Domain: york.ac.uk
Stories and comments across the archive that link to york.ac.uk.
Comments · 147
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Re:Hopefully they will write it in a better languano matter how safe the car is...it wont help you if you are a shitty driver.
All else being equal, that is true. But, it is widely recognized that some vehicles drive easier / better than others. In other words, some vehicles make it harder to be a good driver than others. C feels fast and light, but it has an unfortunate tendency to crash when used in building large software systems due to some design choices in the language.
It isn't just the case that "some languages are more adept for tacking certain types of problems," but in fact that different languages put to the same task can produce different results.
Here is one example, and here is another. Note that this is a separate issue from suitability or special abilities for a particular problem type. For example, Lisp and Prolog are (from what I've skimmed) 2x more efficient than Ada (and probably C) for coding AI related programs.
i was just speaking out against the original posters instance that by using a different language...the result would be more secure systems...which is pure bullshit...you may be solving one set of problems...but there will always be new ones to complain about.
There are two basic causes of security problems associated with the programmer (as opposed to the user): program design problems, and implementation problems. Program design problems aren't likely to be effected by the programming language per se, but the practices that a language encourages can effect program design.
"The tools we use have a profound (and devious) influence on our thinking habits, and, therefore on our thinking abilities". - Dijkstra
The second class of problems is implementation problems, or more specifically programmer errors. These can definitely be effected by the choice of programming language. There are no pointer errors in java because there are no pointers. Ada catches many problems that would have to be found during debugging with C, if they were found at all by the programmer. When the language makes a type of error impossible, or catches it at compile time, the programmer doesn't have to do it. The result is better code. In this case, more secure code. When that language encourages better program design, so much the better.
FWIW - Dijkstra had some strong views on programming languages and their suitability for use, including:
FORTRAN --"the infantile disorder"--, by now nearly 20 years old, is hopelessly inadequate for whatever computer application you have in mind today: it is now too clumsy, too risky, and too expensive to use.
PL/I --"the fatal disease"-- belongs more to the problem set than to the solution set.
It is practically impossible to teach good programming to students that have had a prior exposure to BASIC: as potential programmers they are mentally mutilated beyond hope of regeneration.
The use of COBOL cripples the mind; its teaching should, therefore, be regarded as a criminal offence.
APL is a mistake, carried through to perfection. It is the language of the future for the programming techniques of the past: it creates a new generation of coding bums.
As a default language, C isn't the worst, but it is by no means the best available today either. -
Re:poetry generated by...
Parent reminds me of the adventures of Polly Nomial
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Re:Collision Detection
Hey, some of those Kangaroos might be equipped with beach balls (or in a funner version of the story, stinger missiles.)
Long story, military simulation humor.
The story's not that long. It is funny, though.
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UK version
There's one in the UK too. It's about six miles long (10km) by the side of a cycle path.
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Try "hard SF" rather than hacker SFI'm talking about anything by Arthur Clarke, Stanislaw Lem (his book The Cyberiad is pretty hackish in nature and very good). Also David Brin (e.g. Sundiver)
Less "hard" SF to consider - The Stars My Destination, by Alfred Bester, Nova by Samuel R. Delany. Maybe even Peter F. Hamilton (start with The Reality Dysfunction), if you liked Stephenson.
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Re:Someone has to say it...
You stole that from here, although a previous version there had 20 entries.
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Re:MisquoteNo way would Voltaire have ever said anything about self-sacrifice. In his writing, he is much more detached and urbane, and not nearly so self-righteously overbearing.
According to this website this bit about dying is a paraphrase of "Think for yourselves and let others enjoy the privilege to do so too" which Voltaire did write. I dunno; Voltaire didn't say anything about himself or anybody else dying in the name of free speech.
Aside from Voltaire's lack of interest in self-sacrifice, the misquote is just too clumsy for him. He was consistently witty and well-polished, although I admit the above quote ("Think for yourselves...") doesn't really show his writing skills at their best.
In short, the misquote is certainly NOT the sort of thing Voltaire would write. Thomas Paine, perhaps.
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Re:MisquoteHmm, you learn something every day. Beatrice Hall actually said it in her book The Friends of Voltaire that she wrote under the pseudonym S.G. Tallentyre.
The page linked above had another good quote:
I may disagree with what you say, but I will defend to the death your right to mis-attribute this quote to Voltaire.
---- Avram Grumer, rec.arts.sf.written, May 2000 -
Re:Wow.
Decreasing by the square of the distance IS exponential.
No, it is polynomial.
Squaring involves an exponent.
Right, but he equation is only exponential if that is where the X is. If you don't believe me just check with google labs glossary. "An exponential function is a function of the form , where a > 0 and the variable x occurs as the exponent."
Contrast to linear, or logarithmic
Constant means there is no X.
Logarithmic means the X is inside a log.
Linear means the X has an exponent of 1.
Polynomial means the X's have fixed exponents.
Exponential means the X is inside an exponent.
Super exponential generally takes special notation and there is an X outside even the exponent. These can get big so fast that calling it "unimaginably fast" doesn't begin to describe them. Take a look at this page. If you can actually understand it they are mind boggling.
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Re:OverclockersClub Graphs
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Worst SF Ever
Although this is (-1, offtopic), because of this discussion I have stumbled over what appears to be the arguably worst piece of SF (or fantasy, really) ever published, Argon's Eye. Read it and die a flaming death laughing.
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Re:Ask Slashdot? Other great sci-fi/cyberpunk auth
Well, maybe there's something for you on this rather giant list of SF book reviews, then. It's not mine, but belongs to some other (attractively obsessive) reader of the good stuff. My collection is modest compared to that one, but they do overlap here and there, and I tend to agree with the reviews, which is why I recommend the list to you. Good luck.
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Re:Qt
As for wxWindows (which others have suggested), I tried it some time ago and I think it truly sucked. Hopefully it has improved since then
:-)
How long ago did you try wxWindows? If it was before 2.0, I can forgive you, but especially since version 2.2, wxWindows completely rocks.
wxWindows provides native widgets on more platforms than any other toolkit (Windows, Mac OS 9, Mac OS X, Unix/GTK, plus wxUniversal which gives you themable widgets based on extremely low-level interfaces such as pure X11 or a PDA's framebuffer).
It's closely modeled after the most widely-used GUI toolkit in existence (MFC) yet it deviates from the MFC model when necessary to make it more consistent, more flexible, or easier to use. What this means is that it's reasonably easy for anyone to pick up, but doubly easy for anyone who's used another modern C++ GUI toolkit like MFC, PowerPlant, or Qt.
wxWindows has more utility classes than just about any other toolkit I've seen, too: check out their list of classes. One thing I love about wxWindows is that it goes beyond the least common denominator, and in fact makes it easy to take advantage of platform-specific features when you want to: for example setting the X Display of a window you pop up in X11, changing the Taskbar icon of a window in Windows, or setting the type/creator of a file on the Mac. Oh yes, and it has a perfectly decent OpenGL widget, too.
wxWindows is also not limited to C++ - it works well from Python, too...
Finally, the wxWindows developer and user communities are very helpful. -
Pertinence
So including information for someone else's benefit, that would have to be researched anyway in order to understand a subject, is unimportant now, just because I'm a busy man?
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Re:what's it good for?
and it's still one of only a few compilable languages (excepting gcj == java) that have a gc.
There is nothing special about a "compilable language" (whatever that means) using GC. Lisp has been doing it for decades (and yes, most Lisp systems are native code compilers, such as CMUCL, Allegro, CormanLisp, SBCL, etc). Oberon-2 compilers use GC, including the open source OOC and Oberon System3 from ETH. Ada was designed such that GC could be implemented, but it rarely is. Many FP languages use GC, such as Haskell. Haskell compilers, such as GHC, NHC, and HBC all use GC.
If you haven't gotten the point yet, there is nothing special about implementing languages using garbage collection, and furthermore, there was nothing innovative when Meyer decided to use it for Eiffel. -
Re:Ask Slashdot...A little OTI think two [mis-]quotes about sum it up:
- In the preface to Brian Kernighan & Dennis Ritchie's The C Programming Language, they write:
C is not a big language, and it is not well served by a big book.
- When I was a high school student, my English teacher quoted us a great line from Blaise Pascal:
Je n'ai fait celle-ci plus longue que parce que je n'ai par eu le loisir de la faire plus courte.
Translated: I am sorry for the length of my letter, but I had not the time to write a short one.
What else is there to say? There is wisdom in these two statements that I can't really expand on, and the trend towards bigger tech books certainly ignores.
Like K&R's book, a lot of these tech books of arcana are about highly specialized areas. Taking a random stroll down the books that have a current place on my desk shelf, I've got books on: MySQL & Perl for the Web, HTML4, Programming Internet Email, VPNs, NFS/NIS, SQL, Perl DBI, TCP/IP admin, Bash, mod_perl, Perl LWP, and others. All of these are small subjects, and at a glance it doesn't look like any of these books goes much above 400 pages. Ah, I tell a like -- the mod_perl "eagle book" is much longer, but then it gets deep into the Apache API, so it isn't exactly padded.
On the other hand, some of the longer books I've got -- one of FreeBSD, one on MySQL, Perl Cookbook, etc -- tend to cover a much wider variety of sub-topics within their stated area, but it's hard to do this in a non-superficial way. It's one thing to go down a checklist & mention every subject area (the FreeBSD & MySQL books seem to be guilty of this); it's much harder to say just enough about each area to be continually useful (Perl Cookbook does well here).
In general, there's a sweet spot between brevity & long windedness. A proper density of information is hard to strike. If there is much to be said about a subject, then I personally would rather see aspects of the larger subject broken out into a more coherent text -- witness all the Perl books that, aside from the language itself, really don't have anything to do with one another (algorithm theory, database programming, client side http, server side http, graphics programming, win32 administration, web database automation, xml, bioinformatics, etc). Is the subject is big enough & cohesive enough to cover overlapping, related areas in one text -- Apache/mod_perl being a good example -- then fine, keep them together and let the book grow longer. But on the other hand if everything you need to know about the SQL implementation of half a dozen RDBMS engines will fit in a skinny little 200 page pamphlet, then let's just save everyone some time and not try to pad that out any further. I for one will never spend my money on those 1000+ page monsters unless they're in the remainder bin & it seems like five bucks would be worthwhile if I ever have to deal with one of those beasts some day.
- In the preface to Brian Kernighan & Dennis Ritchie's The C Programming Language, they write:
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Re:How does this work?Okay, time for a clue. As I'm sure you know, your radio antenna receives all wavelengths simultaneously. The receiver has to filter out all but your tuned-in frequency. To do this, a so-called resistor-capacitor (the cap being your tuning knob) "RC tank circuit" is utilized to provide an oscillation to beat against the mish-mash of the received environmental waves. Local oscillators of this kind are powered by a solid-state Gunn oscillator in a Phase-Locked Loop (PLL).
The output is fed through a low-power Schottkey diode to clamp the waveform and lock onto the desired frequency. I'm sure you can tell what I'm getting at: in order to receive frequency RF, one must generate frequency IF via local oscillations (LO), and IF directly corresponds to RF. Stephen Wolfram points out the relationship V[IF] = V[RF] + V[LO] for increasing and V[IF] = V[RF] - V[LO] for decreasing. Armed with this formula and decent knowledge of the radio's tank circuit, it is trivial to pick up the LO and IF frequencies your car radio transmits, albiet inadvertedly, and customize the billboard contents accordingly. Quite simple really.
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Multiverse SchmultiverseDr Lee Smolin wrote an interesting (although difficult) book about the multiple universe theory.
He theorised that all of the universe's parameters (light, gravity, strong and weak nuclear etc) were self-tuned in much the same way that life is tuned for survival. Universes where the gravity was too strong, or the charge of a particle was too weak, didn't develop black holes. Our universe appears to have thousands of black holes, and we know for a fact our universe is tuned to support life, ergo, our universe will have "off-spring", with black holes being the mothers.
He's basically doing what Creationists do - merging biological evolutionary theory with cosmological evolution, something which most scientists are quick to separate. I think he might be onto something...
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SciFi Author Robert A. Heinlein coined "Grok"
In the 1961 book Stranger in a Strange Land. Quite an achievment to add a word to the English language. It means "To understand profoundly through intuition or empathy. to comprehend.
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Re:That plot's been used multiple times
No thanks - the back covers were enough. What's surprising is that "The Eye of Argon" appears to date from 1970, which is early enough that the author probably hadn't read the Gor books at the time; it looks like the earliest one of them was 1969 or so.
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Re:Read a great story about this [Kinda OT]
Found it!
The story is called `Learning to be me', by Greg Egan. I read it in an anthology called MetaWorlds, but you can find it in his collection called Axiomatic.
Certainly well worth a read, if you can find it. -
NT 5 Problem
The best one I've ever seen has to be this one. The worst part is that it makes sense: I'd probably already deleted a directory of that name previously and it was sitting in the Recycle (sic) Bin, so NT tried to copy (rather than move) the new directory.
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Re:isn't SLOC junk?SLOC is not a good measure of how "good" software is; merely of how complex it is, and how long it takes to develop. Studies have shown that SLOC is better at this than most other metrics:
(Citeseer says it was published in 1996, but it's actually from 1998.) ...lines of code has commonly been found to outperform many of the more complex composite measures of software development.- Powell, 1998
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Re:It IS just good business
I liked the sig...saw it on some other chat site. I believe it comes from a movie, but don't know which one.
P.S.: Don't mind the ACs (tokhe straav) who have no honor and no name in a true Klingon's eyes! ;)
Reminds me of the 20 Comments of Klingon Programmers that circulate. Maybe that's what MS needs to fix their problems. -
Perpetual Motion Machine
Some links to other (failed) perpetual motion machines.
http://manor.york.ac.uk/htdocs/perpetual/torus.htm l
http://manor.york.ac.uk/htdocs/perpetual/mtl.html
http://manor.york.ac.uk/htdocs/perpetual/mtl.html
http://manor.york.ac.uk/htdocs/perpetual/cyl.html
More Perpetual motion plus the Laws of Thermodynamics
http://www.chem.unsw.edu.au/staff/hibbert/perpetua l/default.html
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Perpetual Motion Machine
Some links to other (failed) perpetual motion machines.
http://manor.york.ac.uk/htdocs/perpetual/torus.htm l
http://manor.york.ac.uk/htdocs/perpetual/mtl.html
http://manor.york.ac.uk/htdocs/perpetual/mtl.html
http://manor.york.ac.uk/htdocs/perpetual/cyl.html
More Perpetual motion plus the Laws of Thermodynamics
http://www.chem.unsw.edu.au/staff/hibbert/perpetua l/default.html
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Perpetual Motion Machine
Some links to other (failed) perpetual motion machines.
http://manor.york.ac.uk/htdocs/perpetual/torus.htm l
http://manor.york.ac.uk/htdocs/perpetual/mtl.html
http://manor.york.ac.uk/htdocs/perpetual/mtl.html
http://manor.york.ac.uk/htdocs/perpetual/cyl.html
More Perpetual motion plus the Laws of Thermodynamics
http://www.chem.unsw.edu.au/staff/hibbert/perpetua l/default.html
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Perpetual Motion Machine
Some links to other (failed) perpetual motion machines.
http://manor.york.ac.uk/htdocs/perpetual/torus.htm l
http://manor.york.ac.uk/htdocs/perpetual/mtl.html
http://manor.york.ac.uk/htdocs/perpetual/mtl.html
http://manor.york.ac.uk/htdocs/perpetual/cyl.html
More Perpetual motion plus the Laws of Thermodynamics
http://www.chem.unsw.edu.au/staff/hibbert/perpetua l/default.html
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Re:Reality check: Britain
I was about to reply saying that this seemed incorrect, but a quick search showed that only 28% of dead people are buried. Most surprising
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Re:But...
All of those are much slower than the equivalent C code.
Proof? Of course, there cannot be one, but if you like benchmarks, compare the Great Computer Language Shootout. Though C "wins", I wouldn't exactly call it "much slower".
They all use byte-code or generate C code, then compile the C code.
Wrong. For all languages I mentioned there are native compilers available. For all (AFAIK, not sure about Standard ML), there are also bytecode compilers available, for some also compilers to C.
BTW, nobody would ever be so stupid to first generate bytecode, then C out of this (At least I hope so). Oh, and assembly isn't what you compile to in the end, thats why there are assemblers.
None that I know of generate assembly language directly.
If you talk of generating native binaries directly, you surely should try to get to know more. Here are a few:
I'm sure you'll find more. -
Microsoft knows this....
That's one of the reasons they've introduced their 'Student Consultant' program in Europe (and I believe in the States). Microsoft are aware that students often have very strong opinions about Linux and Microsoft, and have been trying to forge a relationship with students to improve matters.
So two years ago a lecturer I knew at my university in England put me forward for a student consultantship. Microsoft were taking between one and four students from the best Comp. Sci. universities in Britain. I got a reasonable sum of (tax-free) money, a laptop, an Aero PocketPC (the precursor to the Ipaq, which I have also received), a couple year's MSDN subscription, and trips to TechEd '00 and '01 in Amsterdam and Barcelona. In return I was to do some research vaguely involving Microsoft technologies over my summer break. It was a pretty sweet deal, and I'm typing this from my free laptop :)
Microsoft have also pushed the 'Academic Alliance', which serves to give Comp. Sci. students at various universities free copies of practically every bit of Microsoft software (they exclude Office) in return for the University handing over a nominal fee. There have also been various deals regarding free games for completed Web Services, and such like.
Of course, in an ideal world, students will leave university with a completely objective viewpoint, ready to pick the software that best fits their (and their company's) needs with respect to price, performance, stability, features etc. Most CS students I know don't really care about the software they use - this reflects the fact that CS degrees should have very little software-specific content. However, there are always a vocal few who are pro- or anti- this or that. They're kinda boring :)
Henry
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Re:HaskellNope - They going for nhc98 at last check. I should know - I was given it to do as an 4th year engineering project (Computer Systems Engineering), last year.
However due to lack of funding, the university didn't have any Win2k installs, so I was told to aim to have a Haskell to Java converter.
It proved to be impossibly large for a 4th year project, but I got a working framework, and a skeletal converter (i.e. it compiles simple single file programs).
I'm still waiting on the marking of it (supervisor problems). However nhc98 claims to be open source, which I believe would mean that my one would also have to be so as well. If I can get the university to put what I've done up on a web page I'll do so, and notify those at nhc98 so they can do what they want with it.
I have no idea what M$ are doing with it now (if anything at all) - as they went through my supervisor, and I was only interested in getting it done as a project.
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Re:HaskellNope - They going for nhc98 at last check. I should know - I was given it to do as an 4th year engineering project (Computer Systems Engineering), last year.
However due to lack of funding, the university didn't have any Win2k installs, so I was told to aim to have a Haskell to Java converter.
It proved to be impossibly large for a 4th year project, but I got a working framework, and a skeletal converter (i.e. it compiles simple single file programs).
I'm still waiting on the marking of it (supervisor problems). However nhc98 claims to be open source, which I believe would mean that my one would also have to be so as well. If I can get the university to put what I've done up on a web page I'll do so, and notify those at nhc98 so they can do what they want with it.
I have no idea what M$ are doing with it now (if anything at all) - as they went through my supervisor, and I was only interested in getting it done as a project.
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Idiot on the internet
It's hard to believe so many respectable publications ran the perpetual motion story, but we shouldn't be surprised; there have always been gullible people.
In fact, check out this guy's website: he's selling a book he wrote that explains the secrets of a true perpetual motion machine!
Fortunately, there are some sane people in the world too. Check out Professor Hibbert's Perpetual Motion Page, as well as Eric's History of Perpetual Motion and Free Energy Machines and Prof. R.P. Feynman's Perpetual Motion Page -
Perpetual Motion website
So this guy claims to have made a perpetual motion machine? Here are some examples of other "revolutionary" perpetual motion machines--which of course don't work. (from the website of Professor R.P. Feynman.)
The underwater spinning donut
A pulley-based system
and a piston-based machine -
Perpetual Motion website
So this guy claims to have made a perpetual motion machine? Here are some examples of other "revolutionary" perpetual motion machines--which of course don't work. (from the website of Professor R.P. Feynman.)
The underwater spinning donut
A pulley-based system
and a piston-based machine -
Perpetual Motion website
So this guy claims to have made a perpetual motion machine? Here are some examples of other "revolutionary" perpetual motion machines--which of course don't work. (from the website of Professor R.P. Feynman.)
The underwater spinning donut
A pulley-based system
and a piston-based machine -
Perpetual Motion website
So this guy claims to have made a perpetual motion machine? Here are some examples of other "revolutionary" perpetual motion machines--which of course don't work. (from the website of Professor R.P. Feynman.)
The underwater spinning donut
A pulley-based system
and a piston-based machine -
This is a no brainer!!!
Programming is the act of creating automations of complexities that are made up of simpler things.
Does the programmer re-write open() every time they need to open a file?
There is not only nothing wrong with making it easier to build a custom kernel, but in fact there should be a growing interest in doing this sort of simplifying, given the GNU Hurd is about not only modularity but about servers/transltors and creating such, even custom as is needed.
This can be taken even further in that autocoding tools can be and should be built for the GNU users.
In a hundred years from now, how do you suppose programming will be done (given programming today is only about 50 years young)?
As things are being done today, it is not possible to do such a program of complexity as can be imagined of what would be a holodeck program (And we do have such virtual reality cudes today in university labs).
It won't be untill the general programming field realized the need to genuinely and honestly address and do the automation of the field of programming. Certainly everything else can be automated, including human balance and movement (segway).
It's fooling to continue the illusion that programming is not itself automatable. And to begin making it happen, where better than on higher level like autoconfiguration system that allow custom kernels to be done? (Or at least one place for it to begin)
A recent research paper on autocoding presents the current/recent mindset on autocoding. It's worth reading to see how young and admitedly immature the field is. Open system and Open Source Software such as the GNU efforts (Linux, the Hurd, etc..) with their open community has far better ability to do what needs to be done than any private effort which will be biased away from doing the things that need to be done.
Soooo, anything that automates computers and their use is inherently a good thing, for iot will allow us all to reach and achieve much more advanced systems and the benefits of. -
Re:renewable ... but is it clean?
Most non-brazilians don't know that in Brazil we have been using renewable fuel ( alcohol ) on our cars for 22 years. And it is, in fact, cleaner than gasoline. I mean a lot cleaner.
A government program called proalcool was created after the first oil crisis. A good english written document about it can be found here but do scroll down or search for proalcool.
Alcohol is available in every gas station in Brazil to this date. In fact, our gasoline is mixed with 25% alcohol. And the alcohol comes from Sugar Cane produced in Brazil.
I use to have a alcohol car. It was cheaper then gasoline, but consumed more fuel. In the end, I guess, it kind of had the same cost. On very cold days, we had to inject gasoline on the engine to get it started ( a button on the console ). Newer cars have that automatically.
I remember that when it started, cars had sticker that said "Moved by alcohol". And as we brazilians love making fun of everything, we soon had stickers in our cars that said: "Moved by alcohol, but just the drivers". Any chance this would be legal in the States?
Another story, on the grim side, is when there was a lack of sugar cane production, Brazil imported Methanol from abroad, and a few people died from drinking the poisonous imported alcohol. People would drink the fuel, after all, at less than a dollar a liter... -
The Controversy: not cloning itself
I believe one of the big controversies in the field of cloning at the moment is not the fact that exact genetic duplicates are being made, but rather that the science of cloning at the moment isn't exact. There have been a few reported incidents were clones died shortly after birth. As well, dolly the sheep had tolemeres (DNA counters that specifiy how many times more a cell can devide) as short as her mother, which may imply that if you were to have a clone, the two of you would expect to die about the same year (your clones life expectancy would be shortened by your current life span.) There are several other aspects of the science as yet undetermined.
Would it be ethical for a 50 year old woman to clone herself, only to find out 10 years later that her daughter had a life expectancy of 30? -
Late news for UK Aurora watchers
The University of York has set up a UK Aurorawatch site, complete with an Aurora Alert by email or SMS.
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Re:Logo isn't dead; Methods for teaching Children."I'm still debating whether I'd rather use Pascal than Python, because it's strongly typed, but the quick turnaround for type-it, eval-it environments is nice for teaching."
Hmm, how about haskell and get the both of both worlds? Actually, for both the original post and your dilema it would suit nicely. It is THE strongly-typed, purely functional language, it has free (speech and beer) interpreters (like hugs) and compilers (like nhc98), and plenty of libraries (including graphics and OpenGL). Lastly, there are a number of places where it is taught as a first language or as a second language; it is very much worth checking out.
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Read it, weep and get smart about post-MS era
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The article doesn't inspire confidence...X-rays (in crystallography experiments) are not scattered by nuclei, they are scattered by the electron density in the crystal, just like the electron beams. If you want to image nuclei, you have to go to neutron scattering.
The X-ray and electron beams are not combined, they are collected separately, and the information is combined.
Moreover, the principle difficulty has been completely ignored. Electron beams can be focused to produce a direct image. X-rays cannot be focused for imaging purposes (although crude focussing to concentrate a beam is just possible). As a result, you only get a diffraction pattern with no phase information. The image must be reconstructed by Fourier transformation, which needs the phases. (There is a strong analogy with optical holography, in which a reference beam must be interfered with the diffracted beam to obtain phase information, but with x-rays the coherence length is too short to get a reference beam).
The trick is to use the phases from the low resolution electron image, and some mathematical relationships to reconstruct the missing phases in the high resolution image, which will show your electron orbitals. The problem is unless the statistics are treated very carefully, all you get is an image which confirms the assumtions of the model you used to get the relationships with which you reconstruct the phases.
The mathematical techniques were just coming on line in X-ray crystallography in 1996 and there was still considerable debate back then over their correct application. So there is a fair possibility that these results are correct, but I would suspend judgement until they have been scrutinised for a year or two.
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Flower Flyby
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Oh how I love to eat bugs!
No. Terragen is a new program for Windows written by Matt Fairclough. Look at http://www.york.ac.uk/~mpf103/terragen/