Month: April 2026

DeWitt is a ‘de-influencer’?

The Indian Express recently reported that “Author Helen DeWitt’s refusal to accept the prestigious Windham-Campbell Prize is a reminder that in a noisy world, the most imaginative stance may well be to let the book stand on its own.”

To quote: “DeWitt’s refusal, like Ferrante’s silence, is a reminder that in a noisy world, the most imaginative stance may well be to let the book stand on its own.” This kind of thinking and action is rare nowadays. Good to see this still persists. Perhaps, such people should be called ‘de-influencers’.

I have to add that DeWitt is already an established name in her field. By established, I mean, by name and perhaps by income too.

2 questions:

1) It may be relatively easier for a person of fame to reject further recognition. Will an upcoming writer (or equivalent in other fields) be able to do this?

2) The same person in a different situation may have reacted differently, and a different person in the same situation, too. In the human context, do we fully understand what an incentive is?

Conversation with Binay Panda

Binay Panda is a Professor at JNU’s School of Biotechnology. The Oxford-educated scientist specializes in genome science, cancer genomics, and data integration, while advocating for open science and Indian biofoundries. He is also an avid long-distance cyclist.

In this freewheeling conversation, we discuss his intellectual journey and his thoughts on doing science, particularly in India.

References:

‘B. R. Panda | Official Website of Jawaharlal Nehru University, New Delhi, India’. Accessed 16 April 2026. https://www.jnu.ac.in/content/binaypanda.

Mysite. ‘Home’. Accessed 16 April 2026. https://www.binaypandalab.org.

Mysite. ‘Open Science’. Accessed 16 April 2026. https://www.binaypandalab.org/open-science.

Mysite. ‘People’. Accessed 16 April 2026. https://www.binaypandalab.org/people.

YouTube. ‘Science Frontiers’. Accessed 16 April 2026. https://www.youtube.com/channel/UCaNkEDS8jRgNZciARfza_ag.

Sean B. Carroll. ‘The Story’. Accessed 16 April 2026. https://www.seanbcarroll.com/brave-genius-story.

Dr. Sanjib Malik. Ek Doctor Ki Maut (1990) by Tapan Sinha [ Full Movie in 4K or Ultra HD  ]. 2024. https://www.youtube.com/watch?v=5qLFGW8SU38.

Open Source – an example

Open source done with expertise and correct intent looks like the link below.

The world, irrespective of the location, can adapt a lot more to the ‘creative commons’ principle than it has done over the years.

When it comes to knowledge generation and sharing, open source has great value to the world. Think Internet in its early days. The motivation for its propulsion was to connect the nodes of knowledge (www stands for World Wide Web).

Having said that, I acknowledge that commercialization is important, but it has its relevance in certain domains downstream of knowledge, especially where engineering has to interface with the scale, scope and demands of the market. Not at the origins, learning and coupling with the society.

If anything, open source knowledge, harnessed properly with fair markets, may lead to far more commercialization and entrepreneurial opportunities.

For the scale and variety of India, open source has a lot to offer. Are we ready to adopt and adapt?

Intensity Interferometer – connection to coherence

My previous blog discussed some historical papers related to the intensity interferometer and its connection to quantum optics. Here, I explain the basic physics of an intensity interferometer.

In the context of spatial coherence, the coherence theory expresses the degree of spatial coherence as,

$$ \gamma_{12} = \frac{\left\langle U_1(t) U_2^\ast(t) \right\rangle}{\sqrt{\left\langle |U_1|^2 \right\rangle \left\langle |U_2|^2 \right\rangle}} $$

with \( U_i(t) \) representing the fields of sources \( i = 1 \) and \( 2 \).

An intensity interferometer measures the intensity correlation function between such sources. If \( I_1(t) \) is the intensity of source 1 and \( I_2(t) \) is the intensity of source 2, then the intensity correlation function is given by:

$$ \left\langle I_1(t) \cdot I_2(t) \right\rangle $$

where the enclosing brackets denote a time average.

This correlation, measured in the intensity interferometer, is related to the degree of spatial coherence in the following way:

$$ \left\langle I_1 I_2 \right\rangle = \left\langle I_1 \right\rangle \left\langle I_2 \right\rangle \left(1 + \left| \gamma_{12} \right|^2 \right) $$

If one ignores the background (the first term in the sum of the above equation) and considers only the fluctuations in the signal (the second term), then the term of relevance will be:

$$ \left\langle \Delta I_1 \Delta I_2 \right\rangle = \left\langle I_1 \right\rangle \left\langle I_2 \right\rangle \left| \gamma_{12} \right|^2 $$

The signal in the intensity interferometer is thus proportional to \( \left| \gamma_{12} \right|^2 \).

A conventional interferometer measures a signal that is proportional to \( \left| \gamma_{12} \right| \), which includes the amplitude and phase, whereas an intensity interferometer measures a signal proportional to \( \left| \gamma_{12} \right|^2 \), which is not sensitive to the phase.

Intensity interferometers have certain advantages compared to conventional interferometers (such as the Michelson interferometer). Below is a partial list:

  • Intensity measurements (unlike amplitude or phase) can be done directly using optoelectronic instruments.
  • They do not require precise, sub-wavelength optical alignment, unlike amplitude- or wavefront-dividing interferometers.
  • They can be used with two detectors that are placed far apart, thereby improving the spatial resolution of the measurement (relevant in astronomy).

A constraint of an intensity interferometer is that the intensity of the participating source should be bright.

Reference:

Dravins, Dainis. ‘Intensity Interferometry: Optical Imaging with Kilometer Baselines’. arXiv.Org, 12 July 2016. https://arxiv.org/abs/1607.03490