Quantum states are the key mathematical objects in quantum theory. It is therefore surprising that physicists have been unable to agree on what a quantum state represents. There are at least two opposing schools of thought, each almost as old as quantum theory itself. One is that a pure state is a physical property of system, much like position and momentum in classical mechanics. Another is that even a pure state has only a statistical significance, akin to a probability distribution in statistical mechanics. Here we show that, given only very mild assumptions, the statistical interpretation of the quantum state is inconsistent with the predictions of quantum theory....
Progress in atomic, optical and quantum science1, 2 has led to rapid improvements in atomic clocks. At the same time, atomic clock research has helped to advance the frontiers of science, affecting both fundamental and applied research. The ability to control quantum states of individual atoms and photons is central to quantum information science and precision measurement, and optical clocks based on single ions have achieved the lowest systematic uncertainty of any frequency standard3, 4, 5. Although many-atom lattice clocks have shown advantages in measurement precision over trapped-ion clocks6, 7, their accuracy has remained 16 times worse8, 9, 10. Here we demonstrate a many-atom system that achieves an accuracy of 6.4 × 10−18, which is not only better than a single-ion-based clock, but also reduces the required measurement time by two orders of magnitude. By systematically evaluating all known sources of uncertainty, including in situ monitoring of the blackbody radiation environment, we improve the accuracy of optical lattice clocks by a factor of 22. This single clock has simultaneously achieved the best known performance in the key characteristics necessary for consideration as a primary standard-stability and accuracy. More stable and accurate atomic clocks will benefit a wide range of fields, such as the realization and distribution of SI units11, the search for time variation of fundamental constants12, clock-based geodesy13 and other precision tests of the fundamental laws of nature. This work also connects to the development of quantum sensors and many-body quantum state engineering14 (such as spin squeezing) to advance measurement precision beyond the standard quantum limit.
Be careful, the article is written by the company who did the migration to Ubuntu. Here is a comment by a police guy from IT (in french...). In brief he says that tyhe migration was not a problem for most of the people; exepc for some probleme with access. But it did cost money ! and the saving was not the main argument.
"Personnellement concerné par la news qui n'en est pas une, je peux vous assurer que le message de Canonical est surtout commercial...
Le choix d'Ubuntu est dû à son hégémonie et le fait que ce soit basé sur du Debian qui est considéré comme très stable. La distrib est d'une maintenance plus aisée que la plupart de celles qui ont été testées.
"4500 postes" veut dire "4500 unités de gendarmerie" donc dans les brigades que vous connaissez...
Pour ce qui est d'OpenOffice, le passage s'est fait assez tranquillement sauf pour les applis Access qui ont eu un peu de mal à passer sur le module Base...La plupart ont été reprise au sein d'applis php/mysql ou d'applis centralisées...
Aujourd'hui, les gendarmes qui je le rappelle ne sont pas informaticiens mais vivent pour vous (au sens le plus strict je vous l'assure) utilisent donc firefox/thunderbird et oppenoffice en clients lourds, le reste étant des applis sur l'intranet ou "invisibles" pour l'utilisateur. Le passage à Ubuntu ne gène en rien dans l'utilisation car le trio précédemment cité est déjà connu et maîtrisé par nombre de mes collègues.
Je ne suis pas censé m'exprimer en lieu et place de mes supérieurs mais à titre personnel, le choix d'Ubuntu est un choix intelligent car c'est une distribution avec une prise en main très accessible et avec une maintenance vraiment aisée pour les spécialistes informatiques dont je fais partie...Il ne faut pas oublier qu'une distribution plus élitiste aurait été maîtrisée par moins de monde et donc la maintenance aurait été plus coûteuse...
Donc aujourd'hui nous "maîtrisons" cette part de notre infrastructure et la trans
Combined method of construction and transportation for access to space of distributed heavyweight cargo and personnel with safe, economical and renewable characteristics.
Finding power laws has now become de rigueur when analyzing popularity distributions. Long tails have been reported for the frequency of word usage in many languages [2], the number of citations of scientific papers [3], the number of visits (hits) to individual websites in a given time interval [4], and many more.
Well, the topic GPL vs other open-source licenses (e.g., BSD, MIT, etc.) is old as the internet and it has provided material for long and glorious flame wars.
The executive summary is that the GPL license (the one used by Linux) is a license which imposes some restrictions on the way you are allowed to (re)use the code. Specifically, if you re-use or modify GPL code and re-distribute it, you are required to make it available again under the GPL license. It is called "viral" because once you use a bit of GPL code, you are required to make the whole application GPL - so in this sense GPL code replicates like a virus.
On the other side of the spectrum, there are the so-called BSD-like licenses which have more relaxed requirements. Usually, the only obligation they impose is to acknowledge somewhere (e.g., in a README file) that you have used some BSD code and who wrote it (this is called "attribution clause"), but they do not require to re-distribute the whole application under the same license.
GPL critics usually claim that the license is not really "free" because it does not allow you to do whatever you want with the code without restrictions. GPL proponents claim that the requirements imposed by the GPL are necessary to safeguard the freedom of the code, in order to avoid being able to re-use GPL code without giving anything back to the community (which the BSD license allow: early versions of Microsoft Windows, for instance, had the networking code basically copy-pasted from BSD-licensed versions of Unix).
In my opinion (and this point is often brought up in the debates) the division pro/against GPL mirrors somehow the division between anti/pro anarchism. Anarchists claim that the only way to be really free is the absence of laws, while non-anarchist maintain that the only practical way to be free is to have laws (which by definition limit certain freedoms).
So you can see how the topic can quickly become inflammatory :) GPL at the current time is used by aro
whoa, the comment got cut off.
Anyway, I was just saying that at the present time the GPL license is used by around 65% of open source projects, including the Linux kernel, KDE, Samba, GCC, all the GNU utils, etc.
The topic is much deeper than this brief summary, so if you are interested in it, Leopold, we can discuss it at length in another place.
Thanks for the record long comment - am sure that this is longest ever made to an ACT diigo post!
On the topic, I would rather lean for the GPL license (which I also advocated for the Marek viewer programme we put on source forge btw), mainly because I don't trust that open source is by nature delivering a better product and thus will prevail but I still would like to succeed, which I am not sure it would if there were mainly BSD like licenses around. ... but clearly, this is an outsider talking :-)
Well, not going into the discussion about GPL/BSD, the viral license in this particular case in my view simply undermines the "clean and clear" motivations of the initiative authors - why should *they* be credited for using something they have no rights for?
And I don't like viral licences because they prevent using things released under this licence to all those people who want to release their stuff under a different licence, thus limiting the usefulness of the stuff released on that licence :)
BSD is not a perfect license too, it also had major flaws
And I'm not an anarchist, lol
Quantum internet will enable perfectly secure communications, but the technology and means to build the required quantum memories and routers are still many years distant. The proposal here is to store qubits and send them in containers over the oceans. Researchers claim that it is possible to send information at bandwidths measured in teraahertz outperforming the predictions of a quantum router internet.
It can be thought in space systems as well. Then the problem is still for how long are we able to store a qubit, without dephasing...
PS: As a curiosity, you can find a very interesting book about containers and how in some way they changed our world: Mark Levinson's book 'The Box' http://press.princeton.edu/titles/9383.html
Maybe they will do it again
NASA has confirmed the presence of water on the moon's sunlit surface, a breakthrough that suggests the chemical compound that is vital to life on Earth could be distributed across more parts of the lunar surface than the ice that has previously been found in dark and cold areas.
A new blob-like robot described in the journal Advanced Robotics uses springs, feet, "protoplasm" and a distributed nervous system to move in a manner inspired by the slime mold Physarum polycepharum. Watch it ooze across a flat surface, The Blob style: Skip to 1:00 if you just want to be creeped out by its life-like quivering.
As William Gibson famously said "The future is already here - it's just not very evenly distributed."
Many of the listed technologies are already here, in one way or another, the authors are just putting dates on when they think they'll achieve greater consumer impact. I have issues with many of those dates. I think there are a lot of under- and overestimations.
Also, what a bleak future for AI it that's all it'll give the world in the next 30 years!
The idea has been around for already some time (2008) but I like it despite the challenges/trade-off: visible vs IR photovoltaics, black leaves would be better... Piezo + classical PV would already be great...
Optimizing the leave shape & distribution for both wind and sun energy harvesting could be interesting...