Register | Sign In


Understanding through Discussion


EvC Forum active members: 64 (9159 total)
1 online now:
Newest Member: K.Rose
Post Volume: Total: 914,969 Year: 2,226/9,624 Month: 71/1,588 Week: 267/338 Day: 16/55 Hour: 0/0


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   Julian Barbour on Time
GDR
Member
Posts: 6189
From: Sidney, BC, Canada
Joined: 05-22-2005


Message 1 of 2 (231973)
08-10-2005 3:42 PM


I am wondering if there is anyone on the forum that is familiar with and has an opinion on the theories of Julian Barbour. He wrote a book called The End of Time, in which he claims that time does not exist. He claims as I understand it that we function in a series of nows, and that each now exists forever. This is an excerpt from a book review.
Julian Barbour writes:
Specifically, DeWitt hijacked the Schrdinger equation, named for the great
Austrian physicist who created it. In its original form, the equation reveals how
the arrangement of electrons determines the geometrical shapes of atoms and
molecules. As modified by DeWitt, the equation describes different possible
shapes for the entire universe and the position of everything in it. The key
difference between Schrdinger's quantum and DeWitt's cosmic version of the
equation besides the scale of the things involved is that atoms, over time,
can interact with other atoms and change their energies. But the universe has
nothing to interact with except itself and has only a fixed total energy. Because
the energy of the universe doesn't change with time, the easiest of the many
ways to solve what has become known as the Wheeler-DeWitt equation is to
eliminate time.
Most physicists balk at that solution, believing it couldn't possibly describe the
real universe. But a number of respected theorists, Barbour and Stephen
Hawking among them, take DeWitt's work seriously. Barbour sees it as the
best path to a real theory of everything, even with its staggering implication that
we live in a universe without time, motion, or change of any kind.
Strolling in the meadows of oxford's Christ Church College with Julian Barbour,
time and motion seem undeniable. Towering cumulus clouds float overhead,
ferried by a gentle breeze. Children run and shout in the same field where Alice
Liddell, the girl who inspired Lewis Carroll's Alice's Adventures in
Wonderland, often played. How can there be no time, no movement? Barbour
settles his tall, lean frame into the grass, readying himself for a long explanation
to yet another skeptic. He begins with what seems a most straightforward
proposition: Time is nothing but a measure of the changing positions of objects.
A pendulum swings, the hands on a clock advance. Objects and their
positions he argues, are therefore more fundamental than time. The universe
at any given instant simply consists of many different objects in many different
positions.
That sounds reasonable, as it should, coming from a thoughtful gentleman like
Barbour. But the next part of his argument the crux of his view is much
harder to swallow: Every possible configuration of the universe, past, present,
and future, exists separately and eternally. We don't live in a single universe that
passes through time. Instead, we or many slightly different versions of
ourselves simultaneously inhabit a multitude of static, everlasting tableaux that
include everything in the universe at any given moment. Barbour calls each of
these possible still-life configurations a "Now." Every Now is a complete,
self-contained, timeless, unchanging universe. We mistakenly perceive the
Nows as fleeting, when in fact each one persists forever. Because the word
universe seems too small to encompass all possible Nows, Barbour coined a
new word for it: Platonia. The name honors the ancient Greek philosopher who
argued that reality is composed of eternal and changeless forms, even though
the physical world we perceive through our senses appears to be in constant
flux.
The following is another quote from the review on the reaction of some of his peers.
interviewer writes:
How does the physics community react to such ideas? Physicists who know
Barbour's work agree that it shouldn't be dismissed out of hand. At a physics
conference in Spain, Barbour conducted an informal poll. He asked how many
of the physicists believed that time would not be a part of a final, complete
description of the universe. A majority were inclined to agree.
Don Page, a cosmologist at the University of Alberta in Edmonton who
frequently collaborates with Stephen Hawking, raised his hand that day. "I think
Julian's work clears up a lot of misconceptions," says Page. "Physicists might
not need time as much as we might have thought before. He is really
questioning the basic nature of time, its nonexistence. You can't make technical
advances if you're stuck in a conceptual muddle." Strangely enough, Page feels
that Barbour might actually be too conservative. When physicists finally iron
out a new theory of the universe, Page suspects that time won't be the only
casualty. "I think space will go too," he says cryptically.
Here is the link:
Discover Financial Services
I realize that I should develop this more than I have, but I don’t have the personal knowledge to make any type of intelligent comment. I would just like to know what the opinion is of those who do know what they’re talking about.
I suggest that this should be posted under "Big Bang and Cosmology"

Admin
Director
Posts: 12989
From: EvC Forum
Joined: 06-14-2002


Message 2 of 2 (232525)
08-12-2005 7:51 AM


Thread copied to the Julian Barbour on Time thread in the Big Bang and Cosmology forum, this copy of the thread has been closed.

Newer Topic | Older Topic
Jump to:


Copyright 2001-2023 by EvC Forum, All Rights Reserved

™ Version 4.2
Innovative software from Qwixotic © 2024