First Unitarian Church of Des Moines
9:30 a.m. -- August 24, 2003
"Three Revolutions in Cosmology"
Sam Wormley
Unitarian Universalist Fellowship of Eau Claire
10:00 a.m. -- September 28, 2003
"Three Revolutions in Cosmology"
Sam Wormley
Unitarian Universalist Fellowship of North Central Iowa
10:30 a.m. -- November 9, 2003
"Three Revolutions in Cosmology"
Sam Wormley
Iowa Lakes Unitarian Universalist Fellowship
10:30 a.m. -- March 11, 2007
"Three Revolutions in Cosmology"
Sam Wormley
READING from "Celebrating Creation" by Chet Raymo, Skeptical Inquirer
magazine: July/August 1999
"Traditional religious faiths have three components: a shared
cosmology (a story of the universe and our place in it),
spirituality (personal response to the numinous), and liturgy
(public expressions of celebration and gratitude, including rites
of passage). The apparent antagonism of science and religion
centers almost entirely on cosmology: What is the universe? Where
did it come from? How does it work? What is the human self? What
is our fate? Humans have always had answers to these questions.
The answers have been embodied in stories-tribal myths,
scriptures, church traditions. All of these stories derived from
a raw experience of the creation, such as my experiences inside
and outside of the Gallarus Oratory. All of them contain enduring
wisdom. But as a reliable cosmological component of religious
faith they have been superseded by what, cultural historian and
Roman Catholic priest, Thomas Berry calls the New Story-the
scientific story of the world".
"The New Story is the product of thousands of years of human
curiosity, observation, experimentation, and creativity. It is an
evolving story, not yet finished. Perhaps it will never be
finished. It is a story that begins with an explosion from a seed
of infinite energy. The seed expands and cools. Particles form,
then atoms of hydrogen and helium. Stars and galaxies coalesce
from swirling gas. Stars burn and explode, forging heavy
elements-carbon, nitrogen, oxygen-and hurl them into space. New
stars are born, with planets made of heavy elements. On one
planet near a typical star in a typical galaxy life appears in
the form of microscopic self-replicating ensembles of atoms. Life
evolves, over billions of years, resulting in ever more complex
organisms. Continents move. Seas rise and fall. The atmosphere
changes. Millions of species of life appear and become extinct.
Others adapt, survive, and spill out progeny. At last, human
consciousness appears. One species experiences the ineffable and
wonders what it means, and makes up stories-of invisible spirits
who harbor in darkness, of gods who light up the sky in answer to
our prayers-eventually making up the New Story".
________________
PRESENTATION
THREE REVOLUTIONS IN COSMOLOGY
There is a branch of science, Cosmology it's called, that
concerns itself with the past, present, and the future of the
universe as a whole. How did it begin? How has it evolved and
where is it going?
Carl Sagan, in his Cosmos series that aired on Public Television
twenty years ago, notes that we live in a world were things
change, but according to patterns, rules, or, as we call them,
laws of nature. If I throw a stick up in the air, it always falls
down. If the Sun sets in the west, it rises again the next
morning in the east. And so it becomes possible to figure things
out. We can do science, and with it improve our lives.
Human beings are good at understanding the world. We always have
been. We were able to hunt game or build fires only because we
had figured something out.
There was a time before television, before motion pictures,
before radio, before books--a time when the night was lit only by
fire. The greatest part of human existence was spent in such a
time. Over the dying embers of the campfire, on a moonless night,
we watched the stars. Ancient civilization paid great attention
to the sky. They built devices to measure the passing of the
seasons.
In Chaco Canyon, in New Mexico, there is a great roofless
ceremonial kiva or temple, dating from the eleventh century. On
June 21, the longest day of the year, a shaft of Sunlight enters
a window at dawn and slowly moves so that it covers a special
niche. One can imagine the proud Anasazi people, who describe
themselves as "the ancient ones", gathered in their pews every
June 21, dressed in feathers and rattles and turquoise to
celebrate the power of the Sun.
They also monitored the apparent motion of the Moon: the
twenty-eight higher niches in the kiva may represent the number
of days for the Moon to return to the same position among the
constellations. These people paid close attention to the Sun and
Moon and the stars.
Other devices based on similar ideas are found at Angkor Wat in
Cambodia; Stonehenge in England; Abu Simbel in Egypt; Chichén
Itzá in Mexico; and the Great Plains of North America.
Some alleged calendrical devices may just possibly be due to
chance--an accidental alignment of window and niche on June 21,
say. But there are other devices wonderfully different.
At one place in the American Southwest is a set of three upright
slabs which were moved from their original positions, about a
thousand years ago. A spiral, a little like a galaxy, has been
carved in the rock.
On December 21, the first day of winter, there are two daggers of
Sunlight that flank the spiral. And on June 21, the first day of
summer, a dagger of Sunlight pouring through an opening between
the slabs bisects the spiral, piercing the heart of this spiral
on this day alone--a unique application of the midday Sun to read
the calendar of the sky.
________________
Different cultures developed different cosmologies over the
millennia. For almost 2000 years, our western view of the
Universe was the one we received from the ancient Greeks, mainly
in the words of Plato and Aristotle.
In that view, the crystal spheres of the heavens were immutable,
serene, eternal and Perfect. Only down here on this lowly Earth
was there confusion, decay, disorder and death. It was a view
that was literally designed to put us in our place.
But that place, the Earth, was at the center of the Universe and
we could easily imagine ourselves to be the purpose of creation.
Then four hundred years ago, Copernicus, Johannes Kepler,
Galileo, and later Isaac Newton, shook our ideas that the Earth
was the center of Universe, and that we were the purpose of it
all.
We now know that we are on a habitable planet, circling an
average star, lost on the edge of a typical Galaxy in a lost
corner of the Universe. No matter how lowly Plato and Aristotle
had tried to make us, never in their wildest dreams, did they
think to do that to us.
________________
Actually this first revolution in cosmology starts with the
beginnings of Christianity and culminates in the Renaissance.
The Book of Joshua, Chapter 10, tells of a battle between the
Israelites and the inhabitants of the land of Canaan: "And the
Sun stood still, and the moon stayed, until the people had
avenged themselves upon their enemies." The men of Israel were
happily smiting and slaying, even though the heavenly bodies had
stopped in their tracks. This biblical passage directly
contradicts Aristotle, who's theory implies that Israelites
should have been as motionless as the Sun and moon.
Realizing the contradiction between the Bible and Greek
philosophy, Augustine, argued that the passage of time was
independent of the motion of the heavenly bodies; if the Sun and
moon stood still in the heavens, a potter's wheel would still
whirl around, unabated. If Aristotelian philosophy and the Bible
clashed, then Aristotle had to give way.
However, the friction between Aristotle and the Bible was
inevitable. The Bible is based on Eastern philosophy, while
medieval cosmology was built upon the Western philosophy of
Aristotle and his successors. The two cultures had very different
views about how the universe works, yet the two were forced into
an uneasy marriage within church theology. The inherent
contradictions reached a peak in the 1200s.
Science would have never come into conflict with the church, if
the scientific revolution had dealt with disciplines largely
devoid of spiritual implications, like botany or chemistry. But
scientists ventured into cosmology, a very touchy subject,
because it was traditionally the territory of theologians and
philosophers, not scientists (natural philosophers).
Johannas Kepler believed in Copernicus's Sun centered theory,
having learned it from his mathematical mentor in school. Kepler
seemed to be attracted to the simplicity of the heliocentric
universe, even though it was still less accurate than the ancient
Ptolemaic, geocentric cosmology. Kepler fixed the defect in 1609
when he announced that the planets move in ellipses rather than
circles. After years of tedious labor, Kepler broke out of the
circular universe imposed by Ptolemy and by Copernicus.
Everything fell into place, and the heliocentric universe, freed
from all the philosophical preconceptions that held it back,
described the motions of the planets more accurately than did the
Ptolemaic system. Heliocentrism was simpler, more accurate, and
more elegant than geocentrism. It was the death knell for Ptolemy
and Aristotle, and for the cosmology that underpinned the
theology of the church.
The church was fully awake to the danger posed by the new
philosophy, and everyone who threatened Aristotle's framework was
himself, in mortal peril. Even Galileo Galilei, friend of Pope
Urban VIII, was in danger of being burned at the stake.
I'm sure you all know of the discoveries that Galileo made by
turning his telescope on the heavens.
Despite the Inquisition's judicial triumph over Galileo, the
first cosmological revolution had unseated nearly two millennia
of philosophy and theology and replaced it with science. Much to
the chagrin of the church, when science contradicted theology,
theology had to change.
In 1822, the Catholic Church finally removed Copernicus's "On the
Revolutions of the Heavenly Spheres", Kepler's "New Astronomy",
and Galileo's "Dialogue Concerning the Two Chief Systems of the
World" from the Index of Forbidden Books. The church accepted the
new cosmology; indeed, the clergymen began to explore it,
eventually founding their own observatory.
By the way, the discoveries made by Kepler and by Galileo were
subtle and they were profound; but they were tantalizingly
incomplete as well, every issue that they settled prompting
another in return. The air of mystery deepens when the work of
Galileo and Kepler are considered jointly. Isaac Newton would
stand on the shoulders of these two giants and give us a complete
mechanical understanding of our universe a few decades later.
________________
Today, the science of astronomy is being transformed by a new age
of technological advances. On mountaintops around the world,
scientists are opening ever larger telescopes, capturing light
from ever more distant reaches of the Universe.
Marc, when you look at me, we're about 20 feet from each other,
you don't see me as I am now, you see me as I was 20 nanoseconds
ago. When you look at the Moon you see it as it was more than a
second ago. You see the Sun as it was eight minutes ago. If the
Sun blew up, we wouldn't know it for eight minutes. And when we
go out into the country side far away from city lights and look
at the faint smudge of light that is the Andromeda Galaxy, you
don't see that galaxy as it is now, but as it was 2.3 million
years ago.
Astronomer Sandy Faber points out:
"These giant telescopes, they are the only true time machines
that human beings have and they are totally faithful. There's
nothing hokey about this. You look through a giant telescope, you
get a view of a very distant region of space, and it is as though
you were a historian and could put your eye to a telescope and
actually see Hannibal crossing the Alps and all those elephants
trotting along. We are actually seeing the Universe and the
things in it behaving as they did billions of years ago".
The deeper into space we peer, the farther back in time we
venture. This notion that we can study the history of the cosmos
is only a few decades old.
Early in this last century, astronomers believed that the
Universe was eternal, infinite and unchanging. Edwin Hubble was
interested in mysterious cloud-like objects known as nebulae. He
turned the new Hooker telescope at Mt. Wilson on the fabled
Andromeda nebula.
Astronomer Sandy Faber notes:
"Andromeda was very important to Hubble because astronomers were
wondering what all these little fuzzy blobs that we now call
galaxies were. And there were lots of astronomers who thought
that they were small little things that were just pieces of the
Milky Way. But Hubble was able to discover stars in Andromeda
that were -- that he could see were very much like stars in our
own galaxy. And at this point everything clicked into place. He
got the scale. He could see that it was far away. It was big.
There was no way that it was a little piece of our own Milky
Way".
Hubble discovered that the Universe contains other galaxies --
that it's far larger than we dared imagine. But he didn't stop
there. He analyzed the light of distant galaxies, and found that
it is skewed slightly to the red.
This "redshift" is the result of the "Doppler Effect." It's like
the sound of a train whistle that changes pitch as it speeds
past. The redder the galaxy's light, the farther away it is, and
the faster it is moving away from us. The Universe, Hubble found,
is not static, but expanding rapidly in all directions.
"This discovery had a profound consequence. If the Universe is
getting larger, we can make a movie, a cosmic movie, and we can
run it backwards. It would look very comical. All the galaxies
would be getting closer together and we can see that the
expansion of the Universe implies that there was a first moment,
a Big Bang".
Even Albert Einstein's Relativity equations predicted that the
Universe was not static an unchanging, but that it is dynamic and
must either be expanding or contracting. Einstein found the idea
of a changing universe so abhorrent that he tinkered with his
equations.
To "fix" the problem of a finite universe he added the term, a
constant denoted with the Greek capital letter lambda, which
balance the forces of gravity. Einstein's cosmological constant
was a way of avoiding the consequences of an ever changing
universe, a universe with a beginning and an ending.
When he learned of Hubble's discovery, something that Einstein's
own equations could have predicted, he called the cosmological
constant the greatest blunder of his career. So in 1931, Einstein
lent his prestige to Hubble's discovery. He conceded that his own
model of the Universe was wrong. It was not a "repellent force"
that kept the Universe from collapsing -- only its relentless
expansion.
________________
The big bang was a massive explosion that created all the mass
and energy in the universe, as well as the fabric of spacetime.
This fabric, which is described by Einstein's GTR, inflated
rapidly after the cataclysm, but within a tiny fraction of a
second, the rapid inflation slowed down and freely roaming
subatomic particles, quarks, began to form protons an neutrons,
which where constantly being buffeted about by incredibly intense
and energetic light (gamma photons). As objects expand, they
cool, so the ever expanding universe cooled down.
The universe was filled with atomic nuclei and electrons--and
with light. Whenever an electron tried to combine with a nucleus,
it was struck by a photon an stripped away again; conversely, a
photon could not get very far before it scattered off an atom.
Light was trapped.
This was the nature of the universe until about 380,000 years
after the big bang, when the expanding universe cooled enough for
another change; electrons combined with their nuclei once and for
all. The light was at last free bursting forth as the light of
creation and has been roaming the universe ever since. As the
universe has expanded the wavelength of the light stretches...
becoming redder and is now stretched down in to the microwave
range.
Princeton University physicists had theorized about this after
glow of the big bang, but before they could get together
experiments to try to detect it, Penzias and Wilson from Bell
Laboratories, in 1965, discovered the Cosmic Microwave Background
Radiation (CMB) for which they received the Nobel Prize.
________________
The second cosmological revolution was complete--no longer could
cosmologists console themselves with the picture of an eternal,
unchanging universe. All scientists now know the cosmos has a
birth date, because we have seen the cosmos's baby pictures.
The first two cosmological revolutions shattered the way we think
about the universe and our place within it. The Copernican
revolution destroyed the comfortable Aristotelian universe, where
the Earth was safely ensconced within a tiny nutshell. Hubble's
revolution and the discovery of the cosmic microwave background
showed that the cosmos had a beginning and an ending.
________________
The third cosmological revolution took scientists by surprise,
because they thought they already had a pretty good idea about
how the universe worked. After the discovery of the cosmic
background radiation, scientists understood the rough outlines of
the birth of the universe.
The exact age of the universe was known only as well as the rate
of expansion--and measuring that expansion was very difficult,
plagued with a great deal of uncertainty. Beyond that,
cosmologists had little idea about the ultimate fate of the
universe. They didn't know whether it would expand forever, or
whether it would re-collapse into a reverse big bang--a big
crunch.
Please imagine...
More than half way across the universe, mismatched partners are
locked in a dance of death. Two stars, near the end of their
lifetimes, circle each other, in Keplarian orbits held together
by their mutual gravity. One of the stars is a hot white dwarf,
the shrunken remnant of a star like our own Sun, compressed into
a space smaller than the Earth.
The other partner is bloated to enormous size; it is a cool red
giant puffed out to many times its original girth and ferociously
burning its remaining fuel.
Tugged by its partner, the swollen giant is pulled and distorted
into a monstrous teardrop. Gas from the red giant streams from
the teardrop's tip and spirals lazily into to white dwarf, like
water running down a drain. As the white dwarf swallows the gas,
year after year, it gets imperceptibly heavier.
When the white dwarf becomes too heavy--1.44 times the mass of
our Sun, to be precise--the extra mass it has accumulated crushes
the uneasy equilibrium of the shrunken star. One dollop of gas
too many and the star suddenly, catastrophically collapses. In a
flash the star crumples, heats up, and roars in to a blinding
Type Ia supernova, completely blowing itself apart in one of the
biggest explosions since the big bang. Because the mass is always
1.44 solar masses at the collapse, the liberated energy is the
same every time a Type Ia supernova occurs.
Supernovae can be seen more than half way across the universe.
Distance can be estimated from the supernova's peak brightness
and the expansion rate can be inferred from the redshift of its
light.
The Hubble Space Telescope's prime mission, was to determine,
once and for all, how fast the universe is expanding. Astronomers
working with the Hubble telescope made lots of pretty pictures of
exotica in space, but more important, they gathered reams and
reams of data on Cepheid variable stars in an attempt to
calculate the Hubble constant. After years of data the answer
from Hubble is 72 km/s/Mpc!
Two competing teams of astronomers, also using the Hubble Space
Telescope, had been spending years studying Type Ia supernovae,
hoping to use them to figure out the Hubble constant, both now
and in the past.
The two teams did not expect to see anything unusual when they
analyzed their data--But what they found was the expansion of the
universe is no longer slowing because of its gravitation, it is
now speeding up--we are in a runaway universe!
Totally independent of supernovae data, the Wilkinson Microwave
Anisotropy Probe (WMAP) team made the first detailed full-sky map
of the oldest light in the universe. It is a "baby picture" of
the universe. The results from the first year of observing by the
WMAP were announced in February of 2003. Important results
include:
o The satellite has been renamed in honor of the late David T.
Wilkinson of Princeton University, a key member of the project
from its conception.
o The polarization of the microwave background anisotropy coming
from scattering by electrons 200 million years after the Big
Bang has been detected. This is evidence for an early
generation of stars existing 4 to 5 times earlier than any
object yet observed.
o The WMAP data agree with previous work showing the universe is
in an accelerating expansion and that it is flat. Space all
across the universe is flat, just like the familiar space right
around us. That is, parallel lines will never meet no matter
how far they are extended, and other aspects of geometry work
normally no matter how far you look. Flat space is a sign that
the cosmic inflation theory underlying the Big Bang is right on
target. This in turn implies that the familiar scenery of
galaxies and galaxy clusters that we see extending across the
universe continues infinitely far beyond our cosmic horizon".
o The WMAP data give the most precise value for the age of the
Universe: 13.7 billion years ± 150 million years. The Hubble
constant, H_o = 71 ± 4 km/s/Mpc, and the vacuum energy density
corresponds to lambda = 0.73 ± 0.04.
________________
In conclusion--it is just fascinating that we can piece together
a reasonably accurate picture of the history of the Universe.
We only "know" anything about the world on the basis of various
assumptions. If our assumptions turn out to be wrong, our
"knowledge" may turn out to be wrong too. Even worse, our
favorite concepts may turn out to be meaningless, or meaningful
only under some restrictions.
So, when we talk about what happened, say, in the first
microsecond after the Big Bang, we're not claiming absolute
certainty. Instead, we're using various widely accepted
assumptions about physics to guess what happened. Given these
assumptions, the concept of "the first microsecond after the Big
Bang" makes perfect sense. But if these assumptions are wrong,
the whole question could dissolve into meaninglessness. That's
just a risk we have to run.
What are these assumptions, exactly? They include:
1. Einstein's GTR
2. the Standard Model of particle physics
supplemented by
3. some form form are dark energy, in other words a nonzero
cosmological constant, lambda, the same lambda that Albert
Einstein inserted in his equation and later considered it to be
his biggest blunder. If Einstein were alive today, he would have
been thrilled to find that his cosmological constant appears to
be a necessary ingredient in the way the universe works. And
Einstein's "biggest blunder" has instantly become the greatest
mystery in science.
4. some form of "cold dark matter", unseen matter whose
gravitational effects are observed in the motions galaxies and
clusters of galaxies.
Assumptions 3 and 4 are the ones most people like to worry
about, because our only evidence for them comes from cosmological
observations, and if they're true, they probably require some
sort of modification of the Standard Model. But if we don't make
these assumptions, our model of cosmology just doesn't work...
while if we *do*, it seems to work quite well as is shown with
the WMAP data!
Talk about spirituality--for me understanding the Universe... How
it began... How it has evolved... and where it is going... is
indeed spiritual! And we are an integral part.
Lines from the Hymn, "We Laugh, We Cry" which seem appropriate to
today include:
I.
We laugh, we cry, we live, we die;
we dance, we sing our song.
+> We need to feel there's something here
+> to which we can belong.
We need to feel the freedom
just to have some time alone.
But most of all we need close friends
we can call our very own.
And we believe in life,
and in the strength of love;
and we have found a need
to be together.
We have our hearts to give,
we have our thoughts to receive;
and we believe that sharing
is an answer.
II.
A child is born among us
and we feel a special glow.
We see time's endless journey
as we watch the baby grow.
We thrill to hear imagination
freely running wild.
We dedicate our minds and hearts
to the spirit of this child.
And we believe in life,
and in the strength of love;
and we have found a time
to be together.
And with the grace of age,
we share the wonder of youth,
+> and we believe that growing
+> is an answer.
III.
+> Our lives are full of wonder and
+> our time is very brief.
The death of one among us
fills us all with pain and grief.
But as we live so shall we die
and when our lives are done
the memories we shared with friends
they will linger on and on.
And we believe in life,
and in the strength of love;
and we have found a place
to be together.
We have the right to grow,
we have the gift to believe
that peace within our living
is an answer.
IV.
+> We seek elusive answers to
+> the questions of this life.
We seek to put an end to all
the waste of human strife.
We search for truth, equality,
and blessed peace of mind.
And then, we come together here
to make sense of what we find.
And we believe in life,
and in the strength of love;
and we have found a joy
being together.
And in our search of peace,
maybe we'll finally see:
+> even to question truly
+> is an answer.
REFERENCES
o Baez, "This Week's Finds in Mathematical Physics:196", UCR (2003)
http://math.ucr.edu/home/baez/week196.html
o Berlinski, "Newton's Gift", Simon & Schuster, (2000)
o Goodstein, "Mechanical Universe", Annenberg CPB Project (1985)
http://www.themechanicaluniverse.com/
o Nova, "Mysteries of Deep Space" transcripts, PBS (1997)
o Raymo, "Celebrating Creation", Skeptical Inquirer magazine: July/August 1999
o Sagan, "Cosmos: Harmony of the Worlds", Random House (1980)
o Seife, "Alpha & Omega", Viking (2003)
o Wright, "Ned Wright's Cosmology Tutorial "
http://www.astro.ucla.edu/~wright/cosmolog.htm
o Hymn, "We Laugh, We Cry"
http://www.focol.org/fvuuf/hymn.htm