Maquina Lectora

Notes of a curious mind

Tag: science

The Gene: An Intimate History

The science of genetics was born in mid-19th century with the discovery of the basic mechanisms of heredity in the pea garden of an Austrian monk. Although, humans have acted as agents of genetic selection, for thousands of years, by breeding offspring with desired traits, it was Mendel’s discovery of the existence of dominant and recessive traits in pea plants, that set into motion the modern field of genetics.

 Siddhartha Mukherjee, a cancer physician and researcher has written a comprehensive, engaging and insightful history of the gene as well as  an analysis of the ethical dilemmas, the challenges and the medical benefits of the genomic science in the 21st century.

The Gene is also a personal history. Entwined with the Gene’s history is Mukherjee’s own Bengali family history of mental illness, which erupts from shared genetic inheritances and define the lives of past, present and future family members.

The book covers 150 years of history, from Gregor Mendel, the monk who discovered the basic principles of heredity, working in his pea garden in Brno, through to Darwin and to his half- cousin, Francis Galton, one of the first proponents of the ‘eugenics movement’ to Oswald Avery’s pinpointing of DNA as the carrier of genetic information, to James Watson and Francis Crick and to the recent years where the sheer ingenuity of the scientists demystified the genome.

The Gene is a book of scientific progress, the benefits of direct genetic modification can be enormous, “to carve out a life of happiness and achievement without undue suffering”, but the possibilities of a  serious, irreversible mistake are also immense. Genetic modification has the potential to alter the course of human evolution to something completely unexpected, even harmful. Are we really ready to take this step?

The Invention of Nature: Alexander von Humboldt’s New World

‘With Knowledge comes thought and with thought comes power’

Alexander Von Humboldt

This a wonderful book about one of the most greatest polymaths and inter-disciplinarians of all time. Alexander von Humboldt is a forgotten hero of science, an exceptional man, a restless explorer, “a man who sought to see and understand everything”, a passionate scientist who could speak to the soul of people.

Ralph Waldo Emerson described him as ‘one of those wonders of the world, like Aristotle, like Julius Caesar… who appear from time to time, as if to show us the possibilities of the human mind’, and Simon Bolivar said that Humboldt ‘has done more good for America than all her conquerors’. His name lingers everywhere, there is the Humboldt current that flows north along the west coast of South America from the southern tip of Chile to northern Peru, there is the Humboldt penguin, the Humboldt’s lily, Lilium humboldtii, a perennial herb that is native to California. There are mountains, parks, and rivers named after him.

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The optical illusion of the spinning ballet dancer

You may be familiar with this silhouette image of ballet dancer that is standing on her left leg and spinning to the right. The image that was created by the Japanese Web designer Nobuyuki Kayahara, it is not a brain test. Instead, it is simply an optical illusion called a reversible, or ambiguous, image. Images like this one have been long studied by scientists to learn more about how vision works.

What you actually see is a deforming shadow – a black silhouette – but your brain makes sense of it instantly to see a young woman in full 3-D spinning on her vertical axis in one direction, clockwise or counterclockwise. But keep looking continuously at the picture a bit longer, and you will find out that her movement is ambiguous; indeed, you will probably see the dancer change – for just couple of seconds – direction.

Our brains draw inferences from the world. In terms of perception an example is that everyone has a blind spot on their retina, which means that there is a place that corresponds to that spot where you actually can’t see anything. But you don’t see that blind spot because your brain fills it in. So, that’s basically a hard wired kind of inference.

Optical illusions take advantage of this. When it comes to optical illusions it’s clear that we can’t change what we see, so these are hard wired inferences that our perceptual system makes.

Now, scientists say that what we perceive as a trick of the mind, or an optical illusion, is the need of human brain for symmetry. The conceptual importance of symmetry which has been explored by the Gestalt psychologists since early in the 20th century has been extended by Vilayanur S. Ramachandran and Diane Rogers- Ramachandran in the processing of motion.

The Gestaltists, emphasised that it is the relation of all elements in a scene, rather than the individual elements by themselves that influence our final perception, and they identified “laws” of perceptual organisation for determining, what is seen as figure, display or motion perception. The coupling of motion and direction is based partially on the object’s synchronicity in time (and speed). They tried -unsuccessfully – to explain visual illusions in terms of electromagnetic force fields on the surface of the brain. They never found these fields.

Thus, as the ballerina is spinning, each half of the display is synchronised to one direction, as expected, but across the axis of symmetry, both halves are synchronised to the opposite direction of movement. In other worlds, the two fields appeared to spin either toward or away from each other. Brain’s need of symmetry overrides our tendency to see synchronised and identical motion throughout the visual field.

Have fun!!

Sources and further reading: Scientific American April/May 2009, New York Times

The Lunar Men: Five Friends Whose Curiosity Changed the World

What was happening in England, during the Georgian period, was dramatic. In two generations, roughly from 1730 to 1800, the country changed from a mainly agricultural nation into an emerging industrial force. The same time, new political ideas and revolutions, transformed the social and political status quo and forged the British Empire, affecting the lives of millions and opening the way to the industrialised age.

Within this political and social unrest, a diverse group of men, in Birmingham, are pursuing, as a hobby, scientific knowledge. Each of them has its own strong character and temperament. All are passionate, venturous, and progressive. They found a society, the Lunar Society of  Birmingham. Their meetings are held every month, on a date near the full moon, starting with dinner at two and following with discussions and experiments until late evening. The discussed topics are many and diverse, from literature and philosophy to chemistry and engineering. These are the Lunar men, the men that by using science and technology, transform the way of doing things and lead the way towards the industrial revolution.

The ingenious engineer James Watt, who improved the Newcomen’s design and created with his partner Matthew Boulton, a market for a new, improved steam engine. The same Matthew Boulton, the “toymaker” who also established the Soho manufactory north of Birmingham and when asked by the George III what he was doing for living, he replied: “I am engaged, your majesty, in the production of a commodity which is the desire of Kings”. When the King what was that, Boulton said “Power, your Majesty”.

The potter Josiah Wedgwood, the fist to industrialise pottery manufacturing; he experimented with a wide variety of pottery techniques and used artists to garnish his vases. His interests were many and diverse, and it was in his house, the Etruria Hall, where photography was first invented.

Joseph Priestley, a theologian and natural philosopher, a teacher and political theorist. His work is vast, it is expanded to scientific inventions, most considerable his invention of soda water. He wrote about electricity and photosynthesis but become famous with the discovery of oxygen – the “dephlogisticated air” as he dubbed it. He was a minister within the Unitarian church and his theses about political and civil liberties caused strong opposition. His house and books were burnt by the mobs during the riots against intellectualism; his exile to America was the start of the end for the Lunar Society.

Perhaps the most interesting figure in the book is Erasmus Darwin, grandfather of Charles, the founder of the theory of Evolution. He was a doctor by profession, but his interests were many and diverse. Gardening, agriculture, chemistry and engineering, poetry and philosophy, even cosmology, were some of his intellectual passions and pursuits. He also had a vague idea about evolution; he increasingly felt that every living organism had descended from one common microscopic organism, a single filament. Darwin would construct the first coherent theory of evolution, of competition and survival. He added to his family crest the motto E conchis omnia “everything from shells”, an action that outraged his clerical friends. Canon Seward sputtered that Darwin was a follower of Epicurus, who claimed that the world was created by accident and not God. Fearing for his practice, Darwin caved in and painted out his blasphemous Latin. (pages 152-153)

 After her excellent biography of Hogarth, Jenny Uglow gives us a nice and detailed history of the Lunar men. Their personal adventures and family stories and tragedies are intertwined beautifully with their intellectual passions and scientific pursuits. She describes sufficiently the revolutions of this period that changed the political and social systems, such as the French and the American Revolutions as well as, the revolutionary advances in science, such as these of Linnaeus and Lavoisier.

She has researched her subject widely and indeed, the reference list is detailed and extensive. It is a useful tool for anyone who wants to examine and study more extensively the period and the lives of these extraordinary men. The book is supported by beautiful illustrations and portraits of these passionate men and their inventions. It is a very well written book that demonstrates that even in difficult periods there are determined and passionate people that can lead the way and really change the world.

The End Of Science: Facing The Limits Of Knowledge In The Twilight Of The Scientific Age by John Horgan

How can science be approaching a culmination when we haven’t invented spaceships that travel at warp speed yet?

John Horgan is pursuing some provocative questions.

  • Has science been entered an era of diminishing returns?
  • Is physics moving towards absolute truth?
  • Would be able physicists to prove a final theory in the same way that mathematicians prove theorems?

His thesis is that we are coming to an era where all the fundamental scientific theories have been discovered and science as we know today is coming altogether in an end. Horgan considers fundamental, theories such as Darwin’s natural selection, Einstein’s general relativity and quantum electrodynamics. That means theories that can apply, to the best of our knowledge, throughout the entire universe at all times since its birth.

In order to prove his thesis, Horgan has interviewed interesting scientists and philosophers from the entire scientific and social-philosophical landscape. Roger Penrose, Noam Chomsky, Thomas Kuhn, Paul Feyerabend, Freeman Dyson, Stephen Jay Gould, Carl Popper, David Bohm, Edward Wilson, John Wheeler, Lynn Margulis, Andrei Linde, Daniel Dennet and many

Horgan is not the first or the last person to argue over the-end-of-science-era. At the end of the nineteen century, physicists also thought they knew everything. But only two decades later Einstein and other physicists discovered relativity theory and quantum mechanics. These theories transformed physics and opened up vast new vistas for modern physics and other branches of science.

The end-of-science argument and timing (millennium and link with Fucuyama’s End of History) have caused wide-range and “confusing” reactions and responses form science critics, scientists themselves, and even from Clinton’s Science Advisor who publicly repudiated Horgan’s argument. We can safely say that it is a discussion/debate that still goes on.

The value of the book is not in the message and if we are/ or not denouncing it. Horgan is a science journalist with an education in literature and his background makes the difference in the way he writes about science. With his prose style, he manages to fill gaps that other science writers fail to do, and make scientific writing an interesting adventure. He has the gift not only to make scientific theories understandable for the non-scientists readers but also to reveal beautifully his interviewee’s personalities. These interviews, the presentation of scientists as human beings, are the most interesting insight for me in the book.

Reading the book I had the feeling that Horgan tried to construct a psychological and ideological profile of each one person and it was fascinating to “discover” the eccentricities of the scientists who invented?/developed? some of the most interesting scientific and philosophical theories in the 20th century.

As for the end of science, I am optimistic. The best in science are still to come. But my view is possibly distorted by what Horgan call in his book the Star Trek factor.

The Callendar Effect by James Rodger Flemming

Guy Callendar was an English engineer, who in the 1930s estimated that man had added about 150,000 million tonnes of CO2 during the past century and the planet had undergone warming on the order of one degree Fahrenheit (0.5 degrees Celsius).

CallendarIn his first published paper, in February 1938, titled “The artificial Production of Carbon Dioxide and its Influence on Temperature”, Callendar showed that there is “a quantitative relation between the natural movement of this gas and the amounts produced by the combustion of fossil fuel”, and argued “that the activities of man could have any influence upon phenomena of so vast a scale… that is not only possible, but is actually occurring at the present time.”

He also referred to the oceans as a “giant regulator of carbon dioxide” which had exceeded the limits of the natural carbon cycle and would not be able to absorb all or most of its excess. But as Arrhenius before him, Callendar appealed the idea of atmospheric warming. Concluding his article he speculated that the combustion of fossil fuels “is likely to prove beneficial to mankind in several ways, besides the provision of heat and power…..  Small increases of mean temperature would be important at the northern margin of cultivation, and the growth of favourably situated plants is directly proportional to the carbon dioxide pressure. In any case the return of the deadly glaciers should be delayed indefinitely.”

Callendar published his discoveries in a series of papers, but they did not raise any interest from the scientific community. Only, later, in 1957, just before the beginning of the International Geophysical Year (IGY) – the first global scale experiment that recognised the potential of satellite technology in studying the Earth -, Hans Seuss and Roger Revelle, although they believed “that it was absolutely impossible to have had a sufficient increase in the CO2 amount in this century”, they referred to the “Callendar effect,” defining it as “climatic change brought about by anthropogenic increases in the concentration of atmospheric carbon dioxide, primarily through the processes of combustion.” Suggestive of Callendar’s brilliance was the fact that years later, scientists forecasted that some countries (Russia, Canada, New Zealand) will gain form climate change through an improved capacity for growing food, and used his prognosis that to promote and gain political support for their research projects to study climate change.

James Rodger Fleming is a professor at Colby College and a leading historian of atmospheric sciences and weather prediction. He has written a really fascinated book.

 

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