When to give solid feed to baby

We were confused as to when to give solid feed [cerelac etc.] to our baby. We researched quite a bit and found this from The American Academy of Pediatrics very informative.

The American Academy of Pediatrics (AAP) believes that breastfeeding is the optimal source of nutrition through the first year of life. We recommend exclusively breastfeeding for a minimum of four months but preferably for six months.

 

Why plants reject green, most abundant wavelength in sun?

When we look at the solar spectrum it has its maximum around green.

 
So it is really odd, that plants reject green light  when it has the most energy. Is it simply the quirk of evolution [chlorophyll won out as the top photo synthesizer] or is there a deeper reason?

Very courteous and helpful Bangalore police!

I was pleasantly surprised when I went to Ulsoor and Indira nagar police station near me. Upto that most of my experiences in Coimbatore, Hyderabad and Guwahati were par for our country.

But when I went to Ulsoor police station I went straight to traffic police station and they very helpfully redirected me to law and order police station. In Ulsoor station they were very helpful and when I asked for a particular document they promptly gave it instead of making me run around.

In Indira nagar police station as well they were very helpful and one of the officer there actually even xeroxed one of my documents for me [can you believe that?] In fact one of the police man actually gave his seat to me [I am not an old man, BTW] for me to fill some forms along with an officer. To top it all, when I asked for Indira Nagar police station number, the officer actually gave his number and asked me to call him in case the document doesn't go through etc.

During whole of this exercise I was very pleasantly surprised by How courteous and helpful Bangalore police, particularly in these police stations are!

A real big thanks and shout out to Bangalore police!

Installing Firefox5 on RHEL5

I found these instructions Godsend after a lot of blind alleys.

CentOS 5.x FireFox 5 working install

Standard model looks ugly...

I was reading http://en.wikipedia.org/wiki/Subatomic_particle

Elementary particles of the Standard Model include:[2]
Six "flavors" of quarks: up, down, bottom, top, strange, and charm;
Six types of leptons: electron, electron neutrino, muon, muon neutrino, tau, tau neutrino;
Thirteen gauge bosons (force carriers): the graviton of gravity, the photon of electromagnetism, the three W and Z bosons of the weak force, and the eight gluons of the strong force.

and was thinking to myself, holy crap - standard model for sure looks ugly. It looked more like intelligent design theory of physics rather than theory of evolution - that is every particle [species] was created independently instead of being essentially variation on the same thing .

So I looked in the net and even Great Stephen hawking seems to feel that way!

If we understand the universe, then we control it, in a sense. The standard model is clearly unsatisfactory in this respect. First of all, it is ugly and ad hoc. The particles are grouped in an apparently arbitrary way, and the standard model depends on 24 numbers whose values can not be deduced from first principles, but which have to be chosen to fit the observations. What understanding is there in that?

Clearly something needs to be done, and it is not complicating life more by introducing multiple universes [To me all the universes comprise to become one true universe - which is what I would call THE universe. No universes] - It is inaccessible to us is irrelevant. Even in our universe, observable part is not the whole universe - It is only what is called 'observable universe'.

Thomas Nagel's interesting papers!

I came across these two papers from Philosopher Thomas Nagel by accident.

Sexual perversion

and

What it is like to be bat?

Both are amazingly well reasoned arguments and for the first one I was happy someone tried to scientifically define 'perversion' and second one is better known for his arguments for taking human mentality seriously quite independent of its physical reduction.

Both are nice read!

My meaning of life!

I have finally finalized [and approved by a committee of 1] my "meaning of life".

1. My wife and kids [upto 18] - live and let them live happy life. No explanation here.
2. Physics/Mathematics - This probably gave me the most happiness in my life. First time when I understood that light is just electro magnetic wave, first time when I could calculate a complicated figure's area with calculus I was simply blown away.

When I read Euclid's abstract geometry it really looked like absolute heaven - no uncertainities, just beautiful theorems, using elegant arguments.

Or when I realized first time, that real numbers are not real after all!

Or when I understood geometry of our space [space-time actually] is not Euclidean [In hindsight even geometry of our earth is not Euclidean]. Or there is nothing like an absolute simultaneity.

Or the weird quantum world which I never could understand so far. Being not a professional in physics, I am never happy with it giving accurate results. It needs to explain, which always bothers me. I learn physics to understand the universe, not to make money or not even for its enormous applications from Satellite TV to nuclear power.

To those who do not know mathematics it is difficult to get across a real feeling as to the beauty, the deepest beauty, of nature ...
-Feynman

3. Biology - Since I am a biological organism and biology really cured me of things like Islam, superstition, God etc. Always I want to understand about this biological marvel called Brain, which can hold a model of the universe inside! Amazing!

Particularly Selfish Gene of Dr. Dawkins really changed my outlook on life and cured me of all superstitions. When I was in 11th/12th in 1995/96 I tried hard to not look at evidence for evolution - Digits of all Mammals, embryos of humans and fish and an overarching one - We all share the fundamental alphabets of genetic information. But only a blind [in thinking that is ]
man can hold out for too long, particularly after reading book like 'Selfish Gene'.

4. Computer science - of course I love my professional field. But here both for its practical applications as well as theorems like Godel's or Turing's.

5. Travel the world with my wife and baby - Travelling is real rejuventor - Whether to Los Angeles or to Goa. That really clears my mind and almost gives me a fresh start!

I don't believe in sugar coated goals like:
1. help others [then what their life is for?] - That doesn't mean I won't help anyone
2. change the world - most of the change the world impacts of individuals are bad - Muhammed, Hitler, Genghis khan, Alexander etc. In the context of whole universe I living in a fleeting moment [1/50000000 of the life of the earth, if I were to live for 100 years ] am too insignificant an event for the universe. In any case as Richard Feynman said 'it is not my responsibility to change the world'

[John] von Neumann gave me an interesting idea: that you don't have to be responsible for the world that you're in. So I have developed a very powerful sense of social irresponsibility as a result of von Neumann's advice. It's made me a very happy man ever since. But it was von Neumann who put the seed in that grew into my active irresponsibility!

3. Live up to others expectations!

You have no responsibility to live up to what other people think you ought to accomplish. I have no responsibility to be like they expect me to be.

Again to quote Feynman!

Computer playing Rock-paper-scissors!

Computers mimic human reasoning by building on simple rules and statistical averages. Test your strategy against the computer in this rock-paper-scissors game illustrating basic artificial intelligence. Choose from two different modes: novice, where the computer learns to play from scratch, and veteran, where the computer pits over 200,000 rounds of previous experience against you.

http://www.nytimes.com/interactive/science/rock-paper-scissors.html?ref=science

I managed to beat it reasonably easily. Still interesting ...

to see before you die!

One thing I would say you must see before you die is Giant sequoias like the one here.

It is the photo of Mariposa grove giant which I took when I visited last year. I really felt like It made my life worth something...

Yet another Great doodle!

Google's new doodle eclipses everything

"this doodle not only shows you the moon's movement, but allows you to move a dial as far backwards and forwards as you like in order to observe whichever minute detail takes your fancy."

This is amazing! In fact many of Google's doodles are awesome. Yet another one I love is this, for pacman!

BTW, I learned of this when searching for this article, it is amazing too - Les paul!

Great Rowan Atkinson (Mr.Bean)!

This person is simply amazing! He is real Genius!

I watched a lot of Mr.bean episodes in the past! I am pretty much addicted to them.

Recently I started watching his stand up comedy in youtube - this is Great! It changed my perception of Mr. Atkinson.

See this video - for example:

Lunar eclipse

We watched full lunar eclipse today. It was nice to know and see the red glow of moon [picture courtesy scienceblogs]. We watched about 99% then cloud screwed it up.

BTW, you could see it from google doodle as well! Very nice job from Google.

http://abcnews.go.com/Technology/lunar-eclipse-2011-shown-live-google-doodle/story?id=13841381

Dog vision is way worse than ours!

It seems a dog's vision is way worse than a man!

It is 20/75 instead of 20/20. That is what a normal man see at 75 ft can be seen only by dog at 20ft.


http://www.psychologytoday.com/blog/canine-corner/201009/how-good-is-dog-s-visual-acuity-compared-people

I heard this in this talk:

http://www.youtube.com/watch?v=rconzwB422s&playnext=1&list=PL680E0DEE270EF70E

and wanted to confirm and inded Dog is legally blind!

Blackberry yellow circle indicator!

It is the most stupid icon I have seen!

I searched for the actual reason for this indicator for 15 minutes. Indicators have to be intuitive, But it is not even close.

In the end I found out that it is for WAP push messages by mobile provider [ads basically], which endup in Messages in a separate folder. It can also be browser feeds, BTW.

Print screen in mac

Simple.

Command+Shift+4

Elegant integration of sinx/x from 0 to infinity

I learned two things called Contour integral and Jordan's lemma today.

It helps solve this integral elegantly.

To evaluate this you can use e^iz/z and integrate it over 2 semi circles and 2 line segments and residue theorem to convert this into evaluation of this integral. It is really elegant.
It uses Jordan's lemma along the way to make one of the semi circle integral 0 as its radius R goes to infinity.

Waking Up in the Universe - Growing Up in the Universe - Richard Dawkins

Great lecture! You really feel special and motivated to do something special and useful with your life.
1. Illustration of the power of exponential.
2. How lucky we are to born over other possible sperms and eggs and even over other ancestors.
3. Power of scientific prediction with a heavy ball.
4. Illustration of time scales involved with 500 million etc.
5. Why very eerie occurences are no so special after all, given the number of people.

Genesis of purpose!

Great video from christmas lectures of 1991 by Dr. Richard Dawkins.

I was feeling a bit blue yesterday and tried to find purpose in life [I have long outgrown religions] and hit upon this video. I was totally refreshed by this video. Although I have seen it earlier, every time I see it, I get a different perspective. His style of explanation is excellent.

mT4EWCRfdUg

qm-0Z0ceezQ

Ep5: The Genesis of Purpose - Growing Up

Nice putnam question

Prove that this is not prime for any n.

I found this question in putnam question paper and it has real elegant solution too.
It is too good to not to solve it yourself.

How to setup own SVN server in 5 minutes on Mac OS X

1. Install Macports
2. Install subversion

sudo port install subversion

3. Start svn server

svnserve -d --listen-port 4000 -r /repository -T

4. Create repository

svnadmin create /repository/testPrograms

5. Configure repository
Edit /repository/testPrograms/conf/svnserve.conf
and uncomment

auth-access = write
password-db = passwd

Edit /repository/testPrograms/conf/passwd
and add users

[users]
Fakrudeen Ali Ahmed = mypassword

Now svn server is ready to serve the repository.

Create a client folder
and do

svn co svn://localhost:4000/testPrograms

and we are ready to use our repository!

Top Must have developer tools

It is a mix of Top tools and some tools won't apply to some developers.
1. IntelliJ IDEA - Best IDE in the world for JAVA. Or Resharper for C# developers.
2. Textpad - Best text editor
3. Beyond Compare - Best diff tool
4. MIT-Scheme - Rapid proto typing of simple algorthms or rapid calculation of familiar functions like n!
5. SVN - Our own version repository for versioning local test programs, docs and so on.

How to become good theoretical physicist

How to become good theoretical physicist.
't hooft is a Nobel laureate who worked in both general relativity and quantum field theory and great teacher.

http://www.phys.uu.nl/~thooft/theorist.html

Greatest mathematicians ever!

I got a question today in aardvark - who are greatest 20th century mathematicians?

I answered Turing, Godel and Von Neumann.

Then I searched in google about who are greatest mathematicians. I saw many lists and I decided to create my own list based on my own knowledge - of course it need not be objective as it is my own list!

My criteria are a bit harsh - If two people invented the same thing, the person who invented it first or Who is more influential in other respects are given the credit. One good example is evolution. We always credit it to Darwin although Wallace came up with the idea around the same time. So credit for calculus goes to Newton not his opponent. Also I give more credit for a great foundational discovery than breadth of output - Best example is Euler for the latter - but Godel beats him with his incompleteness theorem.
1. Sir Isaac Newton
Greatest by a long distance to me. His invention of Calculus alone would have placed him here. But he discovered binomial theorem, Newton's method for square roots etc.
2. Carl Frederich Gauss
Greatest pure mathematician [or at least one mainly known for mathematics]. He discovered many things like Non Euclidean geometry, Gaussian curvature etc.
3. Kurt Godel
He found incompleteness theorem, which shattered the hope for a theorem proving machine which will find all theorems.
4. Archimedes
From his writings I can see he almost invented integral calculus. Particularly have a look at things like his approximation for PI.
5. Riemann
Invented things which were precursor to General Relativity [Riemann curvature] and a rigorous definition for Integral calculus and contributed to the theory of prime numbers [Riemann zeta function]
6. George Cantor
He proved real numbers aren't countable - so vastly bigger than natural numbers using his famous diagonal slash argument.
7. Alan Turing
He discovered the theory of computability with his Turing machines. It provided the formal basis for computers and proved there are things in Mathematics which are un computable.
8. Euclid
I think he is more of a chronicler than discoverer. But since I don't know who actually discovered his results I might as well give him the credit. Of course he gets into the list due to Elements.
9. Euler
I have to include Euler for the sheer amount of his work. On complex numbers like Euler's formula or his discovery of the sum of 1/1^2+1/2^2 etc. Although in my personal opinion none of them are as path breaking as others in the list.
10. Dedekind
I am including Dedekind for his rigorous definition of real numbers [which are anything but real!] - Although we should probably mention people like Cauchy and Weirstrass, I still think single most important was that of Dedekind.

How the distance from stars are measured

We all know it is using parallax. But I didn't understand how we can actually measure the parallax angle. Finally this link explained it well. It is because we know the angle subtended by telescope's field of view.

If whole picture is 10 degrees and picture width is 10 centimeter and star seems to move 1 centimeter its angle is 1 degree. of course at 1 degree we will be fried to death - but that was just an example!

Why we are evolved animals

I was thinking about similarities and differences between animals [minus humans of course] and us.
If God wanted us to be different from Animals he could have done so many different things. Why should he so confuse us faithfuls by implying with so many "signs of the devil".

1. Base our genetic code on something other than DNA. Even retro viruses are better than us in this respect - they use RNA. Replacing the carbon in nuclic acid with say silicon, because we are special.

2. Why are we based on same cells as other animals - or based on cells at all. We could have used some other mechanism which would have removed cancer from us forever as well. Surely a benevolent [particularly to people, given that we are special] God should have gone with this.

3. Why do we have the same micro organism [mito chondria] for oxidation processes. Atleast if we are diffrent we could have had different mito chondria with different DNA.

4. Why our embryos look so similar to other animals, even to fish. Even we have a tail as embryo, which is so lowly considering exalted state of human beings.

5. Even obvious external apperance, why do we have same four limbs and two eyes and two ears as all other mammals. In this sense, Dolphins and Whales are more special than us. I seriously think they are the ones especially chosen by God. Devil is just misleading us to think that it is we who are special, particularly with the help of some human beings who claim to be prophets etc. We should better beware of God's wrath. What if these guys claiming to be prophets are lying? I have never known them personally anyway. Particularly some prophets morals look much worse than me, a known sinner! Atleast I wouldn't want to marry a 6 year old or ask people to hate their parents for me.

Google sets

I wanted to find website creation softwares similar to wordpress and I used
Google sets to generalise wordpress and joomla and it quickly turned up mambo and drupal.

It is pretty useful. I played with it and it generalised Tendulkar and Kallis to Lara, Murali etc.
But it didn't work for Karunanidhi and Jayalalitha!

Xserver unable to start after reboot

Suddenly my xserver stopped working after reboot.
I wasted almost a day trying to start xserver again. Then I went through some sites and finally I found a work around. I simply linked usr/X11R6/lib/libXfont.so.1 to libXfont.so.1.4.1 through the intermediary of libXfont.so.1.5 symbolic link and it started working.

ls -la /usr/X11R6/lib/libXfont.so*
lrwxrwxrwx 1 root root 15 Jan 3 11:16 /usr/X11R6/lib/libXfont.so.1 -> libXfont.so.1.5
lrwxrwxrwx 1 root root 22 Jul 16 17:49 /usr/X11R6/lib/libXfont.so.1.4.1 -> /usr/lib/libXfont.so.1
lrwxrwxrwx 1 root root 32 Jul 16 18:33 /usr/X11R6/lib/libXfont.so.1.5 -> /usr/X11R6/lib/libXfont.so.1.4.1
-rwxr-xr-x 1 root root 388012 Jul 26 2008 /usr/X11R6/lib/libXfont.so.1.5.bak