• Volume 24, Issue 6

June 2019,   pages  611-179

• Editorial

• Science Smiles

• The Man Who Knew Humanity: Luigi Luca Cavalli-Sforza (1922-2018)

• I Am the Light Beneath Your Eyes... A Short History of the Discovery and Properties of Fluorescence

This article forays into the history of fluorescence and discussesits occurrences along with the applications that haveevolved over the years.

• Composition of Binary Quadratic Forms: Understanding the Approaches of Gauss, Dirichlet and Bhargava

In 2004, Bhargava introduced a new way to understand thecomposition law of integral binary quadratic forms throughwhat he calls the ‘cubes of integers’. The goal of this articleis to introduce the reader to Bhargava’s cubes and this newcomposition law, as well as to relate it to the composition lawas it is known classically. We will present a historical expositionof the subject, from Gauss to Bhargava, and see howthe different formulations of the composition laws are equivalent.

• Feynman Diagrams: A Toy Example

We examine the moments of the Gaussian integral and relatethem to Feynman diagrams. We next introduce a quarticterm and show how it leads to a seemingly paradoxical result.The article is addressed to the novice, but we believe that itmay also serve as an opening lecture on the topic of Feynmandiagrams.

• Foucault’s Pendulum Exploration Using MAPLE18

In this article, we develop the traditional differential equation forFoucault’s pendulum from physical situation and solve it fromstandard form. The sublimation of boundary condition eliminatesthe constants and choice of the local parameters (latitude, pendulumspecifications) offers an equation that can be used for a plotfollowed by animation using MAPLE. The fundamental conceptualcomponents involved in preparing differential equation viz;(i) rotating coordinate system, (ii) rotation of the plane of oscillationand its dependence on the latitude, (iii) effective gravity withlatitude, etc., are discussed in detail. The accurate calculationsoffer quantities up to the sixth decimal point which are used forplotting and animation. This study offers a hands-on experience.Present article offers a know-how to devise a Foucault’s pendulumjust by plugging in the latitude of reader’s choice. Studentscan develop a miniature working model/project of the pendulum.

• Win or Lose? Listen to a Martingale!

The author did not learn probability theory properly whenit was taught to him as an undergraduate. However, nowthat he has to teach, it has become a fascination. The problemstated below was given to second year students of theIISER BS-MS programme as an examination question; theyanswered it in interesting ways. An earlier article in Resonance

• Functional Group Analysis in Undergraduate Laboratory: Safe, Cost-effective and Micro-scale Alternatives

Functional group analysis is an integral part of the universitycurriculumsince it forms the basis of identification of unknownorganic compounds. Traditional methods of analyzingfunctional groups employ an excess of reagents and generateenormous waste material, disposal of which is of prime concern.The present article focuses on alternative methods forthe detection of some of the functional groups such as carboxylicacid, alcohol, phenol, carbonyl, ester, and carbohydrateswith considerably less volume (few drops) of conventionalreagents on a grooved tile. The procedures adopted arein accordance with the principles of green chemistry – consumptionof less solvents and minimizing the waste. Hence,the mentioned experiments afford an efficient, safe and economicalapproach to functional group investigation. In addition,a comparison of this micro-scale green approach withconventional methods is presented. The success of the tests isvalid for general organic compounds, and hence can be satisfactorilyemployed in undergraduate laboratories for analysisof functional groups.

• Who Are We Indians?

• Face to Face with Professor P Balaram

• The great human expansion

• Birds in the Backyard