Newton's and Einstein's Universe

Introduction:

Dictionaries define the universe as the total of all the matter, energy, and space that man is capable of experiencing.  It contains some 1041 kilograms of matter, collected in some 109 galaxies.  It was Newton and Einstein who contributed significantly to the understanding of how our universe is functioning.

Sir Isaac Newton, English natural philosopher and scientist, was born prematurely on 1642. He had a very unhappy childhood, which explains why during all his life he showed signs of a persecution mania. He died on 1727 leaving a safe world from the scientific point of view.  Surprisingly, Newton was highly productive only for about twenty years, 1670-1690.  He then became a highly paid government official in London with little further interest in mathematical research.  Newton never married, but was at his happiest in the role of patron to young scientists while from 1703 he served as president of the Royal Society until his death.  He was knighted in 1705.

Albert Einstein was born in Ulm, Germany, on March 14, 1879, and died on April 18, 1955, in Princeton, USA.  Many of his teachers thought he was a slow learner, partly because he could not talk until the age of 3.  In 1894 he moved with his family to Italy and then to Switzerland where he graduated the Swiss Federal Institute of Technology in Zurich.  He could not find a job in any university because he was considered very lazy. In 1902 he started to work in the patent office in Bern where he had sufficient time to think about physics.  He modified Newton’s universe, while his is now a days being also modified by others.

Fig.1: Newton and Einstein

Newton's Universe in Art

Laws of science exist in the universe since its creation.  However, it was Newton who revealed and formulated the four laws related to mechanics that govern about 99% or more of our everyday experience.  These laws are applicable either to bodies in the universe or to billiard balls.

His 1^st Law indicates that “a moving body at a constant speed in a straight line tends to stay at that constant speed”.  The 2^nd Law establishes that “an object accelerates when a force is acting on it”.  According to his 3^rd Law “for every action there is an equal and opposite reaction”, where his Universal Law of Gravity postulates that “each mass in the universe attracts another mass by a force F which is proportional to the product of the masses m₁ and m₂ and inversely proportional to the square of the distance between them, namely, F = m₁m₂/r²”.  These laws have made it possible to design and construct vehicles that move on Earth, as well as satellites that are launched into space and move there safely.  In addition, the combination of the laws ensures that our planets don’t fall on each other and collapse; a fact due to a balance between the attraction forces between the masses and the centripetal force generated due to the motion of the stars in an elliptical trajectory. 

The “stage” on which Newton’s mechanics functions is absolute. In other words, length, mass and time, are absolute quantities, universal and independent of the motion of bodies.  The “space” of Newton’s mechanics is an unchangeable two-dimensional “screen”, completely described by Euclidean geometry, on which interacting bodies are moving.  Moreover, in order to create an attraction force between bodies, at least two masses are required, where the physical reason for such a force is not clear.  The artwork in Fig.2 by Ron Miller, a space artist, demonstrates the solar system.  It gives an observer the feeling of a stable universe, which, however, according to modern theories is continuously expanding.

Fig.2: The solar system in Newton’s 2-dimensional universe by Ron Miller

Einstein's Universe in Art

Special Relativity: The essence of Einstein’s universe lies in the concept of relativity.  Actually,  the idea of relativity was first expressed by Galileo Galilei (1564-1642), some 300 years before Einstein.  Galileo stated that only a relative motion is important, thus, an absolute motion is impossible.  Einstein’s version to the principle of relativity was that all laws of nature must be identical for all observers moving in a relative motion at a constant speed.  In addition, space and time are interrelated and their magnitude depends on the relative velocity between an object and its observer.  In other words, every event and measurement is viewed differently depending on the observer's velocity where the only quantity that remains constant is the speed of light C in vacuum.  It is also the maximum speed in nature.  The astounding results of Einstein’s Theory of Special Relativity, which he introduced in 1905 indicated the following for an object neared the speed of light: 1) It would appear shorter to an observer, while appearing of zero length at the speed of light.  Rene Magritte (1898-1967), a Belgian surrealist, in his painting "The House of Glass"(1939), left-hand-side in Fig.3, demonstrates unknowingly that a traveler moving at the speed of light becomes totally flattened, so that his face could be seen in the rear of his skull.  2) The passage of time for the object would appear to be slower.  Time becomes infinite slow if the object moves at the speed of light with respect to an observer.  "The Persistence of Memory" (1931) in Fig.3, center, by Salvador Dali, (1904-1989), Spanish, demonstrates the stretch ability of time.  The softness of the watches in the painting creates a sensation of stretching of time and consequently, a time interval of, say, one second, will extend to infinity if an identical watch would have been be traveling at the speed of light.  3) As the object gets nearer and nearer to the speed of light it begins to gain more and more energy and, therefore, mass.  If it ever got to the light speed it would have an infinite mass (and energy).  "The Listening Room"(1952), right-hand-side in Fig.3, shows how the size of the apple in relation to the room can create a sensation that at the speed of light the mass of the apple approaches infinity as predicted by the theory. 

Fig.3: Einstein’s special relativity

General Relativity

The major deficiency of Special Relativity  is that it deals with bodies moving at a constant relative velocity.  In other words, it is restricted to motions at a constant speed in the absence of external forces such as gravity.  Einstein’s General Relativity, stated in 1915, deals with accelerated motion and gravity.  It considers gravity as a property of space and not as a force acting between masses.  According to this theory the presence of matter causes space to become curved.  This theory was proven experimentally in 1919 by photographing the curving of light beams passing near the sun during a solar eclipse.  This coincides also with Einstein’s equivalence between mass and energy, here the light being a dispersed mass.

The formation of space curvature may be clarified as follows.  Imagine the space as a wide rubber sheet held at its edges.  If we put on the sheet a heavy body, like a bowling ball, a concavity will be formed in the sheet.  If then a small ball is put on the sheet, it will move towards the concavity formed by the heavy body.  Therefore, General Relativity considers gravity as property of space and not as force acting between bodies.  From this point of view, and in contrast to Newton’s demand that the formation of force requires at least two masses, in Einstein’s universe, only one mass is required to curve the space.  In the curved space, bodies are able to move in trajectories of minimal resistance.  Fig.6 by Victor Vasarely (1906-1997), Hungarian, demonstrates a curved space. The big mass (big apple) creates curvatures in space in which the small mass (small apple) is moving.  In addition it curves the light beams.

Fig.6: Curved space and light beam according to Vasarely (slightly modified)

Fig.7, the “Print Gallery” (1956) by M.C. Escher (1898-1972) a Dutch Illustrator, gives an impression of a curved space.  Actually the picture depicts a man standing in a gallery who looks at a print of a city that contains the building that he is standing in himself.  It contains also in the middle a mysterious white hole.  The latter reminds the black bole, which is a logical extension of Einstein’s General Relativity making different phenomena comprehensible, otherwise impossible.  A black hole possesses a gravitational field so intense that no matter and light cannot escape from it.  Thus, we cannot see it.  Scientists think that deep inside the black hole we would come to its center, called the singularity, where all things disappear from our universe.  However, on the basis of a theoretical hypothesis there is a possibility that a thing will escape from the singularity and will fall through a wormhole and get out through a white hole.  Hieronymus Bosch (c.1450-1516), a Netherlands painter, was probably the first who’s painting "Hell" (c.1504) in Fig.8, demonstrates the black hole and the white hole.  The latter is a throughout way, and follows the black hole that surrounds it.

Fig.7: Curved space according to M.C. Escher

 

Fig.8: Black and white holes according to Hieronymus Bosch

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