Subject: Your third (as-yet-untitled) book
Date: Wed, 14 Oct 2009 08:06:43 +0300
From: Dimi Chakalov <firstname.lastname@example.org>
Jennifer Ouellette <JenLuc@gmail.com>
I downloaded the DVD of the tall cosmologist (named
Sean), and noticed some serious inconsistencies in Lect. 3, 29:01 --
29:04 ("More and more space is coming into existence") and Lect. 14,
22:25 -- 22:49, to name but a few.
If your third book involves theoretical physics, may I offer you an alternative
Should you have questions, please do write me back.
All the best,
Subject: Re: Your third (as-yet-untitled) book
Date: Fri, 16 Oct 2009 15:30:26 +0300
From: Dimi Chakalov <email@example.com>
To: Jennifer Ouellette <JenLuc@gmail.com>, firstname.lastname@example.org
P.S. Thank you very much for reading my email; now our brains are entangled
(included the one hold by Sean),
Sean: I would like to use your DVD in my DVD tutorials explaining the arrow of
Hope you don't mind. If you disagree, please write me back.
Best - D.
Subject: Dark smooth dynamical tension
Date: Sun, 19 Oct 2003 00:22:15 +0300
From: Dimi Chakalov <email@example.com>
To: Sean Carroll <firstname.lastname@example.org>
CC: email@example.com, firstname.lastname@example.org,
Dear Professor Carroll,
Your recent paper about the apparent acceleration of the
universe [Ref. 1] is the best I've ever read. Thank you!
Regarding the "scandal" due to the coincidence problem,
and Sec. 1.3.3, Is dark energy dynamical?, please see
I will highly appreciate your comments, as well as those
from your colleagues. I will keep them private and confidential.
[Ref. 1] Sean Carroll, Why is the Universe
Accelerating? Mon, 13 Oct 2003 22:55:24 GMT, astro-ph/0310342
"In trying to understand the universe in which we apparently
live, we are faced with a problem, a puzzle, and a scandal.
"Dark energy" is not, strictly speaking, the most descriptive
name for this substance; lots of things are dark, and everything has energy.
The feature which distinguishes dark energy from ordinary matter is not
the energy but the pressure, so "dark pressure" would be a better term.
However, it is not the existence of the pressure, but the fact that it
is negative -- tension rather than ordinary pressure -- that drives the
acceleration of the universe, so "dark tension" would be better yet. And
we would have detected it long ago if it had collected into potential wells
rather than being smoothly distributed, so "smooth tension" would be the
best term of all, not to mention sexier.
"The acceleration of the universe presents us with mysteries
and opportunities. The fact that this behavior is so puzzling is a sign
that there is something fundamental we don’t understand. We don’t even
know whether our misunderstanding originates with gravity
described by general relativity, with some source of dynamical or constant
dark energy, or with the structure of the universe on
scales. Regardless of what the answer is, we seem poised to discover
something profound about how the universe
Note: It seems
to me that the "dark" component of the universe is both constant and dynamical,
and we could model the universe as a huge
brain that "thinks" with its virtual or "dark" state. But before going
into such speculations, let's examine the bold data.
Look at the black dots in Fig. 4
from Saul Perlmutter's Supernovae, Dark Energy, and the Accelerating
Today, April 2003, p. 57),
You can download the image (expansionhistoryphystoday.pdf)
by clicking on the thumbnail above, and the article by Saul Perlmutter
He wrote (p. 57): "Given these two fine-tuning coincidences, it seems likely
that the standard model is missing some fundamental physics. Perhaps we
need some new kind of accelerating energy -- a "dark energy" that, unlike
[lambda], is not constant."
The observations (black dots in Fig.
4 above) permit one conclusion only: the history and the fate of the
universe are undecidable. See also Paul Frampton and Tomo Takahashi,
The Fate of Dark Energy,
v4: "Our dreadful conclusion is that no amount of data from our past light-cone
can select between these future scenarios."
The assumption of flat cosmic
geometry in Saul Perlmutter's article (see also Ryan Scranton et al.,
Physical Evidence for Dark Energy,
v2) is crucial for understanding the re-interpretation of the these observations:
we shall drop this presumption and consider the most general case of dual
topology, namely, closed-and-open in the global mode of spacetime, and
in the local mode of spacetime, as suggested here
and here. Hence the universe has a
dual age as well: finite in the local mode of spacetime, some 13.7
B years, and infinite (indecisive) in the global mode. The hypothesis
for two modes of spacetime is explained here.
Now comes the hard question: what
the heck is the source of this dark stuff? Let me quote from Paul Preuss'
is Dark Energy?:
"For the cosmological constant, the
vacuum -- space itself -- possesses a certain springiness," says Eric Linder,
a cosmologist at Berkeley Lab and director of the Center for Cosmology
and Spacetime Physics at Florida Atlantic University. "As you stretch it,
you don't lose energy, you store extra energy in it just like a rubber
The puzzle is that the more energy
you poor into the universe for stretching the good old metric of spacetime,
the more energy you get. From where?
How about Hermann Bondi's negative
mass? The idea has been posted on this web site (Sunday, 3 November 2002)
The source of this dark stuff could be the most widely known object in
the past 2060 years: the atom of Lucretius.
It is a special state of the whole universe as ONE. The positive and negative
components of the universe are not exactly canceled, however. C’est la
dissymétrie qui crée le phenomène, Pierre Curie (Journal de Physique 3
(1894) 393-415, p. 401). Hence we have a cosmological constant.
I think no new ideas are needed,
just some real good math. Not
One final quote, from astro-ph/0309368
by Robert A. Knop et al., p. 40: "As new instruments
available, it will begin to be possible to relax the condition of a
constant equation of state parameter, and to question whether the properties
of the dark energy have been changing throughout the history of the Universe."
Perhaps Mother Nature is smarter
and has managed to employ all alternatives. Maybe the universe does evolve
like a human brain (just don't ask
Let's be prepared for a delightful
surprise. Only please don't tell me you knew nothing about it, okay?
October 19, 2003
P.S. Steven Weinberg believes in the anthropic principle. No, this
is not a joke.
He presented a Public Lecture entitled "The Origin of the Universe" at the
Cleveland Museum of Natural History at 7:30pm on Thursday, October 9th (see
David Gross described it as a
disease: "Anthropic reasoning is a kind of virus. It infects people, and once infected they are lost forever."
I firmly agree. If the universe evolves as a human
brain, there is no room for anthropic reasoning. Just biocosmology: the universe
would anticipate its potential state some 13.7 billion years "after" The
Beginning, and will proceed with fixing the initial boundary conditions suitable
for life and consciousness. Why? Because it has two constituents,
res extensa and res cogitans,
in line with the basic ideas of Leibnitz and Pauli.
Besides, please note
that 'the creation of the universe' -- a phrase which many
cosmologists use without hesitation -- is a bona fide
self-referential logical paradox. Let me
The proposition 'the
universe was created at some instant of time' is true if, and only if, it is
false; and is false if, and only if, it is true. In order to identify the
instant of Creation, t_c, we need a finite time interval, (t_c, t_n),
where the index n refers to the instant 'now', some 13.7 billion
years after t_c. However, here's the Catch 22: any finite time interval
requires a cut-off that must be placed before t_c, therefore the initial
proposition is false. To resolve this paradox, we place the cut-off, t_0,
in the global mode of spacetime, where it can be
safely canceled: (t_n - t_0) - (t_c -
t_0) = t_n - t_c = 13.7 billion years, as read by your good old wristwatch, in
your local reference frame (local mode of spacetime).
Mind you, the task of identifying the instant
'now' is a very old story, as told by St.
Augustine of Hippo (354-430 AD). I've tried to elaborate on it
To cut the long story
short, the very
Act of Creation requires the Aristotelian First Cause endowed with self-acting
faculties, just like the human brain: we
think about the brain, with the brain. Hence
The Universe (inside-the-universe plus its
current Holon at time 'now', t_n) should be modeled as a brain.
As I am writing these
lines, there is an ongoing
Superstring Cosmology Conference at the Kavli Institute for Theoretical
Physics at the University of California, Santa Barbara (Friday, October 24th,
9:00 AM PST, Main Seminar Room, limited to registered participants). This is
what Jung and Pauli called synchronicity, isn't it?
I sincerely wish all my colleagues from the Kavli Institute for Theoretical
Physics best of luck in their endeavors.
There is no need to invent the wheel.
Friday, October 24, 2003, 10:45:54 AM PST
Cosmology Meeting Explores the Outer Limits
Despite decades of living with Lou
Gehrig's disease, Stephen Hawking
continues to present papers at
conferences such as the one in Cleveland
last weekend. On the screen is an
all-sky map of the cosmic microwave
background from the WMAP satellite. Photo
by Dan Falk.
October 15, 2003 |
Seventy cosmologists gathered in Cleveland last weekend to discuss the
latest observations and theories about the universe as a whole, and to
speculate on what the next 25 years will bring. The first
Kavali-CERCA Conference on the Future of Cosmology took place at
Case Western Reserve University. It drew such luminaries as Steven
Weinberg, Nobel laureate and author of The First Three Minutes,
and Stephen Hawking of Cambridge University, author of A Brief
History of Time.
Speaker after speaker agreed that we're
in a "golden age" of cosmological discovery, with many fundamental
parameters of the universe — including its age, density, geometry,
history, and overall composition — finally getting pinned down. Much of
the best data in this regard
came just this year from the spectacularly successful
Anisotropy Probe, WMAP, which continues to map the cosmic microwave
background radiation — the sky-filling "echo" of the Big Bang — better
than has ever been done before.
But many mysteries remain. What is the
"dark energy" that's currently giving the expansion of the universe a
boost of acceleration? What caused the Big Bang itself 13.7 billion
years ago? Did it originate in a "singularity," an infinitesimal point
at which the laws of physics break down? Or did it spring from some
larger, underlying space-time and avoid a singularity? Are there many
other bangs in this underlying realm, leading to many other, different
universes? Does space have 10 dimensions instead of three, as string
theorists suggest? If so, where are the other seven hiding? These and
other questions will keep cosmologists busy for decades, speakers
was a hot topic. It amounts to about 73 percent of all the matter and
energy in the cosmos, but its nature is completely unknown. However,
astronomers are beginning to trace the history of its effects with some
Adam Riess presenting the latest
findings on dark energy from his group's
measurements of supernova distances and
by Dan Falk.
Adam Riess (Space Telescope Science
Institute) announced that his team has gotten a firmer fix on the time
when the repulsive force of dark energy began overpowering the
attractive force of gravity as galaxies spread apart from each other;
this transition began the present era of cosmic acceleration. The
change, he said, happened about 5 billion years ago — in line with
previous, more tentative findings and nicely matching theoretical
expectations. Riess's team is measuring the brightnesses of extremely
distant Type 1a supernovae, "standard candles" that can be seen far
across the universe, to track the history of cosmic redshifts. So is
another team, led by Saul Perlmutter of the Lawrence Berkeley Laboratory
Cosmologists have long wondered about the geometry of the universe —
whether space is flat or curved. The last few years have brought the
answer: space is flat, and seemingly infinite. But what about its "topology,"
or connectedness? A finite volume of flat space could give the
appearance of being infinite. A two-dimensional analogy might help: in a
Pac-Man game, the video screen is small, but because the right-hand side
is connected to the left (making the topology identical to that of a
cylinder), Pac-Man can journey endlessly in one direction, even though
the space he traverses is finite.
Cosmologist Glenn Starkman (Case Western
Reserve University) illustrated some of
the ways space could fold back on
by Dan Falk.
French cosmologist Jean-Pierre Luminet,
US mathematician Jeffrey Weeks, and other colleagues published a
in the October 9th Nature suggesting that we live in a relatively
small universe with the topology of a hyper-dodecahedron -- a
four-dimensional analog of the three-dimensional, 12-sided structure
that roughly resembles a soccer ball. Their study was based on WMAP data
suggesting a puzzling lack of very-large-scale patterns in the cosmic
microwave background. However, by the time of the conference other
researchers had taken a closer look and ruled out many scenarios for a
connected universe, including the hyper-dodecahedron. (The possibility
remains that connectedness exists on a scale larger than our
13.7-billion-light-year horizon, but we can never get any evidence about
Nobel laureate Steven Weinberg believes
the anthropic principle offers the only
good explanation for why the
"cosmological constant" embedded in
spacetime — one proposed basis for dark
energy — is very small but not zero. Photo
by Dan Falk.
Anthropics. One of the conference's more
heated panel discussions focused on "anthropic reasoning," the idea that
our own existence provides a basis for making scientific deductions that
are reachable no other way.
In its simplest form, the "anthropic
principle" is uncontroversial. For instance, life requires air and
water. So when scientists are born and notice their surroundings, they
discover that they are on a world with air and water, rather than on a
world like the Moon — even though Moonlike worlds are probably much more
common in the universe.
A key anthropic controversy centers on
the fundamental constants of physics, such as the charge of the electron
and the speed of light. Why do these have the particular values they do?
There is no apparent reason for these values — they just "are." However,
it turns out that any kind of life or organized matter — even such
simple organized matter as atoms and molecules — requires many
fundamental constants and laws to have special, seemingly "fine-tuned"
Of course, we necessarily find
ourselves living in just such a fine-tuned, life-friendly universe —
otherwise we wouldn't exist to be thinking about it. Does this imply
that there are many other universes having many other, random values for
the constants, and in most of them life never happens? Does our universe
appear special merely because we are engaging in self-selection from a
much larger number of universes? Does this explain the special values we
measure for such things as the atomic fine-structure constant?
David Gross, on the other hand,
considers the anthropic principle worse
than useless. Photo
by Dan Falk.
The debate centered
on whether such logic constitutes a scientific "explanation." To some
leading physicists at the conference, such as Andrei Linde (Stanford)
and Steven Weinberg (University of Texas), it does — giving us real
information about the existence of larger realms we cannot observe.
Weinberg applies it in particular to why Einstein's cosmological
constant has a value that allows stars, planets, and life to exist. To
opponents, this is quasi-religious tail-chasing and hand-waving. David
Gross (University of California at Santa Barbara) described it as a
disease: "Anthropic reasoning is a kind of virus," he said. "It infects
people, and once infected they are lost forever."
The anthropic principle, and its
growing influence on the outer shores of cosmology, will be explored in
an upcoming issue of Sky & Telescope.