Friday, August 28, 2009

coherent dedispersion: 2



I can now reproduce the results of Adithya completely. There is the issue of the code being too slow. I am working with cProfile to fix the slower portions of it. Shown above is the pulse region (B0809+74) at high resolution (16 micro-seconds) at 24 MHz. The pulse peak is 50 times above the noise, roughly. I suspect at higher resolution, it will be even sharper.

More is yet to come, when i make the code faster.

Sunday, August 23, 2009

Lessons for my child: logic and rationality

Let us start with a story of a girl, who went to school regularly, studied on time and had her fun on playground. She was obedient, respected her parents and believed deeply in God. When going for an exam she would bow to her Gods, and then touch her mother's feet. She always received highest scores in exams.

Over a few years this became a pattern. However, owing to a relative's illness, her mother had to leave their home for a few weeks. The girl was without supervision, and over those weeks, she did not study well, and wasted her time in front of television. When it came to exams, she realised that she could not touch her mother's feet, since her mother was not at home. She was terribly anxious and nervous. She did poorly in exams, and to believe that her exam scores had something to do with touching her mother's feet. It required her mother all her (mother's) wit and patience to point out the obvious flaw in this logic.

Touching feet was a sign of respect, not the cause of respect. Touching feet followed from loving her mother, and acting according to mother's advice. If the girl failed to respect motther's advice about timely studies in mother's absence, touching feet would not bring in results. This is rational thinking, it connects one thought with another, and makes one 'logical' chain.

So, here is what I would emhpasise on:

  1. An enquiry into natural world has to be rational, and not based on only faith. Thus, the enquiry is not based on some book, some (God-) man's words, or Nobel Laureate's recommendation. Logical connections remove individual subjectivity, and bring in an element of unbiased understanding of nature's work.
  2. Simple explanations of phenomena are most profound, think of Einstein's equation (energy is equivalent of mass times light-velocity squared) or Newton's law of gravity.
  3. There is no role for any dogma, religion or faith based. This is not to say that science opposes any religion. Quite the opposite, as Einstein said, "Subtle is the Lord, but malicious (S)He is not". In order to understand God's (substitute with karma, nature, whatever) creations, we have to believe that He obeys his own rules, laws. Those rules have no bias or arbitrariness. To illustrate the above, think of the following: "It rains because it is God's will". This statement is very agreeable, however does not give us any predictive power. Therefore, this statement alone is not very useful. We always knew God does everything. However, a statement like "Clouds cause rains" is very useful. Again, one can discount "Clouds are because it is God's will" as per above logic, and continue to resort to natural explanations to understand the phenomena of rains.
  4. Question everything (including this statement) rationally, everything! Why, why not, what, what not, how, and how not... Convince yourself of your chain of logic entirely. It should allow you to have confidence about predicting something using your logic. Only then it will make any sense.

After all, we started with why think. It was to make our lives better, more meaningful, whatever that means. This may take you Buddha's way, or along with the Western civilization. Keep working , and keep thinking.

When you do that, remain open to enquiry from others, learn to respect opinions and debate honestly. That is going to be next in this series.

Tuesday, August 11, 2009

Discovery and spirit of observation

We all believe (rightfully so) that Jocelyn Bell Burnell discovered pulsars. However, there remains a very curious case of a military officer in Alaska who may have detected not just the first pulsar, but did a sky survey for them. He was alone, in a remote army camp, with a radar built to detect incoming missiles. He found pulses (specifically flashes) from Crab and other pulsars, and scouted the sky for more.

Mr. Charles Schisler was his name, you will find more on the link provided. He may not have been trained to 'analyse', but certainly knew how to discover. He knew when he did find something new. He had remarkable skill to know the preserve, to correlate, and put all those pieces together over a long interval time. All this was done at his own initiative.

He should get a honorary PhD, this man deserves that more than myself (and presumably others like me.)

To me, this just happens to show how diverse the nature of 'discovery' can be , and tells us about human spirit, in its rawest form, to know about new things. It also shows how secrecy can diminish importance of knowledge that can be shared by the rest of the humanity. This points to faulty patent scheme and copy-rights that exist today...

Find out more on links below:

http://visibleuniverse.blogspot.com/2007/08/charles-schisler-pulsar-pioneer.html

http://www.nature.com/nature/journal/v448/n7157/full/448974a.html



An Independent 1967 Discovery of Pulsars

AIP Conf. Proc. 983, 642 (2008)

http://link.aip.org/link/?APCPCS/983/642/1