Like what you've read?

On Line Opinion is the only Australian site where you get all sides of the story. We don't
charge, but we need your support. Here’s how you can help.

  • Advertise

    We have a monthly audience of 70,000 and advertising packages from $200 a month.

  • Volunteer

    We always need commissioning editors and sub-editors.

  • Contribute

    Got something to say? Submit an essay.


 The National Forum   Donate   Your Account   On Line Opinion   Forum   Blogs   Polling   About   
On Line Opinion logo ON LINE OPINION - Australia's e-journal of social and political debate

Subscribe!
Subscribe





On Line Opinion is a not-for-profit publication and relies on the generosity of its sponsors, editors and contributors. If you would like to help, contact us.
___________

Syndicate
RSS/XML


RSS 2.0

The nature of reality

By George Virsik - posted Wednesday, 12 December 2012


Richard Dawkins begins his popular "The Magic of Reality" (Free Press, 2011) with the sentence "Reality is everything that exists". This is a good definition of "reality" if we can agree on what the verb "exists" means; and a good definition of "exists" if we can agree on what "reality" means. Unfortunately, strictly speaking, neither is the case, although for those who use the terms only for everyday purposes - and Dawkins' book is after all aimed at them - this does not represent a problem.

On a different level, the NewScientist ended its recent series of ten articles entitled "What is Reality?" rather inconclusively:

"Do we make reality, or does it make us? Probe the existence of the universe's supposed building blocks - quarks, electrons, neutrinos and the rest - and you eventually end up back in your own mind. Alternatively, discount everything human and settle for 'a world without us' - a reality that might also be unknowable by us …These options are as viscerally unsettling as they are intellectually challenging".

Advertisement

What is then the nature of reality? This is one of the questions also Stephen Hawking and Leonard Mlodinow ask at the very beginning of their book "The Grand Design" (Bantam Press, 2010), followed by the often quoted "philosophy is dead" claim. Taken as such, this claim is obviously an exaggeration ad absurdum. However, if in the actual context one replaces it with an ellipsis, we get "traditionally these were questions for philosophy, but philosophy … has not kept up with modern developments in science, particularly physics", a criticism that many of us can agree with. So what are the insights from physics offered by Hawking and Mlodinow? They call it "model-dependent realism" that I think could represent an intriguing contribution of physics to philosophy, (misunderstood by many, although already hinted at by Einstein when he wrote that reality was merely an illusion), and best expressed by:

"According to the idea of model-dependent realism ..., our brains interpret the input from our sensory organs by making a model of the outside world. We form mental concepts of our home, trees, other people, the electricity that flows from wall sockets, atoms, molecules, and other universes. These mental concepts are the only reality we can know. There is no model-independent test of reality. It follows that a well-constructed model creates a reality of its own."

What this means is that physics/science cannot provide any guarantee ("evidence") that there is a reality independent of what "model", i.e. physical theory, one uses to represent (describe) it with.

Nevertheless, and the authors admit that much, for practical purposes one cannot live without the assumption ("belief"?) that there exists such a reality, that there is a "truth" about this reality, that scientists are striving to know. In philosophy (of science) if this assumption is explicit, one speaks about scientific realism. On the other hand, a strict adherence to model-dependent realism of Hawking and Mlodinow would correspond more or less to the position of constructive empiricism of Bas C. Van Fraassen: "Science aims to give us theories which are empirically adequate; and acceptance of a theory involves as belief only that it is empirically adequate".

Another approach is to first look not so much at what is "reality" and what "exists" but to start with the three worlds - mental, mathematical, physical - of Roger Penrose (see e.g. The Road to Reality, Alfred A. Knopf, 2004). It is related to, and inspired by, but not identical to, Karl Popper's three worlds, mental, objective knowledge, physical. Penrose's model is primarily aimed at explaining the role of mathematics in our understanding of the structure of reality studied by physics, but it could perhaps be extended by adding other conceptual constructions to the mathematical world, thus ending more or less in Popper's world of "objective knowledge". I shall not consider this generality, so that also the mental world will be restricted mainly to ideas (what is understood either by a particular individual or by humanity as such) related to physical reality and mathematics.

There is no need for an a priori assumption about the "independent existence" (although here "irreducibility " is a better word) of these three worlds of Penrose, although many scientists and mathematicians believe that neither of them is reducible to any of the other two. For instance, many, probably most, mathematicians (so called Platonists or realists) believe in a world of mathematical concepts and relations independent of the human mind. For practical purposes, i.e. in order to better understand the interrelatedness of these three worlds, it is better to formally assume this mutual irreducibility. (Actually, one could similarly think of a fourth world, spiritual or transcendental, with some people believing in its irreducibility, and others seeing it as reducible to - if not contained in - the mental and/or physical worlds.)

Advertisement

There is a rich literature on the interrelations between these three worlds. I shall mention here only the three enigmas, or mysteries, that haunt our attempts to properly understand them:

The Wigner enigma, haunting the mathematical-physicalworlds interrelation. It is about the "unreasonable effectiveness of mathematics", meaning that most of the seemingly purely mental constructions in mathematics find applications as models describing some features of thephysical world, including making verifiable predictions.

The working mathematician's creation/discovery enigma haunts the mathematical-mentalworlds interrelation. Does a mathematician create his mathematics, or does he/she discover something that pre-exists in the "objective" world of mathematics? The answer is that both, although it is not easy to tell whether in a particular situation the creation or the discovery aspect prevails.

The quantum enigma haunts the mental-physicalworlds interrelation. It concerns the situation in modern physics, where observations seemingly create the physical reality observed, or in Wigner's words, the situation when "it was not possible to formulate the laws of quantum mechanics in a fully consistent way without reference to the consciousness". This hints at the Copenhagen interpretation of quantum mechanics, but even if abandoned, and replaced by Everett's many world's interpretation, as seems to be the preference among contemporary physicists, the enigmatic nature of this, or other interpretations, remains.

And perhaps the greatest enigma of them all is the following. In spite of all these uncertainties and ambiguities - concerning the nature of reality, its structure and the working of consciousness - when we need a level of understanding sufficient for everyday life, common sense is a practically reliable (albeit in most cases) guide.

  1. Pages:
  2. Page 1
  3. All


Discuss in our Forums

See what other readers are saying about this article!

Click here to read & post comments.

23 posts so far.

Share this:
reddit this reddit thisbookmark with del.icio.us Del.icio.usdigg thisseed newsvineSeed NewsvineStumbleUpon StumbleUponsubmit to propellerkwoff it

About the Author

George Virsik is a retired mathematician from Monash University living in Germany since 2000. He can be contacted at gvirsik@t-online.de.

Other articles by this Author

All articles by George Virsik

Creative Commons LicenseThis work is licensed under a Creative Commons License.

Article Tools
Comment 23 comments
Print Printable version
Subscribe Subscribe
Email Email a friend
Deals from Sponsor
Flipit.com Australia
Get Glasses discount code: Get 20% off on all sunglasses including Ray-Ban, Oakley, Gucci, Prada and more for Flipit Frenzy
Photobook Australia voucher code: Get 56% off on all products
Hilton promotional code: Get 25% off all Hilton hotels in Thailand
SurfStitch promo code: Get a free O'neill torch when you purchase any men's or women's O'neill jacket
Merry early Christmas from Toffee! Get 15% off site wide when you use this voucher code
Advertisement

About Us Search Discuss Feedback Legals Privacy