Sorry, English is my third language. How many languages do you speak? Dutch, German and English, Dutch being my native language. How many languages is that? I mean, Dutch being a mixture of English and German as some say...
In other words, I don't think that I wasted my money by buying a Core 2 Duo laptop instead of a single core machine. I notice a very real performance improvement because of an extra core. I run a numerical simulation module on one core and the system and other stuff like browsing the web and office apps can have an extra core all to themselves! You can do it very likely even better: just run two numerical applications simultaneously (provided of course that there is enough memory and any kind of "farming" parallelism present in your calculation). On Core 2 anyway kernel and most of the GUI take so little CPU (and there you can also switch to a lighter GUI, I use WindowMaker) that even with only one core free and lots of GUI stuff running (like browser and multimedia) there is still plenty of remaining CPU time available...
...heterogeneous cores? Like where both cores are from the software perspective still SMP but one core is
physically better for overclocking. For example, manufacturing standards could be raised so that
one core has better specifications than the other and/or chips manufactured so that
one core gets more cooling, etc...
As one "mature" implementation, we could all start coding in HPF. Well, not really, and to see this we can ask few questions: why is there no HPF compiler for Linux?
Why does not gfortran FORTRAN 90 simply "fall back" onto gcc? In both cases the answer is
same: FORTRAN, any standard of it, is designed primarily with the numerical applications in mind.
So FORTAN compilers are traditionally very good at optimizing numerical code exactly because they were
designed to optimize numerical code.
Seriously, several constructs in Fortran are designed specifically for parallel execution. Not quite. FORTRAN 90 was an attempt to freshen up FORTRAN 77 to become like other languages (pointers, recursion, structures, dynamical memory management), but nothing there is particularly suited for or enforcing the parallel programming. There is an attempt though to make FORTRAN 90 "high performance", HPF (High-Performance Fortran), by adding some even older things, like side-effect free constructs that would help compiler automatically vectorize certain operations (vectorization is important in scientific/engineering applications), but, historically speaking, already LISP was better for parallelization than FORTRAN, like when you add two lists with (mapcar #'+ a b), compiler knows that all individual additions can be done in parallel. Nowadays you can use OpenMP (which is SMP oriented and newest versions of gcc support it) or MPI (which is message-passing oriented) both in FORTAN or C(++) that lets you give instructions where and how to parallelize; in terms of more general programming languages, there are Erlang and Ocamm.
Obviously the Soviets were our allies in WWII, and a huge concerted effort was made to erase the 'Socialism' word from 'National Socialism.' There were strong soviet allies in the west who helped make sure it was so. Not really a conspiracy, just a good media campaign. Let me try to deconfuse you a bit: communism, socialism and national-socialism are three different things...
They clashed briefly with police clad in riot gear...A couple of protesters threw bottles before the presidential limousine arrived, and one hurled an egg that landed near the motorcade... A reality where peaceful protesting doesn't include hard, glass projectiles and violence. What about eggs? Are eggs allowed?
Argument: "Lots of people stole stuff."
Counter-Argument: "You're wrong: Persons A, B and C did not steal stuff."
Do you see the logical fallacy in your arugment? There is no logical fallacy because of at least two reason: 1)
the IP argument is that not any one should steal IP--
the argument is not logical but legal/moral.
2) Even logically speaking, "Lots of people" does not imply "all of people".
I didn't quite get how this freifunk works: does one register and then can use the network in areas that are
covered or is it also necessary to contribute to the network by sharing one's internet resources?
Oh great! I'm as calm as a cucumber now that I know that there is a common understanding at CERN that the truth *will* reveal itself, although it cannot be determined when... what?
One of the cool features of Debian is that one can download loads of packages
from the net (3 dvd's in this case, and already the first dvd alone is sufficient to
get a pretty decent system) and install them on box w/o internet connection (which happens
to be exactly what I need).
The only other distro that I know of with the same capability is Fedora Core (ok, CentOS
too but with less "edge"), so it seems that Debian was just enough faster with the release
of Etch than Fedora with FC7 (even if the later will be edgier it is still probably a month
of CPU time for me).
In any case, AMD64 Etch ended up on my new comp (Core 2 with one of
the fancier nvidias) last night, and the installation (using installgui option, dual boot)
was trivial, particularly comparing with the previous installation of Debian I did about a
year ago, and just as easy if not easier compared with other distros I tried (Xubuntu 6.05,
Gentoo 2006.1, FC6 and one Mandriva power pack, all 64bit). Almost all of things just work
without any editing of any files, only installing of packages from dvds (in particular,
movies do play; I didn't configure any nvidia specific stuff yet;
desktops are all there working fine). Now I'll have to tweak few things but overall it
is already usable (things compiled and running full speed).
One thing I miss is ntfs-3g.
Sure, it's not stable yet but it did work for me (on another comp with FC6) and
it seems that what is packaged is just not enough to get my ntfs partitions and
external drives writable, but then I might just not know how to
do it with what's in the distro.
From the thermodynamics point of view, there is no problem with cooling some system
down by adding some energy to it from the outside of the system. Thermodynamics
basically says that in order to take some heat away from the given system, some work
has to be done from the outside of the system, and the amount of work done is
always greater than the amount of heat taken ("work" and "heat" are just two
different kinds of energy). So, if we think in terms of energy and know that the
total energy is conserved, it boils down to redistribution of this total energy:
We take energy from inside of the refrigerator and put it ouside, heating the room,
and in order to do so we need some electrical energy.
Now, laser cooling is just a very fancy refrigerator, looking from the
thermodynamics point of view. But of course the devil is in details, and
laser cooling works along the following lines:
1. To cool atoms/molecules of some solid object means to make them vibrate less.
2. This vibration of molecules is like swinging of someone on the swing, but with one crucial difference: while person on the swing can pretty much swing as high or low as he/she wants, molecules can swing
only in certain discreet amounts of energy: E0, E1, E2,.... because of quantum mechanics.
3. Now, lets say that molecules are mostly vibrating with energy E1, and we want to make
them vibrate mostly with energy E0. By doing so we would cool the system.
4. For some kinds of molecules this can be made so in the following way: we first add energy
to make them swing even higher, with energy E2.
5. Since molecules do want to lower their energy, they will try to go back to a lower energy state
by emitting some radiation ("heat"). But this kind of molecules, instead of going back to E1,
will go to E0. This is possible because it might just happen so that it is
easier for molecules to get from E2 to E0 than it is to get from E1 to E0.
6. Most of these molecules began at E1, then we added some energy to get them to E2, and
they go after that to E0, emitting some energy out (i.e the heat has been taken out of the system by
adding some energy to it).
My refrigerator repair man was explaining to me in a very pedantic way that a refrigerator doesn't make cold, but rather it moves heat out of the inside and pushes it to the outside. This is the conservation of energy.[...]So what am I missing here, because this sounds remarkable to me. Well, does that mean that your refrigerator does not make your electricity bill higher? I honestly
doubt. In order to move heat out of the inside outside, refrigerator needs energy, electrical energy that is.
So, in fact, refrigerator is a heater: it converts electrical energy into heat. Just like an air-conditioner.
Nice, but why is the Scientist character a white male, and the interviewer a dark-skinned female? I suppose that is a combination of sexual and racial stereotyping.
This should answer the age old question, if a mirror at absolute zero breaks, do you have bad luck? Absolutely not positively nor negatively absolute bad luck.
I'm a physicist. I even have a very small bit of experience with low-temperature work (as an undergrad, I once used a dilution refrigerator to get a macroscopic object down to about 0.5 K, or half a degree above absolute zero). I'm now a theorist, working (in theory) with laser-cooled cold atoms, among other things. Despite all this, I have no clue what the significance is. Then how about then getting yourself educated a bit?
From what I understand about absolute zero, there is no energy in the system, including the energy required to keep electrons in orbit around the nucleus of an atom. Absolute Zero means that the temperature of the system is exactly 0 Kelvin.
What is temperature, on the other hand, is not so easy to define. For example, it has nothing to
do with the Heisenberg uncertainty principle, which relates energy and time, or position and momentum.
Energy is an all together different physical quantity than temperature.
Therefore, the atoms would collapse in on themselves, creating an extremely dense substance. Am I right in thinking this would happen? Not quite: the laws of quantum mechanics would prevent such collapse: standard quantum-mechanical description of atom already presupposes that the atom is at 0 Kelvin. What happens however is that
matter at low temperature can undergo phase transitions, like when water freezes and becomes in many regards
quite different a substance, ice.
Similarly, when many ordinary metals are cooled down they become superconducting (conduct electricity without
any resistance), or liquid Helium becomes
superfluid (can flow outside the open container in which it was stored at higher temperatures). The latter two phenomena are essentially quantum-mechanical, and they tell us to expect new phenomena/states of matter sitting at low temperatures. That's one of the reasons why low temperatures are interesting.
If so, would this doom the earth to become a black hole, or do something similar? Many think the main problem with Earth is about its warming up, not cooling down...
He was not only skeptic and critic of the quantum theory, he was also one of its more successful practitioners: like the Einstein-Rosen-Podolski paradox.
Slashdot Mirror
Records are there to be broken.
Thanks for the explanation!
...heterogeneous cores? Like where both cores are from the software perspective still SMP but one core is physically better for overclocking. For example, manufacturing standards could be raised so that one core has better specifications than the other and/or chips manufactured so that one core gets more cooling, etc...
Seriously, several constructs in Fortran are designed specifically for parallel execution. Not quite. FORTRAN 90 was an attempt to freshen up FORTRAN 77 to become like other languages (pointers, recursion, structures, dynamical memory management), but nothing there is particularly suited for or enforcing the parallel programming. There is an attempt though to make FORTRAN 90 "high performance", HPF (High-Performance Fortran), by adding some even older things, like side-effect free constructs that would help compiler automatically vectorize certain operations (vectorization is important in scientific/engineering applications), but, historically speaking, already LISP was better for parallelization than FORTRAN, like when you add two lists with (mapcar #'+ a b), compiler knows that all individual additions can be done in parallel. Nowadays you can use OpenMP (which is SMP oriented and newest versions of gcc support it) or MPI (which is message-passing oriented) both in FORTAN or C(++) that lets you give instructions where and how to parallelize; in terms of more general programming languages, there are Erlang and Ocamm.
Ok then, I didn't get it.
Do you see the logical fallacy in your arugment? There is no logical fallacy because of at least two reason: 1) the IP argument is that not any one should steal IP-- the argument is not logical but legal/moral. 2) Even logically speaking, "Lots of people" does not imply "all of people".
I didn't quite get how this freifunk works: does one register and then can use the network in areas that are covered or is it also necessary to contribute to the network by sharing one's internet resources?
It works though if one turns off the pop-up blocker...
Oh great! I'm as calm as a cucumber now that I know that there is a common understanding at CERN that the truth *will* reveal itself, although it cannot be determined when... what?
One of the cool features of Debian is that one can download loads of packages from the net (3 dvd's in this case, and already the first dvd alone is sufficient to get a pretty decent system) and install them on box w/o internet connection (which happens to be exactly what I need). The only other distro that I know of with the same capability is Fedora Core (ok, CentOS too but with less "edge"), so it seems that Debian was just enough faster with the release of Etch than Fedora with FC7 (even if the later will be edgier it is still probably a month of CPU time for me).
In any case, AMD64 Etch ended up on my new comp (Core 2 with one of the fancier nvidias) last night, and the installation (using installgui option, dual boot) was trivial, particularly comparing with the previous installation of Debian I did about a year ago, and just as easy if not easier compared with other distros I tried (Xubuntu 6.05, Gentoo 2006.1, FC6 and one Mandriva power pack, all 64bit). Almost all of things just work without any editing of any files, only installing of packages from dvds (in particular, movies do play; I didn't configure any nvidia specific stuff yet; desktops are all there working fine). Now I'll have to tweak few things but overall it is already usable (things compiled and running full speed).
One thing I miss is ntfs-3g. Sure, it's not stable yet but it did work for me (on another comp with FC6) and it seems that what is packaged is just not enough to get my ntfs partitions and external drives writable, but then I might just not know how to do it with what's in the distro.
From the thermodynamics point of view, there is no problem with cooling some system down by adding some energy to it from the outside of the system. Thermodynamics basically says that in order to take some heat away from the given system, some work has to be done from the outside of the system, and the amount of work done is always greater than the amount of heat taken ("work" and "heat" are just two different kinds of energy). So, if we think in terms of energy and know that the total energy is conserved, it boils down to redistribution of this total energy: We take energy from inside of the refrigerator and put it ouside, heating the room, and in order to do so we need some electrical energy.
Now, laser cooling is just a very fancy refrigerator, looking from the thermodynamics point of view. But of course the devil is in details, and laser cooling works along the following lines:
1. To cool atoms/molecules of some solid object means to make them vibrate less.
2. This vibration of molecules is like swinging of someone on the swing, but with one crucial difference: while person on the swing can pretty much swing as high or low as he/she wants, molecules can swing only in certain discreet amounts of energy: E0, E1, E2,.... because of quantum mechanics.
3. Now, lets say that molecules are mostly vibrating with energy E1, and we want to make them vibrate mostly with energy E0. By doing so we would cool the system.
4. For some kinds of molecules this can be made so in the following way: we first add energy to make them swing even higher, with energy E2.
5. Since molecules do want to lower their energy, they will try to go back to a lower energy state by emitting some radiation ("heat"). But this kind of molecules, instead of going back to E1, will go to E0. This is possible because it might just happen so that it is easier for molecules to get from E2 to E0 than it is to get from E1 to E0.
6. Most of these molecules began at E1, then we added some energy to get them to E2, and they go after that to E0, emitting some energy out (i.e the heat has been taken out of the system by adding some energy to it).
PS: You can look for "Penrose bomb", or, for instance: The Meaning of the Interaction-Free Measurements
Similarly, when many ordinary metals are cooled down they become superconducting (conduct electricity without any resistance), or liquid Helium becomes superfluid (can flow outside the open container in which it was stored at higher temperatures). The latter two phenomena are essentially quantum-mechanical, and they tell us to expect new phenomena/states of matter sitting at low temperatures. That's one of the reasons why low temperatures are interesting. If so, would this doom the earth to become a black hole, or do something similar? Many think the main problem with Earth is about its warming up, not cooling down...
He was not only skeptic and critic of the quantum theory, he was also one of its more successful practitioners: like the Einstein-Rosen-Podolski paradox.
and Fermilab dudes are like: "you see, we knew that God is on our side!"