Though I haven't read the book, my Ph.D. in physics makes me inclined to join the discussion anyway.

GaryG48 wrote:“Traditionally these are questions for philosophy, but philosophy is dead. Philosophy has not kept up with modern developments in science, particularly physics. Scientists have become the bearers of the torch of discovery in our quest for knowledge.”

I think the point is that traditional philosophy which tried to answer all questions has been replaced by modern science. Probably got that right. But, since the book is almost completely philosophy of science, philosophy is far from dead.

The point is probably that traditional philosophy, which largely ignores physics theories like quantum mechanics, can't be taken seriously as a way of understand the nature of reality.

GaryG48 wrote: “According to Feynman, a system has not just one history but every possible history.”

Now, that certainly sounds like something Feynman would say but, since there are no formal references in this book, there is no easy way to know for sure.

Actually, that sounds a bit poetic for Feynman. That statement is more a way of translating the path-integral formulation into words.

Jim Watters wrote: The way I understood Feyman's sum-over-histories (Path Integral) approach, which has been scientifically proven correct in so many ways, is his thought experiment of the standard double-slit experiment:

Actually, there are (at least) three different ways of expressing the equations of quantum mechanics: matrices / Hilbert spaces, operators / differential equations, and path integrals / sum-over-histories. However, they are all mathematically equivalent, which implies that the correctness of one implies the correctness of the others.

However, there's definite value in having multiple mathematical representations. From a technical standpoint, different formulations are more helpful in modeling different physical situations. Philosophically, each mathematical structure provides a different perspective of the physical world.

Thank you for contributing JulianTheApostate, I hope you will be interested enough to get the book and remark on it given your Ph.D in physics.

I was referring to path integrals in the Quantum Field Theory (second quantization) sense, not the simple formalizations of Quantum Mechanics of wave-particle duality (Schrödinger, Heisenberg, Dirac).

In quantum field theory, path integrals are essential. All of the Standard Model is based on path integrals, the most successful being Quantum Electrodynamics.

The point is probably that traditional philosophy, which largely ignores physics theories like quantum mechanics, can't be taken seriously as a way of understand the nature of reality.....Julian the Apostate.

However, if the early philosophers hadn't thought about the issues first, perhaps the world wouldn't have arrived at the proof of them with physics.

Philosophically, each mathematical structure provides a different perspective of the physical world.

So then, all three would be accurate in a way that depends on a single underlying principle, or two could in the future found to be less accurate than the third?

lindad_amato wrote:However, if the early philosophers hadn't thought about the issues first, perhaps the world wouldn't have arrived at the proof of them with physics.

I can understand the statement “philosophy is dead” in regard to theories. But what about hypothesis? Are modern scientists who form a hypothesis different from past philosophers? It is my understanding that philosophy and hypothesis both start with an idea, an idea formed by observation. It is not until this idea is tested successfully that it becomes theory. Has theory replaced philosophy?

From Do You Plan to Participate in this Discussion?

Jim Watters wrote:I believe Hawking's hypothesis is that life evolved on Earth because we live in a Universe that supports the various chemical bonds (a couple dozen precise physical constants) to allow complex molecules to develop, multiply, evolve and then it's survival of the fittest for billions of years. Our Earth is in a very opportune distance away from our pretty much stable Sun that allows water to evaporate and freeze with active tectonic plates, erosion, and weather patterns to spice things up. Jupiter pretty much protects us from most asteroids.

...scientific objectivity, while necessary, is not sufficient to explain meaning and significance in human life, and that philosophy is needed to enframe science within a wholistic worldview.

To me, it all comes down to the Big Bang. Was there absolutely nothing including space and time "before" the Big Bang? Shifting the creation of the Universe to a "Creator" just hides the initial cause. What was "God" doing "before" the Big Bang? Yet people want to find purpose as to why we are here. Sometimes the answer is just pure luck. We evolved into naked apes that had superior brains that would dominate the Earth.

I understand that Hawkings' new book includes imaginative speculation on big questions that are beyond human knowledge such as the origin and extent of the universe. I tend to agree with the Buddhist view that "The Buddha who had truly realized the nature of these issues observed noble silence. An ordinary person who is still unenlightened might have a lot to say, but all of it would be sheer conjecture based on his imagination."

Building on the ability of modern science to provide an ultimate and absolute factual cosmology to the extent we need one, what is at issue is that scientific knowledge provides us with enormous quantities of data, but meaning and significance refer to how we process this data, how we develop a theory of value.

As I see it, the challenge within a theory of meaning is to see how we can base values on facts, how we can assign significance to the most important evidence and develop objective criteria to rank the importance of evidence.

Speculating beyond our knowledge to imagine a turtle at the bottom of the universe is frustrating and pointless. However, the case can be made that the old Indian myth of Kurma the Turtle is a fable based on observation of the Large Magellanic Cloud. This mythological reading brings the infinite imagination of the 'turtles all the way down' type back into the framework of finite observation, enframing cosmology within human ability to find meaning in what we see and know.

Suzanne,
I agree, there has to be some thought in order to form an idea and then test it.

Robert Tulip wrote:'turtles all the way down'.

I always found that ignorant quote unsettling funny: http://en.wikipedia.org/wiki/Turtles_all_the_way_down

Astronomers, Astrophysicists, Cosmologists, Particle Physicists and others are collecting an exponential amount of data about our observable Universe using today's technology. Many scientists have come up with theories to try to explain the data and cross-data, or get really theoretical with crazy-hard mathematics (Superstrings, M Theory) that probably can't be possible to test. But my hope is that our advancements in technology will allow us to finally patch together the fields of cosmology and particle physics within my lifetime. It would be the ultimate achievement of the human race to be able to explain how our Universe came into being.

Suzanne wrote:I can understand the statement “philosophy is dead” in regard to theories. But what about hypothesis? Are modern scientists who form a hypothesis different from past philosophers? It is my understanding that philosophy and hypothesis both start with an idea, an idea formed by observation. It is not until this idea is tested successfully that it becomes theory. Has theory replaced philosophy?

In terms of particle physics, The Standard Model has stood relatively unchanged for about 20 years. We had no particle accelerator to test higher energies than what the current accelerators could achieve.

Superstrings, M-Theory, and Super Gravity were discovered/created purely mathematically in attempt to reconcile the linear mathematics of superposition in Quantum Theory and the non-linear mathematics found in General Relativity. This reconciliation was achieved mainly through the mathematics of Supersymmetry. So theory has gotten ahead of experiment. Two additional hopes of the new Large Hadron Collider is that it will detect a signature of supersymmetry and extra spatial dimensions beyond the three we know of. That would make theoretical particle physicists happy that our "theories" are on the right track, thanks to the experimental particle physicists.

At the risk of scaring people away, the book received a rather scathing review from The Economist, which is probably inevitable for such an ambitious subject matter. I'm a bit wary of the possible "hand-waving" and unsupported speculation (according to the review), but even so I think it's still worth getting a glimpse of what a couple of top physicists think about these issues. I'll be getting the book in the next few days.
http://www.economist.com/node/16990802