Last week we were talking about the development of quantum mechanics and its surprising results.
There is no doubt quantum mechanics is a valid explanation for all there is. It has been tested and re-tested in any number of ways for over 100 years.
While it has undergone modifications, scientists accept it as the best theory we have to explain the universe. It is an incredibly powerful tool. It can describe the interaction of electrons in atoms, the combination of atoms to form molecules, the interaction of molecules with one another to generate complex and chaotic systems, and so much more.
Subsets of quantum mechanics such as quantum chromodynamics (QCD) provide a theoretical framework for the interaction between quarks and gluons while quantum electrodynamics quantifies the strange interaction between light and matter reconciling the theory of relativity with quantum mechanics.
There is no doubt the world around us is described by quantum mechanics.
However, there is still the problem of Schrodinger's Cat. Is the cat alive or dead? Sealed in an impenetrable box with a vial of poison and a radioactive trigger, the cat can be described as both alive and dead until the box is opened.
From our perspective, this seems a silly proposition as something cannot be both dead and alive. But since there is no way to look inside the box, we do not know which state the poor cat is in. Some action - opening the box - must occur to collapse the wave function. That is, up to the point where we open the box, the cat could be in either state but the act of opening the box reveals which one.
Since the trigger inside the box is the radioactive decay of an atom, the cat's fate hinges on whether or not a singular atom underwent radioactive decay or not. There is no way to reasonably predict if the atom decayed. At best, we can only predict the probability that it did.
This inherent randomness in quantum mechanics has resulted in a great deal of contention amongst scientists for the past 100 years. How can we make reasonable predictions about the fate and future of the universe if, at its most fundamental level, it is controlled by randomness?
Indeed, much of physics has been spent trying to evaluate the physical constants of the universe to higher and higher degrees of precision. From these measurements, it would appear all of the interactions in the universe are subject to 19 or 20 constants which quantify all interactions.
But if the universe is inherently random, what does this all mean?
Many modern physicists have resorted to invoking the multiverse as the answer. If there are many possible outcomes with varying probabilities, then all of the outcomes occur. That is, if you role a six-sided die and the result depends on quantum mechanics, then each of the six possible ways the die can fall occurs in six separate and new universes.
This is the many-worlds interpretation of quantum mechanics.
The universe doesn't choose left-or-right, up-or-down, yes-or-no - it chooses both and as a result it bifurcates into two new Universes.
With the collapse of each and every subsequent wave function, the two universes grow further apart. More to the point, each generates its own daughter universes as wave functions continue to collapse.
How many universes have been generated?
Assuming the Big Bang started everything and it occurred 13.7 billion years ago, that would be 4.3 times ten to the 17th power seconds.
Or 432,343,854,700,000,000 seconds ago (approximately). If a new universe is created every second, it would be a very large number.
However, in quantum mechanics there is a concept called Planck's Time. It is the smallest unit of time or the time during which a wave function collapses.
At 10 to the -34th of a second (a 1 preceded by 33 zeros), it implies that for every second of our time, 10^34 universes would be created or a grand total of somewhere around 10^41 universes.
That is a lot of universes by any stretch of the imagination. It is why opponents of the many-world interpretation find it difficult to believe. After all, where are all of these universes? And how do they fit together?
It is also why some physicists and philosophers favour an anthropogenic multiverse where it is the decisions made by sentient beings which split the universe into multiples. It puts complex life back into the mix and at the centre of all there is.
In any case, each universe would evolve in its own way and therefore all possibilities would be realized. In the multiverse anything can happen which makes it a great place for science fiction and fantasy literature.
Who knows? Somewhere in one of the many multiverses, there might even be Guardians of the Galaxy.
