Why is the universe
"just right" for
life?
Do we live in a multiverse
or was our universe designed?
( Part 2 )
Properties — Characteristics,
Constants, and Conditions
When thinking about "what might
not happen" if the universe was slightly different, we can think about three
types of properties — characteristics,
constants, and conditions:
• The basic characteristics of
our universe include matter/energy in a variety of "elementary particle" forms
(like protons, electrons,...) and their possible components (such
as quarks & leptons), + and - charge, wave/particle duality (which prevents
matter
from forming inert clumps of +- charge) and the resulting quantizations,
Pauli Exclusion Principle, 3-dimensional physical space, four basic forces
(gravitational, electromagnetic, weak nuclear, strong nuclear), causal relationships
(as formulated by Newton, Einstein, Faraday, Maxwell, and others) and more.
• Some important features
of these characteristics depend on physical constants such
as the force constants that help determine the strength for each type of force,
Planck's Constant for the quantization of energy, the charge and mass for each
particle, and the relative mass-ratios between protons, neutrons, electrons,....
• The current state of the
universe also depends on initial conditions such
as the initial spatial distribution and amounts of matter and antimatter
(and the excess of matter over antimatter), and the initial rate of expansion
during the Big Bang.
Should we be amazed? If a universe could produce and support life with almost any combination of
properties, we
could
say "Of course there is life, since
wherever
matter exists there will necessarily be life." The reality,
however, is that a universe able to support life is extremely improbable.
Is
carbon-based
life
the
only
possibility? Probably. In principle, life might exist
without familiar ingredients like sunshine or DNA, but most scientists are
convinced that the constraints on a life-allowing universe are very tight,
that small changes would make it impossible to produce
intelligent life of any kind
we can imagine. Based on scientific evidence, there is little
doubt about this
conclusion.
The Science & Theology of Design: A scientific theory of Intelligent Design, when supplemented by a theistic interpretation, can become a theological theory of divine creation. And for those who want to avoid the need for a designer/creator, a scientific theory of Many Universes, when supplemented by an atheistic interpretation, can become a theological theory about a universe without God. {more about science and theology}
Beating the Odds
A
theory of Many Universes (MU)
proposes a way to beat the odds. Imagine
that scientists have analyzed the probability of a universe capable of producing
life-forms that are intelligent (so they can analyze the probability for their
own existence!) and have estimated the odds to be very low, less than
1 in
a thousand
million billion trillion zillion.
If there is only one universe, we must conclude that we are very lucky. But
if there were enough universes (as proposed in MU), and if all properties of
these universes were distributed across a wide range,
the odds
would be highly in favor of having at least one universe with intelligent life.
For example,... {most of what was here is now in the appendix of Part 1}
How could it be produced?
If there is a multiverse (with
many universes) instead of just one universe (the
one we live in and can observe), how was the multiverse produced?
Before our universe, perhaps there
was a long series of sequentially existing universes produced
by cycles involving a Big
Bang expansion followed by a Big Crunch contraction of the whole universe into
a concentrated ball of mass-energy that would cause another Bang (and Crunch)
and then another,
over and over until it produced our
universe. Although
this theory was
popular for awhile, it has been discredited for a variety of reasons (*), and
most current proposals are for simultaneous universes, as explained below. *
There doesn't seem to be enough mass to cause a Big Crunch ( 1 2a 2b ) and "dark energy" causes expansion rather than contraction,
so proposing that another Big Bang would follow is wildly speculative (and in fact it seems to be wrong) and if
properties were different (why? more speculation is required) a universe
would soon occur in which
there would be no crunch, and the series would end.
Currently, most
theories about Many Universes propose a multitude
of simultaneously existing
universes, with a gigantic Mega-Universe containing many smaller universes,
including our own. The
most
popular
theories
propose
that
at
the
beginning
of a big bang there is an inflationary
period (with curved space and vacuum energy, as described
in general
relativity and
quantum
mechanics,
plus
a
hypothetical inflaton field) in which an immense number of additional "big
bang universes"
are
produced. In another MU theory, new universes are born in
the
energy-dense environment within black holes. A variety of speculative
proposals for universe-producing mechanisms include curved space, vacuum energy,
quantum
tunneling,
imaginary
time,
and
backward
causation, and also (or combined with) the "many worlds" interpretation of quantum mechanics.
Would
different universes have different properties?
If all universes are formed
in the same way, we might expect them to have the
same properties. If the properties are different in each universe, as
proposed by MU, why are they different? To explain the origin of many "worlds
with varying properties," scientists have proposed many multiverse-mechanisms,
involving string theory, inflationary expansion, quantum mechanics, black holes,
and colliding 10-dimensional branes. { one possibility }
How plausible are theories about
a multiverse?
For many scientists, a religious
motivation for
proposing MU is to support an atheistic worldview by avoiding a conclusion
that "our
universe
was designed and created by an extremely intelligent and powerful designer/creator." And
for other scientists, a religious motivation for proposing an intelligent
design
of the universe (ID)
is to provide scientific support for a theistic worldview. But in each
case,
with
MU or ID, we can evaluate the scientific theory based on scientific
evidence and logic, independent of any nonscientific motivations for proposing
the theory.
According to current
theories
in
physics,
even
if
other
universes
existed they could not be observed, so there is no direct empirical
evidence
for or against MU. Why? If our theories predicted that we should
be able to observe other universes, and we did not observe them, this would
be
evidence
against MU. But if non-observation is predicted by both MU and ID,
non-observation
is scientifically neutral. Similar logic applies to the current lack of
empirical testability for string theory.
Theories
about
MU
seem
untestable
and
are
highly
speculative, but
(according to
those
who
are more expert than myself in the relevant fields) MU theories are consistent
with
accepted
theories
of
science,
and are worthy of serious consideration. For example, Robin Collins says
that "it is in the realm of real physical plausibility
that a viable inflationary many-universes scenario could be constructed that
would account for the fine-tuning
of the parameters
of physics and the initial conditions of the cosmos," but then he
explains
why "there
still remains
a powerful case for design from physics and cosmology." For
example, "even if a 'many-universes generator' exists
it
seems
to need to be well-designed" in order to produce a multitude of
new
universes
with widely varying properties. Therefore, the correct theory could be
Intelligent Design AND A Multiverse." William Lane Craig
is
more
critical
of
inflationary
theory, but he
agrees that it does not eliminate questions about design: "Inflationary
scenarios
have
problems
of
their own,... [and they] seem to require the same sort of fine-tuning
which
some theorists thought these models had eliminated." {details}
Does MU violate principles of simplicity
and parsimony? Not
necessarily. We know that one universe
exists, but we cannot know with certainty that there is only one universe. Victor
Stenger,
a
proponent
of
MU and opponent of ID, explains: "Some
theologians and scientists dismiss the notion as a gross violation of Occam's
razor. It
is
not. No new hypothesis is needed to consider multiple universes. In
fact, it takes an added hypothesis to rule them out — a super law of nature
that says
only one universe can exist. But we know of no such law, so we would violate
Occam's razor to insist on only one universe." Robin Collins,
a proponent of ID,
agrees: "The only way we could close this door [for MU
theories] is if we discovered that the ultimate laws of physics did not allow
either many-universes
or enough variation in the parameters and laws of physics among universes."
A Conclusion?
How did our universe
begin,
and why does it have properties that allow life? I
think the most plausible explanation is that our universe was designed and
created by a designer/creator whose intelligence and power are
beyond our abilities to comprehend. But
this theory cannot be proved, and alternative theories about "many universes" also
seem impossible to prove or disprove, largely
because
our
evaluations are hindered
by an absence of empirical data about what existed and what happened before
the Big Bang.
Theistic and atheistic worldviews propose
different descriptions of reality (and explanations for it), including
different ideas about what existed before the
beginning
of the universe. An atheist
assumes the existence of a materialistic capability
for creating our universe. A theist assumes the existence of God,
who has this capability. Each asks the other, "Can you explain
what caused the existence of what you assume as the starting point?" Neither
offers an answer that satisfies the other, and neither assumption can be
tested. Should
this lack of a conclusion bother us? No. In fact, I think
that a state
of uncertainty is the
way God wants it to be. What is the spiritual
significance of this logical deadlock, with humans apparently unable to prove
or
disprove the existence
and actions of God? Why isn't God more obvious?
For more information about the many ways in which our universe is "just right" for life, visit the links-page for Design of the Universe. {back to main body}
Is
the universe designed to PRODUCE life?
Why do I describe a universe cleverly designed
"so it would support life" but not "so it would produce life"? Because
natural process does seem sufficient to support life, but I think it seems
unlikely that it will
produce life from lifeless matter. There are two types
of design theories, proposing design-directed action at
the
beginning
of
history (in a design of the universe) and during
the history of nature, as explained in the
homepage for Origins Evidence. In
the community of Christian scientists, there is agreement that the
universe was designed to support life,
but
not
about whether it was designed to produce life, or if design-action during history
was necessary. {back
to main body}
Scientific Theories and Theological Theories
For each of the two main explanations for fine tuning (a designed universe, or a multiverse that may or may not be designed) we should distinguish
between
the basic scientific
theory and a semi-associated theological theory that
is constructed when the science is supplemented by
interpretation. The distinction between design (science) and
creation
(theology) is
summarized in another page. {back
to main
body}
String Theory and "many worlds" Quantum Mechanics
Here is a possible
mechanism (it's one of the numerous speculations) for producing many
universes with varying properties: In string
theory,
during the early high-energy inflationary expansion of
a Big Bang the "string shapes" vary rapidly, thus producing a temporary
variability in the string-shapes until they "freeze" into a stable
form (before the inflationary period ends) and produce the stable properties
of nature in a particular universe. {
But even if string
theory is true,
some properties
would
not
be
controlled
by string-shapes, as explained in the section below.
} Or
there
might
be
other
mechanisms,
either currently
speculated or now unknown,
that
would
produce variability. {string theory: superstringtheory.com &
superstrings! & caltech.edu}
And in a "many
worlds" interpretation of quantum mechanics,
every quantum interaction — including those that would occur during the
inflationary period when property-determining string shapes are changing and
then stabilizing — produces a "splitting" into different histories
in different universes, one history for each of the many quantum possibilities
that could occur at every instant of time, thereby increasing (by exponential
multiplications occurring zillions of times per second!)
the number of new universes with varying properties.
a confession: I
haven't been
keeping
up-to-date in this area, therefore much that is relevant and important has been
omitted
in this section and the two below.
Variations
in Properties (Can they be explained by Variations in Strings?)
Robin
Collins explains what strings (if they exist) would and would not control:
Some
of the background laws of physics must be right for the universes generated
to be life-permitting. For example, without
the principle of quantization,...; without the Pauli-exclusion principle,..... These
background laws and principles... cannot be explained as a many-universes
selection
effect. ... Even if an inflationary/superstring many-universe generator
exists, it along with the background laws and principles could be said to be
an irreducibly complex system...with just the right combination of laws and fields
for the production of life-permitting universes: if one of the components were
missing or different, such as Einstein's equation or the Pauli-exclusion principle,
it is unlikely that any life-permitting universes could be produced. In
the absence of alternative explanations, the existence of such a system suggests
design. ..... {back to Would
different universes have different properties?} { question
for reviewers: Could strings plus a unified theory (to link strings with
other requirements) provide what is required in MU? or if the "other
requirements" just vary widely, as proposed in MU? }
Many
Universes (scientific details from Collins and Craig)
The following excerpts
are from Design
and the Many-Worlds Hypothesis by Robin Collins:
It
is in the realm of real physical plausibility that a viable inflationary many-universes
scenario could be constructed that
would account for the fine-tuning
of the parameters of physics and the initial conditions of the cosmos. ... Despite
the current popularity of both inflationary cosmology and superstring theory,
both are highly speculative. ... Even if superstring theory or inflationary
cosmology turn out to be false, they have opened the door to taking the many-universes
explanation of the fine-tuning
as a serious physical possibility since some other physical mechanisms could
give rise to multiple universes with a sufficiently large number of variations
in the parameters of physics. The only way we could close this door is
if we discovered that the ultimate laws of physics did not allow either many-universes
or enough variation in the parameters and laws of physics among universes.
...
[But] there still remains a powerful case for design from physics and cosmology.
... Much of the evidence for design that we will present cannot be naturally
explained by any many-universe scenario, and thus circumvents any objection
to design based on the many-universe hypothesis.
.....
Even
if a "many-universes generator" exists it seems to need to be "well-designed" in
order to produce life-sustaining universes...[by] the expansion
of a small region of space into a very large region...[with] the sort of mass-energy
we
find in our universe. .....
Finally, it should be stressed that theists
need not be opposed to the inflationary many-universe hypothesis. Indeed,
there are several reasons theists could give in support of a theistic version
of it.
and
these ideas
are from The
Teleological Argument and The Anthropic Principle by William
Lane Craig:
Inflationary scenarios seem to require the same
sort of fine-tuning which some theorists thought these models had eliminated. For
example, in order to proceed appropriately, inflation requires that the
two theoretical components
of Einstein's cosmological constant, "bare lambda" and "quantum
lambda," cancel each other out with an enormously precise though inexplicable
accuracy. A change in the strengths of either aG or aw by as little as
one
part in 10100 would destroy this cancellation on which our lives depend.
back to How plausible are theories about Many Universes?
Can we be certain?
Originally a quoted excerpt was here (from my page asking, Is there
proof of God's existence and activity?) but it has been removed because you can just go to the page and read it, if you want.
This website for Whole-Person Education has TWO KINDS OF LINKS:
an ITALICIZED LINK keeps you inside a page, moving you to another part of it, and a NON-ITALICIZED LINK opens another page. Both keep everything inside this window, so your browser's BACK-button will always take you back to where you were. |
Anthropic Principle & Fine Tuning: Multiverse and/or Intelligent Design? — Part 1 and, for views by other authors, a homepage (with summary and links) page for |
This page is
http://www.asa3.org/ASA/education/origins/anthropic2-cr.htm
Copyright © 2003 by Craig Rusbult
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