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Thursday, December 30, 2010

Infinite Parallel Universes

Since the beginning of civilization, humans have yearned to understand completely the world around them. In the last few centuries, this endeavor has earned our civilization a treasure trove of discoveries, inventions and theories. After making a number of remarkable discoveries and forming numerous theories to scientifically explain the everyday events, some scientists tried to interlink the various theories. At some point in history our target changed form explaining all events scientifically to finding one unified theory that explains literally all the events occurring in the universe.

Stephen Hawking, in his book, “A Brief History of Time”, explains that a problem is generally approached from various angles by different scientists and once each individual scientist has solved his part of the problem, a theory is developed which relates the solutions found by the different scientists for that problem. To find the unified theory, some prominent scientists started at the most basic level, i.e., inside the atoms. Thus, the quantum theory was developed. Others took to explaining the behavior and the patterns of the largest known entity – the universe itself. Albert Einstein, being one of them, developed the General Theory of Relativity.

Once these two theories were developed, attempts were made to unify the quantum theory with the theory of relativity. This new theory was called the String Theory. When formed, it was found that the string theory could unify the four major forces in the world, thus becoming the unified field theory.
According to the string theory, the subatomic particles are made up of tiny one dimensional strings of energy. It thus suggests that the most basic properties of any matter, such as charge, mass, etc are a result of the type of vibrations taking place in the string loop of energy. These strings of energy have a length and are about 10^-23 cm long.
For a long time the string theory was not accepted because it predicted the existence of a mass less particle, which was considered a failed prediction. But the unification of the major forces of the world would require, as predicted by Einstein, a particular mass-less particle. In 1974, the experiments conducted by John Schwarz, Joel Scherk, and Tamiaki Yoneya discovered this very particle. But even so, the string theory was mostly rejected due to its several theoretical problems. One such is that the string theory demanded a total of nine spatial dimensions and a total of ten space time dimensions. Also there seemed to be many inconsistencies in the equations. But in 1984 John Schwarz and Michael Green proved that the equations were afterall consistent. This drew the attention of most of the physicists in the world. The extra 6 dimensions are described thus – the three known dimensions are long, large and hence are easily visible. But the other 6 dimensions are so crumpled and highly intertwined that it is almost impossible to detect these dimensions with the simple macroscopic experiments. It is like our universe requires the three spatial and the time dimensions. Beyond that no dimensions exist for us. This makes the extra dimensions of the string theory a major hurdle. And yet the shape and size of these extra dimensions affect the vibrations in the string.
In 1995, Edward Witten , while trying to refine the approximate equations of the string theory, found that there were, not six but seven extra spatial dimensions. Also these revealed the existence of membrane like objects called the Branes. The seventh dimension is the one that allowed the branes to stretch and expand. This means that the branes could be infinitely large (as large as our universe!) or could even be infinitesimally small.
Implications:
  1. It suggests that there are a total of ten spatial dimensions. This could mean that the other dimensions could exist near us and yet be invisible. The world in these other dimensions will be very much different from what we know. The laws of physics we follow in our three dimensional world might go meaningless.
  2. The extra dimension included by Edward Witten enables the strings to stretch and expand. This means that the Branes could be infinitely long and as thin as one or two millimeters in width.
  3. An interesting fact is that these energy string loops can travel between the dimensions. This means that a split second wormhole is formed every time the string loop crosses over to the other dimension.
The string theory shakes the very foundations of the big bang theory itself. It says that the big bang did not occur just once, but could have occurred an infinite number of times. The string theory explains this by stating that the big bang is nothing but a point in time when two different dimensions collide with each other. It states that whenever the dimensions collide they form the beginning of new matter and a new universe on the whole. This could have happened countless times and could have resulted in infinite parallel universes, each on various different dimensions and entirely invisible to the other!

References: Internet

Tuesday, December 21, 2010

Just Another Day

A breezy noon. Crisp sunlight shining down only to be cooled by the soft drizzle and flowing winds. Outside the window, the colours of the world look bright and vibrant. The various shades and tints posing their distinct nature. Nature. Nature has so many meanings. The world, its characteristics, its properties and what not. Anything and everything. And everything is beautiful.