Given Hawking's statement about philosophy, I thought this was an interesting description of philosophy from Peter Hacker, a Wittgenstein expert who is apparently a critic of neuroscience:

“Philosophy does not contribute to our knowledge of the world we live in after the manner of any of the natural sciences. You can ask any scientist to show you the achievements of science over the past millennium, and they have much to show: libraries full of well-established facts and well-confirmed theories. If you ask a philosopher to produce a handbook of well-established and unchallengeable philosophical truths, there’s nothing to show. I think that is because philosophy is not a quest for knowledge about the world, but rather a quest for understanding the conceptual scheme in terms of which we conceive of the knowledge we achieve about the world. One of the rewards of doing philosophy is a clearer understanding of the way we think about ourselves and about the world we live in, not fresh facts about reality.”

http://www.philosophypress.co.uk/?p=1583

Robert Tulip wrote:Here we zero in on the philosophical and epistemological flaws in the mainstream modern logic of physics as ably articulated by Hawking. We have to assume the universe exists. This assumption provides an axiomatic foundation for all knowledge. It is absurd to say we can't know that components of a model correspond to real entities when these entities are as obvious as planets and stars, in their features that are abundantly verified by consistency with observation.

When considering a scientific theory, there are two questions you can ask. Does the theory accurately predict experimental results? What does the theory mean; for example, are the components of the theory real? It's entirely possible for a theory to be predictive even though its components are dubious.

Ptolemaic Astronomy is a good example of that. Its ideas seem rather ridiculous to anyone alive today, who believe that the Earth revolves around the sun. However, it did a pretty good job of predicting the movement of planets and the timing of eclipses.

Dexter wrote:Until we see some replication of this study, I think the proper response is skepticism.

What I was pointing out isn't if the study is correct but that the study mimics the alternate histories of quantum mechanics. It reflects the idea that the oddness of quantum might not be so odd. For example: The uncertainty principle is not unique to quantum but goes through most mathematics but is called something else in various disciplines. You can even get it with driving a car. You can't know exactly your speed or location in the road when driving. When you glance down to the speedometer you have taken your eyes off the road and will travel up to hundreds of feet before you can look up and find out your location again.

Robert Tulip wrote: but there are projections that show all parts of the globe

Yes but every projection produces distortions and it is impossible to get a non-distorted 2-d map of a sphere.

I noticed that Brian Greene is coming out with his own "multiverse" book:
http://www.amazon.com/Hidden-Reality-Pa ... N014EEF6D6

I would like to hear some of the scientist dissenters on this view, I found a few comments in looking for reviews of Hawking. I guess essentially the criticism is that, at this point (and possibly forever) it is all unfalsifiable speculation.

Dexter wrote:I would like to hear some of the scientist dissenters on this view, I found a few comments in looking for reviews of Hawking. I guess essentially the criticism is that, at this point (and possibly forever) it is all unfalsifiable speculation.

The answer is yes and no as speculation. The problem is how you define proving. Physicists are getting to the point in understanding that what is uncertain is just as important as what is. M-theory and even String theory will possibly always have big unknowns, possibly bigger unknowns than what is known. But just because you don't have an exact answer doesn't mean that they are incorrect. Consider your typical CSI TV show. You find someone with a bullet hole in them and dead. After investigating the possibilities you can give the result that the person was shot by someone. You might not have a who or why--you might even have to leave in the possibility that the person was shot by an animal or a robot. If you want the level of proof that is frequently used in mathematics and science you will never be able to say that another person shot the dead one but you have to have a logical starting point and in this case M-theory is holding this starting point open. Because you have M-theory holding open the door to understanding the universe, you are left with a whole set of options and things to look for and consider. Just like in the CSI show, you start investigating the people who knew the dead person because of the logical assumption that a person was doing the shooting. M-theory puts you on the track in finding answers that without it you are just left with a dead person and no where to go. It is very possible that at some future time M-theory will be replaced but at this monent in the universe nothing else is there to frame the question on what to look for next but M-theory.

WONK wrote:It is very possible that at some future time M-theory will be replaced but at this monent in the universe nothing else is there to frame the question on what to look for next but M-theory.

Maybe I just didn't get it, but after reading Hawking's book, I'm no closer to understanding why he and others think that M-theory is so promising.

I realize we're dealing with difficult theories, but I don't have much understanding of quantum theory beyond a superficial level either, yet I have read books that at least gave me some insight into what it's all about. (Of course, I'm criticizing Hawking's book rather than the theory itself.)

M-Theory is just as hard to understand as Quantum Mechanics and it is half a century younger so there are not as many examples created to make it easier to understand. Basically it comes down to that because of the imprints left in our 4-D universe there is enough evidence that there are more dimensions (this has been shown by both the standard theory and string--this has been known for 60 years) also there are artifacts in the mathematics used every day that indicate that there are multiple universes. When you combine these bits of information you get M-theory. But it isn't a theory most people think about but a framework from standard theory, string theory and multiple universes (from the mathematics) that tells us which questions to ask next and how to put the parts that don't overlap, such as Relativity and Quantum, together so you can transfer the information from one field into another. Because it is more of a question and transfer method than a new theory that explains physical events by itself many scientists don't like it and want to find and use something better. But most of the scientists doing the very advanced work in these fields think that it is the best we can do for now. The reason is that, since quantum, scientists have started to accept that uncertainty has to be included in the advanced sciences we are not working in and M-theory is framed around the uncertainties. It is a version of the uncertainty principle but for how different theories interact.