BONDI HERMANN

Bondi an atheist Jewish Anglo – Austrian, was an eminent mathematical physicist, astronomer and cosmologist. He is probably best known as one of the chief architects of the steady state model of the universe, which he defended between 1948 and the mid – 1960s when it was disproved by observations. However, it would be unfair to identify his scientific work with the steady state theory.

From 1947 to the 1990s, Bondi contributed to a variety of problems in astrophysics and relativity theory and he was a central figure in the renaissance of general relativity, roughly the 1955-1975 period.

Bondi’s interest in and contributions to science were far from limited to theoretical physics and astronomy. More than able as an organizer and administrator, from the late 1960s, Bondi got increasingly involved in science policy, internationally as well as on the government level.

He was instrumental in the establishment of the European Space Research 1990, he was master of Churchill College, University of Cambridge. He served as secretary of the Royal Astronomical Society 1956 – 1964. Bondi received many honors for his contributions to science and science policy. He became a Fellow of the Royal Scoiety in 1959.

In 1947, Bondi married Christine Stockman, an astrophysics research student supervised by Fred Hoyle. Together with her husband, Christine Bondi published several papers on stellar structure. The couple had five children, two sons and three daughters. His wife and children survived him.

Bondi belonged to a nonreligious Jewish family that had moved from Germany to Vienna in 1884. He attended a Realgymnasium (secondary school focused on science, rather than traditional classical education), where he demonstrated a remarkable talent for mathematics and physics.

The Steady State theory of the Universe

To the extent that there existed a standard cosmology in the late 1940s, it was the evolutionary universe based on Einstein’s field equations of 1917, either in the big bang version or the ever-expanding but no-bang lemaitre-Eddington version. In their discussions of 1946 and 1947. Hoyle, Gold, and Bondi agreed that an evolutionary universe governed by general relativity was unsatisfactory in whatever version.

They concluded that an unchanging yet expanding universe was preferable, and for this reason they postulated continual creation of matter to occur throughout space at such a rate that it compensated for the expansion and left the average density of matter constant (the idea came from Gold). In early 1948, Gold and Bondi and, independently, Hoyle worked out their two formulations of the steady state universe.

Works in relativity and astrophysics

Bondi’s work in astrophysics started in the mid 1940s when he, inspired by Hoyle, got interested in how a star in a gas cloud accretes interstellar matter by way of gravitational attraction. His work in this area, in part done in collaboration with Hoyle and Lyttleton, continued for several years and led to concepts named after him, such as Bondi accretion and Bondi mass. In 1952, he collaborated with Edwin Salpeter in  a study of thermonuclear reactions in stars, his only work in nuclear astrophysics.

Among the books that Bondi wrote during his long scientific career, Cosmology (1952) was an excellent introduction to and survey of the contemporary state of cosmology, including relativistic cosmology as well as steady state theory and Edward A Milne’s kinematic relativity. Reprinted in 1960, it was for a long time the standard textbook on the subject.

In the early 1960s, he wrote two popular books, The Universe at Large (1961) and Relativity and Common Sense (1964), and in 1968, he published Assumption and Myth in Physical and Common Sense (1964), and in 1968, he published Assumption and Myth in Physical Science. His autobiography, focusing more on his administrative and political work than on his scientific contributions, appeared in 1990 under the title Science.

Statesman of Science.

In spite of his scientific work being highly theoretical. Bondi was far from an ivory – tower scientist. As early as 1953, while deeply engaged in the cosmological controversy, he wrote a report on the floods that devastated parts of eastern England that year. It was largely as a result of Bondi’s report that the London Barrier was a build a few years later. After he left King’s College, London, he began a parallel career in public service, first from 1967 to 1971 as director general for the European Space Research Organization.

ESRO, the predecessor of ESA, the European Space Agency. From 1971 to 1984, Bondi worked as a high – level public servant, first as chief scientific advisor for the Ministry of Defense and subsequently as chief scientist in the Department of Energy, where he laid the groundwork for Britain’s first long-term energy policy. During the 1980 – 1984 period he served as chairman and chief executive of the Natural Environment Research Council. Remarkably, during these busy years in public service, he continued doing work in pure physics.

Bondi’s views on science and society were in line with the ideals of the Enlightenment  era. He strongly believed in the social value of science and the social responsibility of scientists, including educational reforms based on science. He was active in the scientific education of the public and published several articles in the journal Physics Education. Philosophically, he was a follower of Popper, whom he greatly admired and in 1992 characterized as “the philosopher of science.” When Popper died in 1994, Bondi wrote his obituary in Nature.

An Atheist

Since his childhood in Vienna Bondi had been an atheist, developing from an early age a view on religion that associated it with repression and intolerance. This view, which he shared with Hoyle, never left him. On several occasions he spoke out on behalf of freethinking so-called, and became early on active in British atheist or “humanist” circles. From 1982 to 1999, he was president of the British Humanist Association, and he also served as president of the Rationalist Press Association of United Kingdom.

Compiled by : nietzsche


HUMAN EVOLUTION IS STILL GOING ON

Humans are still evolving even though modern housing and sanitation, medical science and a rich and varied diet appear to have largely insulated much of the population from the life-or-death struggle of natural selection, a study has found.

Falling death rates and a decrease in family size in the western world since the start of the industrial revolution 250 years ago have not prevented Darwinian evolution from exerting its effect on the human gene pool, scientists said. They analysed church records of births, marriages and deaths for 10,000 inhabitants of seven parishes in Finland since the beginning of the 18th Century and concluded that evolution is still occurring.

“We are still evolving. As long as some individuals have more children and others have fewer, there is potential for evolution to take place,” said Elisabeth Bolund of Uppsala University in Sweden.

“As long as there is variation in the population in terms of reproduction, there will be a difference in reproductive success, which means there’s something for natural selection to work on,” Bolund said.

Bolund and her colleagues at the universities of Sheffield and Turku in Finland found that cultural influences were not everything because there were small but significant effects caused by genetic inheritance.

They found that between four and 18 per cent of the variations between individuals in lifespan, family size and ages of first and last childbirth were influenced by genes.

“This is exciting because if genes affected differences between individuals in these traits, it means they could change in response to natural selection,” Bolund said. The study, published in the journal Evolution, showed that the genetic influence on timing of when someone is likely to begin a family and the overall size of family has actually risen in recent times compared to 18th and 19th Centuries.

This means that modern humans could still be evolving because people are responding to Darwinian natural selection on the genetic differences between individuals within the population, the scientists said.

Courtesy : The Times of India

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