Human knowledge has never ceased to expand as our horizon widens. We used to think that it was us, our planet, that was the epicenter of the universe. Up to the point Copernicus, and later Galileo, debunked the myth, we surrendered our title to the Sun. It was not until after Clyde Tombaugh discovered Pluto, and clusters of stars later on, that our humility increasingly grew; the Sun is no more than one among countless stars within a system we now recognize as galaxy. And a few decades later, our galaxy is only among another string of numberless ones scattered across the universe.
And now physicists have tried to figure out what might be ‘the final frontier’ – probably one among the many ‘lasts’ – that our universe itself, so bulky itself we the humans are no more than a little dirt, is possibly only one ‘lucky world’ compared to its limitless counterparts, possibly in trillions, or even in trillions of trillions. We never know if it may be proven within our generation, but such discussion keeps the world of astronomy and physics continuously interesting.
Andrei Linde, a Russian-born American physicist, explains his theory in Discover Magazine, December 2008 issue.
Dark energy makes it impossible to ignore the multiverse theory.Another branch of physics—string theory—lends support as well. Although experimental evidence for string theory is still lacking, many physicists believe it to be their best candidate for a theory of everything, a comprehensive description of the universe, from quarks to quasars. According to string theory, the ultimate constituents of physical reality are not particles but minuscule vibrating strings whose different oscillations give rise to all the particles and forces in the universe. Although string theory is enormously complex, requiring a total of 11 dimensions to work correctly, it is a mathematically convincing way to knit together all the known laws of physics.
In 2000, however, new theoretical work threatened to unravel string theory. Joe Polchinski at the University of California at Santa Barbara and Raphael Bousso at the University of California at Berkeley calculated that the basic equations of string theory have an astronomical number of different possible solutions, perhaps as many as 101,000*. Each solution represents a unique way to describe the universe. This meant that almost any experimental result would be consistent with string theory; the theory could never be proved right or wrong.
Some critics say this realization dooms string theory as a scientific enterprise. Others insist it is yet another clue that the multiverse is real. Susskind, a leading proponent of that interpretation, thinks the various versions of string theory may describe different universes that are all real. He believes the anthropic principle, the multiverse, and string theory are converging to produce a coherent, if exceedingly strange, new view in which our universe is just one of a multitude—one that happened to be born with the right kind of physics for our kind of life.
Picture source: Fine Art America