Albert Einstein is the most influential physicist of 20th century, and one of the most influential scientists of all times in the world. He was born on March 14, 1879 in Germany as a first child of the Jewish couple Hermann and Pauline Einstein.

As child he was quite normal but his family was worried because he did not learn to speak until at a late age (age of 9). In 1885, he started playing violin which he played throughout his life. School education was not in his interest. He did not get along with his form-master he left this school in 1894 without a degree and joined his family in Italy where they had settled meanwhile. Einstein’s formal secondary education ended at age sixteen.

Einstein tried to enter the Federal Institute of Technology (FIT) in Zurich, Switzerland, but his knowledge of subjects other than mathematics was not up to the level so he failed the entrance examination. On the advice of the principal, he first obtained his diploma at the Cantonal School in Aarau, Switzerland, and in 1896 and he was automatically admitted into the FIT.

There he came to realize that he was more interested in and better suited for physics than mathematics. Einstein had gained a lot of knowledge in the field of calculus by age sixteen. On January 6, 1903 he married Mileva Maric – against the wills of both families.

He had two sons Hans Albert, and Eduard in 1904 and in 1910 respectively. In April 1905 Einstein submitted his doctoral thesis “A New Determination of Molecular Dimensions” to the university in Zurich which was accepted in July. It was the same year, when he published his first theory of Relativity, and second part of it was published in 1915.

“By 1908, he was recognized as a leading scientist and was appointed lecturer at the University of Bern” (En.wikipedia.org, 2019). He also won the Nobel Prize for Physics in 1921 for his explanation of the photoelectric effect. His theory of relativity which brought miracle in the field of physics has two parts the special and general theories of relativity.

The term ‘relativity’ was first coined by Physicist, Mathematician and also known as smartest person till the date named Albert Einstein in 1905. Einstein developed this theory by thinking about fundamental contradiction between Newton’s law and Maxwell’s theories. Before Einstein’s theory was invented people used to believe Newton’s law of motion (law of inertia, law of relationship between force and time, and law of opposite reaction) and Maxwell’s law of electro magnetism (relationships between electric and magnetic field and their properties).

Einstein’s theory of relativity states that every observer must see the universe operating according to the same law. Because the speed of light is built into Maxwell’s equations, this principle requires that all observers must see the same speed of light from their frame of reference. This theory describes the law of motion at velocity of light or close to it. Thus, Einstein sub divided his theory into two parts. In the paragraphs, the outcomes and changes brought by these two sub classes in today’s world will be discussed.

Einstein’s special theory of relativity is the first part of theory of relativity which was published on 1905. It explains how to interpret motions between different inertial frames of reference which means places that are moving at constant speeds relative to each other. It basically focuses on non-accelerating objects.

This theory explains that law of physics is same for non- accelerating observers. “In special relativity, simple argument leads to the conclusion that moving clocks appears to tick more slowly than stationery ones – a phenomenon called time dilation” (Trefil & Hazen, p.167).

Einstein also claimed that the speed of light within the vacuum is same regardless of speed of an observer travels. Here he realized that time are interlinked into a single continuum called space-time. The special-theory of relativity is known as ‘Special’ as it is confined to the inertial frames of reference where Newton’s first law of motion works. According to newton “Space and time were absolute, and motion was also absolute.” Newton believed that motion is inertial which means the moving object moves with constant velocity or remains at rest with respect to absolute space.

However, Einstein had different notion. He replaced space and time with 4D space-time continuum and explained that inertial motion was relative. Thus, special theory of relativity is all about relative motion of objects in inertial frames of reference. This theory was a milestone in the history of physics as it linked the space and time in the universe which could be viewed.

In addition, the special theory of relativity also tells that a moving object measures shorter in its direction as its velocity increases until at the speed of light, they stop running together. “So, the special theory of relativity cannot be negated that real motion at a speed greater than the speed of light in vacuum which we call superluminal speed could exist.” (Shenglin, 239).

Besides, Einstein’s special theory of relativity physics a new direction which comes from the invention of time dilation and formula E= mc2. It means energy is equal to multiplication of mass and square of speed of the light.

Here, Einstein claimed that mass and energy are interchangeable; basically, they are different form of same energy. This formula is demonstrated in atom bomb where mass is converted into huge amount of energy. The equation also explains that mass increases with its speed. The speed of light has the fastest velocity in which object travels in a vacuum. Thus, when the object’s velocity reaches to the velocity of light then the mass of object also becomes infinity and hence it needs infinite energy to continue the same speed.

Thereafter huge amount of energy is created. As an outcome, larger implication of nuclear energy has become a good alternative to hydroelectricity in the country like USA and Canada. However, the advent of nuclear bomb as a product of this theory is the dark side and we can take an example of catastrophic attack of nuclear bomb in Hiroshima and Nagasaki in Japan in World War II. Though the theory is the boon to the science but it killed the thousands of living beings. However, his theory is not faultless and has to be clarified and researched to reach in a broad conclusion. “Both the principle of relativity and the law of propagation of light have been misinterpreted and twisted by Einstein, and need to be clarified and rectified” ( X. Shaozhi and X. Xiangqun, p.83).

On the other hand, second product of theory of relativity was coined 10 years later after invention of special theory on 1915 by Albert Einstein called general theory of relativity. It is one of the towering achievements in the 20th century. In one interview Nobel laureate Max Born praised general relativity as the “greatest feat of human thinking about nature”; fellow laureate Paul Dirac was quoted saying it was “probably the greatest scientific discovery ever made”( Schmidhuber, 2019).

It deals with the observation of that the forces of gravity is connected to acceleration and explains the universe in which heavy masses warp up the space-time and affect the motion of objects. In other words, theory revealed that the universe is an extreme place. It predicts that universe is full of exotic phenomena.

Space-time cam move like the surface of the pond and it seems to be full of mysterious form of energy that push apart. Einstein believes that space-time to be so wrapped that it is possible to travel backwards in time. The general theory of relativity is the theory of space and time which are of two aspects of space time. Einstein explains that space-time is curved when there is gravity, matter, energy and momentum.

Theory of relativity’s main essence is principle of equivalence. For example, one person in the elevator sitting on the surface of the earth while other sitting in the elevator outer space accelerating at 9.8m/s2, when the ball drops from both the head of each person, both will observe the same behaviour.

The object that falls from each person’s accelerate towards the surface at same acceleration rate. “There are three classic tests of general relativity-the bending of light rays passing near the Sun, the changing orientation of the orbit of Mercury, and the redshift of light passing through a gravitational field.” (Trefil & Hazen 167).

Besides general theory of relativity describes the history of the universe and the physics of black holes.

In addition, the general theory of relativity will have a greater impact on future to have a greater understanding of stars and other heavenly bodies. The theory has also paved the way to research on dark energy and dark matter to understand the universe in better way. Similarly, GPS is another great achievement of general relativity. Considering the accuracy of time and effect predicted by general theory of relativity. GPS can accurately find the place and time. Special relativity explains that maximum speed is finite mass energy conversion time dilation and length contraction.

Einstein was confident that his general theory of relativity was correct because of “its mathematical beauty and because it accurately predicted the precession of the perihelion of Mercury’s orbit around the Sun” (Kaku 2019). His was a pacifist. He was only one of four intellectuals in Germany to sign a manifesto opposing Germany’s entry into war. He was against so called nationalism called it as ‘the measles of mankind.’

In December 1932 Einstein decided to leave Germany forever. A Nazi organization published a magazine with Einstein’s picture and the caption “Not Yet Hanged” on the cover. Einstein split with his pacifist friends and said that it was justified to defend yourself with arms against Nazi aggression. “After the Nazis seized power in Germany, Einstein immigrated to the US, where he worked at the Institute for Advanced Study in Princeton, New Jersey” (“Albert Einstein – Facts”, 2019). He went to America in 1933. Einstein played a key role (1939) in the construction of the atomic bomb by signing a famous letter to President Franklin D. Roosevelt (1882–1945).

“Einstein was deeply shocked and saddened when his famous equation E=mc 2 was finally demonstrated in the most awesome and terrifying way by using the bomb to destroy Hiroshima, Japan, in 1945” (“Albert Einstein Biography”, 2019). He never wanted his theory to be applied in such wrong way.

Although Einstein continued to pioneer many key developments in the theory of general relativity—such as wormholes, higher dimensions, the possibility of time travel, the existence of black holes, and the creation of the universe—he was increasingly isolated from the rest of the physics community. The physics community was working on the quantum theory, not relativity.

Einstein’s work continues to be given importance. The examples of that is that Nobel Prizes were being offered for succeeding physicists who continued Einstein’s theory. “In 1993 a Nobel Prize was awarded to the discoverers of gravitation waves, predicted by Einstein. In 1995 a Nobel Prize was awarded to the discoverers of Bose-Einstein condensates” (Kaku 2019). Today many leading physicists are trying to finish Einstein’s ultimate dream of a ‘theory of everything.’

Albert Einstein died on April 18, 1955, at age 76 at the University Medical Center at Princeton. The previous day, while he was working on a speech to honor Israel’s seventh anniversary, Einstein suffered an abdominal aortic aneurysm. “He was taken to the hospital for treatment but refused surgery, believing that he had lived his life and was content to accept his fate.” (“Albert Einstein” 2019). He said that he had done his share and it was his time to go. Einstein also has may ups and downs in his personal as well as professional life. His theory was not free from criticisms, but he is and will be towering figure in the world in many centuries to come. It is very important to do more research to understand the universe that would be a great respect to Einstein.

## References

- “Albert Einstein – Facts”. NobelPrize.org. Nobel Media AB 2019. Mon. 15 Apr 2019.
- “Albert Einstein.” Biography.com, A&E Networks Television, 10 Apr. 2019, www.biography.com/people/albert-einstein-9285408.
- “Albert Einstein Biography.” Encyclopedia of World Biography, www.notablebiographies.com/Du-Fi/Einstein-Albert.html.

C. ShengLin, “The theory of relativity on the Finsler spacetime,” in Journal of Systems Engineering and Electronics, vol. 6, no. 4, pp. 239-252, Dec. 1995. - En.wikipedia.org. (2019). Albert Einstein. [online] Available at: https://en.wikipedia.org/wiki/Albert_Einstein#Academic_career [Accessed 15 Apr. 2019].
- Kaku, Michio. “Albert Einstein.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 10 Mar. 2019, www.britannica.com/biography/Albert-Einstein.
- Trefil, James, and Robert M. Hazen. Sciences an Integrated Approach. Wiley, 2013.pdf.

X. Shaozhi and X. Xiangqun, “Systematical scrutiny into special relativity,” in Journal of Systems Engineering and Electronics, vol. 4, no. 2, pp. 75-85, June 1993. - Schmidhuber, Jürgen. “Albert Einstein (1879–1955) and the Greatest Scientific Discovery Ever”. IDSIA, 2006. Retrieved April 15, 2019.