Universe(s) Origin(s) 3 of 7 - Multiverse?
(Top Posts - Science - 072802)

Excerpts from "Before the Beginning, Our Universe and
Others" (Martin Reese, ISBN 0-7382-0033-6) ...
http://www.amazon.com/exec/obidos/ASIN/0738200336

... Colossal though they may be, stars and galaxies rank
low on the scale of complexity. That is why it isn't pre-
sumptuous to aspire to understand them. A frog poses
a more daunting scientific challenge than a star.

Planetary systems are common around other stars. Given
a propitious environment, what's then the chance of life
getting started, and of evolving to an "interesting" stage?

This biological question is still unsettled.

... We can confidently trace cosmic history back to the
first second. The ground gets shakier when we extrapolate
still farther back, into the first millisecond.

... The challenge facing the next Newton or Einstein is to
"unify" the forces of nature: to interpret electric, nuclear,
and gravitational forces as different manifestations of a
single primeval force.

... As our universe cooled, its specific mix of energy and
radiation, even perhaps the number of dimensions in its
space, may have arisen as "accidentally" as the patterns
in the ice when a lake freezes. The physical laws were
themselves "laid down" in the big bang.

... Our entire universe may be just one element -- one atom,
as it were -- in an infinite ensemble: a cosmic archipelago.
Each universe starts with its own big bang, acquires a dis-
tinctive imprint (and its individual physical laws) as it cools,
and traces out its own cosmic cycle. The big bang that trig-
gered our entire universe is, in this grander perspective, an
infinitesimal part of an elaborate structure that extends far
beyond the range of any telescopes.

---
-insert-

Sir Martin Rees, Astronomer Royal and Royal
Society Research Professor at Cambridge University
http://www.petergruberfoundation.org/rees.htm
Excerpt: ... renowned for his extraordinary intuition in
unraveling the complexities of the universe. He has been
a leader in the quest to understand the physical processes
near black holes and is responsible for major advances in
our understanding of the cosmic background radiation,
quasars, gamma-ray bursts, and galaxy formation. He has
contributed to almost every area of cosmology and astro-
physics and has been an inspiring leader, eloquent spokes-
person, and patient guide for astronomers all over the
world. ...

-end insert-
---

Some cosmologists speculate that new "embryo" universes
can form within existing ones. Implosion to a colossal den-
sity (around, for instance, a small black hole) could trigger
the expansion of a new spatial domain inaccessible to us.

Universes could even be "manufactured" -- the experimen-
tal challenge is far beyond present human resources, but
may become feasible, especially if we recall that our uni-
verse has most of its course still to run. No information
could be exchanged with a daughter universe, but it could
bear imprint of its parentage.

Our own universe might be the (planned or unplanned)
outcome of such an event in some preceding cosmos.
The traditional theological "argument from design" then
reasserts itself in novel guise.

Most naturally created universes would be stillborn in the
sense that they could not offer an environment propitious
for complex evolution: they would have too short a time
span, the wrong number of dimensions, allow no chem-
istry, or be otherwise maladjusted. But our universe may
not be the most complex: others in the ensemble may
have richer structure, beyond anything we can imagine.

... Should We Believe In a Hot Big Bang?

... There is firm empirical support (and a firm link with
known physics) for inferences going back to when our
universe was just a few seconds old -- the implications
from the microwave background, and from cosmic hel-
ium.

... when ... we venture all the way back into the first mil-
lisecond, we are on shakier ground, and shouldn't disguise
this.

Cosmologists shouldn't conflate things that are quite well
established with those that are not yet in that state.

... But some questions that were once entirely speculative
are now coming into serious scientific focus.

... You may be thinking: Isn't it absurdly presumptuous
to claim that we can ever know anything about the begin-
nings of our entire universe? Not necessarily. It is com-
plexity, and not sheer size, that makes a system hard to
understand.

The sun is easier to understand than the earth ... in the
even more extreme environment of the primordial fireball,
everything must surely have been reduced to its most
basic components. The early universe could be easier to
understand than the smallest living organism. It's biolo-
gists and the Darwinians who face the toughest challenge.

... Dark matter dominates galaxies. How galaxies form,
what they look like, and the way they cluster depend on
how the dark matter behaved as our universe expanded.
... Ordinary atoms may comprise less than 10 percent
of the universe, in terms of mass; cosmic dynamics
would be only slightly changed if they weren't there at
all. But atoms are plainly a prerequisite for our existence.

... Cosmology used to be derided as a science in which
facts were so scarce that theory was unconstrained. That
is certainly the case no longer: indeed, rather than there
being a lack of facts, it is already a challenge to recon-
cile all the data with any single scheme.

... The Russian cosmologist Andrei Linde advocates
chaotic inflation -- a more complex scenario where the
entire universe (the "multiverse" in the terminology I'm
using) could be infinite and eternal, but continually gener-
ates inflating regions which evolve into separate universes.

What we call our universe may be one domain of an
eternally reproducing cycle of different universes. These
are now disconnected from ours, but can be traced back
to common ancestors. The big bang that led to our uni-
verse is just one event in a grander structure.

... Separate universes, or separate domains within an infi-
nite universe, might have cooled down differently, even
ending up governed by different laws.

... Light that reaches us in the far future, from regions far
beyond our present horizon, may reveal that we occupy
a (perhaps atypical) patch embedded in a grander structure.
We could even, for instance, inhabit a finite or "island"
universe, whose edge may sometime come into view.

Even a universe that collapses, after tracing out a vast cos-
mic cycle, need in no sense be the whole of reality: in the
grander perspective of the multiverse, it is just one "epi-
sode", or one domain.

An "eternally inflating" multiverse may sprout separate do-
mains; the laws of physics may vary between one universe
and the next. Moreover, inside every black hole that col-
lapses may lie the seeds of a new expanding universe.

This ensemble, the multiverse, could encompass universes
governed by different laws and fundamental forces, and
containing different kinds of particle. Universes would not
live equally long, nor have equally eventful histories: some,
like ours, may expand more than 10 billion years; others
may be stillborn because they recollapse after a brief exis-
tence, or because the physical laws governing them aren't
rich enough to permit complex consequences.

... Only some universes (our own, of course, among them)
would end up as propitious locations for complexity and
evolution.

---
-insert-

Interview of Sir Martin Rees regarding his book,
"Our Cosmic Habitat"
http://www.space.com/spacelibrary/books/library_rees_020104.html
Excerpt: ... Can you define what you mean by different
universes? What are the possible types that have been
conceived?

Several theorists have speculated on different lines.
There's the concept of 'eternal inflation' due to Linde
and others, in which big bangs recur repeatedly in an
ever-expanding substratum. Some theorists have con-
jectured that new 'big bangs' could sprout inside black
holes.

And there is the idea that there could be a 4th spatial
dimension, so that other universes could exist just a few
millimeters away from us in a dimension we can't pene-
trate (since we are 'imprisoned' in three spatial dimen-
sions).

There is also the rather different idea of 'parallel worlds'
which some people believe offers the best interpretation
of quantum mechanics. Even if other universes existed,
we would still need to ask whether they are replicas of
ours, or if different laws could govern them. ...

-end insert-
---

... Time In Other Universes

... Near the beginning ... of the universe, everything would
be squeezed into an exotic state that mixes up the dimen-
sions of "space" and "time". ... On this tiny scale, some
theories, going back to Wheeler's pioneering ideas in the
1950s, suggest that the time dimension was intermingled
with the three spatial dimensions [left/right, forward/back-
ward, up/down] into a froth of "space-time foam."

According to currently popular superstring theories, there
may be six extra dimensions. Space is tightly "rolled up"
in these extra dimensions, so they manifest themselves
only on very tiny scales. Hartle and Hawking have devel-
oped a different approach to "quantum cosmology" and
the beginning of time. They suggest that the distinction
between time and space was initially blurred.

... Our concepts of space and time derive from experience
and perceptions in the everyday world. We shouldn't be
surprised that our intuition fails on either the cosmic or the
submicroscopic scale.

... Some new insight may eventually reveal that space-time
with 3 + 1 dimensions, like ours, is the only possible one.
But there currently seems nothing absurd about a universe
with extra dimensions.

According to superstring theories, the ultraearly universe
had 10 dimensions. The extra six would have rolled up and
"compactified", rather than expanding along with the others.
Theorists can't yet tell us whether this compactification
inevitably leads to our 3 + 1 dimensions.

(Whether a universe could have more than one time-dimen-
sion is less straightforward. Certainly a language with more
tenses would be needed to describe what happens in it!)

... There may be other universes -- uncountably many of
them -- of which ours is just one. In others, the laws and
constants are different.

... Another approach to quantum mechanics is the "many-
worlds" theory, proposed by Hugh Everett in the 1950s.

... The "many-worlds" approach envisages our entire uni-
verse as a single quantum system. ... A newer variant due
to David Deutsch replaces the idea of branching universes
by an infinite ensemble of universes, evolving in parallel
and displaying greater variety as time goes on.

... Smolin's Speculation

Natural selection of "favored universes seems the stuff of
science fiction. However the American cosmologist Lee
Smolin conjectures that the multiverse could display the
effects of heredity and selection. When a black hole col-
lapses, he speculates that another universe sprouts from
its interior, creating a new expanse of space and time dis-
joint from our own.

Small universes, in which there was too little space or
time to form many black holes, would not leave many
progeny. Nor, he argues, would even a large universe if
its physics prohibited stars from ever terminating as black
holes.

... Since the number of progeny a universe has depends
on the laws prevailing within it, there is a selection pres-
sure. Many generations, or many iterations, would lead
to a "takeover" by the universes that generate the most
numerous progeny. These would be the ones governed
by laws that allowed the largest number of black holes
to form. ...

(end excerpts)

- - -

Parallel Universes (BBC)
Most recently broadcast on 14 February 2002
http://www.bbc.co.uk/science/horizon/2001/paralleluni.shtml
Excerpt: Everything you're about to read here seems
impossible and insane, beyond science fiction. Yet it's
all true. Scientists now believe there may really be a
parallel universe - in fact, there may be an infinite number
of parallel universes, and we just happen to live in one
of them. ...

Parallel Universes - Transcript (BBC)
Most recently broadcast on 14 February 2002
http://www.bbc.co.uk/science/horizon/2001/parallelunitrans.shtml

Excerpts:

NARRATOR (DILLY BARLOW): Imagine you could
find an explanation for everything in the Universe, from
the smallest events possible to the biggest. This is the
dream which has captivated the most brilliant scientists
since Einstein. Now they think they may have found it.
The theory is breathtaking and it has an extraordinary
conclusion: that the Universe we live in is not the only
one.

MICHIO KAKU (City University of New York): That there
could be an infinite number of universes each with a differ-
ent law of physics. Our Universe could be just one bubble
floating in an ocean of other bubbles.

... ALAN GUTH (Massachusetts Institute of Technology):
When one studies the properties of atoms one found that
the reality is far stranger than anybody would have invented
in the form of fiction. Particles really do have the possibility
of, in some sense, being in more than one place at one time.

... BURT OVRUT (University of Pennsylvania): It has been
thought since physics began that matter was made up of
particles. We had changed that point of view now. We now
think that matter is made up of little strings.

... NARRATOR: The tiny invisible strings of String Theory
was supposed to be the fundamental building blocks of all
the matter in the Universe, but now, with the addition of the
eleventh dimension, they changed. They stretched and they
combined.

The astonishing conclusion was that all the matter in the
Universe was connected to one vast structure: a membrane.
In effect our entire Universe is a membrane. The quest to
explain everything in the Universe could begin again and
at its heart would be this new theory. It was dubbed Mem-
brane Theory, or M Theory, but so enigmatic and pro-
found did the idea seem that some thought M should
stand for other things.

... PAUL STEINHARDT: Physicists get kind of dreamy-
eyed when they talk about M Theory.

... MICHAEL DUFF: This eleventh dimension not only
had the membrane which was the bubble-like or sheet-like
object, but it had a whole wealth of different branes of
varying dimensions, unfortunately called pea branes.

NARRATOR: Each of these membranes was a possible
other universe. M Theory had unwittingly made the idea
of parallel universes respectable again.

MICHIO KAKU: In another universe the proton may be
unstable, in which case atoms would dissolve and DNA
cannot form and therefore there's no intelligent life in these
universes. Perhaps it's a universe of electrons and electricity,
perhaps a universe of lightening bolts and neutrinos, but no
stable matter.

MICHAEL DUFF: The other universes are parallel to ours
and may be quite close to ours, but of which we'd never be
aware. They may be completely different with completely
different laws of nature operating.

ALAN GUTH: It may not all have life, but some fraction
of them will have life and whatever that fraction is if there's
an infinite number of these universes there'll be an infinite
number of universes that have living civilisations.

MICHIO KAKU: Some of these universes may look just like
ours, except perhaps you're not there.

NARRATOR: M Theory was getting stranger and stranger,
but could it really be a theory which explained everything in
our Universe? To have any chance of that it would have to
do something no other rival theory had ever been able to do.

It would have to make sense of the baffling singularity at
the beginning of the Big Bang. M Theory was about to
come up with a suitably outrageous answer and parallel
universes would be at the very heart of it.

... NARRATOR: Waves had long fascinated Burt Ovrut.
Now they were just about to turn M Theory upside down.
At the beginning of 2001 the received wisdom was that the
eleventh dimension was a tranquil place with membrane uni-
verses gently floating in it, but Burt suggested a much more
exciting idea. Universes moving through the eleventh dimen-
sion like giant, turbulent waves.

BURT OVRUT: These things can move. They are not static,
they're, you know, like everything else in the world they can
move around and there's not much room for them to move in.
In fact if they move they're very likely to bang into each other.
In fact they either move away from each other, or they bang
into each other, and one thing that had occurred to me very
early on is what happens if they collide?

NARRATOR: To a new generation of cosmologists like
Neil Turok Burt's vision of the eleventh dimension sounded
intriguing, but he and his colleagues had other things on their
mind. They were still wrestling with the big problems of
cosmology.

NEIL TUROK: Was there a beginning? Did time continue
before the Big Bang? Where did the Universe come from?

NARRATOR: Above all, they were still trying to solve the
biggest problem of all: what caused the very start of the Big
Bang, the singularity?

NEIL TUROK: Nobody has a solution for the singularity
problem other than essentially by hand starting the Universe
at a certain time and saying let's go from there and let's not
worry about what happened before and that's very unsatis-
factory. This is the deepest problem in cosmology. If you
can get through the singularity you're on your way to a com-
plete theory of the Universe.

NARRATOR: Most cosmologists have begun to think they
might never find a solution. They'd almost given up completely,
which is when Turok and his colleagues heard Burt explain his
idea properly for the first time. At a conference in Cambridge
pioneers of M Theory had been brought together to explore
its implications.

Burt was the star of the show. His vision of a violent eleventh
dimension wowed the assembled physicists and caught the
attention of the cosmologists.

PAUL STEINHARDT: We heard about a vast variety of ideas.
The ideas that struck both Neil and myself most strongly were
the ideas that Burt presented.

NARRATOR: On the last day of the conference Neil Turok,
Paul Steinhardt and Burt decided to take time out. They went
to see a play.

BURT OVRUT: We wanted to see the play Copenhagen
which was being performed in London at the time and the
three of us took the train down to London one evening and
we had whatever it was, an hour or so on the train to sit
and talk about these ideas.

NARRATOR: On the journey they began to throw ideas
around. Three physicists, one train, and the biggest secret
about our Universe: what caused the Big Bang.

PAUL STEINHARDT: I think people get the wrong impres-
sion about scientists in that they think in an orderly, rigid way
from step 1 to step 2 to step 3. What really happens that often
you make some imaginative leap which at the time may seem
nonsensical. When you capture the field at those stages it
looks like poetry in which you are imagining without yet
proving.

NEIL TUROK: Paul, Burt and me were sitting together on the
train and just free associating.

PAUL STEINHARDT: One of us, maybe it was me, began
by saying oh well why can't we make a universe out of colli-
sion and Neil sort of pitching in and saying well, if you did
that then you could create all the matter and radiation of the
Universe, so we had this conversation, one of us completing
the sentences of the other in which we kind of just, just let
our imaginations go.

BURT OVRUT: And as we went along, at least I learned more
and more about how it might be possible to have these brane
collisions produce all of the effects of the early Universe and
in particular it's just easy to do with my hands, when they
collide you might have a Big Bang.

NEIL TUROK: And the Big Bang is the aftermath of some
encounter between two parallel worlds.

NARRATOR: But how could such a collision go on to cause
the world we know? The Universe we live in has vast clumps
of matter we call stars and galaxies.

BURT OVRUT: We know that things are not smooth out in
the Universe. In fact we have little clumps, we have stars, we
have galaxies, we have quasars, we have clumps of matter.

NARRATOR: Now they had to explain how the collision of
two parallel universes could go on to create these lumps of
matter. Was there something about the membranes, or branes,
which could explain it?

NEIL TUROK: People tended to think of branes as being flat,
perfect sheets, geometrical plains, but I think to us it was clear
that that picture could not be correct. It cannot be perfectly
flat. It has to ripple.

PAUL STEINHARDT: What would happen as these branes
approach that there are ripples in the surface of each brane
and when they come together they don't hit at exactly the same
time, same place, but in fact they hit at different points and at
different times.

BURT OVRUT: We found that as the brane moves it literally
ripples, so when the collision takes place it imparts those rip-
ples into real matter.

NARRATOR: The parallel universes move through the elev-
enth dimension like waves and like any wave these would rip-
ple. It was the ripples which went on to cause the clumps of
matter after the Big Bang. They finally had their complete
explanation of the birth of our Universe and now they could
do something even more profound. They could take the laws
of physics back in time to the moment of the Big Bang and
through to the other side.

NEIL TUROK: The existence of branes before the singularity
implies there was time before the Big Bang. Time could, can
be followed through the initial singularity.

BURT OVRUT: You sort of go back and back and back
until you get near the place where the expansion would have
taken place and then it just sort of changes into another world.
When the branes collide the collision of those can be ex-
plained within M Theory, so it just simply enters the realm
of mathematics and science now rather than being a, an
unknown point that exploded.

NARRATOR: The singularity had disappeared and it had
taken them just under an hour.

PAUL STEINHARDT: Then we went to see the play.

NARRATOR: This idea is so new it's only begun to be dis-
cussed, but if it's accepted it will mean Einstein's missing
theory has finally been found. M Theory may really be able
to explain everything in the Universe, but the victory will be
bittersweet, for at the end of its long quest, science has
discovered that the Universe it's thought to explain may be
nothing special. It is nothing more than one of an infinite
number of membranes, just one of the many universes which
make up the multiverse.

MICHIO KAKU: The latest understanding of the multiverse
is that there could be an infinite number of universes each with
a different law of physics. Big Bangs probably take place all
the time. Our Universe co-exists with other membranes, other
universes which are also in the process of expansion. Our
Universe could be just one bubble floating in an ocean of
other bubbles.

NARRATOR: But this isn't quite the end of the story. Now
that the Theory of Everything may have been found some are
keen to use it. Physics is preparing for the ultimate flight of
fancy: to make a universe of its very own without any myster-
ies or unanswered questions at all.

ALAN GUTH: I in fact have worked with several other peo-
ple for some period of time on the question of whether or not
it's in principle possible to create a new universe in the labora-
tory. Whether or not it really works we don't know for sure.
It looks like it probably would work.

It's actually safe to create a universe in your basement. It
would not displace the universe around it even though it
would grow tremendously. It would actually create its own
space as it grows and in fact in a very short fraction of a
second it would splice itself off completely from our Universe
and evolve as an isolated closed universe growing to cosmic
proportions without displacing any of the territory that we
currently lay claim to.

(end excerpts)

- - -

Posts in this series:

Universe(s) Origin(s) Preface
http://prohuman.net/universes_origins_preface.htm

Universe(s) Origin(s) - 1 of 7
}}} String Theory / Infinities / Singularities {{{
http://prohuman.net/universes_origins_1_of_7.htm

Universe(s) Origin(s) - 2 of 7
}}} No Origin of the Universe? {{{
http://prohuman.net/universes_origins_2_of_7.htm

Universe(s) Origin(s) - 3 of 7
}}} Multiverse? {{{
http://prohuman.net/universes_origins_3_of_7.htm

Universe(s) Origin(s) - 4 of 7
}}} Universes from Black Holes? {{{
http://prohuman.net/universes_origins_4_of_7.htm

Universe(s) Origin(s) - 5 of 7
}}} Cyclic Universe? {{{
http://prohuman.net/universes_origins_5_of_7.htm

Universe(s) Origin(s) - 6 of 7
}}} Einstein / Big Bang / Superstrings {{{
http://prohuman.net/universes_origins_6_of_7.htm

Universe(s) Origin(s) - 7 of 7
}}} Nothing / Everything {{{

http://prohuman.net/universes_origins_7_of_7.htm

- - -