Monday, October 6, 2014

Time Is Real, Part I

Time is real. Some of you may be thinking, of course. What's your point? Others of you might be saying, no way. I've studied physics and philosophy, or I've studied theology, and time is just an illusion. It is literally only measured unto men, and there are definitely things that transcend time. As a Mormon, I'm going to add my voice to Lee Smolin's physicist voice, and say that to move forward most effectively we need to give up the idea of things outside of time. The laws of physics are laws inside of time, tied to relationships among matter and energy, and evolving as time progresses and new properties emerge. God is within time, and while we may not fully understand His power or knowledge, God only transcends our current existence in the way that humanity may eventually transcend itself. I know Smolin is a proclaimed atheist, but I am passionately drawn to his ideas, so it's time for a review of another of his books: Time Reborn.

What follows is a summary with some commentary. If my summary doesn't make sense, and you are interested, check the book out from the library. It is very approachable and easy to follow. He doesn't weigh the discussion down with difficult technical details, but he also isn't boring for someone familiar with the history and subject matter. I can also try to answer some questions in the comments.


Chapter 1

Properties that transcend time and space are attractive to us for explaining the universe, but will never be as productive as explanations limited to within the observable universe, because they can never be tested.

Chapter 2

Isaac Newton made math an amazingly powerful tool for unifying and describing the universe, but time went away in his conception. Newton posited absolute space and time through which everything moved. Relativity got rid of absolute space (but not transcendent time).

Chapter 3

Mathematics is not reality. It is an incomplete representation of reality, particularly because it is timeless. It doesn't include the experience of now. Smolin introduces some loaded language at this point, and possibly a false dichotomy. He calls the person who believes math is reality a mystic (I agree), and the person who views math as an incomplete representation a pragmatist (I agree again). However, I'm not sure either is truly free of mysticism. I suppose we will see how far Smolin gets with this distinction.

Chapter 4

Science by reduction. This is a great, non-technical explanation of how reductionism works and the assumptions it introduces. The idea is that everything can be described as isolated systems where we know the initial conditions and the rules that govern changes. Thus, the whole history (and future) of the universe could be theoretically known if we simply understood all the laws and the initial conditions (or conditions at any time) of the entire universe.

Chapter 5

Determinism is an immense claim. Every aspect of our great-great-grandchildren's future was determined and theoretically knowable back at the Big Bang. A favorite quote from this chapter is about Smolin's relationship with Einstein:
Later I discovered that there's very little in physics to match the conceptual clarity and elegance of Einstein's theories. . . . But because I began with Einstein, his work became my scientific standard and his theories of relativity became my touchstones, their principles as sacred as any text could be to one schooled in the skepticism of science. pp. 54-55
I do wonder about this quote, though. Is it really impossible for someone schooled in the skepticism of science to find things truly sacred? Or impossible for one who believes in the sacred to be correctly schooled in science? I don't believe it, and think Smolin limits himself by taking this stance, but that's not very relevant to the current chapter.

Chapter 6

Special and general relativity are deterministic and they make the present even less special than it was with Newton. We can't even agree on when now is, so time must not be fundamental. Plus, time had a beginning, while the laws of relativity somehow transcend that time, so time is just one more element of timeless spacetime.

Chapter 7

Quantum cosmology (in some forms) says everything is now. We just experience one (collection) of nows, but all of them are real and eternally present. Time is an illusion.


At this point Smolin shifts from showing how time was turned into an illusion to beginning his argument for why it is real. I give two quotes:
If science must tell a story that encompasses and explains everything we observe in nature, shouldn't that include our experience of the world as a flow of moments? Isn't the most basic fact about how experience is structured a part of nature that a fundamental theory of physics should incorporate?

Everything we experience, every thought, impression, action, intention, is part of a moment. The world is presented to us as a series of moments. We have no choice about this. No choice about which moment we inhabit now, no choice about whether to go forward or back in time. No choice to jump ahead. No choice about the rate of flow of the moments. In this way, time is completely unlike space. (p. 92)
In other words, science that doesn't recognize the reality of time is very likely an incomplete representation, rather than our perception of time being an illusion. At this point, Smolin lists the arguments that removed time from reality and that he now needs to address to reestablish the reality of time.
The nine arguments fall into three classes:  
Newtonian arguments (that is, arguments stemming from Newton's physics or Newton's paradigm for doing physics):
  • The freezing of motion by graphing records of past observations (Chapter 1)
  • The invention of the timeless configuration space (Chapter 2)
  • The Newtonian paradigm (Chapter 3)
  • The argument for determinism (Chapter 4-5)
  • Time-reversibility (Chapter 5)
Einsteinian arguments, stemming from the theories of special and general relativity:
  • The relativity of simultaneity (Chapter 6)
  • The block-universe picture of spacetime (Chapter 6)
  • The beginning of time in the Big Bang (Chapter 6)
Cosmological arguments, stemming from extending physics to the universe as a whole:
  • Quantum cosmology and the end of time (Chapter 7)
Now it's on to part II of the book--just as soon as I finish reading it.

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