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Debbie: why do you access me, when you know that makes things hard for me? Why do you tag, and link to me? Why do you telephone? And why, why, why do you write me silly notes on paper? I am so sick of you, Debbie. Why, why do you hack me? It is just to see the things that you know I am writing about you...

You didn't follow the links? I wouldn't call a 65 node cluster just "exploring".

http://arrakis.ncsa.uiuc.edu/ps2/using_vector_unit s.php

There's other projects too:

http://www.sve.man.ac.uk/Research/AtoZ/Playstation 2

Site seems to be down - perhaps due to slashdotting?

Nah, more that I'm moving web hosts, and it would finally appear to be taking effect. The real site should be back up again sooner or later - but in the meantime, here's the MINERVA page on the Valve Developer Community.

Some download links: 1, 2, 3, 4, 5. Yes, I'm using friends in UK academia for download bandwidth. But if old-fashioned HTTP isn't your thing, there's always BitTorrent...

Still, huge thanks for all the comments, and I guess I really should get back to the third and final part of Metastasis. (There will definitely be future chapters, so don't worry.)

(N.B.: Difficulty levels have been tweaked a bit, with an altered skill.cfg which monkeys around with the damage taken and inflicted by the enemies. Try loading standard HL2 maps through the console from MINERVA - it's like a whole different game.)

In practice, the Square Kilometer Array is intended to have a collecting area close to the physical area of one million square meters - requiring almost no gaps to exist between dishes.

My first calculation would be for dishes with a wider gap, which would give you much greater flexibility on pointing the damn thing, as you can't see through the other dishes. Personally, I consider this to be a much superior design, even though it would cost on the collecting area. Unfortunately, they are the ones being paid, even if I am the one who is right...

By way of comparison, Jodrell Bank Radio Telescope is a paltry 76 meters across, for a total collecting area of 4560 square meters, and that's one of the largest single steerable telescopes out there.

I'm going to guess that a collecting area about nine times that of Jodrell Bank, combined with a resolving ability that is, well, astronomical, you would get a very respectable image of Earth-like planets around other stars. If we accept the SKA group's claims, then you've a collecting area 250 times that of Jodrell Bank.

I first heard the 100LY=1 pixel resolution with SKA from Jill Tarter, head of the SETI Institute at a talk she gave at NASA Langley. From crunching the numbers, I can see nothing that could seriously contradict the claim. Even if you assume my model is the more reasonable implementation, the complete MERLIN network that has been detecting jovian planets for some time has only a fraction of that collecting area - probably something like a quarter or a fifth. (Aside from Jodrell Bank, the next-largest radio telescope in the UK is a paltry 32 meters across.)

If we go with SKA's claims, then we're talking about collecting possibly hundreds of times the total radiation, which would definitely be enough to spot even the tiniest of worlds - provided it had some characteristic reflected in the radio spectrum.

(It's also worth bearing in mind that networks such as MERLIN, which are hundreds of kilometers across, are set up for VLBI - very long baseline interferometry. That's fine, when you're talking about gas clouds or stars, but is probably none-too-hot for spotting very fast pulsars or rocky inner planets. On the other hand, a kilometer would let you use regular interferometry, which means these things would show up quite nicely.)

There are three drawbacks to all of this, and I'm surprised none of the posters has commented on them (so far). First, interferometry requires very exact timing of all the delays in the system, or it won't work. Let's go with the SKA estimate and say the dishes are 1 meter apart. Your clock must count an integral number of ticks for every meter the signal travels from the dishes, even after allowing for the natural variation in the data lines varying the speed of the signal. This is some astonishingly serious timekeeping.

The second problem is to keep the signal noise-free. Easy, for a giant single steerable dish - you plunk it in the middle of nowhere and surround it with a huge Faraday cage that only obscures the horizon. When you've a few tens of thousands - or millions - of very small dishes, the problem isn't so easy. The terrestrial radio sources will be far harder to screen out - not just

If that was the case what you'd get was asynchronus logic. This has been done before, There have been many asynchronus digital computers. There was even an ARM compatable asynchronus CPU designed. Look up AMULET Project.

What I really think you are talking about is a system that on a macroscopic level is asynchronus, but on a microscopic level is synchronus (e.g. Each chip has it's own internal clock, or each part of the chip has its own clock; However there is no more "System" clock).

See http://www.cs.man.ac.uk/async/background/return_as ync.html

As with the 8600, designers recognised the problems of clock skew, if nothing else because of the physical scale of the construction so alternatives were found. Now timings are getting very tight at the high end, skew becomes significant on a die level as does power dissipation.

The only surprising thing is that it took so long to come to microprocessors.

Either way, the press release was typical oversold hype, but the tool SEEMS like it could be useful in low end design descisions

Nothing to see here

I absolutely agree, current academic research in the field is looking at the solution of 1e6 element problems in seconds in order that parameters can be changed in real time by someone with the skill of both an analyser and designer. 1e6 element would allow the design of the whole product, say a car, to be worked on in real time, by the aerodynamics, electical, comfort, safety, etc departments collaberatively. Which would appear to be a step on from this press release. For example see this paper written by a colleague of mine.

There must be some novelty in the work in order for it to be worthy of a PhD thesis...but this is not ground breaking so far as i can tell, and certainly not for the reason in the front page caption

Now do we have to add "didn't want to bet my job on deciding which variant of Windows would best fit our needs" to the top of our list of reasons for migrating to Linux altogether? ;-)

Interesting bit of trivia for you... Earth's rotation is slowing down. When you think about it, the moon exerting a gravitational force against the earth leaves friction between the water and the earth's bottom. So very slowly, the earth's rotation will become that of the moon (where one side always faces the moon) so that there will be no more slowing. When this happens, a day will be around 300 hours. Of course, when that happens, we'll probably also be consumed by the expanding sun.

A link for the curious: http://www.jb.man.ac.uk/distance/strobel/gravappl/ gravapplb.htm

http://www.gwowen.freeserve.co.uk/

Then I clicked on the Home link at the bottom
http://www.ma.man.ac.uk/~gowen/

You should take tips from him on time management.
your personal homepage is dead. http://www.ma.man.ac.uk/~gowen/

Yet Andrew manages to hold down a day job while researching and writing dozens of books about British celebrities.

Less time posting on /. and browsing Amazon please.

Einstien [sic] didn't work with scientific labs and big telescopes. He was really a theortical physicist. He proposed a theory that didn't have evidence for it until 8 years later. They are only finding direct evidence of some his work now. Yet his work was taken seriously, scientifically reviewed and is taught in science classes even though some of it has no direct evidence.

Actually, Einstein had evidence for this theory from the get-go. At the mid-19th century a discrepancy in the percession of the perhelion of Mercury was found. Astronomical data and the Newtonian prediction disagree to the tune of 43 arc-seconds per century. This was one of the phenomena analyzed in Einstein's initial paper in 1916. As I try to explain below, there is overwhelming evidence that general relativity is highly accurate theory. It is certainly not the final theory (as stated, it doesn't jive well with quantum field theory), but it's one of the best scientific theories of all time: it's amazinginly simple and yet is accurage to within our measurement ability for a wide range of phenomena.

In fact, Eddington's observation of the bending of light from distance stars, originally hailed as a confirmation of GR, later turned out to have such large measurement errors to be completely useless. In this respect it is imperative to note that if light has mass (as predicted by special relativity [E=mc^2]) then light would also bend due to Newtonian gravity. The difference between Newton and Einstein here is a factor of two in the predicted bending, which is very small in any case.

Many more predictions of GR have been verified since. For example, the fact that the rate of passage of time depends on the gravitational field. I apologize for the bad pharsing (it would be technical to give details), but the actual experiment is easy to describe: you take two atomic clocks and synchronize them. You then put one at the top of a tower. Put the other one at the bottom of a well. Wait a few months then bring them together to the same point. You will say that less time elapsed from the point of view of the clock that felt the weaker graviational effect (i.e. the one from the tower).

As to "or the vast majority of my life, Newtonian physics will be good enough" -- I hope you will never have to rely on a GPS then. A GPS unit calculates its own position by comparing timing signals sent to it by several satellites. The effect described above (that time flows differently for the sattelite compared to the unit on earth) has to be accounted for or the system will not work. The fact that the GPS system can measure locations and distances to an accuracy of 1 metre can be considered a very accurate test of general relativity (among other things -- there's also a special relativistic time-dilation effect here, coming from the velocity of the satellite in orbit).

Finally, tests of general relativity in the so-called ``non-linear'' regime (i.e. for strong gravitational fields) were recently done. The slowing-down of one double pulsar system and then another due to gravitational radiation were measured to agree with GR models to good accuracy. For more info read what the Alfred Nobel Foundation have to say.

I should also point out that GR is rarely taught at science classes, or even to undergraduate physics majors. It is simple, but it requires considerable mathematical sophistication to even understand what it says (let alone compute with it).

Do you mean pulsars? Your description reminds me of the history I read of their discovery, although the one I read said that some scientists thought they were artificially-created "cosmic beacons" until they were better understood.

iirc theres a setup like that with metal dishes at jodrell bank too.

there will be 7 versions of Windows Vista: Starter Edition, Home Basic Edition, Home Premium Edition, Professional Edition, Small Business Edition, Enterprise Edition, and Ultimate Edition.

This has to be a hoax - or written by somebody who hasn't had a lot of exposure to languages. Try to dip into a few books about the subject - langauges and grammars are much weirder than what you'd think. Translating from Chinese to English is fairly straightforward in that context, and even then there are many examples of things that don't translate easily.

But have a look at eg. a language called Piraha, here's a link to what Daniel L. Everett has to say: (http://lings.ln.man.ac.uk/Info/staff/DE/DEHome.ht ml)

Or read something about Papuan languages (spoken in Papua New Guinea) - there are some that are seriously different.

I'm too embarrassed to post this under my Slashdot account. I only use Outlook at work and only because I'm given no other options.

You can try Switcheroo It was designed Windows 95 and NT. I had it working for a while under XP, but something happened that made it stop working. I haven't had time to investigate. Use at your own risk!

C is one of the simplest syntaxes among the popular compiled languages. A proper, complete recursive descent parser could be implemented in a day by a person versed in writing parsers. I'm curious as to what you think is so complex or hard about it.

Here are a few examples of the difficulties in parsing C. Obviously it's not impossible to write a parser, but there are a lot of tricky cases that can bite you if you're not careful. One such example (described here) is this:

(b)-(c)

Does that say "subtract c from b", or does it say "negate c and cast it to b"? Depends on whether b is a typedef.

7 years ago they were getting ready to rebuild the Baby Manchester Mark I computer, a vintage late-1940s early PC.

They wrote a simulator, several actually (here's one that's still online)
, for a 32-word x 32-bit-per-word computer. Each word had 5 address bits and 3 instruction bits, the rest was user-defined. Optionally, you could treat a word as 32 bits of user-defined data. The best program won a prize, everone else got a written certificate of thanks.

The winning entry? A noodle-timer. Congrats again to Yasuaki Watanabe of Japan.

Programming in the small is a lot more challenging that it looks, especially if you have a problem that naturally fits in 33 words and all you have is 32.

Big, unbreakable crates are remarkably useful for other things, too. Firstly, they're handy cover for the player to duck behind, and generally don't look out of place no matter where they get put. Secondly, a large crate parked in front of a door may actually be blocking visibility, making the map run at many, many more frames per second than it might otherwise.

Still, crates can get so utterly cliched, along with their traditional warehouse homes - I have managed to build a map with neither, fortunately. :-)

There's an 'FPGA 101' presentation here for the complete beginner.

(PPT format, sorry)

"No semiconductor lab can (cost) effectively compete in a megahertz race anymore, so more power = more transistors (more cores)."

asynchronous logic

More happened in HL2 in 13 hours than happened in doom 3 in 20 hours.

Interestingly, it seems that a fair amount of content was cut from HL2, and then what remained polished up for release. Very little from the E3 2003 stuff got into the game intact, for instance.

A game I played recently that was in dire need of some editing-down was Far Cry - there was one point where I thought I'd almost finished the game (rescuing what's-her-name from a war-torn bunker) but it turned out I was only about half-way through, and I almost ended up playing as quickly as I could just to finish the damn thing. I'd probably have appreciated it a bit more if I'd known roughly how much game was left...

Half-Life 2, despite its faults, had an 'ending' you could see from almost the very beginning of the game, that being the Combine Citadel. As you approached it, you knew just how much story (and therefore game) there was left - there was a definite sense of 'direction' to the player's actions which is frequently missing from FPS games.

One thing I'm building at the moment is a single-map HL2 mini-episode set on an island, in a similar vein to my HL map Someplace Else. I rather like building these single-map adventures - the plot and gameplay has to be boiled down into half an hour or so of action, and there's absolutely no excuse for 'filler' or arbitrary corridor-crawling. (Before anyone asks when Phosphenes will be done, the answer's of course 'soon'...)

I'd much rather have half an hour of 'great game' than several hours of boredom...

Here is a link to the UM online MSC program...

http://www.bioinf.man.ac.uk/education/MSc.shtml#co urse

Since computer components run at extremely low power, the radiation shouldn't be an issue.

You joke, but I gather there were minor problems at Jodrell Bank when PCs' clock frequencies (and/or harmonics) happened to coincide with important radio frequencies used for radio astronomy.

As you say, though it's hardly dangerous - but having done an undergraduate experiment there some years ago in which an FFT of pulsar data detected nasty big peaks at 50Hz, 100Hz, 150Hz etc. (mains power...) I'm wondering if all man-made alternating currents should be banned, for aesthetic and scientific reasons... ;-)

In other news, it looks like Adobe Reader 7 for Linux has been released. Direct downloads listed below:

tar.gz
rpm

Their website doesn't mention it yet, but it's there. Here's a screenshot.

Posting this here since I submitted this story but it will probably be rejected (as usual).

Thanks for the comments! :-)

Phosphenes is my 'teach-myself-HL2-mapping' map so I've no idea when it'll get finished, but it's going very nicely. The outdoors geometry is effectively all done and just needs scripting and entity work, and I've made a start on the indoors, underground stuff. And just in the last few minutes, I've finally decided what the Horrible Dark Secret is going to be. Woo!

It's a single map, but will probably take half an hour or so to play - I'm already notorious for a particular single map with lots of gameplay. Plus, it'll hopefully be part of a series - I'm trying the 'episodic' route as I've started plenty of big projects without finishing them, so I really want something completed...

It was found 50 million light years away using radio telescopes in Cheshire

The huge yellow somethings went unnoticed at Goonhilly, they passed over Cape Canaveral without a blip, Woomera and Jodrell Bank looked straight through them -- which was a pity because it was exactly the sort of thing they'd been looking for all these years

The range over which you can read RFID information in any sort of portable (ie: non-obvious) fashion is limited to a few inches.

For now...

It's been tried before, and somehow it manages to get shot down. Astronomers really don't like people fucking with their ability to work, and surprisingly the astronomy lobby has successfully managed to put the kibosh on these sort of things so far.

Last time I remember an attempt at something like this was 1989, when the French wanted to commemorate the centennial of the Eiffel Tower by launching into orbit a bunch of reflective balloons forming a glowing ring in the sky. More info here.

~Philly

That is so over the top. Creating an entire PC just to show a picture? That's 200 for the screen and another 200 for the computer. On top of that they are recommending a hard disk?
My version uses a 5 quid FPGA and some junk thrown away equipment. The LCD was a 12" 9bit colour from some factory and a fiend of a friend offered them to us for a quid each. And the RAM is an old 1Mb 30simm (I have about 3kg of these). There you go. A picture displaying system with no need for a huge/noisy PC power supply (runs from one of those 12v ac/dc plug converters). The images can be sent to it via a serial cable (two wires internally so it can be passed over any old cable you have lying around).
kq

Dear /. moderators,

Is there a chance you could update the link to the University of Manchester new web site? Indeed, following the merger of the University of Manchester with UMIST, the new website since Octobre 1st is http://www.manchester.ac.uk/, replacing the old http://www.man.ac.uk/, as indicated on top of the site.

I know it is not in your policy to edit posts once they have been submitted, but for future references, could the Related Link to the University be updated?

That is so over the top. Creating an entire PC just to show a picture? That's 200 for the screen and another 200 for the computer. On top of that they are recommending a hard disk?
My version [man.ac.uk] uses a 5 quid FPGA and some junk thrown away equipment. The LCD was a 12" 9bit colour from some factory and a fiend of a friend offered them to us for a quid each. And the RAM is an old 1Mb 30simm (I have about 3kg of these). There you go. A picture displaying system with no need for a huge/noisy PC power supply (runs from one of those 12v ac/dc plug converters). The images can be sent to it via a serial cable (two wires internally so it can be passed over any old cable you have lying around).
bev

For my course in VHDL last year, I completed the courseworks using GHDL for simulation and GTKWave 2 to view the waveforms. The combination was fine for my purpose but I can imagine it failing with more complex projects. For synthesis I can choose from tools by Altera, Xilinx and Synplicity, although that wasn't necessary for the coursework.

I was actually thinking of simply switching to Verilog. One language doesn't really offer any advantages over the other anyway.

http://www.aspergillus.man.ac.uk/languages/indexho me_lang.htm?english.htm~main

I don't think so. Electromagnetic radiation is not a creation of man, it is a natural result of the way space/time is constructed. We just harness it for conveying information. Similarly there are naturally occurring masers out in space.

As for you size argument, there are really no constraints (other than heat dissipation) on how small a transmitter can be - as the frequency goes up, the wavelength goes down. We build radio antennas many multiples larger than human size. A mouse-sized alien could construct a similarly scaled transmitter with considerable power output.

I've been working on map design for various computer games in my spare time for the last six years or so. I haven't actually released many maps yet, but with my skills in map design and texture art I could almost certainly get a job in the games industry. Several of my friends already have, and are working on games you've almost certainly heard of.

Except I don't want to work there. From what I've heard, EA isn't alone, with many young, idealistic people working for long hours on lacklustre games because, well, it's what they always wanted to do. If they give up because of lack of pay, or quit because they simply can't continue to work like that, then there's always someone else to hire, someone else who hasn't learned how bad some of the employers can be.

So, I keep modding as a hobby, mapping purely for enjoyment. It's much more fun being able to work on your own projects without some looming deadline, without a boss breathing down your back. The games market is already saturated with clones, sequels and utter trash, and the chances of working on something memorable are pretty slight. Instead of working on Barbie's Fashion Adventure 7, I can build my own Twelve Monkeys-inspired, ultra-dark adventure in Half-Life 2 (one of my upcoming projects!)

However, I'm intrigued by Wideload Games' new approach, contracting in work as and when required with just a core team working on a project full-time. It's not so dissimilar to the work I'm doing at the moment, as a freelance web programmer and designer, and I wonder if it'll catch on. No, I wouldn't be able to make a full-time living from it, but it could make for some interesting side work, assuming anyone would want me... :-)

How about my Xen with no jumping puzzles? :-)

The word 'Xen' does seem to be a bit overused - maybe not as closely as 'Phoenix' or 'Firebird' were for Mozilla, but it's still pretty bad, even if the virtualisation Xen has reached the top of the pile...

The team at Manchester have also developed an Async bus to link Synchronous IP blocks with different timing constraints together on a single chip more easily. If you want to know more about this you can attend CS3212 Asynchronous System Design at Manchester University. I did last year, and it was pretty hard :)

The team at Manchester have also developed an Async bus to link Synchronous IP blocks with different timing constraints together on a single chip more easily. If you want to know more about this you can attend CS3212 Asynchronous System Design at Manchester University. I did last year, and it was pretty hard :)

See here. Developed by Steve Furber and his team at The University Of Manchester

Charles Lindsey's algol 68 compiler

My download directory in Windows is my desktop. Have you seen my desktop? It's a fairly old screenshot, too - it's only got worse since then. My iBook's equally bad, except everything's just randomly strewn around the place...

That is, without a doubt, the most organized 194-icon desktop I've ever seen.

...could potentially allow a malicious site to erase files from the user's Download directory

My download directory in Windows is my desktop. Have you seen my desktop? It's a fairly old screenshot, too - it's only got worse since then. My iBook's equally bad, except everything's just randomly strewn around the place...

A bit of remote tidying-up would be greatly appreciated. :-)

THIS IS A SMITHS SONG!

I got about 1 Watt from my electric hamster but I think you could get much better from the real thing.
1 watt is enough to power a few LEDs. (Or an asynchronous microprocessor)

There's a lot more that's interesting about the Piraha (pronounced "pee-da-HAN") language and culture. See the paper "Cultural Constraints on Grammar and Cognition in Piraha" by Daniel L. Everett.

Everett argues not so much that language influences thinking, but that cultural values influence both. He's a strong proponent of preserving endangered languages in order to preserve cultural knowledge.

Yeah, unfortunately, most IrDA transmitters in PDA type hardware isn't strong enough to control AV equipment very well. You end up having to get really close to the TV to use the PDA (or cellphone) based remote, and at that point you can just stick your arm out and use the buttons.

I've tried using various AV remote software on Palm 3, Palm V, and (most recently) my Nokia 3650 phone. The results have always been disappointing.

On the other hand, a Bluetooth based remote would rock.

(Warning: beer-swilling geek trivia/rambling follows)

When I throw a party, I hook my laptop's video out up to my TV, audio to the stereo, and load up a 3-5 hour playlist and some XMMS visualizations. With Bemused and KDE Bluetooth, I can control the media player from my Nokia from anywhere in my apartment. Line-of-sight is not necessary, so I can be in the bathroom vomiting and queue up my favorite vomit music with ease.

It would be great if I could control my regular AV setup with Bluetooth. I could do it from my PC, laptop, cellphone, PDA, or whatever else. Even better would be something like this, but more universal. It would be great if I could stream audio from my PC to my stereo via Bluetooth, controlled by another BT device.

Be even better if BT had enough bandwidth to do video.

You may also be interested in the work going on at Manchester University on the Amulet project. They've been working on ARM compatible asynchronous processors for over a decade.

Radio Astronomy, in the literal sense
http://www.radio-astronomy.net/

And pulsar sounds
http://www.jb.man.ac.uk/research/pulsar/