Sunday, August 28, 2005

The Elegant Universe

The title of the post as it suggests is all about trying to answer the fundamental question concerning the creation of universe and certain other things for which even the most advanced of sciences have no answers. But after seeing the program "The Elegant Universe" on Discovery Channel I feel we are very close to perhaps understanding the most intriguing question: How come the Universe came into existence.

From the child hood one thing which has been haunting me till date is this universe. How come this universe came into existence and why does life exist only on earth and no other planet was so fortunate to have life on its surface. Of course I have not been able to do any justice to my inquisitiveness over a period of time because of prior engagements but one program on Discovery has actually given a new thought and a new insight to my thought process.

I usually do not watch discovery. Very rarely once in a while when I get bored out of watching each and every channel of the umpteen numbers which our cable operator provides, I do surf Discovery. But this time while I was watching KBC in the break the promotional campaign for this series appeared and I decided come what may I am going to watch this series. I do not know how many of us have watched it but perhaps it was one of the fascinating programs with absolutely superb effects and picturisation which made all the difference. It was aired on Discovery from 2200 hours to 2300 hours on 26th, 27th and 28th of August. The title of the series was "The Elegant Universe".

Now I will go back about 10 years down the line way back in my 10th standard in school. That was the time when I was first introduced to the topic of Atomic Structure. Atomic Structure deals as the title suggests with the structure of atom, composition of matter, electrons, protons, discoveries like mass of electron etc. It starts with the famous Sir Ernest Rutherford Alpha Scattering Experiment and ends with the conflict between Quantum Theory and General Theory of Relativity.

General Theory of Relativity as all of us was proposed by the genius Albert Einstein who is said to have used his brain to the maximum possible extent among all the human beings on earth. The extent to which he used his brain was about 11 %! The General Theory of Relativity gives an explanation as to how come the strong force which is Gravitational force between earth and the sun comes into existence. It postulates that the sun creates around it a very calm and quiet surface something like a mesh and and the gravitational pull which exists within this mesh actually makes earth revolve around the sun. But this theory does not say anything about the other three fundamental forces which exist in nature. The Weak force, the electromagnetic force and the Nuclear force. Enter Quantum theory.

Quantum Theory considers the electron having a dual character. It says that the electron possesses both wave as well as particle nature. This was very well supported by the Heisenberg's Uncertainty Principle, The Debroglie Law, The Pauli's Exclusion Principle and the most famous of all the Max Planck's Quantum Equation. So according to the quantum theory it’s impossible to distinguish between wave and particle. Quantum theory was able to explain very well the weak force, the electro magnetic force and the nuclear force but it could not explain the very fundamental force of nature – The Gravitational Force. There lies the major problem.

The General theory of relativity can explain the fundamental force of gravity but cannot explain the forces which exist at the atomic level whereas the quantum theory can explain the forces at the atomic and sub atomic level but cannot explain the gravitational pull. It is said that Einstein spent last 30 years of his life in trying to figure out how can general theory of relativity explain the sub atomic forces.

So in short we can say that, Relativistic quantum field theory has worked very well to describe the observed behaviors and properties of elementary particles. But the theory itself only works well when gravity is so weak that it can be neglected. Particle theory only works when we pretend gravity doesn't exist.
General theory of relativity has yielded a wealth of insight into the Universe, the orbits of planets, the evolution of stars and galaxies, the Big Bang and recently observed black holes and gravitational lenses. However, the theory itself only works when we pretend that the Universe is purely classical and that quantum mechanics is not needed in our description of Nature.

String theory is believed to close this gap. Now what string theory is all about is one of the major questions which the program answered in a very nice manner. We talk about atoms. Inside atoms we have electrons revolving around the nucleus which consists of protons and neutrons. Beyond this we have not really gone. But we know numerous tiny particles like gravitons, bosons etc which exist in the atom. Now if we look inside electrons, the string theory proposes that there are strings like structures which are the most fundamental elementary particles which constitute the matter.

This is an example which was shown in the Discovery channel and which clearly explains the principle of string theory. Think of a guitar string that has been tuned by stretching the string under tension across the guitar. Depending on how the string is plucked and how much tension is in the string, different musical notes will be created by the string. These musical notes could be said to be excitation modes of that guitar string under tension.
In a similar manner, in string theory, the elementary particles we observe in particle accelerators could be thought of as the "musical notes" or excitation modes of elementary strings. In string theory, as in guitar playing, the string must be stretched under tension in order to become excited. However, the strings in string theory are floating in space-time; they aren't tied down to a guitar. Nonetheless, they have tension. The string tension in string theory is denoted by the quantity 1/ (2 p a'), where a' is pronounced "alpha prime” and is equal to the square of the string length scale.

If we imagine the size of atom as the size of this Solar System, then perhaps the size of the string would be a Tree on our planet!!!!!!!!!!!!! This makes impossible for the physicists to see it in reality. Post to be continued.
The title of the post as it suggests is all about trying to answer the fundamental question concerning the creation of universe and certain other things for which even the most advanced of sciences have no answers. But after seeing the program "The Elegant Universe" on Discovery Channel I feel we are very close to perhaps understanding the most intriguing question: How come the Universe came into existence.

From the child hood one thing which has been haunting me till date is this universe. How come this universe came into existence and why does life exist only on earth and no other planet was so fortunate to have life on its surface. Of course I have not been able to do any justice to my inquisitiveness over a period of time because of prior engagements but one program on Discovery has actually given a new thought and a new insight to my thought process.

I usually do not watch discovery. Very rarely once in a while when I get bored out of watching each and every channel of the umpteen numbers which our cable operator provides, I do surf Discovery. But this time while I was watching KBC in the break the promotional campaign for this series appeared and I decided come what may I am going to watch this series. I do not know how many of us have watched it but perhaps it was one of the fascinating programs with absolutely superb effects and picturisation which made all the difference. It was aired on Discovery from 2200 hours to 2300 hours on 26th, 27th and 28th of August. The title of the series was "The Elegant Universe".

Now I will go back about 10 years down the line way back in my 10th standard in school. That was the time when I was first introduced to the topic of Atomic Structure. Atomic Structure deals as the title suggests with the structure of atom, composition of matter, electrons, protons, discoveries like mass of electron etc. It starts with the famous Sir Ernest Rutherford Alpha Scattering Experiment and ends with the conflict between Quantum Theory and General Theory of Relativity.

General Theory of Relativity as all of us was proposed by the genius Albert Einstein who is said to have used his brain to the maximum possible extent among all the human beings on earth. The extent to which he used his brain was about 11 %! The General Theory of Relativity gives an explanation as to how come the strong force which is Gravitational force between earth and the sun comes into existence. It postulates that the sun creates around it a very calm and quiet surface something like a mesh and and the gravitational pull which exists within this mesh actually makes earth revolve around the sun. But this theory does not say anything about the other three fundamental forces which exist in nature. The Weak force, the electromagnetic force and the Nuclear force. Enter Quantum theory.

Quantum Theory considers the electron having a dual character. It says that the electron possesses both wave as well as particle nature. This was very well supported by the Heisenberg's Uncertainty Principle, The Debroglie Law, The Pauli's Exclusion Principle and the most famous of all the Max Planck's Quantum Equation. So according to the quantum theory it’s impossible to distinguish between wave and particle. Quantum theory was able to explain very well the weak force, the electro magnetic force and the nuclear force but it could not explain the very fundamental force of nature – The Gravitational Force. There lies the major problem.

The General theory of relativity can explain the fundamental force of gravity but cannot explain the forces which exist at the atomic level whereas the quantum theory can explain the forces at the atomic and sub atomic level but cannot explain the gravitational pull. It is said that Einstein spent last 30 years of his life in trying to figure out how can general theory of relativity explain the sub atomic forces.

So in short we can say that, Relativistic quantum field theory has worked very well to describe the observed behaviors and properties of elementary particles. But the theory itself only works well when gravity is so weak that it can be neglected. Particle theory only works when we pretend gravity doesn't exist.
General theory of relativity has yielded a wealth of insight into the Universe, the orbits of planets, the evolution of stars and galaxies, the Big Bang and recently observed black holes and gravitational lenses. However, the theory itself only works when we pretend that the Universe is purely classical and that quantum mechanics is not needed in our description of Nature.

String theory is believed to close this gap. Now what string theory is all about is one of the major questions which the program answered in a very nice manner. We talk about atoms. Inside atoms we have electrons revolving around the nucleus which consists of protons and neutrons. Beyond this we have not really gone. But we know numerous tiny particles like gravitons, bosons etc which exist in the atom. Now if we look inside electrons, the string theory proposes that there are strings like structures which are the most fundamental elementary particles which constitute the matter.

This is an example which was shown in the Discovery channel and which clearly explains the principle of string theory. Think of a guitar string that has been tuned by stretching the string under tension across the guitar. Depending on how the string is plucked and how much tension is in the string, different musical notes will be created by the string. These musical notes could be said to be excitation modes of that guitar string under tension.
In a similar manner, in string theory, the elementary particles we observe in particle accelerators could be thought of as the "musical notes" or excitation modes of elementary strings. In string theory, as in guitar playing, the string must be stretched under tension in order to become excited. However, the strings in string theory are floating in space-time; they aren't tied down to a guitar. Nonetheless, they have tension. The string tension in string theory is denoted by the quantity 1/ (2 p a'), where a' is pronounced "alpha prime” and is equal to the square of the string length scale.

If we imagine the size of atom as the size of this Solar System, then perhaps the size of the string would be a Tree on our planet!!!!!!!!!!!!! This makes impossible for the physicists to see it in reality. Post to be continued.

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