Gravitational Waves, LIGO and Inside the Pearl
On Thursday, February
11, 2016 the scientists at the Laser Interferometer Gravitational-Wave
Observatory (LIGO) have called a press conference to announce their discovery
of gravitational waves. These waves are
what bend space and time. The ripples
that LIGO has detected are probably the result of two black holes running into
each other. This is science for the sake
of science. Knowledge for the sake of
knowledge. It will change how we see the
universe. It may or may not be helpful
in an as yet unknown way, but it is definitely another counterpoint in the
music of the spheres. The following is an article I wrote for the
Mensa Bulletin on June 6, 2006 about gravitational waves, dark energy and
Albert Einstein.
Has your eye ever been captured by the beauty of a pearl,
the milky sheen with just a hint—almost imagined—of blush? That
blush makes pearls seem to be living things.
When I first learned what a pearl was and how it was made I thought it
was a grand mystery. I got my mother’s
pearls out of the drawer where they were kept, carefully wrapped in tissue and
velvet, and stared intently at the large center pearl of the strand. I imagined myself growing very, very small
and diving through the layers of nacre to the center of the pearl. There I would live in my own tiny world. In my mind, when I sat on the center grain of
sand that was my pearly home and looked at the curved sky of solid, yet
seemingly transparent white, to the curved shell of pearly heaven, my world
always seemed very large to me, even though I was a spec and my universe only a
pearl.
When I
study astronomy, I feel like I am back inside that pearl. Physicists understand what it is like to be
very small and very large all at the same time.
The works of Jastrow, Sagan and Hawking have always been part of my
library.
That is why
I have been following, with constant wonder, the gradual confirmation,
challenge and acceptance of the concept of dark energy. It also affirms what I have always felt about
Albert Einstein—he had the ability to be right without even knowing he was, or
why such rightness had to be. On the
matter of Dark Energy, Einstein was right in two ways, first his cosmological
constant (which he later repudiated, like any good scientist, for lack of
confirming empirical data) does work to explain the presence of Dark Energy. Second, and most important, he was right in
his belief that the unifying aspect of all theories would be in gravity. The child in me knows this truth, but I must
count on the theoreticians to give me the hard cold facts. Thankfully, they are working at that with
technology Einstein would have loved.
Cosmic
Microwave Background (CMB) has provided both answers and questions to
cosmologists. Microwave energy, measured
through an alphabet soup of new devices, is a remnant of the Big Bang. The fluctuation of the CMB shows the kind of
hot and cold spots scientists expect from the results of the Big Bang. An explosion in the relative vacuum of space will
expand in a sphere, but debris—even primordial atomic debris—will scatter in
clumps, braids and strands. Cosmic
Microwave Background reflects this dispersal as we believe it may have looked
from about 400,000 years after the Big Bang.
The alternating compression and
expansion of microwaves (compressed by gravity, expanded by radiation) produce
both a sound wave and heat. If you want
to illustrate this principle in a highly simplified way, take a thick rubber
band and rapidly expand and release it.
Listen to the low thumping sound it makes. On one of the last expansions, touch the
rubber band to your upper lip. It will
be warm. While the heat signature of the
microwave background is too delicate to be detected, that rhythmic throb of the
microwave expansion and contraction is what cosmologists are listening for.
There is
also ample evidence to confirm that what you and I would call, “mass,” makes up
only about 5% of the universe. Another
30 % has been identified as dark matter—physically there, but unseen. That leaves a whooping 65% currently supposed
to be dark energy. Dark energy (oh,
would Einstein love this!) apparently is antigravity.
I once had
the pleasure of hearing Dr. Margaret J. Geller talk about her study of
galaxies. She is the Harvard astrophysicist
who proved that galaxies cluster on what appear to be the surface of
cosmological bubbles. Just as soap
bubbles coalesce along the rim of connected bubbles, sharing some space side by
side, while leaving huge arcs of the bubble untouched, so galaxies form in our
universe. These are not real bubbles of
course, but the bubble analogy explains the structure.
Bubbles,
planets, and stars, like my pearls, are all spheres. And there is a very good reason. Everything that exists in the physical world,
no matter how large or small, has mass.
Everything with mass, has a gravitational force. Gravity exerts a force that is directly proportional
to the size of its mass and inversely proportional to the square of the
distance between it and any other mass.
This force is exerted equally in every direction from the mass
itself. Because of this, objects left at
the mercy of their own gravitational fields, tend to form themselves into
spheres. Stars are very large
spheres. Atoms are very small ones.
Now let’s think about Dr. Geller’s
galaxies, forming, as they seem, on the surface of bubbles, and all of that
dark energy that seems to be at work in our universe.
Dark energy
is antigravity, pushing the mass of the universe away from itself at a rate
that creates a flat, not a pulsating universe.
If that is so, would it not then behave as gravity does, only in
reverse? Would dark energy not have
spewed from the Big Bang in the same haphazard and pervasive way as did nascent
matter? Would central cores of dark
energy not exert a force equally in all directions away from itself? Would dark energy not form bubbles of antigravity,
with the world of matter occupying the skin of those bubbles where dark energy
has stretched itself too thin to counteract the positive gravitation of the
world of physical mass? The logic as well as the mathematics fit
together neatly.
The awesome combination of matter,
dark matter and dark energy form a delicate equation that turns scientists into
philosophers. Physics is why I keep the faith.
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