July 5: Newton’s Principia, William Rankine, George de Hevesy, Dolly the sheep

Newton’s Principia published

Isaac Newton’s Philosophiæ Naturalis Principia Mathematica (from Latin: Mathematical Principles of Natural Philosophy) was published by the Royal Society on 5 July 1687.

Isaac newton philosophiæ naturalis principia mathematica title page
Credit: The Royal Society of London (Public domain)

The Principia, expounding Newton’s laws of motion and his law of universal gravitation, forms the foundation of classical mechanics and is one of the most important works in the history of science. It was described by Albert Einstein as “perhaps the greatest intellectual stride that has ever been granted to any man to make”. In 2016 a first edition of the Principia went for $US3.7 million at auction.


William Rankine

William John Macquorn Rankine was a Scottish engineer and physicist born on this day in 1820.

William rankine
Credit: Thomas Annan (Public domain)

He was one of the founders of the science of thermodynamics, particularly in the area of steam-engine theory. With the railways always front of mind, Rankine developed methods to solve the force distribution in frame structures and worked on fatigue in the metal of railway axles.

In 1841, while surveying on the Dublin and Drogheda Railway, he invented a technique, later known as Rankine’s method, for laying out circular curves. This technique, one of the first to be based on the use of the theodolite, was more accurate and faster to use than any other then available.

George de Hevesy 

George de Hevesy was a Hungarian-Danish-Swedish chemist specialising in inorganic chemistry and nuclear chemistry. He was awarded the 1943 Nobel Prize in Chemistry “for his work on the use of isotopes as tracers in the study of chemical processes.” This has been important for work on the metabolism of animals.

George de hevesy
Credit: unknown (Public domain)

de Hevesy was awarded the 1943 Nobel Prize in Chemistry “for his work on the use of isotopes as tracers in the study of chemical processes.”

Together with Dutch physicist Dirk Coster, de Hevesy also discovered the element hafnium in 1923.

He died on this day in 1966 aged 80.

Dolly the sheep

On 5 July 1996, Dolly, a female Finnish Dorset sheep, became the first mammal cloned from an adult somatic cell.

Dolly the sheep
Credit: Toni Barros, Creative Commons

The cloning took place at the Roslin Institute in Scotland, using the process of nuclear transfer from a cell taken from a mammary gland. Her birth proved that a cloned organism could be produced from a mature cell taken from a specific body part.

The egg cell reprogrammed the donated DNA contained within its new nucleus, and Dolly was the result. The manipulation was done using microscopic needles – a method pioneered in human fertility treatments – and the embryo was implanted into the womb of a third, surrogate sheep.

The key legacy of Dolly has been in advances into stem cell research. The process allowed researchers to understand how ordinary cells could be reprogrammed to induced pluripotent stem cells, which can be grown into any tissue.

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