Arts, History, Philosophy, Science

Quantum Leaps: Robert Hooke…

1635 – 1703

Perhaps one of the most ‘underrated’ scientists of the seventeenth century, Robert Hooke, an Englishman, experimented and made advances in a wide range of scientific areas. Yet because of this breadth of coverage, he seldom developed any of his concepts to their fullest extent. This explains why he rarely gained credit for them. Indeed, it is arguable that his role as a provider and facilitator to others is his most important legacy.

Boyle’s Assistant – The most obvious example of his contribution to others was the work he undertook with Robert Boyle at Oxford, where they met in 1656. Boyle, as the aristocrat, was clearly the dominant partner in the relationship, in social terms at least. Hooke, as his assistant, acted on Boyle’s instructions, yet many of his creations were worthy inventions in their own right. The most obvious example is the air pump that he devised in 1659, the most efficient vacuum creator of its time. It enabled Boyle to go on to make many of his discoveries.

Provider of Ideas – Moreover, Boyle was responsible, albeit indirectly, for keeping Hooke in his position as jack of all sciences, master of none. The aristocrat had been influential in having Hooke elevated to the position of Curator of Experiments for the Royal Society in 1662. While the prestige of the role pleased Hooke, the job requirement of showing ‘three or four considerable experiments’ to the Society at each of its weekly meetings was almost certainly the factor that ensured Hooke would never have the time to develop any of his findings fully.

A Source of Ideas – Another scientist to whom Hooke felt he had provided source material was the Dutch physicist Christian Huygens. Huygens is credited with creating the influential wave theory of light, which he published in 1690. Yet as early as 1672, Hooke had explained his discovery of diffraction (the bending of light rays) by suggesting that light might behave in a wave-like fashion.

In 1662, Robert Hooke became the first Curator of Experiments to the Royal Society. In 1670 he discovered the ‘law of elasticity’.

In 1662, Robert Hooke became the first Curator of Experiments to the Royal Society. In 1670 he discovered the ‘law of elasticity’.

Isaac Newton vehemently argued against Hooke’s theory of light, beginning a bitter feud which would continue for the rest of Hooke’s life. Hooke also claimed to have discovered one of the most important theories credited to Newton, arguing that the latter had plagiarised his ideas from correspondence between the two during 1680. Certainly, Hooke’s letters suggested some notion of universal gravitation and hinted at an understanding of what later became Newton’s law of gravity. In spite of this, though, it is unquestionable that Newton’s mathematical calculations and endeavours in proving the law give him a much stronger claim.

Robert Hooke’s countless experiments did, however, result in some other discoveries solely credited to him. He was, for example, the first to describe the universal law that all matter will expand upon heating. He is credited with the law of elasticity, discovered in 1670. Also known as Hooke’s Law, it states that the strain, or change in size, placed upon a solid – when stretched – is directly proportional to the stress, or force, applied to it. Hooke was also the first person to use the word ‘cell’ in the scientific sense understood by us today, after observing the properties of cork under one of the powerful microscopes that he had developed. This word was used in his 1665 work Micrographia or Small Drawings, which also included many other advances such as Hooke’s theory of combustion, as well as other discoveries of the microscope. These included crystalline structure of snow, and studies of fossils which led to the proposition that they were the remains of once living creatures. He suggested that whole species had lived and died out long before man, centuries before Charles Darwin came to the same conclusion.

Hooke also made discoveries in astronomy, locating Jupiter’s Great Red Spot, and proposed that the huge planet rotated on its axis.

Further accreditations – Hooke’s inventions were greatly influential. He either invented or significantly improved the reflecting telescope, compound microscope, dial barometer, anemometer, hygrometer, balance spring (for use in watches), quadrant, universal joint and iris diaphragm (later used in cameras). He also showed impressive vision, foreseeing the development of the steam engine and the telegraph system.

Beyond this he was an accomplished architect who designed parts of London following the great fire of 1666.

Inset – In 1662, Robert Hooke became the first Curator of Experiments to the Royal Society. In 1670 he discovered the ‘law of elasticity’.

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Arts, Environment, Nature, Photography

MD Photography: Eurasian Eagle-Owl…

Eurasian eagle-owl, south-west Scotland. Photograph: © Mark Dowe 2013: all rights reserved

ABOUT THE EURASIAN EAGLE-OWL

Eagle Owls occupy a variety of habitats, from coniferous forests to warm deserts. Rocky landscapes are often favoured. Adequate food supply and nesting sites seem to be the most important prerequisites.

Usually most active at dawn and dusk, the Eurasian eagle-owl has a powerful, fast flight, which is somewhat reminiscent of that of a buzzard. Hunting occurs from an open perch or in flight, and the owl may also search rock crevices for roosting birds, take both adult and young birds from nests, or even plunge into water to capture fish. The diet mainly consists of mammals, up to the size of adult hares or even young deer, as well as birds up to the size of herons and buzzards, and occasionally amphibians, reptiles, fish and insects.

The Eurasian eagle-owl usually begins breeding from late winter. The nest might be located on a sheltered cliff ledge, in a cave or crevice, in the old nest of another species (such as storks or large birds of prey), or occasionally in a tree hole or on the ground. The species has always been considered to be monogamous, but some cases of bigamy have been recorded recently. A breeding pair may use the same nest site over several years. Between one and five eggs are laid, and are incubated by the female for 34 to 36 days, during which time the male brings food to the nest. The young owls first leave the nest at around five weeks, but cannot fly until about seven weeks old, and remain dependent on the adults for a further three to four months, not generally starting to disperse until approximately 170 days old. The Eurasian eagle-owl reaches sexually maturity at 1 year, and may live up to 21 years or more in the wild, or to an impressive 60 years in captivity.

The Eurasian eagle-owl has one of the largest ranges of any eagle-owl, being found across much of Europe, through the Middle East, Russia and Asia, and as far east as China, Korea and Japan. Although generally absent from Britain and Ireland, small numbers are now beginning to breed in Britain.

This owl usually inhabits natural rocky areas with cliffs and ravines, as well as quarries and buildings, patches of woodland or scattered trees. It also occurs in open forest, taiga, wooded steppe, semi-desert, and farmland with suitable rocky areas, and can be found at elevations of up to about 2,000 metres in Europe and 4,500 metres in Central Asia and the Himalayas. More recently, this species has started to colonise urban habitats and is now breeding in several towns in Europe.

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Arts, History, Philosophy, Science, Society

Quantum Leaps: ‘Galileo Galilei’…

1564-1642

In both his life and through the imprisonment which he was forced to endure in the years leading up to his death, Galileo more than any other figure personified the optimism and struggle of the scientific revolution. He was responsible for a series of discoveries which would change our understanding of the world, while struggling against a society dominated by religious dogma, bent on suppressing his radical ideas.

Galileo Galilei, was an Italian physicist, mathematician, astronomer, and philosopher who played a major role in the Scientific Revolution.

Galileo Galilei, was an Italian physicist, mathematician, astronomer, and philosopher who played a major role in the Scientific Revolution.

…A Mathematician

Although he was initially encouraged to study medicine, Galileo’s passion was mathematics, and it was his belief in this subject which underpinned all of his work. One of his most significant contributions was not least his application of mathematics to the science of mechanics, forging the modern approach to experimental and mathematical physics. He would take a problem, break it down into a series of simple parts, experiment on those parts, and then analyse the results until he could describe them in a series of mathematical expressions.

One of the areas in which Galileo had most success with this method was in explaining the rules of motion. In particular, the Italian rejected many of the Aristotelian explanations of physics which had largely endured to his day. One example was Aristotle’s view that heavy objects fall towards earth faster than light ones. Through repeated experiments rolling different weighted balls down a slope (and, legend has it, dropping them from the top of the leaning tower of Pisa!), he found that they actually fell at the same rate. This led to his uniform theory of acceleration for falling bodies, which contended that in a vacuum all objects would accelerate at exactly the same rate towards earth, later proved to be true. Galileo also contradicted Aristotle in another area of motion  by contending that a thrown stone had two forces acting upon it at the same time; one which we now know as ‘momentum’ pushing it horizontally, and another pushing downwards upon it, which we now know as ‘gravity’. Galileo’s work in these areas would prove vital to Isaac Newton’s later discoveries.

…The Pendulum

Galileo’s earliest work involved the study of the pendulum, inspired by observing a lamp swinging in Pisa cathedral. Following further experiments, he concluded that a pendulum would take the same time to swing back and forth regardless of the amplitude of the swing. This would prove vital in the development of the pendulum clock, which Galileo designed and was constructed after his death by his son.

…Through The Telescope

One of the inventions Galileo is often mistakenly credited with today is the invention of the telescope. This is not true; there had been numerous early prototypes that had been mostly developed in Holland before him, and a Dutch optician called Hans Lippershey applied for a patent on his version in 1608. Galileo did, however, develop his own far superior astronomical telescope from just a description of Lippershey’s invention, and quickly employed it to make numerous discoveries. A strong advocate of the Copernican view of planetary motion, Galileo’s initial findings published in the Sidereal Messenger (1610) provided the first real physical evidence to back up this interpretation. As well as discovering craters and mountains in the moon, sunspots and the lunar phases of Venus for the first time, he also noted faint, distant stars which supported the Copernican view of a much larger universe than Ptolemy had ever considered. More importantly, he discovered Jupiter had four moons which rotated around it, directly contradicting the still commonly held view, including that of the Church, that all celestial bodies orbited earth, ‘the centre of the universe.’

…Galileo and Copernicus

Galileo’s Dialogue Concerning the Two Chief World Systems – Ptolemaic and Copernican, in which the Ptolemaic view was ridiculed, attracted the attention of the Catholic Inquisition when it was published in 1632. Threatened with torture, Galileo renounced the Copernican System. His work was placed on the banned ‘Index’ by the Church where it remained until 1835, and he was subject to house arrest for life. But the tide of scientific revolution Galileo had helped instigate proved too powerful to hold back.

After being forced to renounce his heliocentric view of the Earth, Galileo said:

… Nevertheless, it turns!

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