Dark
Matters
by
Kenny A. Chaffin
All Rights Reserved © 2013 Kenny A. Chaffin
Hello darkness my old
friend
I’ve come to talk with
you again
- Sounds of Silence
by Paul Simon
I
There is no dark side of the moon really.
I
There is no dark side of the moon really.
Matter of fact it's all dark.
- Eclipse (Dark side of the Moon)
Roger Waters
Dark matter, dark
energy, the dark side of the Moon…..hmmmm….I think we better talk. A couple of decades ago everything was cool.
We knew the universe was expanding and the thought was that it would either
continue expanding or reverse course and begin collapsing due to gravity. In
either case it was assumed that the rate of the expansion would slow due to
gravity. We’d never seen any slowing so have been looking to verify this claim.
Then along comes the damn Hubble Space Telescope screwing everything up! Its
observations of distant galaxies in 1998 showed just the opposite. Not only was
the expansion not slowing but the rate of expansion was increasing! It was as
if some force were pushing the galaxies apart every faster. There was no
explanation that fit. Enter confusion and a new hypothesis – Dark Energy -- thrown
in to the cosmological mix to explain the accelerating rate of expansion. Now if
you’re getting a feeling of déjà vu, blame it on Einstein and his cosmological
constant. He claimed it was his biggest mistake – adding it into his general
relativity equations and then removing it. It has again been resurrected as an
explanation for the accelerating expansion of the universe we now see. Or
perhaps this begins to sound more like Roger Water’s Dark Side of the Moon lunatic
or maybe Roger Penrose’s quantum mind. It’s all dark, really.
Dark energy is the
name cosmologists have assigned to this unexplainable observation, somewhat in
relation to the ‘vacuum’ energy of space. This is not science, this is
speculation. We don’t know what is going on really we only have observations
awaiting an explanation. Dark energy is a hypothesis, not a theory as there is
no way to verify it because on its definition.
It only interacts with normal matter in the form of gravity. There is no
way to observer it, measure it, or test it beyond the indirect observations of
galactic expansion. And how is that different than some unknown feature, force
or characteristic of the universe that we simply do not understand at this
point? The problem as I see it is that this ‘theory’ of dark energy has been
feed to the public in sensational news headlines and popular science articles
as if it were real science. This is misleading at best and deceptive at worst in
my opinion since it makes it sound like there is a clearly identified cause –
dark energy. That is what the public takes from these twitter-like headlines,
particularly since most readers don’t get beyond those headlines. The truth is
that we don’t know if any such thing as dark energy exists, we have an
unexplained observation and that is all we know. Would it not be better to
simply say, “Yes the rate of expansion of the universe appears to be increasing
but we do not know why?” Unfortunately science is acting more like a religion
and claiming that it has answers to the unknown when in fact it does not. In
this age of the media and marketing as kingmaker science communicators can fall
into the same trap of sensationalizing their stories. But enough of that just
call me a lunatic if you like.
Something is
responsible for the accelerating rate of expansion of the universe. Something
we don’t understand, perhaps there is a cosmological constant that we’ve yet to
identify and understand, perhaps there is a problem with Einstein’s General
Relativity Equations, perhaps there really is some form of energy here-to-fore
unidentified that is pushing the galaxies apart faster and faster. Or perhaps
there is some error or issue with our deep-space, deep-time observations.
(Credit: NASA)
As you can
see in the above illustration, measurements show that the direction of the curve
changes about 7.5 billion years ago. What might have happened at that point in
the universe? Could it be that the ‘vacuum energy’ of space changed at that
point due to physical expansion? This is unknown of course. As new space came
into being did additional dark energy appear as well? The belief at this point
is that 68% of the universe is actually dark energy with another 27% is dark
matter. Now it is certainly something of a dark matter that leaves only 5% of
the universe as normal matter. That 5% is everything we know, you, me, all the
planets, stars, asteroids and hydrogen clouds, everything we previously assumed
was the entire constitution of the universe. With the emergence of dark matter
and dark energy everything we thought we knew has been turned upside down as
though we were in an Alice in Wonderland story.
Before we
go too far, let’s look back at dark matter. It was first proposed by Jan Oort (of
Oort cloud fame) in 1932 to account for the orbital velocities of stars in the
Milky Way. Others have shown additional situations that require dark matter in
order to explain gravitational anomalies. Dark matter doesn’t seem to be as
unbelievable as dark energy as it is thought to be ordinary matter which is not
easily detectable either optically or by other observational methods. The
effect is primarily seen through gravity on orbits, velocities and movement of
stars and galaxies. It seems very possible there are massive amounts of normal
matter strewn throughout the universe collectively known as massive compact
halo objects or MACHOs that could be enough to cause gravitational anomalies
but we have not been able to detect enough possible candidates to conclude that
this is the case. Another possibility is nonbaryonic dark matter (such as WIMPS
– weakly interacting massive particles) which would not be detectible by
electromagnetic means. This appears to be the leading candidate for the source
of dark matter. While most cosmologists agree that dark matter exists and
explains the anomalies there are alternative hypotheses/theories of gravity
that attempt to explain the discrepancies without resorting to unobservable
matter.
This three-dimensional map offers a first look at the web-like large-scale distribution of dark matter, an invisible form of matter that accounts for most of the Universe's mass. The map reveals a loose network of dark matter filaments, gradually collapsing under the relentless pull of gravity, and growing clumpier over time. The three axes of the box correspond to sky position (in right ascension and declination), and distance from the Earth increasing from left to right (as measured by cosmological redshift). Note how the clumping of the dark matter becomes more pronounced, moving right to left across the volume map, from the early Universe to the more recent Universe. (Credit: NASA/ESA/Richard Massey (California Institute of Technology))
So the
effect of dark energy we observe is somewhat the opposite of the effect of dark
matter. Dark matter has a gravitational
pull and effect on stars, planets, galaxies and all normal matter in the same
way they affect and attract one another. Dark energy on the other hand creates a
constant ‘anti-gravity’ force that pushes everything apart and accelerates the
on-going expansion of space. The following illustration from NASA shows the
change in composition from the origin of the universe 13.7 billion years ago to
what we see today. Note the increasing percentage of dark energy. This sort of
makes sense as there was only a certain amount of matter in the original
universe and as it expands what is added is space and along with it the vacuum
energy which seems to include increasing amounts of dark energy.
So we have
a mystery. It’s a scientific mystery not unlike others that we encounter at the
edges of science, in this case the science of cosmology. Dark energy is
proposed as a hypothesis to explain the accelerating expansion of the universe
though we have no means of measuring, detecting or verifying that that is the
case. Dark energy is really just a placeholder for something we don’t
understand. It seems to harken back even beyond Einstein’s cosmological
constant to the ether theory that was proposed before Maxwell provided us with
an understanding of electromagnetic waves. For the non-scientist reading about
this research in the media it can be confusing and the casual reader will come
away thinking dark energy is a real thing because science said so. Most readers
don’t think too deeply about it and figure it’s something like atoms or quarks
or photons when in fact it is nothing of the sort. It is nothing more than a
hypothesis, and perhaps not even that because to be a true hypothesis it must
be testable and from what has been proposed there is no way to test, verify, or
validate dark energy. There is only the observation which it is hypothesized to
explain – a circular definition in other words. This is the dark side and dark
matters.
Afterword
It is
incumbent upon all scientists and science communicators to be as up-front, open
and honest as possible with the public. There is a distrust of science that has
been building since the mid-20th century. We must take care to not
exacerbate the situation in these times of global warming and genetic engineering,
these times of political and religious attacks on science. We must work with
the public to build bridges of trust and support by stepping out of the
darkness and conveying scientific knowledge in the light of truth and full disclosure
and thereby regain public trust and support.
References/Resources/Links
The Sounds of Silence:
Dark Energy:
Expansion of Universe Illustration:
Dark Matter:
Distribution map of Dark Matter:
WMAP Content of the Universe graph:
About the Author
Kenny A. Chaffin writes
poetry, fiction and nonfiction and has published poems and fiction in Vision Magazine, The Bay Review, Caney
River Reader, WritersHood, Star*Line, MiPo, Melange and Ad Astra and
has published nonfiction in The
Writer, The Electron, Writers Journal and Today’s Family. He grew up in
southern Oklahoma and now lives in Denver, CO where he works hard to make
enough of a living to support two cats, numerous wild birds and a bevy of
squirrels. His poetry collections No
Longer Dressed in Black, The
Poet of Utah Park, The Joy of Science, A Fleeting Existence, a collection of science essays How do we Know, and a memoir of growing up on an Oklahoma farm - Growing
Up Stories are all available at Amazon.com: http://www.amazon.com/-/e/B007S3SMY8. He
may be contacted through his website at http://www.kacweb.com.
