Much of modern physics is founded on Quantum Physics and Einstein's Theories of Relativity - this is evidenced by a large number of Nobel Prizes related to the development and testing of the predictions of Special and General Relativity.
I give a brief description of the important ones: More detailed information is available in the website of the Nobel Prize Organisation.
http://nobelprize.org/educational/physics/relativity
I shall put a list of Nobel Prizes for work in Quatum Physics to coincide with my talks on Quantum Mechanics sometime in 2011. Watch this space.
1921 - Albert Einstein
Ironically, while relativity has led to so many Nobel prizes, it only played a minor role in Einstein's own. The Nobel committee's brief prize announcement refers to Einstein's "services to Theoretical Physics" with explicit mention given only to his finding the law of the photoelectric effect.
1933 - Paul Dirac
Dirac's prize was the first of many given for work on the connection between special relativity and quantum theory.
Dirac was the pioneer of relativistic quantum mechanics and formulated the Dirac equation, the first equation for the quantum behaviour of relativistic matter particles. He discovered a fundamental relativistic quantum phenomenon: for every species of relativistic particle, there must be a kind of mirror image, a species of corresponding antiparticles. In a world in which electrons exist, which carry negative electric charge, Dirac's equation demands the existence of anti-electrons, particles with the same mass as electrons, but a positive electric charge.
1936 - Carl D. Anderson
What, at first sight, appeared to be a stumbling stone for Dirac's theory - where were those anti-electrons he postulated? - later turned into a triumph. Among the particles of cosmic rays, a highly energetic particle radiation reaching the earth's surface from space, Carl Anderson discovered traces of anti-electrons. Diracs anti-particles, with the same mass as electrons but the opposite electric charge, really do exist! Anti-electrons are now called positrons.
1949 - Hideki Yukawa
The force that bonds protons and neutrons together to form atomic nuclei has a strictly limited range: of the order of a trillionth of a metre. Yukawa found an explanation for the short-range nuclear force that is directly linked to the fact that the carrier particle of nuclear force has a non-zero (rest) mass. He derived this directly from a relativistic quantum equation for massive particles.
1951 - John Cockcroft and Ernest T. S. Walton
Cockcroft and Walton bombarded atomic nuclei of the element Lithium with fast protons, thus creating helium nuclei in the first controlled transmutation of one species of nucleus to another. Summing up the energies before and after the transmutation, they tested directly the equivalence of mass and energy postulated by Einstein: the helium nuclei that result have a slightly lower mass than that of proton and lithium nucleus combined, and this difference in mass leads to a kinetic energy of the resulting nuclei that is higher than expected by non-relativistic physics, exactly following Einstein's prediction.
1955 - Willis Eugene Lamb and Polykarp Kusch
Lamb and Kusch performed precision measurements, establishing the reality of two effects: called the Lamb shift and the electron's magnetic properties that Dirac's equation could not correctly predict. These measurements contributed to the eventual development of relativistic quantum feld theories: of quantum electrodynamics, the relativistic quantum theory of the electromagnetic field.
1959 - Emilio Segrè and Owen Chamberlain
In relativistic quantum theories, for every species of particle, there is a species of antiparticles. Segrè and Chamberlain received their prize for the discovery of anti-protons, the antiparticles of protons.
1963 - Eugene Wigner
The relativity principle states that observers that are in motion relative to each other are on equal footing; the physical laws are exactly the same for each of them. In physics, such equality is called a symmetry. Whether or not a physical theory, be it a model of electromagnetic phenomena, fluid dynamics or a theory of heat, is consistent with the relativity principle can be examined in a general framework that analyzes the theory's symmetries. Wigner was the first to apply this framework to quantum theory, and laid the foundation of modern relativistic quantum feld theories.
1965 - Shin-Itiro Tomonaga, Julian Schwinger, Richard P. Feynman
In quantum field theories, not only the matter particles, but also the forces acting between them follow quantum laws. The distinction between matter and forces becomes blurred: The action of a force is represented by the exchange of particles - the carrier particles.
Tomonaga, Schwinger and Feynman formulated a theory of relativistic quantum forces for the simplest case, that of the electromagnetic force, creating what is known as quantum electrodynamics.
This was the starting point leading to the formulation of the more general quantum field theories of the standard model of particle physics.
1974 - Antony Hewish
The discovery that won Hewish his prize, although not a consequence of relativity, is nonetheless an important step for relativistic astrophysics.
Together with his graduate student Jocelyn Bell-Burnell, Hewish discovered the first pulsar, opening up the field of observational astronomy of neutron stars.
1978 - Arno Penzias and Robert Wilson
Penzias and Wilson won their Nobel prize for the first detection of the cosmic background radiation, an afterglow from the early, hot days of the universe. With their discovery, they confirmed a prediction made by Ralph Alpher and Robert Herman in 1948 on the basis of the relativistic big bang models.
1983 - Subramanyan Chandrasekhar and William A. Fowler
The Chandrasekhar mass is the maximal mass for which the inner pressure of the White Dwarf can resist further collaps. For remnants with higher mass the collapse continues, forming a neutron star or even a black hole.
Fowler won the prize for his research on the origin of the chemical elements in the universe. Part of that work concerned another prediction of the big bang models of relativistic cosmology, namely that of the formation of light elements in the early universe.
1993 - Russell A. Hulse and Joseph H. Taylor
Hulse and Taylor discovered the first binary pulsar: a binary in which a pulsar and a companion neutron star orbit each other. Their observations of this binary pulsar, called PSR1913+16, led to the first indirect detection of gravitational waves and provided some sensitive tests of the General theory of Relativity.
2002 - Riccardo Giacconi
Giacconi won the prize for his pioneering work in X-ray astronomy, in part for the first detection of objects tha are now widely believed to be black holes.
2006 - John C. Mather and George F. Smoot
With the COBE satellite, Mather and Smoot made precise measurements of the black body nature of the cosmic background radiation, confirming an important prediction of the big bang models. The tiny fluctuations observed in the background microwave radiation are the first seeds for the large scale structure in the Universe.
Saturday, 4 December 2010
Friday, 26 November 2010
Einstein's Credo
Einstein was not only a brilliant scientist but also a great thinker. He had profound views about religon, politics and society in general.
EINSTEIN'S CREDO
http://www.einstein-website.de/z_biography/credo.html
In August 1932 Einstein wrote "My Credo" in Caputh (Einstein’s summer house in Potsdam, Germany) and read it for a recording by order and to the benefit of the German League of Human Rights.
My Credo
"It is a special blessing to belong among those who can and may devote their best energies to the contemplation and exploration of objective and timeless things. How happy and grateful I am for having been granted this blessing, which bestows upon one a large measure of independence from one's personal fate and from the attitude of one's contemporaries. Yet this independence must not inure us to the awareness of the duties that constantly bind us to the past, present and future of humankind at large. Our situation on this earth seems strange. Every one of us appears here, involuntarily and uninvited, for a short stay, without knowing the why and the wherefore. In our daily lives we feel only that man is here for the sake of others, for those whom we love and for many other beings whose fate is connected with our own.
I am often troubled by the thought that my life is based to such a large extent on the work of my fellow human beings, and I am aware of my great indebtedness to them.
I do not believe in free will. Schopenhauer's words: 'Man can do what he wants, but he cannot will what he wills,' accompany me in all situations throughout my life and reconcile me with the actions of others, even if they are rather painful to me. This awareness of the lack of free will keeps me from taking myself and my fellow men too seriously as acting and deciding individuals, and from losing my temper.
I have never coveted affluence and luxury and even despise them a good deal. My passion for social justice has often brought me into conflict with people, as has my aversion to any obligation and dependence I did not regard as absolutely necessary.
I have a high regard for the individual and an insuperable distaste for violence and fanaticism. All these motives have made me a passionate pacifist and antimilitarist. I am against any chauvinism, even in the guise of mere patriotism.
Privileges based on position and property have always seemed to me unjust and pernicious, as does any exaggerated personality cult. I am an adherent of the ideal of democracy, although I know well the weaknesses of the democratic form of government. Social equality and economic protection of the individual have always seemed to me the important communal aims of the state.
Although I am a typical loner in daily life, my consciousness of belonging to the invisible community of those who strive for truth, beauty, and justice keeps me from feeling isolated.
The most beautiful and deepest experience a man can have is the sense of the mysterious. It is the underlying principle of religion as well as of all serious endeavor in art and science. He who never had this experience seems to me, if not dead, then at least blind. To sense that behind anything that can be experienced there is a something that our minds cannot grasp, whose beauty and sublimity reaches us only indirectly: this is religiousness. In this sense I am religious. To me it suffices to wonder at these secrets and to attempt humbly to grasp with my mind a mere image of the lofty structure of all there is."
Courtesy of the Albert Einstein Archives, Hebrew University of Jerusalem, Israel.
EINSTEIN'S CREDO
http://www.einstein-website.de/z_biography/credo.html
In August 1932 Einstein wrote "My Credo" in Caputh (Einstein’s summer house in Potsdam, Germany) and read it for a recording by order and to the benefit of the German League of Human Rights.
My Credo
"It is a special blessing to belong among those who can and may devote their best energies to the contemplation and exploration of objective and timeless things. How happy and grateful I am for having been granted this blessing, which bestows upon one a large measure of independence from one's personal fate and from the attitude of one's contemporaries. Yet this independence must not inure us to the awareness of the duties that constantly bind us to the past, present and future of humankind at large. Our situation on this earth seems strange. Every one of us appears here, involuntarily and uninvited, for a short stay, without knowing the why and the wherefore. In our daily lives we feel only that man is here for the sake of others, for those whom we love and for many other beings whose fate is connected with our own.
I am often troubled by the thought that my life is based to such a large extent on the work of my fellow human beings, and I am aware of my great indebtedness to them.
I do not believe in free will. Schopenhauer's words: 'Man can do what he wants, but he cannot will what he wills,' accompany me in all situations throughout my life and reconcile me with the actions of others, even if they are rather painful to me. This awareness of the lack of free will keeps me from taking myself and my fellow men too seriously as acting and deciding individuals, and from losing my temper.
I have never coveted affluence and luxury and even despise them a good deal. My passion for social justice has often brought me into conflict with people, as has my aversion to any obligation and dependence I did not regard as absolutely necessary.
I have a high regard for the individual and an insuperable distaste for violence and fanaticism. All these motives have made me a passionate pacifist and antimilitarist. I am against any chauvinism, even in the guise of mere patriotism.
Privileges based on position and property have always seemed to me unjust and pernicious, as does any exaggerated personality cult. I am an adherent of the ideal of democracy, although I know well the weaknesses of the democratic form of government. Social equality and economic protection of the individual have always seemed to me the important communal aims of the state.
Although I am a typical loner in daily life, my consciousness of belonging to the invisible community of those who strive for truth, beauty, and justice keeps me from feeling isolated.
The most beautiful and deepest experience a man can have is the sense of the mysterious. It is the underlying principle of religion as well as of all serious endeavor in art and science. He who never had this experience seems to me, if not dead, then at least blind. To sense that behind anything that can be experienced there is a something that our minds cannot grasp, whose beauty and sublimity reaches us only indirectly: this is religiousness. In this sense I am religious. To me it suffices to wonder at these secrets and to attempt humbly to grasp with my mind a mere image of the lofty structure of all there is."
Courtesy of the Albert Einstein Archives, Hebrew University of Jerusalem, Israel.
Tuesday, 28 September 2010
Einstein and Relativity talks by Ravi Singhal start in October 2010
11 am to 12 noon on Saturdays
23, 30 October; 6, 13, 20 and 27 November 2010
James Watt Auditorium, E.K. Technology Park, G75 0QD
(Ample free parking on site)
Einstein is considered the greatest physicist of the 20th century. Einstein’s theory of relativity forever altered our understanding of the Universe. In this series of talks, we shall learn about Einstein’s life and how working in isolation he was able to resolve many of the serious difficulties that physics faced around 1900 AD and prepared the ground for the development of modern physics on which most industry is based.
Without using mathematics, we shall learn about the nature of gravity and make sense of some of the bizarre effects like the twin paradox, bending of light by stars that the theory of relativity predicts.
Speed of light plays a fundamental role in the theory of relativity. It is fascinating to learn how light appears to behave both as a wave and as a stream of particles.
Einstein is best remembered for his theory of relativity but it was his work regarding the nature of light that won him the Nobel Prize in 1921. Einstein resolved the longstanding question about the existence of atoms and molecules, and determined their sizes. Among other groundbreaking discoveries, theory of lasers was developed by Einstein more than 40 years before they were invented.
Talks are free to attend; e-mail ekTalks@yahoo.co.uk to confirm interest. Please check http://ektalks.blogspot.com for updates.
23, 30 October; 6, 13, 20 and 27 November 2010
James Watt Auditorium, E.K. Technology Park, G75 0QD
(Ample free parking on site)
Einstein is considered the greatest physicist of the 20th century. Einstein’s theory of relativity forever altered our understanding of the Universe. In this series of talks, we shall learn about Einstein’s life and how working in isolation he was able to resolve many of the serious difficulties that physics faced around 1900 AD and prepared the ground for the development of modern physics on which most industry is based.
Without using mathematics, we shall learn about the nature of gravity and make sense of some of the bizarre effects like the twin paradox, bending of light by stars that the theory of relativity predicts.
Speed of light plays a fundamental role in the theory of relativity. It is fascinating to learn how light appears to behave both as a wave and as a stream of particles.
Einstein is best remembered for his theory of relativity but it was his work regarding the nature of light that won him the Nobel Prize in 1921. Einstein resolved the longstanding question about the existence of atoms and molecules, and determined their sizes. Among other groundbreaking discoveries, theory of lasers was developed by Einstein more than 40 years before they were invented.
Talks are free to attend; e-mail ekTalks@yahoo.co.uk to confirm interest. Please check http://ektalks.blogspot.com for updates.
Friday, 29 January 2010
Why do we always see the same side of the Moon?...
This is due to the effect known as 'Gravitational Locking'. The Earth's gravitational field slowed the Moon's spin over time and now the Moon spins about its axis at a rate such that the time to rotate once on its axis is exactly equal to the time it takes to go round the Earth. The diagram (click on the figure to see it clearly) explains how this results in effectively the same side of the Moon facing the earth all the time.
Gravitational Locking is observed in the case of other planets as well whose satellite moons are locked in the same way as the Moon is locked to the Earth.
Sunday, 17 January 2010
Units in Cosmology...
In the study of cosmolgy, one encounters distances and masses which are extremely large compared with what we can easily comrehend.
It would be fair to say we can judge numbers that are a few hundred times a billion. We hear of companies worth 100 billion pounds etc. and appear to be comfortable with such statements, but a million billion will be difficult to understand.
Average distance of the Sun from the Earth is 150 million km and the diameter of the Milky Way galaxy is about a million million million km.
Mass of the Sun is 2000 billion billion billion kg and the numbers get bigger as we study the galaxies.
Therefore in astronomy we talk about a different set of unit.
Unit of mass is one solar mass = 2000 billion billion billion kg
Rest of the heavenly bodies are weighed relative to the Sun.
The situation about length is not so simple. There are three different units used depending on the context. These are:
1. The astronomical unit or AU:
1 AU ~ 150 million km = 149,597,871 km
An Astronomical Unit is approximately the mean distance between the Earth & the Sun.
AU is used when discussing distances of planets and other objects in the Solar System.
2. The light Year or Ly:
A Ly = about 10 million million km
A light year is the distance traveled by light in vacuum in one year.
It takes light 8.32 minutes to travel from the Sun to the Earth.
Ly is a big unit, it is about 63,000 astronomical units.
Diameter of the Milky Way galaxy is about 100,000 Ly
and the size of the observable Universe is measured in billions of Lys!
Light Year is the most commonly used unit when one is talking about galaxies and the Universe. It is also starightforward to understand.
3. Parsec or pc:
One parsec = 31 million million km or 210260 AU or 3.26 Ly
Parsec is based on the change of angle in a star's position when viewed from the Earth as it revolves round the Sun. We shall not use this unit in our discussions.
It would be fair to say we can judge numbers that are a few hundred times a billion. We hear of companies worth 100 billion pounds etc. and appear to be comfortable with such statements, but a million billion will be difficult to understand.
Average distance of the Sun from the Earth is 150 million km and the diameter of the Milky Way galaxy is about a million million million km.
Mass of the Sun is 2000 billion billion billion kg and the numbers get bigger as we study the galaxies.
Therefore in astronomy we talk about a different set of unit.
Unit of mass is one solar mass = 2000 billion billion billion kg
Rest of the heavenly bodies are weighed relative to the Sun.
The situation about length is not so simple. There are three different units used depending on the context. These are:
1. The astronomical unit or AU:
1 AU ~ 150 million km = 149,597,871 km
An Astronomical Unit is approximately the mean distance between the Earth & the Sun.
AU is used when discussing distances of planets and other objects in the Solar System.
2. The light Year or Ly:
A Ly = about 10 million million km
A light year is the distance traveled by light in vacuum in one year.
It takes light 8.32 minutes to travel from the Sun to the Earth.
Ly is a big unit, it is about 63,000 astronomical units.
Diameter of the Milky Way galaxy is about 100,000 Ly
and the size of the observable Universe is measured in billions of Lys!
Light Year is the most commonly used unit when one is talking about galaxies and the Universe. It is also starightforward to understand.
3. Parsec or pc:
One parsec = 31 million million km or 210260 AU or 3.26 Ly
Parsec is based on the change of angle in a star's position when viewed from the Earth as it revolves round the Sun. We shall not use this unit in our discussions.
Saturday, 16 January 2010
In Cosmology one deals with big numbers...
Writing numbers that are very big or very small ...
In science, you will encounter numbers that are very big or extremely small. These can be rather inconvenient to write out in the normal notation.
Powers of ten is a useful shorthand method of writing very large or very small numbers.
For example:
One thousand (1000) is 103 ; reads 'ten to the power 3' and is 1 followed by 3 zeros
One divided by 1000 is 0.001 or 10-3 ; reads 'ten to the power minus 3'
And that is it -
the positive power on ten tells us how many zeros are after 1.
negative powers of ten tell us the position of the 1 after the decimal point.
Distance of the Sun from the Earth is 150 million km or 150,000,000 km or 15 x 107 km.
Diameter of an atom is 0.0000000002 m or 2 x 10-10 m.
Multiplication and division of powers of ten numbers is very easy...
When you multiply two numbers powers add
When you divide two numebrs powers substract.
Example: Multiply 2 million by 4 million
Longhand: 2,000,000 x 4,000,000 = 8,000,000,000,000
Powers of ten: 2 x 106 x 4 x 106 = 8 x 1012
In science, you will encounter numbers that are very big or extremely small. These can be rather inconvenient to write out in the normal notation.
Powers of ten is a useful shorthand method of writing very large or very small numbers.
For example:
One thousand (1000) is 103 ; reads 'ten to the power 3' and is 1 followed by 3 zeros
One divided by 1000 is 0.001 or 10-3 ; reads 'ten to the power minus 3'
And that is it -
the positive power on ten tells us how many zeros are after 1.
negative powers of ten tell us the position of the 1 after the decimal point.
Distance of the Sun from the Earth is 150 million km or 150,000,000 km or 15 x 107 km.
Diameter of an atom is 0.0000000002 m or 2 x 10-10 m.
Multiplication and division of powers of ten numbers is very easy...
When you multiply two numbers powers add
When you divide two numebrs powers substract.
Example: Multiply 2 million by 4 million
Longhand: 2,000,000 x 4,000,000 = 8,000,000,000,000
Powers of ten: 2 x 106 x 4 x 106 = 8 x 1012
Exploring the Cosmos
Dr Ravi Singhal
Free Science Talks for Secondary Pupils & Adults
No Science Background Needed
No Science Background Needed
11 am to 12 noon on Saturdays
30 January; 6, 13, 20 and 27 February 2010
James Watt Auditorium, E.K. Technology Park, G75 0QD
(Ample free parking on site)
In Partnership with: Glasgow University and Scottish Enterprise, Lanarkshire
The size and complexity of the Universe is truly astounding. The Sun is but one of more than 200 billion stars in the Milky Way galaxy and the observable Universe could contain 100 billion galaxies. It takes light a hundred thousand years to travel across the Milky Way. The Universe
is populated with strange and bizarre objects like the white dwarfs, neutron stars, black holes; the true nature of which we are now beginning to understand. Prodigious amount of energy is produced by the heavenly bodies – the Sun produces a million times more energy in one second than we consume globally in a year!
Human curiosity has always wondered about the nature of the Universe we live in and attempted to rationalise what could be observed. Our understanding has enormously improved due to technological advances of the last century. However, many questions remain unanswered…..
Have you ever wondered how the distance, size, motion, temperature, composition of a star are measured? How are stars formed and how do they die? A frequently asked question is - How do they know? Exploring the Cosmos is a programme of ten talks, five of which are being announced at this stage. Come along to the talks to find out.
The fifth talk will discuss the search for extraterrestrial life.
Talks are free to attend; e-mail ekTalks@yahoo.co.uk to confirm interest. Please check http://ektalks.blogspot.com for updates.
The Science for All programme is a community education initiative. The talks are aimed at the general audience and no prior background in science is assumed. The talks are also suitable for secondary school pupils. The presentation promises to be visually attractive and highly informative.
is populated with strange and bizarre objects like the white dwarfs, neutron stars, black holes; the true nature of which we are now beginning to understand. Prodigious amount of energy is produced by the heavenly bodies – the Sun produces a million times more energy in one second than we consume globally in a year!
Human curiosity has always wondered about the nature of the Universe we live in and attempted to rationalise what could be observed. Our understanding has enormously improved due to technological advances of the last century. However, many questions remain unanswered…..
Have you ever wondered how the distance, size, motion, temperature, composition of a star are measured? How are stars formed and how do they die? A frequently asked question is - How do they know? Exploring the Cosmos is a programme of ten talks, five of which are being announced at this stage. Come along to the talks to find out.
The fifth talk will discuss the search for extraterrestrial life.
Talks are free to attend; e-mail ekTalks@yahoo.co.uk to confirm interest. Please check http://ektalks.blogspot.com for updates.
The Science for All programme is a community education initiative. The talks are aimed at the general audience and no prior background in science is assumed. The talks are also suitable for secondary school pupils. The presentation promises to be visually attractive and highly informative.
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