Monday, November 1, 2010

Just Geometry

I've been hearing lately from people who say they found The Grand Design, the new book by Stephen Hawking and Leonard Mlodinow, easier to digest because of the advanced concepts I had already eased them into through my writing. Thanks for your kind words, everyone!

At the end of our last blog entry, Extra Dimensional Geometry, we talked about how we could work the hard determinist viewpoint into the idea that we are ultimately each just navigating within extra-dimensional patterns that already exist. In The Grand Design, the authors suggest that free will is an illusion. They say that the system of inevitable cause and effect outcomes leading from the big bang to the creation of life to the evolution of humans to an individual such as you or I right "now" is so incredibly complex, saying that we have "free will" works as an effective interpretation, but is ultimately not the correct one. I think the authors are trying to have their cake and eat it too on this point, but we'll return to that thought in a minute.

The Grand Design is a summary of mainstream cosmologists' thinking about the nature of reality, targeted towards an audience with little knowledge of the subject. Some readers may be frustrated by the book's repeating references to M Theory as being the best candidate for the ultimate Theory of Everything, while spending comparatively little time explaining any more about M Theory other than to say that it combines the five other versions of string theory.

(Here's an amusing Venn Diagram example from flickr)
M Theory, which relies on ten spatial dimensions plus one of time, can be thought of as a Venn Diagram: draw five circles which overlap in various ways, they represent the different versions of string theory, and M Theory provides a framework for showing how these different theories fit together and overlap. Hawking and Mlodinow invoke the interesting concept of "model-dependent realism" in their book, which we can sum up like this: reality can be interpreted in a number of ways, and the frame of reference from which you describe reality can make one theory or another appear to be more relevant while your viewpoint is within that frame. One of the more often-quoted examples from this new book appears in Dwight Garner's New York Times book review:
They write about a city in Italy that, a few years ago, barred pet owners from keeping goldfish in curved bowls. Why? Because it is cruel, the city council argued, to give the fish “a distorted view of reality.” We’re quite similar to those goldfish, the authors suggest. Our perceptions are limited and warped by the kind of lenses we see through, “the interpretive structure of our human brains.” Digging deeply into quantum physics, they argue that our universe “doesn’t have just a single history, but every possible history, each with its own probability.”
Which is where I believe the authors are having their cake and eating it too. In my book and this blog, one of the keys to understanding the multiverse is Feynman's "sum over histories" or "sum over paths" concept. Hawking and Mlodinow also talk about this important idea: the wave/particle duality underlying our reality means that there are many many paths a particle could have traveled to get to its current position. When you add all those paths together, you get the path that is most likely, but that is not the path that was necessarily taken. Hawking and Mlodinow say free will is an illusion because of the existence of this "most likely path" for every particle in the universe, which contradicts Feynman's theories and the evidence provided by numerous double-slit experiments clearly showing that particles do indeed take all paths, not just the most likely one provided by Feynman's sum over histories.

(image from Wikimedia Commons)

This double-slit experiment has shown that when a particle passes through a barricade having either one or two slits, when one slit is opened the resulting pattern shows (as you would expect) that only one path was taken. But when two slits are opened an interference pattern results: a particle is going through both slits simultaneously! Each particle interferes with itself as it passes through the two openings.

Now, the common objection to the relevance of all this is that the quantum world is completely separate from our classical reality. I've taken the opposing view, insisting that this is all part of the same continuum, and there really is no dividing line between the one layer of reality and the other.

Hawking and Mlodinow talk about how the double slit experiment has been successfully demonstrated with "buckyballs": molecules created from 60 carbon atoms. A buckyball passing through two slits simultaneously would already be moving uncomfortably far into our classical world for some people: but no more so than the "spooky action at a distance" entanglement experiments being demonstrated with increasingly large molecules over increasingly large distances that we've talked about in past entries.

I use the phrase "just geometry" in my book a number of times, here's an excerpt from chapter 8:
The idea of the moment you are experiencing at this instant as being “just geometry” means that there are multiple paths which could have caused you to arrive at this particular moment, and the path that you remember as being your personal history is only one of many which could have brought you to this present moment in time (as you will recall from the discussion of Feynman’s “sum over paths” theory which we first looked at in chapter four). The image of the extraordinarily extravagant multiverse that is inferred from this concept is something we discussed in the Introduction, as this ties directly to Everett’s “Many Worlds Theory” and “decoherence”, both of which have been enjoying renewed support in the last few years. And finally, we should always be mindful of the double-edged sword that is implied by the idea of the current instant of time being “just geometry”: while this means that the potential for this instant of time has always existed within the tenth dimension (as have all the potential moments to come and all the ones that could have already occurred), it does not mean that our path is somehow carved in stone and unavoidable. As creatures with free will, we are constantly moving through the fifth dimensional paths that are available to us, selecting one of those paths as our personal timeline. The path that we have been on makes the next possible choice the more likely one (and that would be the one predicted by the sum over paths method), but a life-changing decision or event that breaks old habits and old patterns will certainly direct a person’s life to a new trajectory, making other future paths more likely to be followed from that point on.
I hope that the concept of "model-dependent realism" shows another way that my own approach to visualizing the dimensions can be juxtaposed with other theories of reality: it works as a frame of reference, it has its uses because of that, but it is only one way of many systems for describing how our universe fits into the biggest picture of all. We're going to continue this exploration next time in an entry called "Thinking Biggest".

Till then, enjoy the journey!

Rob Bryanton


Ron Krumpos said...

In "The Grand Design" Hawking says that we are somewhat like goldfish in a curved fishbowl. Our perceptions are limited and warped by the kind of lenses we see through, “the interpretive structure of our human brains.” Albert Einstein rejected this subjective approach, common to much of quantum mechanics, but did admit that our view of reality is distorted.

Einstein’s Special Theory of Relativity has the surprising consequences that “the same event, when viewed from inertial systems in motion with respect to each other, will seem to occur at different times, bodies will measure out at different lengths, and clocks will run at different speeds.” Light does travel in a curve, due to the gravity of matter, thereby distorting views from each perspective in this Universe. Similarly, mystics’ experience in divine oneness, which might be considered the same "eternal" event, viewed from various historical, cultural and personal perspectives, have occurred with different frequencies, degrees of realization and durations. This might help to explain the diversity in the expressions or reports of that spiritual awareness. What is seen is the same; it is the "seeing" which differs.

In some sciences, all existence is described as matter or energy. In some of mysticism, only consciousness exists. Dark matter is 25%, and dark energy about 70%, of the critical density of this Universe. Divine essence, also not visible, emanates and sustains universal matter (mass/energy: visible/dark) and cosmic consciousness (f(x) raised to its greatest power). During suprarational consciousness, and beyond, mystics share in that essence to varying extents. [quoted from my e-book on comparative mysticism]

Eamon said...

Hey Rob, I just tried to fathom the idea of exploring the branching futures in the fifth dimension, and then it got mindboggling (more than usual, that is); since I thought, currently, with the 6 or 7 billion people in the planet all making choices at the same time, that means that the number of branches is... whoa.

Michael R said...

Part of this is going to be me regurgitating your 10-dimensions video (which I loved), but perhaps with a few modifications:

"it does not mean that our path is somehow carved in stone and unavoidable. As creatures with free will, we are constantly moving through the fifth dimensional paths that are available to us, selecting one of those paths as our personal timeline." This statement "as creatures with free will, we ARE", assumes free will. It would be more correct to say "Assuming we are creatures with free will, we theoretically COULD". Some say the universe is random, probabilistic or deterministic, yet none of those concepts leaves room for free will.

The statement "selecting one of those paths as our personal timeline", once again assumes free will. IF there are nearly infinite past and future timelines through which we have and will navigate, then we actually don't have free will if we simultaneously are making every choice possible—we’re just blind to our alternative selves. It’s similar to the argument that “the universe could not support life were several constants different”, but we just happen to be in the version of reality where those constants support beings that are able to ponder that very question, just like we just happen to be experiencing this timeline while infinite “selves” simultaneously exist, yet we only remember the past that led to here.

We naturally assume the present we experience is the result of our free will rather than us existing simultaneously in one of infinite realities (some in which just a single particle behaved differently). Likewise, those realities would exist as a subset of all the possible values of constants in the universe (so nearly infinite timelines within this universe, and nearly infinite versions of the universe based on physical constants).

Personally, I’m not yet convinced that given the state of the universe at any point in “time”, that any other past and present is possible. Given different initial conditions of all the matter and energy of a universe with our physics, a different but nearly identical timeline could occur such that we would want to think of it as possible past and presents of our timeline, yet this timeline would be as deterministic and separate as our own. Nearly infinite timelines could exist with infinite initial conditions, and infinite rules of physics could exist with their own sets of infinite initial conditions, creating infinite causal realities. I think free will is an illusion, a side-effect of consciousness and memory, no less Anthropocentric than assuming the universe exists in the colors we perceive it to be, or that time flows--or exists at all—since we perceive a past and flow of events via our memories.

Anonymous said...

Philosophy is dead. Is Logic dead also?

How did the scientists come to know that an entire universe could come out of nothing? Or, how did they come to know that anything at all could come out of nothing? Were they present at that moment when the universe was being born? As they were not present there, therefore they did not get that idea from the creation event. Rather they got this idea being present here on this very earth. They have created a vacuum artificially, and then they have observed that virtual particles (electron-positron pairs) are still appearing spontaneously out of that vacuum and then disappearing again. From that observation they have first speculated, and then ultimately theorized, that an entire universe could also come out of nothing. But here their entire logic is flawed. These scientists are all born and brought up within the Christian tradition. Maybe they have downright rejected the Christian world-view, but they cannot say that they are all ignorant of that world-view. According to that world-view God is omnipotent, omniscient and omnipresent. So as per Christian belief-system, and not only as per Christian belief-system, but as per other belief-systems also, God is everywhere. So when these scientists are saying that the void is a real void, God is already dead and non-existent for them. But these scientists know very well that non-existence of God will not be conclusively established until and unless it can be shown that the origin of the universe can also be explained without invoking God. So how have they accomplished that job, the job of explaining the origin of the universe without invoking God? These were the steps:
1) God is non-existent, and so, the void is a real void. Without the presupposition that God does not exist it cannot be concluded that the void is a real void.
2) As virtual particles can originate from the void, so also the entire universe. Our universe has actually originated due to a quantum fluctuation in the void.
3) This shows that God is in no way necessary for explaining the origin of the universe. There was no creation event.
4) This further shows that God does not exist.
So here what is to be proved has been proved based on the assumption that it has already been proved. Philosophy is dead for these scientists. Is it that logic is also dead for them?

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