This morning I was out on the beach here on Marco Island at
5:45 AM, expecting the predicted fog. In reality, it was a crystal
clear morning with a sky full of stars that we seldom see in New
Jersey. In the many years I’ve walked the beach, I’ve never seen
a bird that I could recognize as a baby seagull or pelican. I’ve
also not seen any nests of these birds and have assumed that they
raise their young somewhere in the open. However, this morning
I saw a gull pick up a rather large twig from a branch washed up
on the shore. The gull dodged a pursuing bird and flew inland
out of sight with the twig. I conclude that gulls do build nests.
This year, in addition to the driftwood washed up on shore, I’ve
seen large, weathered wooden planks, some at least 8 feet long. I
surmise that these planks are debris that floated down from the
hurricane-ravaged areas north of here. The hurricanes left Marco
Island virtually untouched but we snowbirds are suffering from a
problem related to the hurricanes. The problem concerns the
practice of reinforcing concrete flooring with a grid of metal
rods. I’m not an engineer but understand adding the rods has
something to do with interactions with the stresses of tension and
compression that result when the concrete hardens.
Our problem is that, when water seeps in and around the rods,
the rods corrode (rust) and expand, thus cracking and weakening
the concrete flooring. (Tony, my golfing buddy and battery
colleague, pointed out to me in an e-mail the similarity to a lead-
acid battery problem involving corrosion of the lead grids.) How
to correct the problem? We found the answer when one day last
week a crew of Mexican workers appeared out of nowhere on the
deck of our rental fourth-floor condo with jackhammer and
circular saw in hand! Two days were spent tearing up the
concrete, exposing the metal rods. This week, a day was spent
grinding off the rust from the rods. We now await an engineer’s
inspection before they once again appear to lay the concrete.
Why this most annoying work now, at the height of “the season”
in Florida? The work was delayed when the crews were sent to
the hurricane-stricken regions last year to assist in the relief and
construction efforts there. I’ve written in the past about how
sound travels through solid materials as well as through air.
Well, the sound of the jackhammer in one condo reverberates
throughout every unit in our building – not pleasant!
As I began this column writing about the expansion of the metal
rods, I had no idea what the main subject would be. However,
the mail arrived with my copy of the March issue of Scientific
American and on the cover was “Big Bang Bungled: 6 Common
Errors about the Expanding Universe”. How could I resist the
segue from expanding metal rods to expansion of the universe?
When I read that Tamara Davis, coauthor of the universe article,
was Australia’s representative in the sport of Ultimate Frisbee, I
knew she had the credentials to clarify universal misconceptions.
Actually, she and coauthor Charles Lineweaver are Australian
astronomers of excellent credentials.
Lineweaver and Davis believe that the expanding universe is like
Darwin’s evolution in that most scientists think they understand
it but few agree on what it really means. With regard to the
universe, even respected physicists and authors of astronomy
texts have made incorrect and misleading statements that have
led to blatant misconceptions about not only the expanding
universe but also the Big Bang itself. I was surprised to find that
I shared some of the misconceptions.
What do we mean when we talk about the expanding universe?
Let’s pretend that I’ve shrunk down to microscopic size and I’m
living on a big balloon that’s being pumped up, getting bigger
every day. On the balloon, each morning I walk on the
microscopic beach down to the microscopic Hilton resort and
back. But a strange thing is happening – every day it takes me
longer to walk to the Hilton and back. As the balloon inflates,
the distance between my condo and the Hilton gets larger; the
space is expanding. Space is expanding at the same rate all over
the surface of the balloon. As far as the Hilton and my condo are
concerned, we haven’t moved but we’re receding, getting farther
away from each other.
As on the surface of our balloon, space itself is expanding and
has been expanding since the Big Bang. We, our planet, our
solar system and our Milky Way galaxy are not expanding.
Thanks to gravity, we’re staying the same size while the space in
which we exist is expanding. There’s another strange feature.
Let’s go back to the surface of our balloon. Where is the center
of the surface? Remember that we’re confined to the surface
and, if we try to find a center, there is no center! Space is
expanding all over the surface at the same rate no matter where
we are on the surface.
Similarly, no matter where we are in the universe, space is
expanding at the same rate. And, as with our balloon surface,
there is no center of our universe. Wait a minute, you say.
Doesn’t there have to be a center? After all, our universe came
about through a tremendous explosion called the Big Bang. In
the Big Bang, the universe started as a miniscule point in space,
growing to the size of a softball in a tiny fraction of a second and
thence to the enormous size it is today. The center is at that point
where it all got started, right?
One of the misconceptions cited in the Scientific American
article is the nature of the Big Bang itself. It was not your typical
explosion, which starts in a small space and creates a huge
pressure that drives the surrounding material out from the center
of the explosion. No, the Big Bang was an explosion of space,
akin to blowing up that balloon in a real hurry. Space exploded
everywhere and continues to expand today, everywhere – no
huge pressure difference and no center. I’ve said before that one
reason I keep writing about difficult subjects is that I hope that
eventually I’ll think I understand them. I admit to having a
problem with this one.
However, not all is lost. The picture we’ve had of the Big Bang
isn’t totally wrong. Let’s run the clock backwards in time and
collapse our universe back to what it was a fraction of a second
after the big Bang. The universe that we know will have indeed
collapsed back to the softball size that we’ve been told had been
the case. However, it’s just our observable universe that
collapses to that softball. If we were on planet in a distant
galaxy, we would be able to observe other galaxies that we can’t
observe on Earth. If we ran the clock backwards in that distant
galaxy, we would also find that our universe had shrunk to a
softball, but one that included different galaxies than ours as well
as some that we could also observe on Earth.
Lineweaver and Davis suggest that we should consider the early
universe as a pile of overlapping grapefruits (I used softballs
because I love grapefruits, but can’t eat or drink them because of
the effect on my Zocor medication). The pile of grapefruits or
softballs extended infinitely in all directions in those early days
some 14 billion years ago. The bottom line is that the Big Bang
was an even more impressive event of a scope beyond anything I
Allen F. Bortrum