Monday, April 29, 2013


One of the deepest mysteries in science and philosophy is the nature of time. The puzzlement goes back at least as far as Augustine (354-430) who raised a number of perplexing questions about it in his Confessions. Some thinkers, including many physicists, follow Immanuel Kant in believing that time has no existence apart from the human mind and that our experience of time is a kind of illusion. Lee Smolin, however, dissents from the consensus view in his new book Time Reborn.
In a conversation with Duke University neuroscientist Warren Meck, theoretical physicist Smolin, who's based at Canada's Perimeter Institute for Theoretical Physics, argued for the controversial idea that time is real. "Time is paramount," he said, "and the experience we all have of reality being in the present moment is not an illusion, but the deepest clue we have to the fundamental nature of reality."

Smolin said he hadn't come to this concept lightly. He started out thinking, as most physicists do, that time is subjective and illusory. According to Albert Einstein's theory of general relativity, time is just another dimension in space, traversable in either direction, and our human perception of moments passing steadily and sequentially is all in our heads.

Over time, though, Smolin became convinced not only that time was real, but that this notion could be the key to understanding the laws of nature.

"If laws are outside of time, then they're inexplicable," he said. "If law just simply is, there's no explanation. If we want to understand law … then law must evolve, law must change, law must be subject to time. Law then emerges from time and is subject to time rather than the reverse."
This view, however, is subject, as Smolin acknowledges, to a major criticism called the "meta-law dilemma":
If physical laws are subject to time, and evolve over time, then there must be some larger law [i.e. a meta-law] that guides their evolution. But wouldn't this law, then, have to be beyond time, to determine how the other laws change with time? Other physicists have cited this objection in reaction to Smolin's work.

Columbia University physicist Peter Woit wrote to Smolin on his blog that "you speculate a bit in the book on ways to resolve this, but I don't see a convincing answer to the criticism that whatever explanation you come up with for what determines how laws evolve, I’m free to characterize that as just another law."
Smolin is persistent, though. He believes the meta-law problem can be solved. Perhaps it can, but the discussion sounds as though it's pointing to a higher reality beyond the space-time reality in which we are embedded. It's interesting how so much of science tends to do that.

At any rate, the view that time is an illusion is believed by some to entail that all events are simultaneously existent. Future and past events exist concurrently with the present, like frames on a movie film, but our consciousness moves through them in such a way as to give the illusion that they are coming to be and ceasing to be. Think of the movie projector, our consciousness, moving along the film casting the frames on our mind rather than the film moving through the projector.

Unfortunately, if the future already exists then we're not really free to create it. If we're not free to choose what the future will be then we're just so much temporal flotsam carried along by the current of existence, and it's hard to imagine what basis there'd be in such a world for human dignity.
"If I think the future's already written, then the things that are most valuable about being human are illusions along with time," Smolin said. "We still aspire to make choices in life. That is a precious part of our humanity. If the real metaphysical picture is that there are just atoms moving in the void, then nothing is ever new and nothing's ever surprising — it's just the rearrangement of atoms. There's a loss of responsibility as well as a loss of human dignity."
I wonder, though, why time can't be an illusion, a subjective phenomenon created by our minds, without that entailing a predetermined future. I suppose I should read the book.