In her most recent column, New York Times columnist Maureen Dowd confesses to an unhealthy obsession with end of world scenarios. As she puts it:
"I'm worried about those two small asteroids that buzzed the Earth this week, those two big earthquakes in Italy and the countdown to doomsday on Dec. 21 as prophesied in the Mayan Calendar. Will Planet X or Niburu collide with the Earth before Christmas? Will a solar flare cause a geomagnetic reversal of the north and south poles/ Will a black hole swallow us up?'
First of all, Dowd need not worry at all about the near miss of the two small asteroids. Even, if they had struck the damage would have been around the lowest threshold of the Torino scale that calibrates asteroid impact effects. The asteroid she needs to fret over is the one to deliver Earth sterilizing impact. This would leave a devastated area of up to 50 square million kilometers, as gouged out by an object of at least three fifths of a mile diameter - as opposed to a few hundred feet.
Yes, the explosive release, at 100,000 megatons equivalent, would be enough to do away with most life on Earth, but....the collision frequency is less than once every 250,000 years. So Maureen ought to be able to sleep at night.
As for the Mayan, 2012 malarkey....what can I say and how many times do I need to say it? Again, any reversal of the Earth's magnetic field (which is not that far away, but I'd say not as near as Dec. 21 this year) has absolutely nothing to do with any alignment of the Milky Way's dark rift with the Sun as forecast by a Mayan calendar (or more accurately, recent interpretations of said calendar). To suggest such a connection is to practice unwarranted extrapolation which is not based on any credible astrophysical or astronomical data.
The tragedy is that by focusing on fake catastrophes like the Mayan 'end of daylight', people will cease to attend to the real threats by taking actual actions now. Say like cutting back on consumption of fossil fuels to abate or delay the onset of the worst greenhouse gas warming. But more on this in a bit.
Maureen also need not fret over "Niburu" colliding with Earth, before Xmas, or ever, because Niburu is basically a mythical entity with no science to support it. It probably originated, as much of this crap does, with some wannabe scholar who went overboard in seeking to make cosmic connections with ancient mythologies (in this case Sumerian). Thus, Zecharias Sitchin hatched "Niburu" as an unknown planet X beyond Neptune. But since it's a figment of Sitchin's imagination more than anything else, I wouldn't lose too much sleep over it.
What about a solar flare causing a reversal of the geomagnetic north and south poles? Hardly! In any case, based on magnetometer measurements we know the respective poles are weakening which usually portends field reversal. But these are part of a normal cycle, not necessitated by any sort of catastrophic event.
Just at the transition point for reversal, the Earth's magnetic field will effectively be zero Gauss, which will mean our magnetosphere will cease to exist as a protective barrier against highly charged particles, ions - say barrelling in from flares on the Sun. Whereas before the particle would be trapped and forced to oscillate back and forth in a closed field around Earth, see e.g
in zero Gauss conditions, no such impediment will be provided, so that radiation in the form of those charged particles will barrel directly through the Earth's atmosphere to the ground. Does this mean the 'end of the world'? Nooooooooo.......only that if you choose to leave your house during times of high solar activity and hence incident radiation, you take what chances you may......analogous to those brave (foolish) souls who dare to stay in the Sun for hours on end.
As for being swallowed by black holes, not likely! There are no candidates that would meet the Earth-swallowing range within at least 12,000 light years.
Dowd next waxes her fear onward based on a new novel "Age of Miracles" by Karen Thompson Walker that "makes you look around warily as you walk down the street" - according to Maureen. But why? Well because this novel has evidently found a way to roll all the assorted fears into one - starting with Earth's rotation slowing, days and nights stretching the length of weeks, the Earth's magnetic field withering and "gravity going kerflooey" as temperatures become either boiling or freezing.
All of which is sophisticated hogwash. Evidently, the author of the novel got the idea after learning that the infamous 2004 Indonesian quake sped up Earth's rotation and knocked 3 milliseconds off each day. That is 3/1000 of a second.
So, hey, why not extrapolate the other way and imagine something that causes Earth's rotation to slow...to maybe 56 or 100 hours instead of 24, so weeks are now 2 or 4 times longer than they used to be Then, Voila! The Earth loses its magnetic field, and temperatures go crazy while gravity "goes kerflooey". Sorry, ain't gonna happen! Even if Earth's rotation was slowed a factor ten beyond what it is now, say taking 240 hours to make one revolution, one would not behold the disasters proposed by Thompson.
And would gravity change? Uh nooooo. Because the gravitational intensity g is given by:
g = GM/r^2
where G is the Newtonian gravitational constant, 6.7 x 10^-11 Nm^2/kg^2, r is the radius of Earth, r = 6400 km or 6,4 x 10^6 m and M is the Earth's mass, 6.4 x 10^24 kg. Then one obtains g = 9.80 m/s^2.
The only way the gravitational intensity changes (and recall weight is defined as w = mg), would be if the Newtonian constant itself changed, or the Earth's actual mass or radius. And incidentally, none of this has a bearing on temperatures!
So much for another entry into the reasons why all American need to take a basic physics course.
Where Maureen veers closest to a grounded worry, is when she recalls how hot it's been lately, with thousands of records broken. But instead of rightly connecting this to global warming, which it ought to be (never mind what the meteorologists keep yapping about highs) she veers off into an old Twilight Zone episode where the Earth "spins out of its orbit and moves closer to the Sun".
Makes for intriguing reading for sure, but hardly necessary to get humans to take proper stewardship of their home world.
Fact is, we shouldn't have to resort to scaring the shit out of people using elaborate sci-fi scenarios or depictions when real ones (such as ever increasing CO2 levels from man made activities) are quite capable of doing the trick.
Maureen, take note!