Another prophesied Doomsday has passed, leaving doomsayers in deep gloom. But there are two other doom scenarios that should worry us — or at least concern future generations.
We all know about global warming, but I recently started worrying about the twin dangers of global wobbling and solar gobbling.
I discussed these concerns with a leading astronomer, and he both confirmed and consoled me about my fears.
Michael Shara, a former Baltimorean and family friend, now serves as curator of astrophysics at the American Museum of Natural History in New York City. I called him after I heard on a cable TV science program that the moon, whose gravity helps keep the Earth from wobbling, is actually moving away from the Earth and will one day be at such a distance that the Earth will start to wobble.
Stunned, I wanted to know if this was true and how soon would this wobbling happen. After all, how could humans and animals live on a planet with streets constantly undulating and buildings swaying? Is the moon really on a misbegotten path?
"Yes," Mr. Shara said, "the moon is losing angular momentum and is moving away from the Earth at an inch a year. Over the last 30 years, the moon has moved a meter away."
He explained to me that the moon was formed 4.5 billion years ago when a "proto planet" hit the Earth and sent a portion of our planet hurtling into space, where gravity eventually formed this mass into our moon. "We know this for a fact, because the rocks the Apollo astronauts brought back from the moon are all identical to Earth rocks."
At one time, the moon was much closer to the Earth, dominating much of our sky. In its present position, the moon's gravity not only causes the ocean waters to rise and fall in tides but also helps slow down the rotation of the Earth. In fact, the Earth's rotation is slower now than before the moon was formed.
So if we need the moon to provide a stabilizing effect on the Earth, what will happen as the moon keeps moving away? And when can we expect this to occur?
"In 4.5 billion years, the moon will be ten percent further away," Mr. Shara answered. "This will tilt the Earth on its axis and create a chaotic effect, with the equator being where the North Pole is now."
That effect on Earth is the real worry — not the wobbling. In fact, he went on, when the wobbling will really be occurring, people on the planet will not feel it, not any more than we feel the present spinning of the Earth on its axis.
I felt somewhat ridiculous about my original fear when he said this, but he soon said something that made me even more concerned.
What will definitely happen and be a problem to end all problems is that one day the sun will be the death of us. "If there is one thing we know for sure is that the sun will become a red giant, die and swallow up Mercury, Venus and Earth," he pointed out. Mars, Jupiter and the other planets will survive, out of reach of this fiery demise.
Interestingly, Mr. Shara said that projections also call for this to happen in about 4.5 billion years.
So if you're worried about encroaching global warming or imminent Doomsdays, you can at least feel relieved that moon-caused global wobbling and sun-caused global swallowing won't happen anytime soon.
But this does show that, as tsunamis and earthquakes have demonstrated, we live on a less-than-secure planet and need to be concerned about life-altering, possibly life-threatening events. They have happened in the past and seem destined to happen in the future.
Now, go and have a nice day.
M. Hirsh Goldberg is the author of five books and a public relations and public affairs consultant who has served as press secretary to a governor of Maryland and a mayor of Baltimore. His email is firstname.lastname@example.org.