Category Scientist & Invensions

Har Gobind Khorana

Har Gobind Khorana (9 January 1922 – 9 November 2011), was an Indian-American biochemist who shared the 1968 Nobel Prize for Physiology or Medicine with Marshall W. Nirenberg and Robert W. Holley for research that showed how the order of nucleotides in nucleic acids, which carry the genetic code of the cell, control the cell’s synthesis of proteins. Khorana and Nirenberg were also awarded the Louisa Gross Horwitz Prize from Columbia University in the same year.

Khorana was born in Raipur, British India (today Tehsil Kabirwala, Punjab, Pakistan) and later moved to become an Indian citizen after the partition of 1947. 

Fields 

  • Molecular biology

Institutions

  • MIT (1970–2007)
  • University of Wisconsin, Madison (1960–70)
  • University of British Columbia (1952–60)
  • University of Cambridge (1950–52)
  • Swiss Federal Institute of Technology, Zurich (1948–49)

Notable awards

  • Nobel Prize in Medicine (1968)
  • Gairdner Foundation International Award (1980)
  • Louisa Gross Horwitz Prize
  • ForMemRS (1978)
  • Albert Lasker Award for Basic Medical Research
  • Padma Vibhushan
  • Willard Gibbs Award

 To read more about Har Gobind Khorana  Click https://en.wikipedia.org/wiki/Har_Gobind_Khorana

Why is it said that Thales of Miletus played a major role in the history of electricity?

Thales of Miletus is an important figure in the history of electricity. It is said that he discovered static electricity around 600 BC.

Static electricity was first observed when amber, rubbed with animal fur, got charged, and attracted light objects such as dry leaves, or bits of straw. Even though other people may have noticed this before, it was Thales who first recorded his findings. But Thales has never identified it as static electricity. At that time magnetism was also confused with static electricity.

Later, it was proved that the force that works between amber and animal fur is nothing but static electricity. Thales’ role was remarkable because he was the first to record his findings regarding static electricity. Thales was born in the city of Miletus around the mid 620 BC. He was a philosopher, and astronomer and the one who conducted the earliest studies in electricity. Thales’ findings were recorded but none of them survived to modern times. 

Why is it said that Stephen Gray played a major role in the history of electricity?

             Stephen Gray was an English astronomer who made significant contributions to science. These include his experiments with conduction, insulation, and electrostatic induction.

           One of his experiments was done using a glass tube. Gray observed that when the glass was rubbed with a dry hand or dry paper, it obtained electric charge. As a result, it attracted a feather to the glass, as well as the cork with which it was closed. The cork was in fact, used to keep the dust out when not in use.

          From the experiment, Gray concluded that the ‘attractive virtue’ passed from the tube to the cork.

         To clear his doubts, Gray proceeded with a similar experiment. This time, he attached an ivory ball to a piece of wood, and inserted the other end of the wood into the cork. Once it was done, he confirmed that attraction and repulsion passed to the ball, that too stronger than that on the cork.

         Gray observed that substances like silk do not conduct electricity. And that Earth was somehow responsible for conducting electric charge away from the body.

         For his electrical experiments, Stephen Gray received the first Copley Medal instituted by the Royal Society, in 1731. However most of his works went unacknowledged and he died as a poor man.

 

Why was the introduction of the fuel cell a milestone?

        Fuel cells are devices that generate electric current through chemical reactions. To put it better, a fuel cell uses chemical energy of hydrogen (or another fuel) to produce electricity in a clean and efficient manner. Its only products are electricity, heat, and water, and hence it is clean.

            There are a wide range of applications for which fuel cells can be used. This includes transportation, emergency power back up, material handling etc. compared to other technologies, fuel cells have many advantages. They are more efficient, and have lower emissions. That is, they do not emit dangerous substances like carbon dioxide or air pollutants, as their only products are water and heat. Yet another advantage is that fuel cells operate in a silent manner.

            The history of fuel cells began with the Welsh physicist Sir William Grove. In 1839, he demonstrated the first crude fuel cells. Although many people have tried to work on the concept of converting chemical energy into electric power, most of them were unsuccessful due to lack of resources.

            The first successful fuel cell was developed by the British engineer Francis Bacon in 1932, using hydrogen, oxygen, an alkaline electrolyte and nickel electrodes.

 

Why is it said that the invention of the transformer was a turning point?

            A transformer is an electrical device that works on electromagnetic induction to transfer electrical energy between two or more circuits. It is used in a wide range of power appliances to increase, or decrease voltage.

            We see transformers in almost every city. They are used to convert high-voltage electricity from incoming power lines, to lower-voltages.

         

Continue reading “Why is it said that the invention of the transformer was a turning point?”

Why is the introduction of the transistor a major turning point in history?

            To put it simply, a transistor is an electronic component that can do two different jobs. It can act as an amplifier or a switch, depending on the need.

            As an amplifier, a transistor does the job of boosting current. That is, it takes in a tiny input current at one end and produces a bigger output current at the other end.

            It was at the Bell Laboratories in New Jersey that transistor was demonstrated for the first time. That happened on December 23rd, 1947. William Shockley, John Bardeen and Walter Brattain are the three persons credited with its invention.

            In 1956, they were awarded the Nobel Prize in Physics “for their researches on semiconductors and their discovery of the transistor effect”.