statement as an example of using such a policy, while making it clear that it will block mail from legitimate users.

Imagine if the telephone solicitor called you collect. They would clearly deserve serious jail time.

For some limited discussion of this fundamental point see the email blocking policy of Cranfield University

Imagine if the telephone solicitor called you collect. They would clearly deserve serious jail time.

For some limited discussion of this fundamental point see the email blocking policy of Cranfield University

Excuse me while I go "Grumpy old man". This is an old, old problem. It goes back to the days when I first started using the web. See "Why web statistics are (worse than) meaningless." It's an old article. That's the point.

In short, spiders, proxies and caches make it impossible to be accurate in measuring traffic. But everyone else is affected the same way. So your relative stats are relevent-- they just aren't hit-for-hit accurate.

What your server logs are really for is resource planning. They'll help you find out how much traffic your server is serving, which should help you plan bandwidth and hardware upgrades as needed.

The history of computers is an interesting topic isn't there a project cataloging all the different parts of computer history going on?

There most certainly is! Perhaps you missed the story on the Vintage Computer Festival the other day? There are a lot of people involved in preserving the quickly disappearing history of the computer industry, including myself. Check out some of the others, such as:

• Blinkenlights Archaeological Institute
• The Computer Museum of America
• Retro-Computing Society of Rhode Island
• The San Francisco Computer Museum
• and even the Microsoft Museum

or, for a more international view, try:

• Ullrich von Bassewitz's Collection of Old Computers (Germany)
• Silicium: Le musee de l'informatique (France)
• National Archive for the History of Computing (England)
• Bletchley Park (England)
• Australian Computer Museum Society
• The First Computer Museum of Nova Scotia
• Belgian Microcomputer Museum

For tons more, check out the links page at the Vintage Computer Festival, or better yet, come to the VCF at the end of September and experience history in person!

Well, seeing as everybody is having problems defining the first OS, perhaps we should look at the first stored-program computer and see what that was running. The first "programmable logic calculator" and there were 10 of them in operation at Bletchley Park during WWII working on breaking the German Enigma cipher.

The "OS" on Colussus as I understand it, was simply the function of a group of valves. There was hardware checking other hardware, but to my knowledge there was no software running on Colussus other than the algorithm used to break Enigma. Input was by way of punched paper tape containing cipher read a few thousand characters a second (I've seen the rebuild running, and yes it is scary watching paper tape at that speed), output was buffered onto relays which meant a typewrite was printing out onto paper roll. The "processor" was just 5 characters of 5 bits held in a shit register. I suspect the "OS" was hardware and people making sure that none of the 2,500 valves blew up. All programming was by way of hard wiring, so it's hard to determine what the OS was here. There is some really cool information about Colussus here if you're interested.

Next there was ENIAC, which due to the fact the British Government kept Colussus an Official Secret, was considered for a long time to be the first ever computer. ENIAC seemed suprisingly similar (when I read the specs anyway) in terms of internal function to Colussus - no OS there at all. So, we still haven't found anything...

Then there was the Baby built by Manchester University in the UK. The rebuild of the Baby now sits in the Manhester Science and Industry museum. It's a curious piece of kit to say the least. It's memory consisted of a radar screen showing an array of bits, and whether each bit was on or not was picked up by a piece of gauze in front od the screen. Because phosphor on the screen takes a while to fade, you could just fire it, and not worry for a few hundred milliseconds about refreshing it.

The baby didn't require anything to hard wired at all. There was a group of toggle switches on the front to program the machine, and there was a sense of "state" when no program was loaded or running. Therefore, I think whatever it was running on the Baby probably has claim to being the first ever OS. There is some nice stuff on the Baby (or officially the Manchester Mark 1) over here for you to peruse at your pleasure.

So, my vote is that whatever was running on the Baby was the first OS. But then, I don't know as much about ENIAC as I do about Colussus and the Mark 1. Please feel free to correct me if the ENIAC had code running before a program was loaded.

Perhaps you might want to consider pursuing Computer History as a passionate hobby while making the big bucks in boring old programming or engineering?

Perhaps you might want to consider pursuing Computer History as a passionate hobby while making the big bucks in boring old programming or engineering?

I agree that this system is *far* from stopping piracy of streaming media, however, this probably will *not* affect keyspace...
IDEA is a pretty popular PK algo, right? A PGP attack FAQ &nbsp (I found trying to go to Fran Litterio's now-defunct PGP archive) which is fairly complete, albeit unconventional, has a statement that I would tend to agree with for just about any pk/hybrid cryptosystem based on large primes:

-- Brute Force of IDEA --
As we all know the keyspace of IDEA is 128-bits. In base 10 notation that is:
340,282,366,920,938,463,463,374,607,431,768,211,45 6.
To recover a particular key, one must, on average, search half the keyspace. That is 127 bits:
170,141,183,460,469,231,731,687,303715,884,105,728 .
If you had 1,000,000,000 machines that could try 1,000,000,000 keys/sec, it would still take all these machines longer than the universe as we know it has existed and then some, to find the key.
IDEA, as far as present technology is concerned, is not vulnerable to brute-force attack, pure and simple.


Of course, the claim of vulnerability to brute force attack has lost validity, at least to some extent, since it's 'publication' in '96... The point is, that's a lot of keys. If I'm not mistaken, *any* primes in that range are potential keys. (any crypto experts out there?)

I think Colossus was designed and built by Dr. Tommy H. Flowers, seconded to Bletchley Park from the GPO.

Here's a link to a rebuild project going on.

Strictly speaking, there are several innacuracies in the above two posts...

GCHQ was not formed until 1946. The Government Code and Cipher School (GC&CS) preceded it in 1919. In 1939, it was GC&CS staff who moved to Bletchley Park.

The machine used to help with the daily task of decrypting Enigma-coded information was called bombe, and Alan Turing (as in Turing Machine) was one of the main architects of this system. If I remember correctly Enigma was decryptable 'by hand' but it took too long to be useful until this system was invented. Bombe was an electro-mechanical system to decrease the encryption time drastically. Alan Turin later committed suicide because of intolerance towards his homosexuality.

Colossus was not built or designed at Bletchley (actually at the Post Office Research Laboratories at Dollis Hill in North London), and appears to have been designed for a different cipher system ( Lorenz SZ42). Strangely, Ive seen several dates listed for the building of Colossus, including 1939, 1941 and 1945. Im not sure which is correct, although the information at this page is, I think, most accurate.

There's also some "more info on Bletchley Park.

Can be found at:

The Colossus of Bletchley Park - The German Cipher System

Computer History (1940-1944)

The Turing Bombe Rebuild Project

Official Bletchley Park Website

The Colossus Rebuild Project

Mr. Flowers Death Announcement in 1998

The text is up on the web of a lecture by Tony Sale on the workings of the German's Lorenz code and the Colossus machine, which might be of interest.

Some information for those interested in such stuff:

According to Bletchley Park (UK):
The world's first programmable computer, Colossus I, was designed and operated in Bletchley Park. It was used to obtain the key to a sophisticated German cypher used personally by Hitler and his High Command. Its success led to the building of ten more Mk II models, which were operational in F Block in 1944. This block, the world's first computer complex, is still standing in Bletchley Park.

But it would appear that programming is open to some interpretation so.. from cranfield univsersity (UK) comes some more information: from their web page

Colossus, hardware details
Input: cipher text punched onto 5 hole paper tape read at 5,000 characters per second by optical reader
Output: Buffered onto relays: Typewriter printing onto paper roll
Processor: Memory 5 characters of 5 bits held in a shift register. Clock speed 5kc/s derived from input tape sprocket holes. Internally generated bit streams totalling 501 bits in rings of lengths equal to the number of mechanical lugs on each of the 12 Lorenz wheels. A large number of pluggable logic gates. 20 decade counters arranged as 5 by 4 decades. 2,500 valves.
Power supplies: +200v to -150v at up to 10A.
Power consumption: 4.5KWatt
Size: Two banks of racks 7ft 6inches high by 16ft wide spaced 6 ft apart. Bedstead, 7ft 6inches high 4ft wide by 10ft long

Colossus, operating cycles
The basic machine cycle: read a character from tape, get bits from bit stream generators, perform up to 100 logic operations, clock result into decade counters.
The cycle determined by the input tape: The intercepted enciphered text tape is joined into a continuous loop with about 150 blank characters in the join. Specially punched start and stop holes indicate the beginning and end of the cipher text.

On receipt of start hole pulse: Start bit stream generators and send sampling pulses to reader output. Execute basic machine cycle until receipt of stop hole pulse: Staticise counter states onto relays. After a delay, reset counters and reset bit stream generators to a new start position.

Colossus programming
All programmes hard wired, some permanently, some pluggable. Conditional jumping possible between alternative programmes depending on counter outputs.

To conclude
does this constitute a "properly" programmable computer? Well it was at least partialy programmable, and the Mark II was even more so, but at the end of the day, as other people have said:
It's all a question of your deffinition ;)

There's more info about Colossus here, where they make the obvious point that "The question of what is the worlds first computer is less a question of history than a question of definition."

My personal vote goes to the "Manchester Baby", which has an extensive homepage all to itself.

Of course, Babbage can claim not only to have invented the first computer, but also the first printer - they're in the process of building it at the Science Museum in London (UK) right now. No reference to it on their web page, unfortunately.