Category Scientist & Invensions

WHEN WAS HELIUM FIRST LIQUEFIED?

On July 10, 1908, helium was liquefied for the first time ever. It was achieved by Dutch physicist Heike Kamerlingh Onnes, who won the Nobel Prize in Physics in 1913 for his low temperature work that led to the production of liquid helium.

Helium is a chemical element that has the lowest boiling and melting points among all the elements. The first in the noble gas group in the periodic table, helium is a colourless, odourless, non-toxic, inert gas in nature. Liquid helium was produced for the first time only in 1908, thanks to the work done by Dutch physicist Heike Kamerlingh Onnes,

Born in Groningen, The Netherlands in 1853, Kamerlingh Onnes father was the owner of a  brickworks and his mother was the daughter of an architect. He received additional teaching in Greek and Latin after spending his time in a secondary school without classical languages in his native town.

Displays his talents early

From 1871-73, Kamerlingh Onnes went to Heidelberg University as a student of German physicists Robert Bunsen and Gustav Kirchhoff. At the age of 18, his talents in the scientific field were apparent as he was awarded a Gold Medal for a competition sponsored by the Natural Sciences Faculty at the University of Utrecht and followed it up with a Silver Medal in a similar event at the University of Groningen the next year.

He was awarded his doctorate by the University of Groningen in 1879 with a remarkable thesis ‘Nieuwe bewijzen voor de aswenteling der aarde’ (New proofs of the rotation of the Earth). After teaching at the Polytechnic School in Delft until 1882, he was appointed to the Physics Chair at the University of Leiden, where he served as a professor until 1923.

Coldest spot on Earth

Inspired by the theories and works of his compatriots Johannes van der Waals and Hendrik Lorentz Kamerlingh Onnes reorganised the Physical Laboratory at Leiden and built up the Cryogenic Laboratory that now bears his name in order to suit his own programme. This meant that Leiden soon established itself as the low-temperature research centre of the world, with some going to the extent of saying that the coldest spot on Earth was situated at Leiden

He spent over a decade perfecting cryogenic experimental techniques, while also studying metals and fluids at low temperatures, Having succeeded in building an improved hydrogen liquefaction machine by 1906, his efforts adminated in the production of liquid helium on July 10, 1908.

On that wet and windy day, Kamerlingh Onnes woke before dawn and headed to his laboratory in the centre of the town, where technicians were already hard at work. Having already increased the stock of liquid air to 75 litres the previous day, they went about the first task of liquefying hydrogen. By 1.30pm, they had produced the 20 litres of liquid hydrogen necessary to launch the attack on helium and stored it in Dewar flasks.

Based on theory, Kamerlingh Onnes knew how much hydrogen they needed and the amount of time the helium experiment would take. It was time to start cooling the helium at 2.30pm, and in just another half an hour, the temperature had already fallen to 93 Kelvin (-180 degree Celsius).

Iterative technique

Kamerlingh Onnes employed the same iterative technique that had allowed their laboratory to produce liquid hydrogen at the increased rate of 4 litres per hour in 1906. This meant that the helium gas that was pre-cooled by liquid hydrogen and liquid air was allowed to expand through a porous plug, thereby cooling to even lower temperatures. This is then recirculated back to the other side of the plug where the expanded helium is further cooled by expanding through the plug again.

By 6.30pm, the temperatures were lower than that of liquid hydrogen and eventually reached 6 Kelvin (-267 degree Celsius). Down to the last flask of liquid hydrogen, Kamerlingh Onnes attached it to the apparatus and the team was wondering if they were destined for failure as the helium had already circulated 20 times with nothing to show for it.

Small teacup of helium

The temperature stabilised at 4 Kelvin (-269 degree Celsius) by 7.30pm when a colleague who came to see how the experiment was going remarked that the thermometer appeared to be standing in a bath of liquid. On closer inspection, Kamerlingh Onnes was able to make out the liquid surface of liquid helium! The experiment had produced just a small teacup of liquid helium, about 60ml to be precise.

Kamerlingh Onnes also discovered and coined the term superconductivity in 1911, demonstrating that the resistance of certain electrical conductors totally disappeared suddenly at a temperature near absolute zero (-273 degree Celsius). The low-temperature studies that resulted in the liquefaction of helium in 1908 helped him win the Nobel Prize in Physics in 1913, 13 years before his death at Leiden in 1926.

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WHO WAS CHARLES DARWIN?

Charles Darwin was an English scientist who proposed that evolution happened through ‘natural selection’. According to Darwin, the organisms that lived on are those which had the best traits to survive their environment, and passed on those traits to following generations.

Charles Robert Darwin, (12 February 1809 – 19 April 1882) was an English naturalist, geologist and biologist, best known for his contributions to the science of evolution.

The Theory of Evolution by natural selection was first formulated in Charles Darwin’s book “On the Origin of Species” published in 1859. In his book, Darwin describes how organisms evolve over generations through the inheritance of physical or behavioral traits, as National Geographic explains. The theory starts with the premise that within a population, there is variation in traits, such as beak shape in one of the Galapagos finches Darwin studied.

According to the theory, individuals with traits that enable them to adapt to their environments will help them survive and have more offspring, which will inherit those traits. Individuals with less adaptive traits will less frequently survive to pass them on. Over time, the traits that enable species to survive and reproduce will become more frequent in the population and the population will change, or evolve, according to BioMed Central. Through natural selection, Darwin suggested, genetically diverse species could arise from a common ancestor.

Credit: Live Science

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What did Peter Henlein invent?

Peter Henlein, a locksmith from Nuremburg, Germany, is considered as the inventor of the modern day watch. He was one of the first craftsmen to make small ornamental Taschenuhren, portable clocks worn as pendants or attached to clothing, which were regarded as the first watches. The Pomander Watch is one of the world’s earliest known portable timepieces and is thought to have been made by Henlein in 1505.

Peter Henlein was born in 1485, and very little is known about his early life. It is most probable that he became apprentice as a repair man and locksmith. His appearance in history books start on September 7, 1504 after he was involved in a brawl in which his friend and fellow locksmith George Glaser was killed. Peter immediately went to the local Franciscan monastery where he found safety. Four years later he returned to the Nuremberg where he became one of the most famous locksmiths, who was especially praised for his ability to create small spring-powered brass clock which were then very rare and expensive. With such popularity, it was not strange that local and distant nobility contacted him on regular basis, demanding ever more beautiful and smaller clock designs. As far historical records are concerned, Peter’s first clock was made in 1510, and by 1541 he was well known for his craft and has been tasked on building not only small clocks but also big tower clock for Lichtenau castle.

Even though his spring designs were not particular accurate (they could lose several hours during one day’s work) or even portable (with around 3 inches in size, they were more suited to be worn as a pendant than in pocket), clocks that were made by Peter Henlein soon became sensation in Europe scientific circles and later on by general European population.

Today, Peter Henlein is regarded as a father of modern clocks even though he was not the first locksmith that made small clock designs or was responsible for the discovery of key clock component –mainspring. He died in 1547 knowing that his invention will live forever.

Credit : History of watch

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Who was Marie Curie?

Marie Curie (November 7, 1867-July 4, 1934) was a French Polish physicist and chemist, famous for her pioneering research on radioactivity and the discovery of polonium and radium.  She was the first woman to win a Nobel Prize, the only woman to win in two fields, and the only person to win in multiple sciences. She was also the first female professor at the University of Paris (La Sorbonne), and in 1995 became the first woman to be entombed on her own merits in the Pantheon in Paris]

In 1867, Maria Sklodowska was born in Warsaw, Poland. She was a bright and curious child who did well in school. At the time, the University of Warsaw refused students who were women. But that didn’t stop young Maria! Instead, she learned in secret. She went to informal classes held in ever-changing locations, called the “Floating University.”

In 1891, the woman the world would come to know as Marie Curie made her way to Paris. There, she enrolled at the Sorbonne, a university that didn’t discriminate. Over the next few years, she completed advanced degrees in physics and mathematics. She also met French physicist Pierre Curie. The two married in 1895.

Marie and Pierre worked closely over the next decade. Marie’s biggest discoveries came from studying uranium rays. She believed these rays came from the element’s atomic structure. Curie created the term “radioactivity” to name the phenomena she had observed. Her findings led to the field of atomic physics.

Together, the Curies studied the mineral pitchblende. Through their experiments, they discovered a new radioactive element. Marie named it polonium in honor of her native Poland. The two later also discovered the element radium.

In 1903, Marie and Pierre Curie were jointly awarded the Nobel Prize in physics. Marie was the first woman to receive a Nobel Prize. That same year, she also became the first woman to earn a Ph.D. from a French university. After Pierre’s death in 1906, Marie took over his teaching job at the Sorbonne. She was the first female professor at the institution.

In 1911, Curie became the first person—of any gender—to win a second Nobel Prize. This time, she was recognized for her work in the field of chemistry. Curie’s scientific reputation was known around the world. In fact, she was invited to attend the Solvay Congress in Physics. There, she joined other famous scientists of the day, including Albert Einstein.

After World War I began in 1914, Marie used her scientific knowledge to support France’s efforts in the war. She helped to develop the use of portable X-ray machines in the field. In fact, the medical vehicles that carried these machines became known as “Little Curies.”

Marie Curie never knew the toll her work would take on her health. She died in France in 1934 from advanced leukemia related to prolonged exposure to radiation. Today, Curie’s notebooks are still too radioactive to be safely handled. They are stored in lead-lined boxes in France.

Marie Curie left a great legacy of accomplishment and scientific curiosity. Her daughter, Irène Joliot-Curie, followed in her footsteps. Joliot-Curie received the Nobel Prize in chemistry in 1935, one year after her mother’s death.

In 1995, Marie and Pierre Curie’s remains were placed in the Panthéon in Paris. This is known as the final resting place of France’s most distinguished citizens. Marie Curie was the first woman to be interred there on her own merit.

Credit : Wonder Opolis

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When and how the fist steam engines were built?

The invention of the steam engine during the eighteenth century had a fundamental effect on man’s progress. Some earlier forms of this machine had appeared during the previous century. The most famous were those of papin whose work provided a great stimulus for research into steam.

Papin built a boat with steam operated paddles, but builders of sailing boats were hostile to this new craft and papin could not make much progress with it. However, he had proved what a powerful force steam could be in locomotion. Thomas newcomen built a steam engine in 1705. It began to be used for pumping water out of mines about six years later, and by 1725 the engine was widely used in collieries. It continued in use for many years although it was not very efficient and worked slowly. It was James watt (1736-1819) who examined all the previous efforts and perfected them into a steam engine that worked fast and efficiently. For this engine watt invented a steam condenser that was separate from the cylinder which worked the piston.

The steam engine had a sensational success and proved itself enormously useful, especially in factories where it replaced machines that had previously been worked by water or animal power. It was eventually used as a locomotive to pull wagons.

 

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By whom the electric light bulb was born and how?

Thomas Edison had discovered in his experiments that there were certain bodies through which electric power flowed more easily. He called these good conductors and other bodies that resisted the flow of electric power he called bad conductors. When electricity tried to travel along a bad conductor the latter would resist so much that it glowed until became white-hot.

A carbon filament, for example, gave out a good deal of light; but the light did not last very long because the carbon would soon burn itself up as it was in contact with the oxygen in the air.

Edison then carried out an experiment inside a glass bulb from which he had removed all the air. This time the light of the glowing filament lasted much longer and the fist electric light bulb was born.

Carbon filaments have now been replaced by tungsten wire as its high melting point, low rate of evaporation and low electrical consumption make it most suitable for use in light bulbs. A further improvement has been the introduction of an inert gas in to the bulb. This was at first nitrogen but is now a mixture of 88 per cent argon and 12 per cent nitrogen.

 

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