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My favorite geek-flavored advent calendar: https://gravity.astro.cf.ac.uk...

"Of course I know about multiprocessing. Why have one copy of the interpreter and libraries loaded when you can have N, plus its so much more efficient to marshal data across process boundaries than to access a global shared memory block. "

*snort* You obviously don't have a clue about multiprocess. Look up copy-on-write then get back to me.

As for a shared memory block , uuuh , guess what , theres something called "shared memory" specificially for multiprocess access. Its been around since the 70s in unix but I wouldn't expect a clueless (obviously Windows) programmer to know about it though ironically even Windows supports it now.

Here, educate yourself:

http://www.cs.cf.ac.uk/Dave/C/...
http://en.wikipedia.org/wiki/I...

Plan for things to fail, and when they do, you won't be in such a panic.

As for:

on all likely relevant platforms, processes hold resources, not threads. So killing a thread doesn't do anything to help with resource management and/or reclamation.

The open group disagrees

The pthread_detach() function shall indicate to the implementation that storage for the thread thread can be reclaimed when that thread terminates. If thread has not terminated, pthread_detach() shall not cause it to terminate. The effect of multiple pthread_detach() calls on the same target thread is unspecified.

So does the Comp Sci department at Temple U pthread_detatch

You can mark for deletion and reclaim the storage and other resources associated with a thread (of course, after it has terminated executing) with the command:

#include

int pthread_detach(pthread_t thread);

This command will not terminate a thread that is executing, only indicating that we want to reclaim automatically its storage when it terminates execution. Other ways of reclaiming the resources of a thread are:

• If the thread was created with attribute set to PTHREAD_CREATE_DETACHED, or
• If this thread is waited for with a pthread_join call.

So does the Lawrence Livermore National Laboratory pthread_exit() is the way to claim thread-local data.

Regardless of the method of thread termination, any cancellation
cleanup handlers that have been pushed and not yet popped are executed,
and the destructors for any existing thread-specific data are executed.

Normally, you also write clean-up routines for closing file handles, freeing up any manualy malloc'd memory and returning it to the arena, etc.

And Apple here

Because POSIX creates threads as joinable by default, this example changes the thread’s attributes to create a detached thread. Marking the thread as detached gives the system a chance to reclaim the resources for that thread immediately when it exits.

and even the Aussies at Cardiff U agree pthread_destroy() that you can free up all memory allocated, so as long as you clean up the stuff YOU allocated, and allow the library to free up the stuff allocated at thread creation and initialization.

So, what relevant platforms don't support pthreads?

Try looking up the obscufated c code contest.

I love this example (mystery.c):

[Filter error: Please use fewer junk characters] (try this link instead http://www.cs.cf.ac.uk/Dave/C/node4.html#SECTION00420000000000000000)

It's legal C code. Compiling and running produces some quite extraordinary output.

For more information you can catch up with Planck on the mission blog on Planck's twitter, and on the Planck outreach website.

I help maintain the blog and work on both the Planck and Herschel missions.

Parent post is not insightful, it is plain wrong.

As you and the modder seem unable to follow links here's one of their technologies pages

And yet another link about Tai-chi, with videos.

Hey, I thought open-source was supposed to be free!

I call shenanigans!

Guess it's time to go back to my cheaper boot-legged graphics card.

Cool article here...
http://www.cf.ac.uk/biosi/staff/jacob/teaching/sen sory/pherom.html

There has been a speculative proposal by Miguel Alcubierre, in the context of General Relativity, that takes advantage of an imagined negative energy density in some region of spacetime to produce a metric (a special kind of curvature of the spacetime) that allows for superluminal transport of matter. That is, a warp drive.

The good news here is that there is a known phenomenon of quantum field theory (the Casimir effect) that causes the region in between two highly polished metal plates that are extremely close together to develop a measurable negative energy density. (Basically the plates filter out the zero-point energy of long-wavelength electromagnetic quantum fluctuations of the vacuum that would otherwise be present, but cannot fit between the plates.) The bad news is that the effect is utterly negligible in strength.

As the other link in the article http://www.taichi.cf.ac.uk/files/Sound_Rose-Genoa_ Web.wmv shows,
the whole of the surface is touchable. Even the area outside the sensor-square as well as the area next to each sensor.

I would not consider myself an expert, but this is my field, so let me give everyone a REALLY quick lesson in 1) JPEG2000 and 2) "lossy" video compression.

JPEG2000 is an advanced set of tools for video compression. It is used at the highest levels of distribution, and has been proposed for consumer use as is the case here. For more on JPEG2000 a decent primer is here.

If you are watching content at home, it already has gone through a "lossy" compression scheme. Whether it is DTH satellite MPEG2 or MPEG4), cable (MPEG2/NTSC - yes NTSC is a lossy compression scheme), or terrestrial (MPEG2 ATSC or NTSC), DVD (MPEG2), or even LaserDisc (NTSC), your content has gone through a lossy scheme.

Remember, Google is your friend, and although not perfect, wikipedia can answer many questions. For more on video compression here is a nice little presentation.

The short story is everyone shouldn't get real upset about JPEG2000 and it being lossy. Cheers.

How exactly do you determine how old a person is from film?

More analysis showing possible signs of DNA here:

http://www.astrobiology.cf.ac.uk/redrain.html

My understanding of how cell phones work:
  a) Alice calls Bob
      + results in a SS7 data message sent accross the PSN (publicly switched network - aka. legacy phone excahnges) to establish a ring on Bob's set.
      + If they're both cell phone users, then there is additional routing accross each users' cellphone networks.
  b) Bob answers the call and talks with Alice
      + Cell phones often use u-law for voice/data compression. The PSN transmits at a lossless (unless it's VOIP) 8 sample at 1khz See here

With u-law compression (and other regions of the earth use different compression schemes to account for different intonations of the languages used) how can you reliably send lossless data using these phones?

It seems you go through life understanding very little. Pointing out that your post consisted mainly of stuff you made up is not trolling.

...Back in my day, posting were about Facts, not people, dammit! Facts! Back in the old days, people used to post comments to make deeper understandings. They would present evidence, historical and otherwise to create deeper understanding....

It really is a shame that you didn't follow their example, as I have done.

...If you are trying to learn, you have to question everything...

Which is why I questioned you, even though what you posted was patently nonsense. Now if you could only practice what you preached you would have searched for some evidence of what you suggested and posted links to back it up. Or, perhaps you did search, and failed to find the elusive C02 detector?

...If we look at the classic idea of the five sense with this in mind, we find that some senses are a combination of several system in the body...

This is not in dispute. the five senses refer to what we sense, not how we sense it. If you have a look here you will learn that we have five different taste receptors. Are you saying that we should consider each a seperate sense because each uses a different mechanism? Perhaps you are, as you go on to say...

...These are all seperate nerves in the body...there is no reason to group them together under a single sense...

Hmm, perhaps grouping is not such a bad idea.

...Also, it turns out there are perception systems in the body that are unaccounted for, such as propitiation and orientation...

Are you sure we have a sense for propitiation? As for orientation, there is no such sense. That's like saying we have a sense of proximity because we can see how close to a wall we are.

...Aristotle didn't have any access to instruments that could show infrared. People also didn't have microscopes back then, nor did they disect human bodies in order to learn. So now that we have those tools available to us, it becomes obvious that the common wisdom is outdated, and we need to revise the theory...

If you read my post you will see that I wrote, and I quote, "Now it may be that there are more than five senses, but the answer is not here...". What you should have been able to ascertain from this is that

1. I am open to revising my conceptions regarding the senses.
2. Your ramblings about being able to sense how much C02 is in a room, humidity sensors in the lungs, air presure sensors and the like isn't what it takes for me to do so.

Wine tasting IS SNAKE OIL; 100% so. Here's what happens. You get used to tasting specific characteristics of certain types of wine and eventually your brain no longer registers the tastes like you once did. The same is 100% true for vision, smell, and hearing. You then move on to a new wine which offers new flavors (stimulus) that your tongue could not previously discern.

I'd be curious to see some real evidence to back this up. I've had a fair amount of wine, and my fiancee is a sommelier. She has an excellent nose and sense of taste, and according to your theory, she should only be drinking super exotic expensive stuff. That isn't the case. There IS such a thing as good wine, although good is subjective. I don't like many chardonnays, but they are one of the most popular wines in America and a lot of people think they are good.

There are such a things as complex and sophisticated wines, but it sounds like either a) you haven't had any, or b) don't have the palate to make the distinction. That isn't meant as an insult, but rather as what you were born with. Some people just don't have as many taste buds. A complex wine can give many flavors and odors, change as it goes across your tongue, or develop as it sits in a glass.

http://www.cf.ac.uk/biosi/staff/jacob/teaching/sen sory/taste.html#Supertasters

The bottom line is, if you like it, great, if you don't, find something else. It doesn't matter how much it costs.

If you really want to learn a 70's language, you can start with Fortran77, it came hot off the press just a year before you got your first computer. However, I recomend learning in C if you are already computer literate. It's not the most modern programing language but there are lots of resources available and until recently it has probably been the most popular programming languages. With C you will learn all the nasty things like "pointers" and "memory allocation" that the modern langauges tend to hide. You also get to learn a very well structured language.

A good place to start with C is: http://www.cs.cf.ac.uk/Dave/C/CE.html It is a good intro.

Then you will also need a good IDE (integrated development environment) and development platform, for Linux there is Anjuta, Eclipse, Emacs (for those who are not affraid), and many more.

And the thing I most recomend, is just search the web for interesting bits of code, compile and run them, then discect them.

But most of all, Enjoy :)

Thanks for the links and info! I searched for bromelain fingerprints references and found some info.

Toxicity - Workers who cut up pineapples have their fingerprints almost completely obliterated by pressure and the keratolytic effect of bromelain ... and some papers are referenced.

Ananas comosus Merrill (Pineapple) lists the study (Polunin 1951). verifying your info as well.

In 1994, Miguel Alcubierre, then a physicist at the University of Wales, proposed a way in which a hyperdrive could actually be built, without violating the rules of Einstein's general theory of relativity.

A giant mass would be dangled in front of the spaceship, pulling it forward. Then, a "negative mass," an area that weighs even less than empty space, would be placed behind the craft. Space would be warped by the intense gravity so that the spacecraft could move almost instantly from place to place.

In 1994, Miguel Alcubierre, then a physicist at the University of Wales, proposed a way in which a hyperdrive could actually be built, without violating the rules of Einstein's general theory of relativity.

A giant mass would be dangled in front of the spaceship, pulling it forward. Then, a "negative mass," an area that weighs even less than empty space, would be placed behind the craft. Space would be warped by the intense gravity so that the spacecraft could move almost instantly from place to place.

could you levitate a black hole against the force of gravity and feed it matter

Do both at once - feed the matter in fast enough, from underneath. You're now playing the world's most dangerous game of keepy-uppy.

Wonder if this would generate enough power to make the Alcubierre warp drive feasible?

A couple of pointers:

If you want to rebrand the splash screen, text, icons, backgrounds or any other data-related content, you can do so and that remains protected by copyright, not the GPL. You don't have to distribute any changes at all. That's why you can redistribute Red Hat's distro, but must remove their logos and references...

And the GPL states that you only have to give people access to source that you externally distribute the changed binaries to. So if you alter a program and only distribute it within your company, no problem. If you distribute it wider, to customers, or b2b, then you may have to release source.

Any applications that you write yourselves atop Linux are yours to licence as you wish.

The only time you'd ever have to give code access is if you made changes to a GPL program and then sold that at a profit. You've clearly used someone else's work to save you time, so that you don't have to implement it all yourself, and you want to make money from that short-cut. If you want to sell someone else's work without paying them for it, you have to give something back (that's the essence of the GPL, and that something is the code changes).

EO#2: "So what you're saying is that we would be paying our developers to work on this project, and essentially anyone else can just come along, pick up where we left off and that's that? That doesn't really seem fair, if you ask me."

Reponse: So we can essentially just come along, pick up where someone else left off and sell it? Making profit without putting any effort in or rewarding anyone for the use of a product?

Would a manager say that was fair? I think that all the ones I've ever worked for, and your one, would probably see their eyes light up at the prospect of free sellable products like that.

The GPL isn't onerous; all it does is maintain fairness and prevent abuse. Your task isn't abusive, and you can very happily co-exist with the GPL and it can be beneficial to all.

As for the GUI looking old, take a look at my desktop... It's SuSE 9.2, with KDE 3.3, Plastik and Nuvola icons. It's not the default, but it took me 10 minutes to do, and if you wanted to remaster a distro with those changes, you could certainly be done within a few hours.

http://gemini.cs.cf.ac.uk/~dawnrider/snapshot1.jpg

As for naming, your manager seems very hung up on those, and there's not much to be done about that. For what it is worth, every other manager I know would shrug and say "If that's what it's called, that's what the customer will get. They'll get used to it in a day or two." And that is generally the case.

But if you can, I think you really should re-open the discussion in your workplace, perhaps by taking the time to carefully read the GPL yourself and asking your manager for a written list of questions about it (scenarios, what-ifs, descriptions of what changes you might need in the OS/desktop environment etc). Then you can ask GPL developers about the list (maybe the KDE or Gnome mailing lists?) and see what their responses are. I think that your manager would be very happy and impressed that he's getting response from the people who do this for a living, who directly program the software he's thinking of using, and it might also enable him to see whether they intend to make changes he needs in the near future anyway, saving work for his employees. It will also help alleviate management anxiety as to the ability to find intelligent support.

Two things:
- They were probably not using short ints, but regular ints. In 1989, most compilers were 16 bits. It sounds like they just picked the default, especially because the better choice (unsigned int) wouldn't take any more room.
- C has always had 24 bit integers.

that was a good try... but these people werent completely dumb though since there is a sweet authentication page which shows up here,here,here,hereandhere:))

Not to confuse the issue with facts, but Human hearing and voice Range is about 20 Hz to 20 kHz,

No, Gonzo like Gonzo journalism.

QuickTime is the API which started affordable desktop video (nor all-software video editing like Premiere, FCP, etc., incidentally).

QuickTime came out a couple of years before Mplayer, I think...

Aeons ago, the worthies of the Internet created The Usenet Cookbook, a set of files marked up in troff, which had everything one needed for early-netter cuisine. It was a glorious thing back then.

This one for a start. Then there is a first discussion of the paper, and here is even more about the "warp drive".

Have fun!

As someone currently two years into a PhD on heuristic frequency assignment for wireless networks here in cs.cf.ac.uk, I think I'm qualified to hold an opinion here :o)

I started the PhD because I wanted to, not because I thought it would be a great career move. As others have said, it's hard enough to motiviate yourself through a PhD (e.g., I'm reading Slashdot right now and not analysing results...) when you really want it; if you're doing it as a political move, there's no way you'd finish.

Having said that, I can't see it hurting my career. If I don't end up in academia anyway I'm probably going to consult and write freelance and a big fat "Dr." in front my name isn't going to hurt me any. As someone in this thread said. it's not a shortcut to credibility -- you still have to earn that -- but I can't see it ever being a hindrance. The only downside is I've done three years of crappy pay when I could have been earning something decent, but every silver lining has a cloud.

You explain the Archimedes Principle very well, but the threat to the Gulf Stream, which is one of the most serious possible effects of global warming, has little to do with sea temperature reduction in Northern waters. It is a general trend to increasing quantities of fresh water of any temperature being produced as run off in Europe which could stop this salt pump / conveyor belt effect. This has happened at least twice before with the result of major temperature drops in Europe.

There is an excellent summary here. One interesting quote "[the gulf stream] carries over 3 trillion KW of heat to Europe - roughly 100 times the world's consumption of energy"

The other fun part was that, the day after the Gnutella debacle, they managed to sneak in a mention of Nutella (and a picture of it!) into their "Ask Nullsoft" section. I wonder if they'll do something similar with WASTE?

Coincidentally, see also this lecture on this history of Gnutella (warning: PDF), or its handy Google HTML-ized version.

Jouster

To put a couple of things straight first. Professor Wickramasinghe hasn't said that SARS comes from space. In the Lancet letter (free reg required), he says "With respect to the SARS outbreak, a prima facie case for a possible space incidence can already be made". Note the word "possible". Note the words "prima facie" (roughly="sufficient to warrant further investigation").

This isn't some crackpot who's just heard of SARS, can't understand epidemiology and therefore thinks it must have come from outer space without thinking things through. Along with Fred Hoyle, he's long been a proponent of panspermia - the theory that life originated in space, rather than on Earth.

There is plentiful evidence of complex organic molecules in cometary and interstellar material. The environment on periodically warmed comets is every bit as suitable for the generation of life as the alternative theory of the primordial soup. Organic compounds, quite tightly concentrated, intermittent energy, water. The theory is that life on Earth originated Out There, so it would be no surprise that DNA/RNA from space would fit earthly organisms - they share the same origins.

In his letter, Prof. Wickramasinghe estimates that "a tonne of bacterial material falls to Earth from space daily, which translates into some 10^19 bacteria, or 20 000 bacteria per square metre of the Earth's surface". It would be surprising if none of these found a viable host. On the rare occasion that there is a good match, a pandemic could result. We don't know if SARS started this way or not.

Note that meteors aren't involved. Nothing gets burned up on re-entry. The stuff just drifts in.

I don't know what the answer is, but I know that it's not as clear cut as some would like to think. It's just possible that data from Beagle2 this Christmas might help shed a little more light.

To put a couple of things straight first. Professor Wickramasinghe hasn't said that SARS comes from space. In the Lancet letter (free reg required), he says "With respect to the SARS outbreak, a prima facie case for a possible space incidence can already be made". Note the word "possible". Note the words "prima facie" (roughly="sufficient to warrant further investigation").

This isn't some crackpot who's just heard of SARS, can't understand epidemiology and therefore thinks it must have come from outer space without thinking things through. Along with Fred Hoyle, he's long been a proponent of panspermia - the theory that life originated in space, rather than on Earth.

There is plentiful evidence of complex organic molecules in cometary and interstellar material. The environment on periodically warmed comets is every bit as suitable for the generation of life as the alternative theory of the primordial soup. Organic compounds, quite tightly concentrated, intermittent energy, water. The theory is that life on Earth originated Out There, so it would be no surprise that DNA/RNA from space would fit earthly organisms - they share the same origins.

In his letter, Prof. Wickramasinghe estimates that "a tonne of bacterial material falls to Earth from space daily, which translates into some 10^19 bacteria, or 20 000 bacteria per square metre of the Earth's surface". It would be surprising if none of these found a viable host. On the rare occasion that there is a good match, a pandemic could result. We don't know if SARS started this way or not.

Note that meteors aren't involved. Nothing gets burned up on re-entry. The stuff just drifts in.

I don't know what the answer is, but I know that it's not as clear cut as some would like to think. It's just possible that data from Beagle2 this Christmas might help shed a little more light.

Does anyone know if this invalidates the Alcubierre drive?

http://www.astro.cf.ac.uk/groups/relativity/papers /abstracts/miguel94a.html

> Huh? An obvious example would be Warp Drive
> (wormholes are not FTL travel). Unless I haven't
> seen it, I haven't seen any viable theories about
> usurping Einstein.

http://www.astro.cf.ac.uk/groups/relativity/papers /abstracts/miguel94a.html

http://www.wikipedia.org/wiki/Alcubierre+drive

Miguel Alcubierre put together a very interesting hypothesis. It is said to be scientifically valid, save for the requirement of exotic matter and nigh impossible amounts of energy. But it seems to not conflict with existing theory.

"...within the framework of general relativity and without the introduction of wormholes, it is possible to modify a spacetime in a way that allows a spaceship to travel with an arbitrarily large speed. By a purely local expansion of spacetime behind the spaceship and an opposite contraction in front of it, motion faster than the speed of light as seen by observers outside the disturbed region is possible. The resulting distortion is reminiscent of the ``warp drive'' of science fiction"

> Also as far as I know, there is no viable
> theory as to how to make a transporter work
> (quantum-level effects notwithstanding).

Yeah, I'll give you that one. I also agree with your general position, that the vast majority of science in Star Trek is not well thought out with relation to reality. It's too bad, since they started out with so much obvious effort, and now they simply don't care about even a semblance of realism.

-JC
http://www.jc-news.com/

(PCR selectively amplifies DNA fragments, making it easy to detect them. Google is your friend)

1) some electron micrographs showing some clumpy things (putatively cells) and

2) the fact that some clumpy things in their samples can be dyed with flourscent dyes that stain the membranes of viable Earth bacteria.

While I might accept this as weak evidence there are some unknown organisms at high altitude, it is far from proving they are extraterrestial! Besides, why do they assume that an extraterrestial organism would have the same type of cell membrane as an Earth bacterial cell?

1) some electron micrographs showing some clumpy things (putatively cells) and

2) the fact that some clumpy things in their samples can be dyed with flourscent dyes that stain the membranes of viable Earth bacteria.

While I might accept this as weak evidence there are some unknown organisms at high altitude, it is far from proving they are extraterrestial! Besides, why do they assume that an extraterrestial organism would have the same type of cell membrane as an Earth bacterial cell?

Despite worm holes, warp drive, hyper drive, tachyon fields, and all the other SF solutions, nobody has ever come up with a mathematically viable solution to Einstein's limitation on travel speeds in the universe.

According to all the modern literature I've read on taste buds, there are five tastes. Namely
1. Salt (Na+ ions)
2. Sour (H+ ions)
3. Bitter (elevated Ca2+ ions, usually caused by basic substances)
4. Sweet (usually glucose)
5. Umami (some amino acids such as glutamate)

More info found here

People

Richard Stallman -
Eric S. Raymond -
Larry Wall

Linux Programming

Unix

Programming Methodologies

C Programming

C++ Programming

Perl Programming

Network Programming

Open Source

Plot the Fourier transform of a file using a Hanning window.

fd file | fft -h | plot

Generate the default synthestic vowel (200 ms duration, fundamental frequency = 100 Hz and formants, F1 = 650 Hz and F2 = 950 Hz), halve the sampling rate, take the hanning-windowed Fourier transform, and plot

klatt -k | downsample 2 | fft -h | plot

Generate 2000 samples of white noise, pass it through a gamma-tone filterbank (1 channel per ERB), arrange the filtered waveforms in a cascade, such that there is no overlap between them and plot.

gaussian 2000 | fbank -e 1 | cascade -o 0.8 | plot -b

Generate 2000 samples of white noise, store a copy of the original in a file called 'noise0', then phase shift it by 90 and store the phase shifted version as 'noise90'.

gaussian 2000 | store -o noise0 | fft -p | ffilt -a 90 | ift | store noise90

Tons of space dust and comet debris fall to earth every day. Fred Hoyle and Chandra Wickramsinghe speculated that extra-terrestrial microbes routinely cause disease outbreaks.

The elaborate precautions are to keep earth life from contaminating the sample and messing up the science.

Tons of space dust and comet debris fall to earth every day. Fred Hoyle and Chandra Wickramsinghe speculated that extra-terrestrial microbes routinely cause disease outbreaks.

The elaborate precautions are to keep earth life from contaminating the sample and messing up the science.

Tons of space dust and comet debris fall to earth every day. Fred Hoyle and Chandra Wickramsinghe speculated that extra-terrestrial microbes routinely cause disease outbreaks.

The elaborate precautions are to keep earth life from contaminating the sample and messing up the science.

Well, THAT brings back memories...

You've got two options:

1. I found an online version of it here.

2. If you really want to recapture the "old school" experience, you can get the original troff sources here - but then you have to go to Finland to find the "recipes" macro package that you need to process them successfully.

s/Progressive/Progresso (doh)

Yes, and said countries are still using such systems. Japan's MUSE standard is still in use, and probably will be for a while.

Anything that was part of BSD was not developed as open source. BSD was treated as a proprietary operating system. So much for nethack as an example -- BTW, nethack is derived from rogue, another part of UNIX.

You have not named a particular chess client that you believe created the product category and was open source or free software.

I found two pages on X Window history (here and here). Both clearly frame X/Windows as a derivative product that came about after other GUI platforms. (It was also radically inferior to the Macintosh, even though it came afterwards.)

GCC is a clone of the Unix CC.

TeX may be an example of an innovative piece of software that originated under free/open conditions. I can't find anything to the contrary. I have never used TeX so I can't comment on whether it really deserves to be considered innovative; I will note that it came after troff, and that although it came after the GUI revolution it missed the boat, so there may be reason to consider it regressive rather than innovative.

And so on. I don't know all of your examples, but the ones I knew did not encourage me to bother checking out the rest. If you continue to defend that list, please give specific references.

Tim