When the German engineer, Heinrich Hertz, first transmitted and received controlled radio waves in 1886, he was reported to have commented that he did not envisage any practical use for his invention. He did not imagine that the world would never be the same again because of his invention. Nearly a century later, when Martin Cooper, an American engineer, invented the first mobile phone in 1973, he could hardly envisage that his bulky device would one day morph into a smartphone. Today a smartphone serves as an excellent camera, and can record and play video and music and store considerable personal and other data.

A vaccine myth

   There is unwarranted concern, articulated by some, that the use of mRNA vaccine (such as the one developed by Moderna) would upset one’s DNA. This is simply not true. An mRNA (messengerRNA) vaccine is carried into the body with instructions to make a virus that mimics the real one so that the body’s immune....