Our Place in the Cosmos
Sermon by Dr. Forrest Hall, guest speaker:
Pick a number! No,
not just any number, the largest number you’ve ever heard of. How about the U.S.
Have you heard anyone use the number one quadrillion? That’s
a 1 followed by fifteen zeros or 10 to the fifteenth. I’d be willing to bet you have never heard
the number one googol. That’s a one
followed by one hundred zeros or 10100! So what? Who would ever need a number like
that?
When NASA used the space telescope HUBBLE to count the
number of galaxies in the visible universe, we first counted one hundred and
fifty billion galaxies! When later astronauts flew to HUBBLE and installed a
higher resolution camera we then counted 20 times that number or 3,000 billion,
or 3 trillion galaxies. The Milky Way
galaxy contains about 2 billion stars. So a rough estimates of the total star
count in all 3000 billion galaxies within our visible universe is roughly 6
billion trillion stars, or 6 quadrillion stars– give or take a few. If we assume that each of those six
quadrillion stars has roughly the same number of atoms as our sun, we get a
very rough estimate of 10100
atoms in the universe. Not a gaggle of geese but a googol of atoms. Ok, now
there is a practical use for the number, one googol. At your next party, you
can liven up a conversation saying, “Did you know there is a googol of atoms in
our universe?”
How our view of our place in the cosmos has changed in just
three centuries ago. Galileo didn’t even know about atoms, and thought the
universe consisted of just the sun, a few planets that orbited about the sun
and a few stars he could see with his new telescope. In the next couple of centuries the human
imagination was stretched -- almost to the breaking point – we are now forced
to comprehend a universe containing a googol of atoms constituting six
quadrillion stars.
The next shocker is that only 4% of the matter and energy in
the universe is observable. The other
96% that we can’t observe we call “Dark”, meaning that we can’t see it.
Ok. Now get ready to
flex your mind in the other direction – from the unimaginably large to the
unimaginably small.
We also know that the galaxies we can see -- all those six
trillion stars, their hydrogen and helium, were once all contained in a volume
much smaller than the period at the end of a sentence. How much smaller? A billion, billion, billion, billion times
smaller. To be exact, a dot with a
diameter less than 10-35meters. 10-35 is math shorthand
for a number starting with a zero, then a decimal place, followed by thirty
four zeros to the RIGHT ending in the numeral one.
That’s small!!!! But, in the beginning, everything in the
universe was squeezed into that dot!
Whoa, wait a minute you are probably thinking. He’d better explain how we know that.
How do we know? No
matter in which direction we point our powerful telescope, whether it’s in the
southern or the northern hemisphere, or out from the equator, or the north or
south poles, we see every one of those one billion galaxies moving directly
away from us. And fast! And the further away from us a galaxy is, the faster it
moves away. And they have been moving away. Why? And how do we know why?
We know from Einstein’s theory of General Relativity -- you
know, the guy with frizzy hair and mustache who brought you the famous formula
E=MC2 -- that all the galaxies and their stars are racing directly
away from us because the space in which they are embedded is itself
expanding.
We normally think of
space as the absence of something – totally empty. But that is an
illusion. We just can’t see what is
there. Dark matter & dark energy.
Einstein’s theory of General Relativity says that energy, mass, space
and time are really one thing, and that mass can cause mass to contract, and
energy can cause it to expand. The dark energy filling the universe is causing
space to expand.
The best analogy is raisin bread baking in the oven. Space is the dough, and the galaxies are the
raisins. When we bake bread, we begin
with a ball of dough say the size of a golf ball. But when the bread is
finished baking, it’s much larger. In an oven, heat energy causes the yeast in the dough to create bubbles,
expanding or rising the dough. In the
universe, the energy causing the expansion of space is dark energy. Like yeast
in the dough, dark energy fills all the space in the universe. Every grain of
it! Dark energy is in other words, the
yeast of the cosmos. Anyway, from our
galactic raisin and our tiny planet Earth located in the Milky Way raisin, we
look outward and in no matter which direction we look, all the other raisins,
all the other galaxies are rushing away from us as space expands. This is the aftermath
of the Big Bang when someone or something turned on the cosmic oven.
Using physics and observations, we can run the universe
backward in time to see how it all must have begun. When we look at a distant
galaxy we are in effect looking back in time because the further away a galaxy
is, the longer it takes for its light to reach us here. By looking our far
enough with powerful telescopes, we can see almost to the beginning of time,
13.75 billion years ago. And what we find is that all that we now see was then
contained in a dot no larger than 10-35 meters in diameter. In other
words, when we run the cosmic movie backward, the rising bread shrinks to the
size of a nearly infinitesimal dot with an unimaginably high temperature -- a
billion, trillion degrees. Now there is one hot oven!!! Before that physics doesn’t really apply so
we don’t and cannot know what happened before the Big Bang.
That is the stuff of true mystery, the unknowable.
The physics of cosmology tells us that in the beginning, 10-43
seconds to be exact, just after somehow the heat was turned on by the Big Bang,
the size of the cosmic dough ball was not the size of a golf ball, not the size
of a period at the end of a sentence, but no larger than a dot 10-35
m in diameter.
Like every raisin in
the rising loaf of raisin bread, our raisin, the Milky Way appears to be at the
very center of the visible universe. Everywhere we look every galaxy are
rushing away from us. Every raisin,
every galaxy is also at the center of this expansion because space is expanding
uniformly everywhere. Another Whew!!!
How big is the visible
universe? Simply put, it’s the size that we can see – and that is not limited by the power of our
telescope. The size of the visible universe is determined by the basic laws of
physics. And that is, how far light can
travel since the first stars were created.
We cannot see any galaxy further away than that no matter how powerful
the telescope. Their light has not had
time to reach Earth. And that distance is roughly 1028 meters – The
number 10 followed by 28 zeros.
In other words, we have reached our scientific horizons,
limited, not by the power of our tools, but by the laws of physics. And those
horizons range from 10-35 meters, the smallest thing physics allows
us to observe, to 10 28 meters the largest thing physics allows us
to see – We have reached the end of our rope so to speak when it comes to our
ability to observe the universe. Our horizons begin and end at scales spanning
the smallest thing observable to the largest -- roughly 70 orders of magnitude.
Now, if you thought you were beginning to feel your mind
warping under the strain of all those huge numbers, consider this. Not only can we see only 4% of what makes up
our universe, many cosmologists, those who spend their lives studying such
things, think now that our universe is just one slice of bread within an
infinitely large cosmic loaf. This theory is known as the Multi-verse
theory. Cosmologists think that there
may be uncountably many, that is infinitely many universes, slices of bread in
the giant infinitely large cosmic loaf.
Rev. Gabi:
Enough already! J
That’s quite a lot to come to terms with, to visualize! I
can relate to the example of the cosmic bread dough, but beyond that I am
unable to comprehend the size and sheer number of what you are talking about.
But I must say: I am deeply awed by it! It is proof, at least for me, of how
great God is.
Since the beginnings of time, humans have experienced awe -
as well as fear - when confronted with the phenomena of nature. And humans have
felt the need to explain what they could see and observe. Just look at the many
creation myths that you can find in all cultures. They are
an attempt to explain how the world was formed, and where humanity came from.
Whereas you scientists investigate the cosmos with the tools of empiricism and
rationality, and you come up with some answers and many theories, creation myths try to explain humanity’s
meaning with symbolic narratives. The beings referred to in the myth -- gods,
animals, plants -- are forms of power grasped existentially. However, they are not an attempt to work out
a rational explanation of a deity. Explaining God has always been impossible.
And that’s
similar to what physicists are finding out:
they can not explain everything. Let me tell you an anecdote about Richard
Feynman, the famous quantum physicist,
who was awarded the Nobel Prize for his work in quantum electrodynamics:
He was contemplating the Theory
of Everything one night. As the story goes, Feynman was visited by a “divine revelation” that laid it all out for
him. The next morning, in his Physics
class at Cal Tech, he excitedly announced
his discovery to his class.
“Last evening”, he said, “I stumbled upon the entire general
and comprehensive Theory of Everything.”
Feynman then turned toward the classroom’s giant blackboard and selected a chalk from its tray.
A pin drop could have been heard as he raised the chalk
toward its clean blank space.
“Unfortunately”, he said, returning the chalk to the blackboard’s tray,
“I cannot write it down for you, for to
do so would detract from its Generality.”
Dr. Feynman got the point across that the moment we attempt
to describe reality with symbols or
words, we automatically oversimplify and detract from its native grandeur and
inherent complexity.
Dr. Forrest Hall:
In our attempt to describe the universe in mathematical
terms, we see that its grandeur stretches even the limits of mathematics, the
ruler we use to quantify the smallest to the largest things we can measure, a
range extending 70 orders of magnitude.
We have discovered hard limits to what humans can know about
the universe and have been able to quantify the physical extent of those
boundaries. And I am not talking about
limitations of our measuring instruments.
I am talking about the ultimate limits of what we can actually observe
and analyze.
If you look at the emblem that Reverend Gabi has included in
your order of worship, the cosmic Uroboros, you will also find another amazing
thing. Not only are we at the center of
our visible universe with galaxies flying away from us in every direction, the
scale of our body at about 1 meter or so, is located almost exactly in the center
of the cosmic scale. In other words, we humans after all do occupy a unique
place in the universe, the exact center of its observable scales and the exact
center of its observable horizon.
So where do we go from here? We have seen far, and deep into
reality. Our equations are elegant, profound,
powerful. Yet there seems to be no symbol for God in them. If God is anywhere,
God must lie beyond our vast sensual horizons, beyond our physics and beyond
our science.
Rev. Gabi:
In other words, God can not be measured by science!
But, you see, theologians don’t feel the need to measure
God. They know that God is unbelievably great! True, we can not see, hear,
smell, or feel God. And yet we have no doubt that there is something else “out
there:” call it the Transcendent, the Ineffable, the Force, the Ultimate, or
God. We can’t observe it, we can’t measure it, but we can experience it. Of
course, there are as many experiences of God as there are human beings -- and,
possibly other sentient beings.
Throughout the ages, countless people have experienced the
Divine in one form another, and have tried to describe this experience. It
seldom works; or it only works for some of their listeners. And this is where
theologians and other religious folk are limited: we have no common language to share experiences
of a spiritual nature. We are limited by
the lack of words and symbols that evoke the same image in all listeners or
readers. As the philosopher and Rabbi Abraham Joshua Heschel puts it: “To
become aware of God is to part company with words. Nevertheless, we will never
sneer at the stars, mock the dawn, or scoff at the totality of being. Sublime
grandeur evokes unhesitating, unflinching awe. Away from the immense,
cloistered in our own concepts, we may scorn and revile everything. But
standing between earth and sky, we are silenced by the sight.”
Dr. Forrest Hall:
So there is that boundary, as Gabi has just said between the
known, the knowable and the unknowable - Rabbi Heschel calls it the ineffable - that
which cannot be observed or analyzed. The realm of true mystery. That which in not only not yet known, but
that which we know now is forever unknowable – at least by the tools of
science.
But the more we learn about the physical universe, the more
of what we know, in my mind, points to the nature of a transcendent
intelligence that goes beyond the that which we measure with the tools of
science, no matter how powerful.
To be sure, we have been amazed by what we have learned
using those tools. We have learned that
we are cosmic dust that in 13.75 billion years, was made flesh. A process
beyond our understanding and power of observation breathed life into that
cosmic dust, life able to stare out onto the twinkling necklaces draped over
the night sky and wonder in awe at the great drama, the miraculous process of
cosmic creation, like an illusion or dream, being sustained by laws whose
source we can never know.
Each night, when we
look into the sky, or at an ant, or flower, that wonder can be ours.
Rev. Gabi:
But it depends on your level of awareness! As Heschel also
reminds us “. . . we need to be aware of the tangent of the Beyond at the
whirling wheel of experience.” Because,
in our passion for knowledge, our minds prey upon the wealth of an unresisting
world. We quickly lose ourselves in the whirlwind of our knowledge. But, you
see, the horizon of knowledge is lost in the mist produced by fads and phrases.
In order to change this, we have to take notice of what is
beyond our sight. We should not be content with converting realities into
opinions, mysteries into dogma, and ideas into a multitude of words. Let us not
be blinded to the point that what is extraordinary appears to us as a habit,
and the dawn becomes a daily routine of nature.
I’d like to conclude with one more quote by Rabbi Heschel:
“In the confinement of our study rooms, our knowledge seems to be a pillar of
light. But when we stand at the door which opens out to the infinite, we
realize that all concepts are but glittering motes that populate a sunbeam.”
posted by marylandgis at
9:18 PM
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