That, my friends, is my
version of click bait. I definitely believe there have been thousands,
maybe tens of thousands, of sightings of unidentified flying objects.
What led to this essay was a
goofy discussion I saw on a Facebook page for my hometown, North Bergen,
N.J., just north of Jersey City. Someone had posted newspaper articles
about repeated UFO sightings in North Hudson Park there in the '70s,
'80s, and even the '90s. North Hudson Park lies directly across the
Hudson from Manhattan. I guess it’s possible aliens were trying to
decipher sounds made by earthlings who all sounded like Tony Soprano.
Most sightings can be explained. Even so, many sightings have not been explained and remain unidentified.
The logical leap from “that
UFO can’t be explained by me or anyone I know, so it MUST be an alien
spacecraft!” is not exactly an exercise in logic. It’s not
mathematically impossible, but it is emphatically unlikely.
Let’s begin with scales of time and space. This amazing American Museum of Natural History video is definitely worth your time:
The known universe includes
the most distant objects we have observed, quasars, viewing them as they
appeared 13.8 billion years ago. Light from these quasars took that
long to reach our telescopes. If one of them exploded and disappeared 10
billion years ago, we won’t know it for another 3.8 billion years.
Beyond that, most galaxies are moving away from one another. The
universe is expanding.
When astronomer Carl Sagan
was alive, he thought there were hundreds of billions of galaxies. More
recent evidence gathered from superior observation technologies now
suggest there may be 10 times more galaxies than that. In 2016, deep
field images from the Hubble Telescope suggested there may be 2 trillion
galaxies. Going with some smoothed data estimates, Cornell astronomer
David Kornreich published very approximate numbers cited by Space.com:
“Kornreich used a very rough estimate of 10 trillion galaxies in the
universe. Multiplying that by the Milky Way's estimated 100 billion
stars results in a large number indeed:
1,000,000,000,000,000,000,000,000 stars, or a "1" with 24 zeros after it
(1 septillion in the American numbering system; 1 quadrillion in the
European system). Kornreich emphasized that number is likely a gross
underestimation, as more detailed looks at the universe will show even
more galaxies.”
Even assuming the number of
stars with planets which might support life would be a much smaller
minority, that number must still be very large.
Having looked briefly at
scales of time and space, we’ll move to probabilities of
extraterrestrial visits to our planet. If the universe is teeming with
life, we can look to our closest neighboring galaxy, Andromeda. It’s 2
million light years away, and Andromeda is a larger galaxy with
substantially more than the Milky Way’s 100 billion stars. Assuming
advanced life is not uncommon in our closest galaxy, why would a
civilization in Andromeda travel 2 million light years when other
lifeforms would be closer in Andromeda? (All this also assumes
interstellar travel at the speed of light is feasible.) We’ll stick with
our Milky Way.
Astrophysicist Frank Drake is one of the founders of SETI, the Search for Extraterrestrial Life. He developed what is called the Drake Equation estimating the odds of finding intelligent life in the universe.
Drake is very much an
optimist on extraterrestrial life, as was Sagan. However, in a complex
screening for what are the minimal requirements for such advanced
civilizations to evolve, his most optimistic estimate is the possibility
of 50,000 advanced civilizations in the Milky Way. If these
civilizations were nicely equidistant from each other, they would be
2,000 light years apart.
How would any
extraterrestrials know we are here? Well, they might detect our planet
as having an atmosphere and composition which would support life, as we
are beginning to do with exoplanets orbiting other stars. But planet
Earth would be one of so many other exoplanets to examine; the odds that
one had already made such a trip are startlingly low. When you jump
ahead to how would extraterrestrials know humans are here, things get
really, really tough. City lights almost certainly cannot be observed
through interstellar dust. Even if aliens had such observational
technology, electric lights didn’t get going until late in the 19th
century. A much more likely route for the transmission of evidence of
our existence is broadcasting. Broadcast transmissions travel at the
speed of light, and our earliest transmissions are now about 100 light
years out into space. So those early signals from KDKA radio
statistically have another 1,900 years to go to reach such a civilized
target.
Suppose the 2,000 light year
hypothesis is wrong in our case. Tossing that hypothesis aside, our
broadcasts have reached about 15,000 stars. The Planetary Society shows
the blue dot in the lower right is the distance covered compared to the
Milky Way. At those distances, our broadcast signals become very weak.
One physicist postulated listening for such a transmission above the
noise of background radiation would be like trying to detect the ripples of a pebble dropped in California waters with a detector in Japan.
What are the odds among this
small number of stars there are planets with advanced life? What are the
odds any advanced life has the means to hear our weak signals? And,
what are the odds that a civilization existing among this small group
has mastered interstellar travel?
Next, you have to ask why
would such a civilization expend the vast amounts of energy to visit
Earth? Why would they never land and show themselves?
Human hubris makes us think
we are really something special, but biology, physics and math make it
far more likely we are not so special as we think. Further, the idea
we’ve been visited many, many times when such voyages are massive
undertakings is ludicrous. Remember, in the past such sightings were
occurring almost on a daily basis when flying saucers were all the
hysterical rage.
Between nearly all possible
civilizations having no clue we exist, and the incredible odds against
interstellar travel emanating from a nearby star system, I’m confident
aliens have not visited North Bergen. That proportion of UFOs which
remain unidentified are just that: unidentified. On the other hand, if
alien visits were realistically possible, I might have bought into the
swamps out in the Jersey Meadowlands….
By Don Paul – Don Paul worked as a broadcast meteorologist for 34
years at all three Buffalo television stations, serving as chief
meteorologist at WIVB for 29 years and chief at WGRZ for three years.
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