2012-10-15

Philosophy: Kant (Prolegomena)


I was just reading the author's introduction to "Immanuel Kant: Prolegomena to Any Future Metaphysics" in the book "The Great Works of Philosophy" by Robert Paul Wolf [1]. I want to share the last section (pp. 347-348) of this 3-page intro:
"...If the  mind imposes its own subjective forms on nature, then the nature it knows cannot be a realm of things as they are in themselves; it must be merely a realm of things as they appear to us. In short, our knowledge must be limited to appearances; reality is forever obscured from our view. Hence metaphysics, the "science of reality," must be an empty discipline, a mere pretension and illusion to be refuted rather than encouraged.
Thus Kant's philosophy is at one and the same time optimistic and pessimistic. He reassures us that our mathematics and science is valid knowledge, but he cautions us that it is valid only for appearances, not for reality itself. In the end, the transcendental philosophy is a lesson in intellectual humility, for it teaches us that the human mind lacks the power to penetrate the veil of appearance and grasp the inner nature of independent reality."

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Thanks for reading

The Information Diet & LInux

Given that recently I decided to start on an information diet [1], and that the Information Diets' Tools page [2] doesn't mention Linux (practically only 3 times [3]), I am writing this post tailored to Linux in general & Ubuntu in particular.

First I'll leave you with a video about the Information Diet & some quotes:


2012-10-14

Online Security: Rules to stay safe online


Some basic rules of thumb to use when online to increase your safety online, ordered in order of
  • General
    • Never open or reply to any email from an unknown. Consider it suspicious.
    • Never click a link given by a stranger or even by a friend if you've not asked for it.

  • Broswer related
    • Disable redirects (links might redirect you to fake pages!)
    • Use HTTPS instead of plain HTTP
    • Block Javascript & Java
    • Block Ads
    • Block 3rd parties in webpages (most of which are hidden)
    • Control cross-site requests
    • Erase internet history, private data, cookies
    • Erase Flash Local Shared Objects (LSO), also known as long-term Super-Cookies

Note: Pages might not load well enough with the above; you will often need to allow some services & parties, but at least its under your control!


  • Chatting
    • Follow the "General"
    • Use a good Instant Messenger
    • Use encryption

And remember, a computer is as smart as its user is & secure as cautious its user is!


Disclaimer: Please be warned that following the above rules increases your online security but it is by no means guaranteed to be completely safe! As a matter of fact, there's nothing as being completely safe online!

Thanks for reading


last update: 2012-10-14

2012-09-28

Useful #! commands


$ indicates terminal command         
# indicates a comment                   
Bold indicates "not installed by default"

$ lsusb      #list USB devices
$ lspci      #list all PCI devi
$ startx     #initialize an X session
$ more       #filter for paging through text one screenful at a time. (less gives more advanced).
$ less       #opposite of more; allows backward movement in the file as well as forward movement.


File commands

$ locate    #find files by name (for newbies I suggest the gui catfish -requires installation)
$ find      #search for files in a directory hierarchy
$ ls        #list directory contents
$ cd        #change directory
$ pwd       #print name of current/working directory
$ cp        #copy files and directories
$ rm        #remove files or directories
$ rmdir     #remove empty directories

2012-09-27

Take care of your eyes at the screen with Redshift

Before Redshit I was using f.lux [1] which seems to be broken in Ubuntu's Unity. I searched for an alternative & found positive reviews about Redshift, which is inspired by f.lux.

By default, redshift fetches your approximate location using the internet (geoclue method) & uses it. if you prefer to manually set it, check the help. And if you, like me, prefer it to use a preset location &/or other configuration (without having to do it every time you run your system), create a text file named redshift.config under your ~/.config/ directory. You can do this from the terminal:

cd ~/.config/
gedit redshift.config

In this file, copy & edit the content below:

2012-07-04

(Higgs) boson: Update from CERN

Some videos & links about the recent update regarding the (Higgs) boson:

"We know it is a new boson. But we still have to prove definitively that it is the one that Higgs predicted."
"It's a boson:" Higgs quest bears new particle [Reuters]



2012-06-28

What is Computational Physics (Science)?


As a senior physics undergraduate I have come to believe that scientific computation must be part of the physics curriculum. It is true that physics students are required to study and master many topics, languages, techniques, and skills like mathematics, linguistics, & science communication, still I think that computational physics should be a major part of the curriculum. It is not logical to be in the age of supercomputers and the physics curriculum remain bound to pen and paper as it used to be before the advent of computers! I am not suggesting that physics should all be done on computers; absolutely not. The student must acquire the necessary theoretical and mathematical concepts and skills, besides the physics thinking, before delving in computational physics! What use would a computer have if its user doesn't know what he wants to use it for? In other words, how would a physics student who hasn't studied classical mechanics be able to solve a classical mechanics problem on a computer? He will surely not be able to do so, since he will not be able to appropriately instruct the computer due to his lack of conceptual physics and paper & pen problem solving skills. In short, "a computer is as dumb as its user is dump, and a computer is as smart as a smart user; the smarter and knowledgeable the user, the more productive and efficient the computer is"!


The computer is a little over 70 years old. The first computer, many articles & resources claim, is the "Electronic Numerical Integrator And Computer", or ENIAC for short, which is not technically correct. Many other computers preceded ENIAC most of which were developed for military purposes (e.g; calculation of artillery, cryptoanalysis, etc...) and were analogue (or electro-mechanical) & programmed by punched cards. ENIAC was a room-sized computer that required several people to operate by turning on/off switches that made use of vacuum tubes the ancestor of the modern transistor.
One particularly interesting electromechanical machine (could be called a computer) was the "bombe" [1] which was [designed] by the mathematician Alan Turing to be used to crack the Enigma, the code used by the Nazi to encrypt messages.

Working rebuilt bombe at Bletchley Park [2].

Interior of the rebuilt bombe at Bletchley Park.

The bombe was in part successful in breaking the Enigma. Moreover, Alan Turing has impacted the modern day internet as well; everyone of us using the internet have definitely faced the "CAPTCHA" which are used to counter-bots & make sure the user is an actual human being & not a bot (from robot). CAPTCHA is an abbreviation for "Completely Automated Public Turing test to tell Computers and Humans Apart". And yes, Turing in CAPTCHA is the same as Turing the mathematician of the 1940's, though the original Turing test was a human against a machine test not the other way round!

2012-05-18

Compiling Muesli Fortran

Here is the code you need to compile and install the free numerical and graphical MUESLI library, developed by Édouard Canot [1].
sudo apt-get install 'libatlas-dev liblapack-dev zlib1g-dev libreadline6-dev imagemagick \ 
libx11-dev libpng12-dev g++ gfortran' #installing dependencies
 Note: for Ubuntu 10.04 replace "libatlas-dev" by "libatlas-headers")

tar xvfj muesli-linux-all-2.6.3_2012-05-03.tar.bz2 #untar

cd muesli-linux-all-2.6.3_2012-05-03/GNU_GFC
./configure --f90=gfortran --blas=/usr/lib/ --lapack=/usr/lib/lapack/ #configuring

make -s distclean #clean your distribution from previous installation
make -s (or for detailed output: make MODE=verbose) #compiling; this will take some time

cd tests #testing
make #make the test files
./run_all #run all the made test files

cd ..
make install #installing

cd tests/fgl #testing fgl
make #make the test files
./run_all #run all the made test files

2012-05-14

Ubuntu 12.04 & Cinnamon

Hello again,

Precise Pangolin

Those who will try Ubuntu 12.04 & have a multitouch touchpad will notice the new feature (when enabled)!

Some not very apparent new features (relative to 10.04 & not 11.04 or 11.10!) are:
  • Installation time (i.e; start of copying files to notification or required reboot): 6~7 minutes.
  • Properties of an image in the image viewer gives you the folder name the image is located in & the ability (which I like) to open this folder by clicking the name.
  • Two-finger scrolling: In the "Mouse and Touchpad" settings, under Touchpad I enabled horizontal scrolling (which I do not understand why it is not enabled by default) & chose "Two-finger scrolling" instead of "Edge scrolling". The latter was not comfortable in my case; I sometimes couldn't lock the scroll & use it, but with the two-finger option (which needs some time to get used to) is much better; I can now use two fingers anywhere on the pad to scroll not just verticall or horizontally but in any direction (i.e; both vertical & horizontal).

Cinnamon

I'd also like share with you the relatively new desktop graphical user interface (GUI): Cinnamon. Below are two images of the desktop, which unlike Gnome 2 which has two panels, has only one main panel.

Cinnamon might very well appeal to Gnome 2 users who do not wish to switch to neither Gnome 3 that Fedora employs nor Ubuntu's new Unity.

A particular feature employed in Cinnamon that adds to Gnome 2 that I really appreciate is a graphical feature. What I really like is the Mac-like drop-down window when saving a file. All I can show you is the screenshots below:
Cinnamon
The default GUI for Mint 12 with its default one-panel look.

Ubuntu 12.04LTS (Precise Pangolin)




Ubuntu 12.04LTS, otherwise known by Precise Pangolin, is coming soon; it is currently in Beta 2 testing. The final release should come in April. Here are a couple of images:

Ubuntu Precise Beta_Unity_2012-03-26
Unity on Ubuntu Precise Beta 2

Welcome

Welcome to the blog!

This blog has been set up to include posts about, as the name implies, computation & physics. This includes posts mainly about:
  • Linux & Ubuntu,
  • the shell (aka terminal),
  • programming (this is going to be rare as there are lots of other better online resources),
  • physics, astronomy*, astrophysics,
  • scientific software, computational (astro)physics,
  • what ever I see interesting for such a blog,
  • & the like.

If you're interested in the above combination of topics then I suggest you follow the blog by email** (bottom of page).

Also note that this blog is a students blog; I am still a student learning the above mentioned topics!

Welcome aboard!

*I might also refer you my website &/or blog!
**The frequency of posts will be low, so I won't be filling up you're inbox.