Thursday, May 27, 2010

Science in India: current scinario


INDIA: the land of Raman, Bose and Ramanujan. India contributed many things to the scientific world in past. Right now, with increasing number of research articles per year from India, India still needs to show its potential in doing a leading edge research in the field of science and technology. I started thinking on this issue of "science in India" after I read an article by R.A. Mashelkar that appeared in Science magazine in last week of April. That paper analyzes the situation science in India and suggets some points that can be considered for making the situation better. Opening new IISc's has done little to improve the situation.

Picture: Moon's surface taken from lunar orbit by Chandrayaan-1. Chandrayaan I found ice near Moon's north pole. (courtesy THE HINDU website)

detail at: http://www.sciencemag.org/cgi/reprint/328/5978/547.pdf

Friday, May 21, 2010

Phonon Laser: Light from Phonons

Celebrating 50 years of LASER

A phonon laser has been demonstrated by optical pumping of a trapped ion. The optomechanical interaction associated with the scattering force gives rise to a Van der Pol dynamical system in which amplification is provided by stimulated emission of centre-of-mass phonons. Steady-state operation occurs by saturation of the mechanical amplification, and excellent agreement is obtained between theory and observed mechanical motion versus pumping. The ability to locate microscopic sources of vibrational coherence that are optically driven and cooled (and addressable using wavelength) might provide a new tool in the field of trapped-ion physics. The fact that phonon laser action is sustained by very low power levels suggests that the ion might be used as an ultra-sensitive force probe. Moreover, amplification of the centre-of-mass motion36 is potentially useful in its own right. The single ion, as a class of phonon laser, represents a kind of zerodimensional limit in which there is no vibronic output coupling. In a Fabry Perot laser analogy, the mirrors would be 100% reflecting and threshold would be determined by internal cavity losses. At the same time, however, this does not preclude other types of useful coupling to the ion's vibrational motion (such as electromagnetic). For example, successful injection locking of the ion phonon laser, in analogy to slaving of a laser oscillator by an external master oscillator, has been achieved recently and will be reported elsewhere.

Picture: A Continuous Wave argon ion laser (514.5 nm) in use.

More details at:
http://www.nature.com/nphys/journal/v5/n9/full/nphys1367.html

Paul Dirac: Interviewed by Thomas Kuhn and Paul Wigner (Niels Bohr Library and Archives)

Paul Dirac, another legend who was deeply involved in the development of Quantum Mechanics in the decade of 1920-1930's. He was closely associated with other luminaries and visionaries of that era and was highly admired for his simple, deep-rooted physical interpretations without delving too much into Mathematics. His main contributions were fixing the "FREE PARTICLE" problem in Quantum Mechanics by employing Dirac-Delta functions, extending the probabilistic interpretation given by Max Born to many other branches of Physics and Science and formulating the Quantum Mechanics for the relativistic cases.

Here is an transcripted interview of Paul Dirac that I have found at the American Institute of Physics Web-page on Neils Bohr's library and Archives. The interview was taken by great Philosophers (Thomas J. Kuhn and Paul Wigner) who were contemporary to Paul Dirac but were not technically (or mathematically) involved in the development of Quantum Mechanics. Since, they were good friends and great admirers of each other, the straightforward and direct questions are really interesting and reply from Dirac are quite impressive!

Erwin Schroedinger: Indian influence on the development of Quantum Mechanics

Erwin Schrodinger was one of the main architects of quantum mechanics. Schrodinger developed the wave mechanics. It became the second formulation of quantum mechanics. The first formulation, called matrix mechanics, was developed by Werner Heisenberg. Schrodinger’s wave equation (or Schrodinger equation) is one of the most basic equations of quantum mechanics and used to describe all micro- and nano-level phenomenon. Schrodinger was awarded the Nobel Prize for his exemplary work in the year 1933.

As he mentions in his interviews and writings, he was highly inspired by ancient Vedic Philosophy of Karma. Here is an article I found on web which elucidates this aspect of Erwin Schrodinger's life and work.

Theodore Maiman: His invention of Laser

The rapid and unprecedented development of Information Technology, Medical Science and many other fields have some direct or indirect connection with LASERs. Though, this is an acronym for Light Amplification by Stimulated Emission of Radiation, it has been widely accepted as an independent, "stand-alone' word describing the gamut of its variety of applications. It was in the year 1917 when Albert Einstein first conceptualized and put forth the theory of stimulated emission and hence, Lasers but it took more than 4 decades after that to experimentally realize the 1st working of Laser. The first Laser which worked successfully was the "Ruby" Laser and the inventor was Theodore Maiman at the Hughes lab, USA. Maiman was quite an unknown and ordinary figure before the invention of laser and appeared to be of quite small in stature in comparison to some highly-recognized figures employed by BELL LABS. But against all odds and lack of resources, the genius in Maiman gave us the first Laser. Though, this invention of Maiman has been recognized to be one of the greatest inventions in the previous century, he was not awarded Nobel Prize (nominated twice).

Here is a video where Theodore Maiman describes his experience and shows the viewer how he made the first Laser to work. It is highly inspiring to hear from a genius and his pursuit of gaining excellence.

LaserFest - Charles Townes

When I first learned about stimulated emission formulated by Einstein, it was part of introduction to LASER in my post graduation days. If you think I was introduced to it late and that I should have been introduced to it much before in my graduate days or during my high school you are right - I was introduced to it much earlier but never really grasped it and neither do I have any vivid memory of learning it before my post graduation days. Now, because I understood it only with respect to LASER I kind of had the idea that amplification must have been on the mind of Einstein after he formulated it. Also I had the idea that after the stimulated emission was formulated, the scientific world saw clearly that LASER were in principle possible. The only hurdle was to have the technology to do it. Looks like that was not the story!!!

I came across this video wherein Charles Townes, who is credited with developing the MASER - a predecessor to LASER, talks about the time when the idea of MASER came to his mind. What really interested me though was when he mentions that Einstein didn't think much about the amplification and its application!!

IF you are used to watching videos on youtube then you will find the video quality pretty ordinary. Nevertheless, the man in the video is not. Because his work led to the development of LASER which now plays such a vital role in our high tech world.

Ten Simple Rules

Ten Simple Rules (TSR) is a series from the editorial of PLoS Computational Biology (a peer-reviewed open-access journal) that includes compact and very useful guidelines for:

- getting published
- getting grants
- successful collaborations
- making good oral presentations
- reviewers
- selecting a postdoctoral position
- good poster presentations
- doing your best research, according to hamming
- graduate students
- aspiring scientists in a low-income country
- organizing a scientific meeting
- combining teaching and research
- choosing between industry and academia
- chairing a scientific session
- organizing a virtual conference - anywhere