Presentations on Ted

Watched a wonderful presentations by Ken Robinson and Elizabeth Gilbert on Ted today. Both are must watch for every human being.

Broadband over Power Lines

I was just wondering if we can manage data transmission over a power cable and landed up at a page from CarbonMetrics. If what is mentioned in the page can be implemented then time is not far away when we can see every corner of this planet connected by high speed communication network.

What's with infinity ?

As has always been the case I got stuck up at problem of defining countable and uncountable sets. This time though I had wikipedia and other resources on Internet to help me out, yet I was not able to comprehend the Cantor's diagonalization argument clearly, until I read an article Infinity: You can't get there from here at www.mathacademy.com. One of the few good articles for layman to understand about the concepts of infinity.

Cardinality of Power Set

Took some time off to give lectures on Logic and Proof Theory to students enrolled at FPGDST course at C-DAC, Mumbai. It was a wonderful experience and I must say I learnt a lot through this experience. During a session on Set Theory we were discussing PowerSets. Now we all know that a Power Set is a set of all subsets of a set. Or if stated in language of sets:

Given a set S = {x1,x2,...,xn}, the power set P(S) is set of all subsets of S.

Now just after the definition of Power Set was given I found my slide to contain a seemingly easy statement about cardinality of a power set. And it said that if S has n elements then P(S) will have 2^n elements. That's pretty obvious isn't it ? But I don't know why, I decided to proove the statement and boy it wasn't that easy a job and it has been a week and I am still struggling to find a decent proof for the same. Will revert back with a proof as soon as I get one which satisfies me. Till then have fun with mathematics :)

Saving money for a playstation 3

My friend Ruchir is pursuing his masters in hotel management from AIHS, Canberra . He seems to be calling me quite often from his cell phone unlike several of my other friends abroad who just chat with me on net using gtalk or yahoo. When I asked him his secret, he told me that his parents had bought him a matrix Pre Activated mobile connection when he went to Australia last year for his masters. And recently he just renewed his subscription for a second year under a plan called cap 29 plan which gives him a talk time value of around 180 Australian $ on payment of just 29$ which also is incidentally paid by his parents in India. This allows him to make international calls of around 5 minutes everyday for free. And I thought he must be spending a bomb making all these calls. So guys think smart and find money saving deals like this and spend your cash on other more essential necessities like the latest PS 3.

Firefox Memory Management

As a user and as a systems administrator, I've seen many people fuming over the fact that their Firefox installation seems to be running very slow and is even making machines go for a toss. A wonderful article on how to reduce memory usage in Firefox can be found at Mozillazine's Knowledge Base.

Some facts about RHEL License.

Here is what I learnt from one of my friend about RHEL License and this shows why we can't download iso images and copy the media to distribute RHEL.

" Except for a few components provided by third parties (for example, Java) all the code in Red Hat products is open source and licensed under the GPL (or a similar license, such as the LGPL, BSD, MIT). So one always has free access to the source code. However, Red Hat does not provide free access to the binaries of Red Hat Enterprise Linux, and these, combined with an annual subscription to Red Hat Network, access to upgrades, and a selected support services, are the components that Red Hat bundles into each Red Hat Enterprise Linux solution. Since every Red Hat Enterprise Linux product includes support for the system on which it is installed, Red Hat supplies the products with a per-system usage/support subscription. This simple model ensures that systems which use Red Hat Enterprise Linux are able to access the maintenance, services and product upgrades to which they are entitled. Of course, as mentioned before, this has no impact on one's access to the Red Hat Enterprise Linux source code."

So in summary we can conclude that RHEL = Linux Kernel + GPL/LGPL/MIT etc. licensed software + Support + RHEL art work and logos

The last component of RHEL is registered product of Redhat and this is included in the iso images and thus we can't copy RHEL disks and also can't download 'em from Internet.