Newswise — The
universe’s clock has neither a start nor finish, yet time is finite
according to a New Zealand theorist. The theory, which tackles the
age-old mystery of the origin of the universe, along with several
other problems and paradoxes in cosmology, calls for a new take on
our concept of time – one that has more in common with the “cyclic”
views of time held by ancient thinkers such as Plato, Aristotle and
Leonardo da Vinci, than the Christian Calender and Bible-influenced
belief in “linear” time now so deeply imbedded in modern western
thinking.
Following its
initial publication on the arXiv physics archive at Cornell
University earlier this year [url: http://arxiv.org/pdf/physics/0612053],
the author of the theory, Peter Lynds, presented a second paper
about it at the International Conference on Complex Systems in
Boston on November 1 [url: http://necsi.org/events/iccs7/viewpaper.php?id=225].
Another group also presented a conference paper about the
theory.
Lynds’ theory
involves the second law of thermodynamics, a bedrock of physics and
the explanation behind why we only ever experience events evolving
in one time direction in nature. This law is related to the fact
that heat can never pass spontaneously from a colder to a hotter
body. As a function of heat’s ability to disperse, hot flows to
cold. Because of this, natural processes that involve energy
transfer tend to have one direction and to be irreversible.
However, what would happen if, due to certain extreme physical
conditions, heat was unable to flow to cold and was forced to flow
to hotter?
In his theory,
Lynds posits that rather than this inevitably happen and the second
law of the thermodynamics be breached just before the universe
gravitationally collapses to a big crunch or matter reaches the
centre of a black hole, the order of events should reverse
direction. As all of the laws of physics – with the exception of
the second law of thermodynamics – are time reversible and work
equally well in opposing directions, Lynds asserts that no laws of
physics would be contravened by such a reversal, while it would
also allow the second law of thermodynamics to continue to hold.
This is contrast to previous theories involving thermodynamic time
reversal, including those by Thomas Gold in the 1960s and Stephen
Hawking in the 1980s, which all involve the second law of
thermodynamics being breached. Such theories have generally been
dismissed by physicists because of contradictions directly
resulting from such a second law violation – contradictions that
Lynds says his theory avoids.
Lynds asserts that if many billions of years from now the
universe stops expanding and contracts to a big crunch, such a
revised conception of thermodynamic time reversal leads to a
coherent picture of the cosmos in which there is no differentiation
between past and future, and the so-called beginning of the
universe, the big bang, can equally be said to be in the past or
future of the big crunch. This means that the big bang and the big
crunch can also equally be said to cause one another, therefore
providing an answer to that most intractable of questions: what
caused the big bang?
Furthermore,
because events are always evolving away, rather than ever towards
one, there are no gravitational “singularities” – hypothesized
points where gravity and heat become infinite and the laws of
physics break down. Aside from proposed avoidance mechanisms in
theories such as String theory and Loop quantum gravity,
singularities have been a troublesome but inescapable feature of
mathematical physics ever since the 1960s when work by Sir Roger
Penrose and Stephen Hawking showed that they must result at the big
bang, the big crunch, and inside black holes – provided Albert
Einstein’s general theory of relativity is correct and some basic
assumptions are met. One of the assumptions underlying the Penrose
and Hawking singularity theorems is that events and times converge
towards a singularity. In Lynds’ theory, events and times are
always diverging or evolving away from a potential singularity, so
none are encountered. “The reversal of the order of events so that
the second law of thermodynamics can continue to hold, would appear
to be a very good way on Nature’s part of avoiding singularities,
while also guaranteeing that the universe can remain continuous and
without causal contradiction,” says Lynds.
Significantly, the
theory also addresses a famous paradox posed by the 18th-century
German philosopher Immanuel Kant, which concludes that the idea of
the universe extending back infinitely in time is contradictory,
while its antithesis – the idea that the universe began at some
finite time in the past – also results in contradiction. Kant asked
that if the universe did have a beginning, what happened beforehand
to cause it? And what before that? Kant noted that there would
always be an infinite number of “what before that’s.” On the other
hand, if time extended back forever, there would be an infinite
period of time before any event – something that Kant also
considered absurd. “With a universe that stretches back infinitely
in time and has no starting point, it would also be impossible for
the universe to evolve forward, not only to where it is today, but
at all,” says Lynds. Because his theory asserts that the universe
is finite, but yet also has no beginning or first cause (because
the big bang is caused by the big crunch, which would normally be
thought of as being in the future of the big bang), Kant’s paradox
disappears. “A universe in which time is cyclic is really the only
possible answer to a paradox such as Kant’s,” says Lynds. “In
relation to how telling it is, I do not think that people have
generally realised just what a perfect paradox Kant put forward. It
shows that there is something very much going wrong with our
regular assumptions regarding time, cause and cosmology.”
However, Lynds has some caveats for his theory. “It is reliant
on the universe being closed and eventually collapsing,” says
Lynds. “At the moment, it is very uncertain whether there is enough
mass in the universe to cause it to eventually collapse, or if it
will continue expanding forever. If the universe isn’t closed, my
theory is wrong. The detail behind what causes the reversal is also
non-quantitative and speculative, while the paper in general is a
bit awkward, it sitting somewhere between physics and philosophy,
and moving over some different areas. It is a bit of an ugly
duckling, in that it doesn’t neatly fit anywhere.”
From a historical
perspective, Lynds notes the idea that time might be cyclic is an
old one and was very popular in ancient times. “In relation to it
being an old idea, the saying “there is nothing new under the sun”
is itself actually from a passage about cyclicity in the book of
Ecclesiastes circa 250BC,” says Lynds. “It wasn’t until the Middle
Ages when Christianity really took hold in Europe and the Christian
Calendar became firmly established, that the view of time being
linear and going in a straight line, the one we are all now so
familiar with in modern western society, actually became prominent.
Indeed, around this period, a belief in time being cyclic was
actually outlawed by the Catholic Church and chargeable as
blasphemy, as it was opposed to the unique chronology of events
described in the Bible; a drama that, according to scripture, takes
place only once.”
Lynds says he is expecting his theory to be controversial – a
theory that he has only now begun to pursue after it came to him
one night in 1998 while laying in bed. Lynds, a 31-year-old who is
without university qualification, is familiar with controversy,
with another theory causing waves in 2003. That theory also
involved questioning long-held assumptions about time and physics –
the existence of instants in time and of time in general – and
another famous problem, Zeno’s paradox. “I doubt that people who
believe the universe was created will like it as it leaves no place
for a Creator, while due to its nature and some of the questions
involved, I feel it will probably invite cynicism from some as
well. It is also very counterintuitive, requiring one to see beyond
a number of deeply imbedded intuitions and assumptions regarding
time. For the moment, I’m more just happy to get it out there.”
About Lynds’ theory, Dr. Paul Frampton, Louis D. Rubin Jr.
Distinguished Professor of Physics at the University of North
Carolina at Chapel Hill, says, “I enjoyed reading Lynds’ article
about an endless and beginningless universe, especially as I have
myself worked on such a model recently (Phys. Rev. Lett. 98,
071301, 2007). Lynds addresses the key issue of the second law of
thermodynamics in a novel way and I'll be curious to see how far he
can take it.”
Dr. Jonathan Vos
Post, a former Professor of Astronomy at Cyprus, College.
California, and Professor of Mathematics at Woodbury University,
California, says, “I consider Peter Lynds's arXiv paper to be a
bold and magnificent speculation. Those who attack him are
misguided, in that Peter Lynds’ arguments need to be put in proper
historical context, which is apparently outside the educational
background of those who prematurely dismiss the subtleties of Peter
Lynds insights. Let me refer back to an 1895 paper by the immortal
[Ludwig] Boltzmann, which has recently attracted attention in the
controversy over so-called "Boltzmann Brains.” The reference is
Nature 51, 413 (1895). [Long quote by Ludwig Boltzmann
concerning the second law of thermodynamics and the possibility of
universe later returning to its present state]. Peter is cursed
with having brilliant theories that his detractors falsely assume
are based on ignorance. His startling re-analyses of (1) Zeno's
paradox, (2) the nature of Time, and (3) the nature of
consciousness, have been spuriously opposed by naive critics who
claim that Peter does not know (1) Calculus, (2) Relativity, (3)
Psychology. To the contrary, I hold that his ability to ask
"simple" questions, and give extraordinary answers, is close in
many ways to the genius of Einstein, Feynman, Hawking, Paul Erdos,
John Wheeler, Stephen Wolfram, and Frank Zappa.”
Dr. Werner Israel,
a Professor of Physics and Astronomy at the University of Alberta,
Canada, and a Fellow at Canada’s Institute for Advanced Study
Cosmology and Gravity Programme, says, “I found Peter Lynds' ideas
on possible reversals of time's arrow interesting, in part because
I have entertained less bold but not dissimilar ideas myself. In
1991 I co-authored a note in Nature which speculated on the
possibility that the growth of entropy near a big crunch might be,
not reversed exactly, but enormously diluted by a process called
mass inflation at the inner horizons of coalescing black holes.
This would make a transition to an expanding phase very nearly
reversible thermodynamically.”