Parallel universes really do exist, according to a mathematical discovery by Oxford scientists described by one expert as "one of the most important developments in the history of science".

The parallel universe theory, first proposed in 1950 by the US physicist Hugh Everett, helps explain mysteries of quantum mechanics that have baffled scientists for decades, it is claimed.

In Everett's "many worlds" universe, every time a new physical possibility is explored, the universe splits. Given a number of possible alternative outcomes, each one is played out - in its own universe.

A motorist who has a near miss, for instance, might feel relieved at his lucky escape. But in a parallel universe, another version of the same driver will have been killed. Yet another universe will see the motorist recover after treatment in hospital. The number of alternative scenarios is endless.

It is a bizarre idea which has been dismissed as fanciful by many experts. But the new research from Oxford shows that it offers a mathematical answer to quantum conundrums that cannot be dismissed lightly - and suggests that Dr Everett, who was a Phd student at Princeton University when he came up with the theory, was on the right track.

Commenting in New Scientist magazine, Dr Andy Albrecht, a physicist at the University of California at Davis, said: "This work will go down as one of the most important developments in the history of science."

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Here is a story told through quotes, comments and links related to commonsense (naive) realism, epistemology, materialism, information theoretic metaphysics, consciousness, empirical science, mysticism, holistic science and also system theory. There's some fascinating links to profound experiments into the nature of consciousness if you don't already know about them... (The PEAR REG/GCP experiments)

Skepticism

Skepticism "is the application of reason to any and all ideas - no sacred cows allowed... Ideally, skeptics do not go into an investigation closed to the possibility that a phenomenon might be real or that a claim might be true. When we say we are 'skeptical' we mean that we must see compelling evidence before we believe." (http://www.skeptic.com)

Furthermore "To some degree skepticism manifests itself in the scientific method, which demands that all things assumed as facts be questioned. But the positivism of many scientists, whether latent or open, is incompatible with skepticism, for it accepts without question the assumption that material effect is impossible without material cause." (The Columbia Electronic Encyclopedia http://www.answers.com/topic/skepticism)

So materialism is NOT a skeptical position to take - because it is based upon the unquestioned assumption and belief in the primacy of matter. If people were to question it and not simply assert their beliefs it could be a skeptical position but any deep questioning soon shows it to be unable to withstand such questioning.

Commonsense (Naive) Realism

"Naïve realism is a common sense theory of perception. Most people, until they start reflecting philosophically, are naïve realists. This theory is also known as "direct realism" or "common sense realism". Naïve realism claims that the world is pretty much as common sense would have it. All objects are composed of matter, they occupy space, and have properties such as size, shape, texture, smell, taste and colour. [It is assumed that] These properties are usually perceived correctly. So, when we look at and touch things we see and feel those things directly, and so perceive them as they really are." (http://en.wikipedia.org/wiki/Na%C3%AFve_realism)

In its most common form a naive realist thinks "I ... am a human being. There is this one physical world, the space where everything exists and the time in which everything happens. There are many things in this physical world, each largely separate from the other and persisting over a span of time... My senses give me direct knowledge of reality. If I see a chair, it is because there is a chair physically where and when I see it. There are exceptions, like when I am dreaming or watching a movie, but these are rare and obviously not real. I can know things through my senses, through thinking about things, and through communication with other people. Other people's beliefs may be correct or not, but beliefs of people I respect, and beliefs held commonly by most people in my society, are usually true." (http://www.boogieonline.com/seeking/first/yesterday.html)

It is a general tendency of naive realists to be unaware that their beliefs are in fact beliefs. They consider them to simply be obvious facts about the way things are. This is because they have not yet questioned their beliefs. They are naive believers but they often also believe that they are skeptical. It is a habitual credulous state of mind and the habit can be very hard to overcome.

"Karl Popper (1970) pointed out that although Hume’s idealism appeared to him to be a strict refutation of commonsense realism, and although he felt rationally obliged to regard commonsense realism as a mistake, he admitted that he was, in practice, quite unable to disbelieve in it for more than an hour: that, at heart, Hume was a commonsense realist. [And] Edmund Husserl (1970), saw the phenomenologist in Hume when he showed that some perceptions are interrelated or associated to form other perceptions which are then projected onto a world putatively outside the mind." (http://en.wikipedia.org/wiki/David_Hume)

I.e. objects which are assumed to comprise the "external world" are really objects of perception. To attribute them with external reality is an act of belief for which there is no rational basis.  More >

Markus Aspelmeyer, Anton Zeilinger and colleagues from the University of Vienna, however, have now shown that realism is more of a problem than locality in the quantum world. They devised an experiment that violates a different inequality proposed by physicist Anthony Leggett in 2003 that relies only on realism, and relaxes the reliance on locality. To do this, rather than taking measurements along just one plane of polarization, the Austrian team took measurements in additional, perpendicular planes to check for elliptical polarization.

They found that, just as in the realizations of Bell's thought experiment, Leggett's inequality is violated – thus stressing the quantum-mechanical assertion that reality does not exist when we're not observing it. "Our study shows that 'just' giving up the concept of locality would not be enough to obtain a more complete description of quantum mechanics," Aspelmeyer told Physics Web. "You would also have to give up certain intuitive features of realism."