Category: nonlinear dynamics

Optothermally induced active & chiral motion – a new paper

We have a new paper in Soft Matter

link to the paper (free to access, thanks to IISER Pune library)

We use optical illumination to generate thermal fields, creating non-reciprocal interactions between passive and active colloids. Active colloids absorb light and produce thermal gradients, driving thermo-osmotic forces that induce propulsion and chiral motion. Our Langevin simulations, backed by experimental observation, reveal how to control colloidal behavior. May have implications in light-driven chiral motion and nonlinear dynamics.

Super effort by Rahul, Ashutosh & Sneha from our group, who combined numerical simulations, analytical theory, with experimental observations.

The 2 anonymous reviewers made us think and work hard, and we thank them!

Also, the paper is part of the journal’s themed collection on “Colloidal interactions, dynamics and rheology”

Geo-fractal…somewhere over south India

I am always amazed to see fractal-like patterns….this one at a geographical scale…captured somewhere over south India..

I took the photo on my trip back to Pune from IIT Madras…

Thanks to IIT-M physics department for their invitation for colloquium…

Special thanks to Basudev Roy and Nirmala for hosting…. greatly enjoyed the discussion with many faculties and students..

In my talk, I mainly spoke on topics at the interface of statistical optics, Brownian motion and pattern formation..
Was delighted to see (and meet) Profs. Balki, Suresh Govindarajan Sunil Kumar Arnab Pal and many more in the audience.

The photo, retrospectively, captures the essence of the science discussed…

40. Tadashi’s practical application

Steven Strogatz is a well know applied mathematician from Cornell University, and has done some fascinating research on nonlinear dynamics (NLD). His lecture series on NLD and chaos is one of the best I have come across. Apart from writing columns in New York Times, he has also published some fantastic books on explaining mathematics, its relevance and impact on our daily lives, society and ecology.

Steve Strogatz has also been hosting The Joy of x podcast on the Quanta Magazine. In there, he interviews many contemporary mathematicians and scientists, who are actively involved in research and teaching. I found these informal interactions and exchange of ideas very interesting.

In one of the podcasts, Steven interviews Tadashi Tokieda, a mathematician who is interested in toys, and specifically the intriguing mathematics and physics of toys. In this interview, Tadashi describes his journey as an artist, philologist and as a professor who works on mathematics of toys.

Towards the end of the podcast (around 49 min in this audio), Tadashi describes how people (especially adults) ask him about the practical applications of studying toys, and how it can be beneficial to them. To this, his answer is something on the following lines :

When I show these toys to children, and explain to them the science and mathematics related to the toys, they feel very happy about it. What can be a better practical application that this !

Listening this just made my day…