A MAN BEYOND TIME

THE MAN BEYOND TIME

INTRODUCTION

One of the towering achievements of 20^th century physics is the theory of relativity by Albert Einstein. Newton’s theory of gravitation was soon accepted without question and it remained unquestioned until the beginning of this century. Then Albert Einstein shook the foundations of physics with the introduction of his theory of relativity. These theory transformed theoretical physics and astronomy during the 20^th century superseding a 200 years old theory of mechanics created primarily by Isaac Newton.

Let’s go through the mind- blowing theory proposed by Albert Einstein….

THE PIONEER OF MODERN PHYSICS

Albert Einstein was born on March 14, 1879 in Germany to Jewish parents. Einstein was not a very bright student. He even had problems with his speech. When he was 5 years old, Einstein saw a magnetic compass and marveled at the needle that kept moving with an invisible force. At age 12, he found a book on geometry which he read over and over again. He became fascinated by math and taught himself. During 1905, often called Einstein’s “miracle year”, he published four papers in the ANNALEN DER PHYSIK, each of which would alter the course of modern physics. In 1921, Einstein won the noble prize for physics for his explanation of the photoelectric effect, since his ideas on relativity were still considered questionable. And he died on April 18, 1955.

VICTORIOUS FAILURE

Michelson Morley experiment is the most brilliant failure in the all history of science. It was designed to detect the motion of earth through the lumineferuos ether. Ether was the invention of 19^th century’s physicists to explain how the light was transmitted through empty space between sun and earth. The legend about Michelson Morley experiment is that it’s just deeply rooted as the story about Isaac and the apple. Michelson and Morley did their experiment and proved there was no ether and so Einstein was forced to invent the theory of relativity in order to explain the net result.

SPECIAL THEORY OF RELATIVITY:

Special theory of relativity is generally accepted and experimentally well confirmed physical theory regarding the relationship between space and time. It is based on two postulates:

The laws of physics are invariant in all inertial systems. The speed of light in vacuum is the same for all observers, regardless of the motion of the light source. It was originally proposed by Albert Einstein in paper published 26 September 1905, titled “on the electrodynamics of moving bodies”. The inconsistency of  Newtonian mechanics with Maxwell’s equations of electromagnetism and the lack of experimental confirmation for a hypothesized lumineferous ether lead to the development of special relativity, which corrects mechanics to handle situations involving motions at a significant fraction of the speed of light. As of today, special relativity is the most accurate model of motion at any speed when gravitational effects are negligible. Special relativity implies a wide range of consequences, which have been experimentally verified including length contraction, time dilation, relativistic mass, mass- energy equivalence, a universal speed limit and relativity of simultaneity. It has replaced the conventional notion of an absolute universal time with the notion of a time that is dependent on reference frame and special position.

GENERAL THEORY OF RELATIVITY

General theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1915. General theory of relativity explains the law of gravitation and its relation to other forces of nature. It applies to the cosmological and astrophysical realm; including astronomy. General relativity generalizes special relativity and Newton’s law of universal gravitation providing a unified description of gravity as a geometric property of space and time. Some predictions of general relativity differ significantly from those of classical physics especially concerning the passage of time, the geometry of space, the motion of bodies in free fall and the propagation of light. Examples of such differences include gravitational time dilation, gravitational lensing, the gravitational red shift of light, and the gravitational time delay.

Some of the consequences of general relativity are:

• Clocks run slower in deeper gravitational wells. This is called gravitational time dilation.
• Orbits précis in a way unexpected in Newton’s theory of relativity.
• The ray of light bend in the presence of a gravitational field.
• Rotating mass “ drag along” the space time around them ; a phenomenon termed "frame-dragging".
• The universe is expanding, and the far parts of it are moving away from us faster than the speed of light.

CONCEPTS IN A NUTSHELL

Ø Space Time: Einstein realized that space and time are relative. An object in motion actually experiences time at a slower rate at one rest.

Ø Relativity of simultaneity: Two events simultaneous for one observer may not be simultaneous for another observer if the observers are in relative motion.

Ø Time dilation: a clock that is moving relative to an observer will be measured to tick slower than a clock that is at rest in the observers on frame of reference. That is moving clocks are measured to tick more slowly than on observers stationary clock.

Ø Length Contraction: The length of object moving at relativistic speed undergoes a contraction along the dimension of motion. That is a moving objects length is measured to be shorter than its proper length, which is the length as measured in the objects on rest frame.

SOME INTERESTING FACTS

What if you travelled faster than the speed of light? 

As an object approaches the speed of light its mass tends to infinity. So does the energy required to move the object also tends to infinity, which is not possible. For this reason, no normal object can travel as fast as or faster than the speed of light.

Is there really an absolute frame of reference?

General relativity tells us that there is no absolute frame of reference. Actually it tells us that all the frames are relative, which is but not the same as there is no absolute frame.

Is time an illusion?

Time is actually relative and flexible and according to Albert Einstein the dividing line between past, present, futures is an illusion. Time has not always existed, the theory relativity suggests before the big bang, 13.75 billion years ago, time and space did not exist.

DO YOU KNOW?

Ø All though Einstein will forever be associated with the theory of relativity, his Nobel Prize was actually awarded to him for his observation of photoelectric effect. Einstein theory of relativity was not completely accepted by scholars’ until many years.

Ø 1905 is often referred as Einstein’s miracle year. In that year Einstein published four different ground breaking papers, which laid the foundation of modern physics.

Ø The discovery of the hugely important equation E=mc², which showed that energy and matter are interconveratble is considered to be his biggest accomplishment, but there is evident that another physicist published this equation a year before him.

Ø Einstein could have lived longer when he suffered a burst blood vessel, Doctors told him surgery could have saved his life. But he declined the procedure, saying “It is tasteless to prolong life artificially”.

Ø What were the last words of Einstein???

      
His last words will never be known. He said them in German, but attending nurse didn’t speak German and couldn’t recall what he said.

EINSTEIN’S QUEST FOR A UNIFIED THEORY

After having become famous for several brilliant breakthroughs in physics, including Brownian motion, photoelectric effect and the special and general theories of relativity, Einstein spent the last 30 years of his life on a fruitless quest for a way to combine gravity and electromagnetism into single elegant theory.

INCOMPLETENESS OF THEORY RELATIVITY

General relativity as emerged as a highly successful model of gravitation and cosmology. However there are strong indications that, the theory is incomplete. The problem of quantum gravity and the question of the reality of space time singularities remain open. General relativity is incomplete since it does not include the gravitational radiation reaction force and the interaction of gravitation with charged particles. The discovery charge mass interaction establishes the need for unification of electromagnetism and gravitation and would explain many puzzles. Observational data that is taken as evidence for dark energy and dark matter could indicate the need for new physics. Even taken as is, general relativity is rich with possibilities for further explorations.

THE MAN WHO BEHIND:

Ø Photons: he discovered that light is made up of small particles called photon and was awarded the Nobel Prize for physics in 1921.

Ø Bose Einstein condensate: Einstein discovered a state of matter with another scientist, Satyendra Bose. Today it is used in things like lasers.

Ø Atomic bomb: not directly connected with inventing it, but his theory of relativity is connected with the invention of the atomic bomb.

Ø Global positioning system such as GPS, GLONASS and the forthcoming Galileo must account for all of the relativistic effects.

Ø Satellite based measurement need to take into account relativistic effects

Ø Nuclear plants: relativity is one of the many reasons that mass and energy can be converted into each other which is how nuclear power plants work

Ø Study of black holes, supernovas and other space phenomena

Reference:    

 [1] Arthur Beiser : 2005, Concepts of modern physics, New Delhi, Tata  McGraw-Hill

[2] J.C. Upadhyaya: 2003, Mechanics, Agra, Ram Prasad Publications

[3] https://en.m.wikipepedia.org

[4] https://www.space.com

SUBMITTED BY:

Ashna PV

Anusree A

Baby Athira

Deekshitha kumari

Dakshayani P

The Legend of Physics

The Legend of Physics: Stephen William Hawking

INTRODUCTION

He (8 January 1942-14 March 2018) was an English Theoretical Physicist, cosmologist, and author, who was director of research at the Centre for Theoretical cosmology at the University of Cambridge at the time of his death. He was the Lucasian Professor  of Mathematics at the University of Cambridge between 1979 and 2009.

His scientific works included a collaboration with Roger Penrose on gravitational singularity theorems in the frame work of general relativity and the theoretical prediction that black holes emit the radiation, often called Hawking Radiation. Hawking was the first to setout a theory of cosmology explained by a union of the general theory of relativity and quantum mechanics. He was the vigorous supporter of the many worlds interpretation of quantum mechanics.

Hawking achieved commercial success with several works of popular science in which he discuss his own theory and cosmology in general. His book A Brief History Of Time appeared on the British Sunday Times Best seller list for a record breaking 237 weeks. Hawking was the Fellow of the Royal Society(FRS), A  life time member of the Pontifical Academy of Sciences and a recipient of the presidential medal of freedom, the highest civilian awarded in the United States. In 2002, Hawking was ranked a number 25 in the BBC’s poll of the 100 Greatest Britons. Hawking had a rare early –onset slow –Progressing form of motor neurone disease(also known as Amyotrophic lateral sclerosis ‘’ALS’’ or Lou Gehrig’s disease) that gradually paralyzed him over the decades. Even after the loss of his speech, he was still able to communicate through a speech generating device, initially through use of a hand held switch, and eventually by using single cheek muscle. He died on 14 March 2018 at the age of 76.

Some important discoveries of Stephen Hawking:

1. Singularity

Einstein's theory also tells about singularity,that is where the space time appeared to be infinite curve but at that time it was unclear  that singularity was real or not, later Roger Penrose proved that singularity would indeed form in black hole later, Stephen hawking did path breaking work on singularities and applied it for whole universe and told that gravitational force produces singularities. He also told that Einstein's theory produced a singularity that is the big bang and hawking proved it mathematically.

2. Cosmic Inflation theory 1982

This theory was introduced by Alan goth in 1980. That is, in physical cosmology cosmic inflation is a theory in which the universe expands exponentially soon after the big bang. Further Hawking was one of the first who calculated quantum fluctuations which means the small variation in the distribution of matter and shows that, during inflation, it might give rise to the spread of galaxies in the universe.

3. Model on the wave function of the universe 1983

Stephen hawking was interested in establishing a quantum theory of gravity, but with James hartle, he published a model, the hartle - hawking  state in 1983.

This theory states that, time did not exist before the big bang explosion and hence the concept of beginning of the universe is meaningless. The universe does not have any initial boundaries  in time or space.

4. Top-down theory on cosmology 2006

Along with Thomas hertog, he proposed a theory “top-down cosmology" in 2006. It proposed that the universe had not one unique initial state but consisted of a superposition of many possible initial conditions. several other books were also published like “the universe in a nutshell”, “God created the integers: Mathematical breakthrough that changed history" in 2005 etc.

Law of Black Hole Mechanics

Stephen hawking discovered the law of mechanics in 1971 – 1972. His first law states that the total surface area of the black hole will never get smaller. It is also known as the hawking area theorem. Another law states that, Black hole were hot. But it is a contradiction of classical physics which states that black hole doesn’t radiate heat. Another law is no gain theorem of black holes, which states that black hole can be characterized by three numbers; their mass, angular momentum and charge.

One more law is, black holes emit the radiation, which may continue till they exhaust their energy and evaporates. Which is also called as hawking radiation. In 1971 he won the prestigious gravity research foundation award for his essay black hole.

Personal life

Hawking had a rare early onset slow progressing form of motor neuron disease or ALS, that gradually paralyzed him over the decades. The diagnosis of ALS came when he was at 21 in 1963. At the time doctors gave him a life expectancy of two years. In 1960’s his physical abilities declined, he began to use a crutch and as he lost the ability to write he developed compensatory visual methods including seeing equations in terms of geometry and at last he lost his voice and control over his body and he stick into a wheel chair at his younger age only, but his brain was still awake and active and it created magic all over the world. The entire world was shocked because of the discoveries and achievements of a parlayed man, and he became the pole star of physics.

When hawking was a graduate student he met jane wild before his diagnosis of ALS, and the couple became engaged in 1964 and they got 3 children, Robert, Lucy and timothy. But in 1980 they got separated after that he married Mason and this marriage also broke down soon.

Awards

• ·         Adams prize (1966)
• ·         Eddington medal (1975)
• ·         Maxwell medal and prize (1976)
• ·         Heineman prize (1976)
• ·         Hughes medal (1976)
• ·         Albert Einstein award (1978)
• ·         RAS gold medal (1985)
• ·         Dirac medal (1987)
• ·         Wolf prize (1988)
• ·         Prince of Austria’s award (1989)
• ·        Andrew garment award (1998)
• ·         Naylor prize and lectureship (1999)
• ·        Lilienfeld prize (1999)
• ·        Presidential medal of freedom (2016)
•    

Reference:

Internet

Journal