pjk at design.eng.yale.edu
Tue Oct 14 22:51:20 EDT 2003
Subject: Soccerball universe
from PHYSICS NEWS UPDATE
The American Institute of Physics Bulletin of Physics News
Number 657 October 14, 2003 by Phillip F. Schewe, Ben Stein, and
COSMOLOGY THEORIES COME AND GO as new information becomes
available. The geometry and nature of the universe must be one of
the most fascinating questions for the human species. Early
Egyptians thought the universe was a rectangular box. Alexandrian
Greeks pictured the cosmos as a set of concentric crystalline
spheres, a view adopted by the medieval Catholic Church, which
executed Giordano Bruno for holding that the universe was infinite
in extent. In the 20th century Hubble's surveys of receding
galaxies supported the idea of an expanding spacetime scaffolding.
This model, now called the big bang, is generally the accepted
overarching theory, but it has been amended several times to include
an early "inflationary" phase and, more recently, the existence of
dark energy, an entity or mechanism which apparently allows the
expansion of the universe visible to our telescopes to be speeding
up, and not slowing down. Also not slowing down is the list of new
cosmological ideas. Last year's entrant was the "ekpyrotic" model
according to which our universe and all the energy and matter
residing therein arises from the collision of two immense membranes
embedded in an even larger multi-dimensional volume. Last week's
interesting new cosmology development was the suggestion that the
universe is finite and has a dodecahedral (soccerball) geometry
(Luminet et al., Nature, 9 October 2003). Meanwhile, this week's
leading cosmology news, presented at a meeting in Cleveland,
featured observations of very distant (8 to 10 billion light years
away) and unusually bright supernovas, recorded by the Hubble Space
Telescope. This accords with the dark energy model which holds that
the general expansion of the universe was relatively slow 10 billion
years ago and afterwards got much faster, owing to the propulsive
effects of the dark energy winning out over the attractive and
slowing effects of gravity (paper by Adam Reiss,
http://www.phys.cwru.edu/events/cosmol03.php; also see Science News
Online, 11 October ).
Related to this, my colleague Bob Grober pointed me to a charming piece
in the NYT, at
<http://www.nytimes.com/2003/10/12/weekinreview/12JOHN.html>. In case
the fates of file access prove fickle, the text follows. --PJK
October 12, 2003
Tongue-Tied by Physics: The Ineffable Lightness of Being
By GEORGE JOHNSON
It was sometime early in the 1920's when words began to fail us.
Whether one spoke and thought with the sharp granularity of German or
the mellifluousness of French - or in some hodgepodge like English -
it was impossible to translate the strange new ideas of physics into
language. Not even Japanese was spacious enough.
How could something like an electron simultaneously occupy several
different states - assuming multiple positions or momentums or energy
levels - and still be sensibly considered a thing? How could it be
both a particle and a wave? In the midst of this quantum confusion,
the Danish physicist Niels Bohr, trekking through the mountains above
Gottingen with Werner Heisenberg (of Uncertainty Principle fame),
issued one of his famously delphic pronouncements: "We must be clear
that, when it comes to atoms, language can be used only as in poetry."
The problem has only grown worse, as was clear last week when the
latest issue of Nature arrived, posing on its cover the ultimate
question, "Is this the shape of the universe?" The reference was to a
report in which Jean-Pierre Luminet of the Paris Observatory, Jeffrey
R. Weeks, an American mathematician, and three French colleagues
propose that the cosmos consists of a "Poincare dodecahedral space."
The closest analogy is a soccer ball with its 12 flat faces stitched
to approximate a sphere. The universe would not be an ordinary soccer
ball, of course, which consists of a two-dimensional surface residing
in three-dimensional space. The skin of the cosmic hyper-soccer ball
is itself three-dimensional. Impossible to imagine. Literally too big
Fortunately society employs some very smart people who can study such
topological monsters with equations and computer simulations. The
implications are profound. A soccer ball universe would be finite, not
infinite. A spaceship bumping up against one of the universe's 12
faces would punch on through . . . and find itself sneaking back in
from the other side.
In a variation of this intriguing theory, other cosmologists suggest
that the universe is smaller in one direction than in the other - that
it is a kind of hyper-doughnut, or so it would appear to a
four-dimensional being standing outside of creation and viewing it
In one of the more brilliant episodes of "The Simpsons," Homer falls
through a trapdoor in the living room closet and finds himself
flailing about in a 3-D world. Perhaps in a future show he can break
through to the next level, confronting the Krispy Kreme universe in
all its weird glory. All of us would be flatland characters in a great
Hyper-soccer ball or hyper-doughnut, both of these un-image-able
images come from crunching data gathered by a NASA satellite called
the Wilkinson Microwave Anisotropy Probe. Its mission was to measure
the "ripples" (get ready for more Niels Bohrian poetry) emanating from
the "big bang," the primordial "explosion" that occurred both
everywhere and nowhere (neither word is right) creating space and time
. . . and, eventually, a crude system of grunts and whistles to try
and describe it all.
Like oceanographers sounding the ocean bottom with sonar, cosmologists
use the "echoes" of the big bang (we're running out of quotation
marks) to plumb the depths of space. And the limits of language,
leaving scientists tongue-tied over concepts like the "cosmic jerk"
(described last week at a cosmology conference in Cleveland) that
unleashed the "dark energy" that is accelerating universal expansion.
When poetry doesn't do it, scientists sometimes turn to music. Last
month an international team of astronomers reported that a black hole
lurking far away in the Perseus cluster of galaxies is creating
rumbling vibrations of a certain pitch - B flat.
This, however, would be B flat 57 octaves below middle C, toward the
deep end of a piano keyboard some 50 feet long. This is a tone so low
that each wave measures 30,000 light-years from crest to crest (almost
a third the length of the Milky Way). A single undulation takes 10
million years to complete. This would be music only to a creature with
eardrums the size of galaxies and eons of listening time.
It was inner space, the universe inside atoms, that Bohr was musing
about on the hike with Heisenberg. The quantum oddities of this
subatomic realm were just the beginning of the linguistic headaches.
Combine quantum mechanics and general relativity, with its curved
space-time continuums, and you get superstring theory and its
submicroscopic guitar strings plucked by the gods in a universe 10
dimensions in size.
The metaphorical juggling act becomes harder and harder to sustain.
Science's vision of the universe is constantly expanding, but language
remains frozen in place. New words are added all the time, but what is
needed is something like new grammars and new syntaxes. New ways to
"How can we ever hope to understand atoms?" Heisenberg had lamented
"I think we may yet be able to do so," Bohr replied. "But in the
process we may have to learn what the word 'understanding' really
With that they had reached the mountaintop. It was time to change the
subject and head back to town.
Copyright 2003ÊThe New York Times Company
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