Posted: 2008-06-28 12:32
Rydberg atoms are
atoms with a large principle quantum number. One possibility to create
them is to excite ground state atoms with lasers. They are very
sensitive to electric fields, so if you bring them close together they
will experience very strong interactions due to static or induced
electric dipoles.
We have now put a paper onto
the arXiv, where we investigate the properties of the strongly
interacting regime. We have found some interesting links between
Rydberg physics and concepts originally coming from condensed matter
physics.
Read more
Posted: 2008-06-24 06:33
Ever wondered why a Word document you received looks garbled when
opening it in OpenOffice.org under GNU/Linux? Most likely, this is not
a bug in OOo's conversion algorithms, but a problem of missing
fonts. Most Word documents use fonts like "Arial" or "Times New
Roman", which are copyrighted by Microsoft. While Microsoft used to
distribute these so-called "core fonts" for non-Windows users, they
no longer do
so. There are
still places where you can get
them legally, but of course this
is not a free-as-in-speech solution. Therefore, these fonts are not
available by default in many GNU/Linux distros.
While the individual glyphs of a fonts can be copyrighted, their
metrics
(i.e., their spatial dimensions) cannot be, and therefore one can
create a free set of fonts that look different than their proprietary
counterparts, but otherwise behave the same when it comes to things
like linebreaking, hyphenation, etc. Red Hat has done just that, and
some time ago released the Liberation
fonts.
However, due to licensing issues not all major GNU/Linux distros
included the Liberation fonts. But after a long wait and the
persistent work by several people these issues have finally been
settled and the Liberation fonts have been accepted into the
Debian
archive. Other
distros are expected to follow suit soon.
Read more
Posted: 2008-06-06 06:43
A
paper
(also available
here)
published yesterday in Nature analyzes moving patterns of humans based
on position data provided by a European mobile network operator. While
the paper itself is very interesting and provides new insights it also
raises serious privacy concerns, and maybe even legal troubles for the
telco in question.
Read more
Posted: 2008-04-12 15:36
You have probably heard already of
Tor, a tool for
surfing the internet anonymously. It can also be used to evade
censorship, but less known is the fact that you can turn the tables
and monitor internet censorship in various parts of the world. Not
only that, you can use Tor to visit websites pretending you come from
almost any country.
Read more
Posted: 2008-03-27 08:19
Yesterday, Microsoft and Milan-based Sourcesense
announced
they collaborate to contribute code to Apache
POI, a Java library for manipulating
Microsoft Office files. This collaboration has two possible
consequences: either it will turn POI into the greatest patent laundry
of all time, or it will help Microsoft to launch a patent ambush on
the project. Feel free to decide which one is more likely.
Read more
Posted: 2007-09-03 07:13
libquantum 0.9.1 has been released. The new release adds
an interface for time-evolution of arbitrary Hamiltonians using a
fourth-order Runge-Kutta algorithm. The license has been changed to
GPLv3 and several bugs have been fixed. Further information can be
found on the libquantum
website.
Posted: 2007-08-22 06:32
As some of you may know, I wrote my diploma thesis on transport in
quantum thermodynamics. Related to this work, we now put up a
paper on arXiv, describing how
to incorporate the concepts of work and heat, which are well-known
from the classical world, into the quantum realm.
It turns out that if you do it properly, you get some remarkable
consequences, like a machine that both works and does not at the same
time. These strange things arise (hardly surprising) from
non-commuting observables in quantum mechanics.
Read more
Posted: 2007-08-13 20:07
Last Friday, a new law on computer crime came into effect in
Germany. The newly introduced Section 202c of the German penal code
created much
buzz around
the net since it prohibits the distribution of certain computer
programs assisting in committing data espionage.
Although I think the law is bad and creates an uncanny area of
uncertainty it is not the end of all security research done in
Germany. In fact, much of the current outcry is overblown and
counter-productive, as it contributes to spreading FUD about the
issue.
Read more
Posted: 2007-05-29 07:13
Okay, I promise I won't mention every article I write for
OS Reviews on my blog, but here is an exception. I just put up an
article about Nexuiz,
which is definitely the best first-person shooter I've ever
played. And of course it's free as in speech!
Posted: 2007-04-13 07:21
Most of you probably remember the delisting
trouble
SCO got into because they failed to timely file their 10-K back in
2005. The same story will show up again soon, but this time for
another reason: the stock price is too low to meet Nasdaq's
requirements. Read more
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- Copyright 2006--2008 Hendrik Weimer. This document is available under
the terms of the GNU Free Documentation License. See
the licensing terms for further details.