• Issue front cover thumbnailIssue back cover thumbnail

      Volume 25, Issue 7

      July 2020,   pages  887-1063

    • Editorial

      Rajendran C P

      More Details Abstract Fulltext PDF
    • Science Smiles

      More Details Abstract Fulltext PDF
    • Charles Lyell: The Man Who Unlocked the Earth's Sprawling History

      Rajendran C P

      More Details Abstract Fulltext PDF

      Charles Lyell, born in 1797, and Scottish by birth was one among the last generation of British polymaths who contributed much to the development of geology as a scientific discipline. He laid the foundation of modern geology and outlined his geological vision supported by global examples in a treatisecalled the Principles of Geology. This book that became popular with the scholars and the reading public inspired many contemporary researchers, most prominently Charles Darwin to think in new ways about the evolutionary pathways of the Earth and its constituents. Lyell, a heretical thinker in geology in his time was given due recognition by the establishment as he was knighted in 1848 and made a baronet. His lasting legacy lies in providing scientific underpinnings to the study of Earth's history, centered on the foundational principle of uniformitarianism that views all the geological features of the Earth's surface as a product formed in a gradualistic manner, mediated through deep time. And, that the geologic processes acted in the same manner and intensity in the past as they do in the present, summarized in a maxim: ``the present is the key to the past".

    • Apparent Weight of a Photon Box: Revisiting Mass-Energy Equivalence

      Sabarish V M

      More Details Abstract Fulltext PDF

      A photon has zero rest mass. However, it will be shown that when confined in a box, a photon can contribute to the mass of the system. Through this thought experiment, we will revisit the idea of mass-energy equivalence.

    • Approximations in Physics: A Pedagogic Perspective

      Mashood K K Arvind Kumar Anwesh Mazumdar

      More Details Abstract Fulltext PDF

      This article reviews and illustrates some simple aspects of ap-proximations in physics, which should be useful to students at the undergraduate level.

    • Combatting Climate Change Denial

      Abhinaba Das

      More Details Abstract Fulltext PDF

      Despite the scientific consensus on the issue of climate change, we are yet to marshal a social consensus. Sorting this apparent dissonance is a challenge. The topic of climate change has become entrapped in so-called economic and socio-political wars. Scientific miscommunication has thwarted efforts to effectively engage with the public on this issue. If we can actively seek out the reasons that motivate denial, and try to understand the underlying structure that engenders misin-formation, then perhaps we can find ways to address them. There is an acute urgency to better strategize climate change communication. The scientific community should recognize the need for new pathways of effective communication. In summary, we need to adapt. The faster we affect a change, the better chances we have at avoiding a catastrophe. Time is of the essence!

    • Physics of Conductive Conjugated Polymers: A Primer

      Hemanth K Bilihalli

      More Details Abstract Fulltext PDF

      In this expository article, the importance of electron-phonon coupling to charge transport in conductive polymers—as a result of a vanishing $dynamic$ bandgap—is outlined. The author's interpretation of physical models for this process: models are presented for predicting the conduction modes activated during charge transport.

    • Storage of Electrical Energy: Batteries and Supercapacitors

      Trilochan Bagarti Arun M Jayannavar

      More Details Abstract Fulltext PDF

      In this article, we will focus on the development of electri-cal energy storage systems, their working principle, and their fascinating history. Since the early days of electricity, people have tried various methods to store electricity. One of the earliest devices was the Leyden jar which is a simple electrostatic capacitor that could store less than a micro Joule of energy. The battery has been the most popular in storing electricity as it has higher energy density. In this article, we will describe and compare the working of various kinds of batteries and capacitors. We will review the recent technological breakthrough in electrical energy storage devices.

    • Vanillin: One Drug, Many Cures

      Oshin Gulsia

      More Details Abstract Fulltext PDF

      Chemically, `vanillin' belongs to the class of benzaldehydes, its structural formula being 4-hydroxy-3-methoxybenzaldehyde. It is one of the key constituents of vanilla pods, primarily from the species of $Vanilla planifolia$. However, since it is un-economical to grow vanilla on a large scale, it is prepared synthetically to meet the diverse demands of growing food and pharmaceutical industries. Recently, vanillin has warranted the attention of the scientific community because of its versatility and utility. From the medicine cabinet to your savory platter, its ubiquitous presence is what makes one wonder, “is this the next-gen supermolecule we had been waiting for?"

    • The Silver Fox Domestication Experiment: How to Tame a Fox and Build a Dog

      Lee Alan Dugatkin

      More Details Abstract Fulltext PDF

      For the last sixty years, a team of Russian geneticists have been running one of the most important biology experiments of the 20th, and now 21st, century. Each year they have selected the calmest foxes—foxes that are most prosocial to humans—to mimic the early stages of domestication. After providing an overview of how the silver fox domestication study began, I will discuss: 1) work on social cognition in the domesticated silver foxes, 2) work on the molecular genetics of domestication in the silver foxes, including work on changes in allele frequencies and changes in gene expression patterns, 3) a new hypothesis for how selection on tameness leads to the domestication syndrome via changes in the number and migration patterns of neural crest cells very early on in development, and 4) how the silver fox domestication experiment has led to new hypotheses about self-domestication in primates, including humans.

    • Calkin-Wilf Tree

      K Siddharth Choudary A Satyanarayana Reddy

      More Details Abstract Fulltext PDF

      In this article, we prove various properties of the Calkin-Wilf tree. We also see how the Minkowski question mark function acts on the Calkin-Wilf tree and its diagonals.

    • How to Design Experiments in Animal Behaviour: 13. Harmless Snakes Mimic Venomous Snakes to Avoid Predation, But Why Don’t They Do Their Best?

      Raghavendra Gadagkar

      More Details Abstract Fulltext PDF

      There are many examples of perfectly palatable animals re-sembling related unpalatable species and, thereby, avoiding attack by predators who have learnt or evolved to avoid the unpalatable species. To facilitate recognition by predators, unpalatable species often have warning colourations, which is what is mimicked by the palatable species. This form of mimicry is known as Batesian mimicry. While there are many well-documented examples of Batesian mimicry among butterflies and other arthropods, there are somewhat fewer examples amongst vertebrates, and even these examples are of-ten debated. The coral snake mimicry system in North America, where non-venomous kingsnakes and milksnakes mimic venomous coral snakes, is one of the best-studied vertebrate examples of Batesian mimicry. However, it has also been debated for over a century. In this article, I will describe three experiments using plasticine replicas of the mimics designed to understand the effectiveness of their mimicry. These field experiments were performed in the natural habitats of the mimics, the models and their predators, by David W. Pfennig and his students and collaborators, in the states of Florida, North Carolina, South Carolina, and Arizona in the USA. The simple, clever, and low-cost experiments have significantly strengthened the hypothesis of Batesian mimicry in this system. They have also provided an unexpected new understanding of how mimics might evolve from cryptic ancestors through a process of gradual natural selection.

    • Euler's Summation Method

      Kapil Hari Paranjape

      More Details Abstract Fulltext PDF

      What is the meaning of an infinite sum? This question has fascinated mathematicians for a long time; from Zeno's para-dox and the series of Madhava and Leibnitz to more contem-porary times. Euler, Fourier and others played insouciantly with infinite series until Abel, Cauchy and Weierstrass gave us a safe and dependable way to ``do the right thing" with in-finite series. Like other such instances in Mathematics, this did not shut the door on the older playground. Rather it pro-vided a framework to play in it with greater clarity.The author learned a lot about this the topic through the bookon $Divergent Series$ by G. H. Hardy, while teaching a course on ``Computational Methods" at IISER Mohali.

    • Twenty Years with $Resonance$

      V Rajaraman

      More Details Abstract Fulltext PDF
    • Small-clawed Otter

      More Details Abstract Fulltext PDF
  • Resonance – Journal of Science Education | News

© 2017-2019 Indian Academy of Sciences, Bengaluru.