In fact, some physicists have even considered the possibility that space is a Poincare homology 3-sphere! Can light go all the way around in this case? I don't know. If so, we might see bright quasars in a pretty dodecahedral pattern.
Amusingly, Plato hinted at something resembling this in his "Timaeus":
6) Plato, Timaeus, translated by B. Jowett, in The Collected Dialogues, Princeton U. Press, Princeton, 1969 (see line 55c).
This dialog is one the first attempts at doing mathematical physics. In it, the Socrates character guesses that the four elements earth, air, water and fire are made of atoms shaped like four of the five Platonic solids: cubes, octahedra, icosahedra and tetrahedra, respectively. Why? Well, fire obviously feels hot because of those pointy little tetrahedra poking you! Water is liquid because of those round little icosahedra rolling around. Earth is solid because of those little cubes packing together so neatly. And air... well, ahem... we'll get back to you on that one.
But what about the dodecahedron? On this topic, Plato makes only the following cryptic remark: "There was yet a fifth combination which God used in the delineation of the universe with figures of animals."
Huh??? I think this is a feeble attempt to connect the 12 sides of the dodecahedron to the 12 signs of the zodiac. After all, lots of the signs of the zodiac are animals. The word "zodiac" comes from the Greek phrase "zodiakos kuklos", or "circle of carved figures" - where "zodiakos" or "carved figure" is really the diminutive of "zoion", meaning "animal". There may even be a connection between the dodecahedron and the "quintessence": the fifth element, of which the heavenly bodies were supposedly made. I know, this is all pretty weird, but there seems to be some tantalizingly murky connection between the dodecahedron and the heavens in Greek cosmology.... so it would be cool if space turned out to be a Poincare homology 3-sphere. But of course, there's no reason to believe it is.
This is an important point. Why should running an executable be dangerous at all? is it really that difficult to set up a sandbox (a la the JVM) for users to run untrusted executables in? There may be some more hassle involved, but it could be implemented fairly transparently.
Exactly! Files that are executed should always be executed in a sandbox, except if the reside in "/usr/bin" or other system directories. If the common file managers/ email client did that, there would be no problem sending exes per mail.
Someone should implement the following: A program "nobody" that executes a command line and traps all system calls. When the child process does a system call, it asks the user e.g. "The program wants to open a connection to c32x.com. Allow?". If the user answers "No", the system call just returns -1. You could invoke it just like "nice" or "nohup". That should solve the email-attachment problem. Programs like "strace" already trap system calls, so this must be possible.
The VSI has an article about the paper. Some bits translated:
Die Entwicklung, Nutzung und der Vertrieb von Open Source Software (OSS) birgt rechtliche Probleme. Der Grund: Die meisten OSS-Produkte werden unter der so genannten General Public License (GPL) vertrieben. Development, usage, and distribution of open source software (OSS) comes with legal problems. Reason: Most OSS-Products are distributed under the so-called General Public License (GPL).
Die Betrachtung rechtlicher Aspekte steht zunehmend im Zentrum der Debatte um Einsatzmöglichkeiten von 'freier Software'. Die Studie offenbart rechtliche Schwachstellen, die bei der Nutzung von OSS entstehen und die unmittelbare wirtschaftliche Risiken für Entwickler und Nutzer darstellen. Diese unternehmenskritische Relevanz unterstreicht die Bedeutung der Studie?, so Johannes Krüger Generalbevollmächtigter des VSI-Vorstands. "Discussion of legal aspects are increasingly at the center of the debate about 'free software'. The study uncovers legal weaknesses that may arise when using OSS, and that may pose immidiate economic risks for developers and users. This corporate-bound relevance puts emphasis on the meaning of the study." so Johannes Krueger...
Die Bestimmungen der GPL weisen laut Studie aber erhebliche Rechtsunsicherheiten auf. Diese sind nach Ansicht des VSI im Wesentlichen auf die Grundprinzipien von freier Software zurückzuführen, insbesondere die freiwillige Weitergabe der Programmierleistungen, die nicht zentral unter der Leitung eines Unternehmens entwickelt worden sind. According to the study, the terms of the GPL have legal weaknesses. Those are in the opinion of the VSI mainly due to the basic principles of free software, especially the voluntary giving away of programming work that was not developed centrally under the lead of a corporation.
I participated in the petition against software patents. Last friday I received a mail offering a gratis stay for one night at a Brussels hotel. The offer was only valid for a few hours until 3 o'clock pm. I didn't register (I live in Berlin), but that seems very interesting. Here's the e-mail that I got:
From: phm@ffii.org Date: 2 May 2003 09:51:44 -0000 To: Subject: Software Patents Brussels 2003/05/7-8: Hotel Beds for Free
Dear FFII/Eurolinux Supporter[1]!
For the
Software Patent Hearing/Conference/Demo at the European Parliament 2003/05/07-8
http://swpat.ffii.org/termine/2003/europarl/05/
you get
a bed in double room for free
a single room for 50 eur
both in a 3-star hotel
if you register today (friday) before 15.00.
We subsidise your stay, because we really NEED YOU to be there. Please try everything to make it possible.
Your presence alone makes a strong impression, as the parliament is approaching elections. We would not have achieved multi-partisan support for our amendment proposals, if there had not been a full room at the Nov. 26th hearing. This time we are staging a demonstration of quality (well-reasoned support of science and software leaders) and quantity (e.g. rally on Luxembourg Square)
Please try to be there at least on the 8th. Note that Lawrence Lessig, Brian Kahin, Richard Stallman and others are travelling twice around half the globe within a few days because they know how important this is.
To register, you just reply to me or to hotel@ffii.org.
Please tick:
-- Which nights do you want to spend in Brussels?
[ ] 5.-6.
[ ] 6.-7.
[ ] 7.-8.
[ ] 8.-9.
-- [ ] I want one room for myself alone
(50 eur, 70 if you don't show up)
[ ] I prefer a room for myself but wouldn't mind sharing
if there is a shortage of beds.
[ ] I prefer a bed in a double room.
(0 eur, 40 if you don't show up)
[ ] I bring a sleeping bag and would like to stay at the home
of supporters in Brussels.
[ ] I already have a place to stay in Brussels.
-- For the entry to the European Parliament on May 8th, we need your
personal identification data[2]:
Name:
sex (m/f):
nationality:
domicile (address where you live):
date of birth:
passport or identity card number:
this small startup video company takes an 8 hour long documentary based on Eisenhower's memoirs, cuts an hour of footage, and adds a half hour of (the article says new, but considering the way this company operates, probablly also recycled) footage then retitles it with an amazingly similar title and dumps it into discount stores' cheap video bins at a fraction of the cost the original documentary sells for.
If they claim on the box of the video that they where the authors of the whole film, shouldn't Fox be able to accuse them of libel? Since they sell a commercial product, that should be possible whithout invoking copyright law. I think it has happened before that publishers had to change passages of books after receiving complaints that what was presented as fact (e.g. in a biography) was false.
I remember in 3rd grade (1988 or so), we had computers that had the programming language Logo in french. It was "av" for "avance" instead of "fd" for "forward", etc...
are there fundamental design decisions in X11 that make dealing with receiving
events from multiple threads simultaneously, impossible?
You can receive events from different threads. In the other threads, open a new display using XOpenDisplay(). You can then use use XSendEvent() to send an event to the window you want. Window IDs are share between all X clients.
2. Don't use MDI. The solution to number 2 is not to make programs edit multiple documents at once. Each process should edit or view one document. When you close the document, the process terminates. Tabbed windows count also as MDI.
4.a. Use hard links instead of symlinks. A hard link is just that, a link to an inode. The problem is that the file remains under the link name if it is removed, but it should not. The solution would be to label a file as "soft", and when it is deleted under another name, the soft file would become an invalid hard link, or maybe a symlink to the deleted file name.
It would fall down because it has the same mass as matter. Antimatter does not have negative mass. Instead, each particle has opposite charge. One antihydrogen atom is composed of an antiproton (negative charge, same mass as the proton), and a positron (positive charge, same mass as the electron).
On checking in which directory it falls, I think gravity is negligible compared to other forces at the particle level.
Can anyone comment on whether Gcc is the default compiler on the Mac? Is the Mac kernel compiled with Gcc?
I think BSD also uses Gcc. Does that make Gcc the most used compiler on
all systems?
In Qt, objects are always open. There is not "Create()" function. What is when opening fails in the contsructor, does Qt use exceptions? If yes, then correct Qt code has to use "try {...}" on every creation of widgets. In other toolkits, "Create()" returns a BOOL, and you must use "if (Create()) {...}". I think the KDE developers admitted they didn't like exceptions. There's no problem in using exception, but if you write a Qt program, and derive classes from Qt classes, your classes will also throw exceptions in their constructor. Not everyone writes their code like that, and proting existing C++ apps may be difficult for that reason. The other way around, if a library uses "Create()", then wrapping around your own code which calls Create() in the constructor is not hard.
I once built a sphere out of lego. It was completely white and I still have it at home; I see it every day.
I had no computer, not even a graphical calculator, so I had to calculate separately for each dot the distance to the center using and ordinary calculator and the pytogoras formula. The radius was 10 "units". Unfortunately, the unit brick in lego is not a cube. I think to ratio of base to height of these pieces is 5:6. So the sphere now looks more like an ellipsoid. Maybe I should photograph it and put it on the web.
First of all, chess programs don't use floating point calculation, so this aspect is not compared.
Second, there are chances Fritz is optimized for the Intel. It's proprietary so we don't know but Fritz is known for having parts of it written in assembler, and these are surely optimized for Pentium.
Bye the way, wouldn't it have been simpler to just run the Fritz benchmark on both machines?
4. What are your thoughts about moving the codegen after the linker, to allow for global optimization/inlining?
Compile all the program at once. Create one file that includes all source files and compile it in one step. Works fine and eliminates duplicate string constants.
Slashdot Mirror
Exactly! Files that are executed should always be executed in a sandbox, except if the reside in "/usr/bin" or other system directories. If the common file managers/ email client did that, there would be no problem sending exes per mail.
Someone should implement the following: A program "nobody" that executes a command line and traps all system calls. When the child process does a system call, it asks the user e.g. "The program wants to open a connection to c32x.com. Allow?". If the user answers "No", the system call just returns -1. You could invoke it just like "nice" or "nohup". That should solve the email-attachment problem. Programs like "strace" already trap system calls, so this must be possible.
Development, usage, and distribution of open source software (OSS) comes with legal problems. Reason: Most OSS-Products are distributed under the so-called General Public License (GPL).
"Discussion of legal aspects are increasingly at the center of the debate about 'free software'. The study uncovers legal weaknesses that may arise when using OSS, and that may pose immidiate economic risks for developers and users. This corporate-bound relevance puts emphasis on the meaning of the study." so Johannes Krueger...
According to the study, the terms of the GPL have legal weaknesses. Those are in the opinion of the VSI mainly due to the basic principles of free software, especially the voluntary giving away of programming work that was not developed centrally under the lead of a corporation.
1.e4 c6 2.d4 d5 3.Sc3 de4: 4.Se4: Sd7 5.Sg5 Sgf6 6.Ld3 e6 7.S1f3 h6 8.Se6:
It's german chess notation of the beginning of the game Kasparov-Deep Blue that made Kasparov lose the match in 1997.From: phm@ffii.org
Date: 2 May 2003 09:51:44 -0000
To:
Subject: Software Patents Brussels 2003/05/7-8: Hotel Beds for Free
Dear FFII/Eurolinux Supporter[1]!
For the
Software Patent Hearing/Conference/Demo at the European Parliament 2003/05/07-8
http://swpat.ffii.org/termine/2003/europarl/05/
you get
a bed in double room for free
a single room for 50 eur
both in a 3-star hotel
if you register today (friday) before 15.00.
We subsidise your stay, because we really NEED YOU to be there. Please
try everything to make it possible.
Your presence alone makes a strong impression, as the parliament is
approaching elections. We would not have achieved multi-partisan support
for our amendment proposals, if there had not been a full room at the Nov.
26th hearing. This time we are staging a demonstration of quality
(well-reasoned support of science and software leaders) and quantity (e.g.
rally on Luxembourg Square)
Please try to be there at least on the 8th. Note that Lawrence Lessig,
Brian Kahin, Richard Stallman and others are travelling twice around half
the globe within a few days because they know how important this is.
To register, you just reply to me or to hotel@ffii.org.
Please tick:
-- Which nights do you want to spend in Brussels?
[ ] 5.-6.
[ ] 6.-7.
[ ] 7.-8.
[ ] 8.-9.
-- [ ] I want one room for myself alone
(50 eur, 70 if you don't show up)
[ ] I prefer a room for myself but wouldn't mind sharing
if there is a shortage of beds.
[ ] I prefer a bed in a double room.
(0 eur, 40 if you don't show up)
[ ] I bring a sleeping bag and would like to stay at the home
of supporters in Brussels.
[ ] I already have a place to stay in Brussels.
-- For the entry to the European Parliament on May 8th, we need your
personal identification data[2]:
Name:
sex (m/f):
nationality:
domicile (address where you live):
date of birth:
passport or identity card number:
Thank you very much for your support!
If they claim on the box of the video that they where the authors of the whole film, shouldn't Fox be able to accuse them of libel? Since they sell a commercial product, that should be possible whithout invoking copyright law. I think it has happened before that publishers had to change passages of books after receiving complaints that what was presented as fact (e.g. in a biography) was false.
Und mit drei Kommentaren ist hier schon mehr los als auf anderen deutschsprachigen Slashdot-Artigen Webseiten.
Immerhin ist im Titel deutsch enthalten, also kann man dies nicht als offtopic bezeichnen.
I remember in 3rd grade (1988 or so), we had computers that had the programming language Logo in french. It was "av" for "avance" instead of "fd" for "forward", etc...
According to this page, two laptop models are available with RedHat 7.1 or SuSe 7.2.
I thought only few programs used lseek(), e.g. databases. Wouldn't most programs read files sequentially, whitout using off_t at all?
You can receive events from different threads. In the other threads, open a new display using XOpenDisplay(). You can then use use XSendEvent() to send an event to the window you want. Window IDs are share between all X clients.
4.a. Use hard links instead of symlinks. A hard link is just that, a link to an inode. The problem is that the file remains under the link name if it is removed, but it should not. The solution would be to label a file as "soft", and when it is deleted under another name, the soft file would become an invalid hard link, or maybe a symlink to the deleted file name.
I think it's from LZip, but lzip.sourceforge.net seems to be down.
What we need now is the Gnome (or KDE) panel set LD_PRELOAD so that all application can use libtrash.
It would fall down because it has the same mass as matter. Antimatter does not have negative mass. Instead, each particle has opposite charge. One antihydrogen atom is composed of an antiproton (negative charge, same mass as the proton), and a positron (positive charge, same mass as the electron).
On checking in which directory it falls, I think gravity is negligible compared to other forces at the particle level.
Can anyone comment on whether Gcc is the default compiler on the Mac? Is the Mac kernel compiled with Gcc? I think BSD also uses Gcc. Does that make Gcc the most used compiler on all systems?
In Qt, objects are always open. There is not "Create()" function. What is when opening fails in the contsructor, does Qt use exceptions? If yes, then correct Qt code has to use "try {...}" on every creation of widgets. In other toolkits, "Create()" returns a BOOL, and you must use "if (Create()) {...}". I think the KDE developers admitted they didn't like exceptions. There's no problem in using exception, but if you write a Qt program, and derive classes from Qt classes, your classes will also throw exceptions in their constructor. Not everyone writes their code like that, and proting existing C++ apps may be difficult for that reason. The other way around, if a library uses "Create()", then wrapping around your own code which calls Create() in the constructor is not hard.
I had no computer, not even a graphical calculator, so I had to calculate separately for each dot the distance to the center using and ordinary calculator and the pytogoras formula. The radius was 10 "units". Unfortunately, the unit brick in lego is not a cube. I think to ratio of base to height of these pieces is 5:6. So the sphere now looks more like an ellipsoid. Maybe I should photograph it and put it on the web.
First of all, chess programs don't use floating point calculation, so this aspect is not compared.
Second, there are chances Fritz is optimized for the Intel. It's proprietary so we don't know but Fritz is known for having parts of it written in assembler, and these are surely optimized for Pentium.
Bye the way, wouldn't it have been simpler to just run the Fritz benchmark on both machines?
Compile all the program at once. Create one file that includes all source files and compile it in one step. Works fine and eliminates duplicate string constants.