Category Archives: Our world

The Earth and the Moon: A Match Made in the Heavens

The Moon’s a pretty darn awesome thing to have.  Look at all it gives us.  A way to track the days, the majesty of the tides, crackpot prognostication in the daily newspaper … and eclipses!  How cool are eclipses?!  Life would be a lot more boring if it weren’t for the Moon.  The thing that’s not immediately recognizable, though, is that life might not be at all if it weren’t for the Moon.

The Earth’s moon seems to have formed in a similar fashion as the satellites belonging to the other planets in our solar system, but with a key difference.  Recent studies suggest that moons form when material within ring systems, like Saturn’s, coalesce to form the rocky companions.  It’s thought that ring systems of the outer planets were comprised of leftover material from the accretion of each protoplanetary disk, but the debris that encircled the Earth and condensed to create our Moon probably had a different source.  Namely Theia, the postulated, Mars-sized planetoid that smashed into the early Earth and launched a large chunk of it into orbit.

It might sound like a crazy idea, but there’s a decent amount of evidence for it.  There are still kinks to be worked out, like why the Moon’s oxygen isotopic ratios are almost identical to those of the Earth instead of a hodgepodge of ours and the impactor’s, but other similarities in composition actually bolster the hypothesis.  Then you’ve got all the lunar evidence of its impactful origin.  The crystal structure of many of the Moon’s minerals point to a molten beginning, which is hard to come by for a small body without the injection of large amounts of energy, e.g. being blasted off of somewhere else.  Zinc isotopes in particular seem to have been fractionated and volatilized, processes that don’t occur during run-of-the-mill geologic conditions.

And thank goodness it happened.  If the Earth had cooled without disturbance, most of the useful and precious (heavy) metals should have drifted down into the core.  The fact that we have significant amounts of iron, silver and gold so close to the surface is more evidence that something annihilated itself against Earth, leaving its core materials down below, allowing us to make things like cars, computer chips and keychains that make fart noises.  All of which would be useless if life hadn’t come together in the first place, which some think, amazingly, can also be attributed to the Moon.  Shorter, stronger tidal cycles 4 billion years ago may have provided the right changing environments to teach the first “protonucleic acids” how to replicate, leading to the formation of DNA and RNA, the building blocks of us all.

“I just wanted to say … thanks for being there, man.”  Image credit to universetoday.com

But the Moon didn’t stop exerting its beneficial influence there.  Once life got chugging along, the tides may have continued to force adaptations by hurling the fledgling organisms into unfamiliar territory.  Those strong early tides also squeezed and stretched the Earth itself, causing surface displacements up to a kilometer a day, kinetic energy that would slow the planet’s cooling and keep plate tectonics — and thus the carbon cycle — moving.  The Moon’s gravity also helped stabilize our axial tilt, which may have varied wildly without it.  An irregular wobble could have prevented the normal seasons we’re used to and hence made it difficult for complex organisms, that can’t adapt rapidly, to develop.

WHAT DOES THIS MEAN?

While it may not mystically control your personality, the Moon has gone a long way into making you who you are.  With all the mentions of it here, have you figured out why the tides were more frequent and stronger in the ancient past?  The Earth was rotating faster, only to be slowed gravitationally by that big hunk of cheese.  So you can also thank the Moon for a weekend that’s twice as long.  The tides were stronger because the Moon was actually closer to us back then.  Its orbit expands as time goes on.  We live at the exact right time for eclipses to occur!  Pretty darn awesome.

Much of the information here was taken from the very informative “How Earth and the Moon interact” from Astronomy Today.

Atlantis discovered! What, again?!

Holy crap, did you hear the news on Tuesday?  Atlantis, the largely apocryphal, long-lost sunken island first described in Plato’s dialogues (i.e. “stories”) as the doomed home of a highly advanced civilization circa 10,000 BC, has finally been discovered!  Off the coast of Brazil!  That’s not anywhere near Greece, so Plato couldn’t have possibly known about it, but hey!  It seems that two years ago a team of Brazilian scientists dredged up some granite about 900 miles off the coast of Rio de Janeiro, which got them giddy, and now they’ve seen some bad-ass formations in the same place while tooling around in a submersible with their Japanese colleagues.  No artifacts, just rocks.  They think it’s remnants from when Africa and South America split apart 100 million years ago!  And this sounds like the home of a thriving human society… how?

Sounds more like just a rogue piece of South American continental crust.  Many islands, like Hawaii and Iceland, are basaltic in composition, as minerals in oceanic crust are denser and made up of elements like iron and magnesium, whereas the less dense continental crust (which rises higher partly for that reason) is granitic, consisting of elements such as oxygen and silicon.  Some larger islands like Greenland are granitic, as they’re just part of the continental shelf (the extended, lower elevation perimeter of a continent) that hasn’t been submerged.

Either way, they don’t sink!  Islands don’t just sit there and float around the seven seas, like we once thought the continents pushed through oceanic crust as they moved, as in early continental drift proposals.  A strange idea, akin to pushing a piece of paper through a wall, it was replaced in the 20th century by plate tectonics, that instead has both kinds of crust anchored to massive lithospheric plates that are pushed and pulled across the Earth’s surface by underlying differences in temperature.  The edges of some plates are actually sucked into the Earth at subduction zones, like where the Pacific Plate plunges below the South American Plate, giving rise in a roundabout way to the Andes Mountains.  That’s one way to get rid of a landmass, but you sure won’t find any remnants, and it’ll take a good goddamn long time.  The Pacific Plate, to continue the example, currently moves at a rate of about 3 inches per year.  Not exactly “a single day and night,” as Plato recounted.

Erosion can grind a peak down to size; but again, good goddamn long time.  Although if it’s rising faster than the erosion rate, like Mount Everest is, your sinking hypothesis is sunk.  Hawaii too keeps growing, thanks to its active volcanic origin.  Landslides can chip away at the sides, but that still won’t unmoor an island.  A far away landslide could cause a tsunami to wash away what’s on the surface, but one event, even such a powerful one,  won’t smooth a landmass down to sea level.  And if sea level itself rose to conceal something, my God, we’d fricking notice it everywhere!  Not only would there be historical records, but we could read it in the marine rock deposits left behind.

WHAT DOES THIS MEAN?

So if Atlantis is based on a probably fictional story the account of which bears no resemblance to this discovery, where did all these weird websites get their ideas?  How does someplace called “DVICE” go from this:

real atlantis

to this?

fake atlantis

Maybe because the FRIGGING SCIENTISTS BROUGHT IT UP THEMSELVES!

“This could be the Brazilian Atlantis. We are almost certain but we must bolster our hypothesis. We will have final (scientific) recognition this year when we conduct drilling in the area to retrieve more samples of these rocks.”

“This could be the Brazilian Atlantis. We are almost certain but we must bolster our hypothesis. We will have final (scientific) recognition this year when we conduct drilling in the area to retrieve more samples of these rocks,” the news website quoted Ventura as saying.Read more at: http://phys.org/news/2013-05-scientists-brazilian-atlantis.html#jCp

“This could be the Brazilian Atlantis. We are almost certain but we must bolster our hypothesis. We will have final (scientific) recognition this year when we conduct drilling in the area to retrieve more samples of these rocks,” the news website quoted Ventura as saying.Read more at: http://phys.org/news/2013-05-scientists-brazilian-atlantis.html#jCp

In a much less reported following statement, Geology Service of Brazil director Roberto Ventura Santos continued, “We speak of Atlantis more in terms of symbolism.  Obviously, we don’t expect to find a lost city in the middle of the Atlantic.”

Come on.  They knew exactly what they were doing.  From Mauritia to the “Bimini Road” to the plains of Spain (at least that’s closer), media outlets desperate for eyeballs will use any chance to turn heads with woo-woo.  These geologists played into it for reasons that aren’t totally clear.  More exposure?  Funding?  To see something more colorful when they Google themselves?  Whatever the motivation, it’s kind of messed up and unsettling that a group of scientists would willingly court crazy to get people’s attention.  It’s not like there isn’t enough of it out there already without the good guys throwing them another bone to chew apart and spew back.

The Shrinking Ozone Hole: Could We Similarly Reverse Climate Change?

Let’s set the record straight.  The depletion of the atmospheric ozone layer and the climate change often referred to as “global warming” are separate, largely unrelated processes.  I remember a comedian maybe 10 years ago making (or should I say attempting) a joke about about discharging aerosol cans during especially cold winter days to hasten the anthropogenic effect on worldwide temperature increases.  Far be it from me to step on a punchline, but there are a couple things wrong with that.  First, the loss of ozone catalyzed by the chlorine atoms from chlorofluorocarbons (CFC’s), the propellants once used in spray cans, does not accelerate the Earth’s greenhouse effect; it’s the enormous amounts of carbon dioxide gas (and, less directly, methane) we introduce into the environment that pulls off that trick.  In fact, man-made ozone can actually act as a greenhouse gas itself when present in the troposphere, the lowest level of our atmosphere, although its impact in that regard is much, much smaller than that of the other offenders.  Ozone depletion instead heightens our risk for skin cancer, as the upper atmospheric layer of the compound functions as something of a shield against carcinogenic ultraviolet radiation from the Sun.

Secondly, the widespread use of CFC’s in consumer products ceased in 1994, thanks to the internationally instituted Montreal Protocol.  Even their less hazardous temporary replacements, hydrochlorofluorocarbons, will be phased out in much of the world by 2020 and will likely disappear entirely a decade later, to be supplanted by non-destructive hydrofluorocarbons.  Due to these burdensome but necessary measures, a study published in February shows that the Antarctic ozone hole has shrunk to its smallest size in 10 years, and some scientists estimate that stratospheric ozone levels should rebound to pre-1970 levels by the year 2050.  Now that’s a system workin’!  With such an unequivocal environmental success now precedented, could we take similar steps to mitigate that other dilemma, global climate change?  Let’s compare and contrast the histories and natures of the two phenomena to find out.

Chlorofluorocarbons are just what they sound like, compounds that contain only chlorine, fluorine, carbon and hydrogen.  Belgian chemist Frédéric Swarts pioneered their synthesis in the 1890′s, and some species were used as fire suppressants during World War II.  The compounds found greater commercial use in refrigerators and aerosol cans in subsequent decades.  University of California at Irvine Scientists Frank Sherwood Rowland and Mario J. Molina first suggested the devastating effects of atmospheric chlorine on ozone in 1974, after James Lovelock had discovered that nearly all the poorly reactive CFC’s ever released into the air were still present.  Unsurprisingly DuPont, a heavy producer of the chemicals and creator of the brand name Freon, called their work “utter nonsense.”  Rowland and Molina were proved right by laboratory experiments and the direct observation by James G. Anderson of chlorine monoxide, a product of the reaction, in the atmosphere.  For their research on the issue, the pair won the Nobel Prize in Chemistry in 1995.

The United States, Canada and Norway banned the use of CFC’s in aerosol cans in 1978, but not much other action was taken until the “holy shit” moment 7 years later.  That was when the British Antarctic Survey team announced massive springtime losses of ozone over the South Pole, “holes” that in later years would reduce the stratospheric presence of the compound by up to 70%.  The occurrence could have been detected much earlier, but NASA scientists hadn’t noticed the numbers, as values that extreme were automatically eliminated from their data, deemed “impossible.”  That’s how bad things had gotten in a short period of time.  The international community immediately took notice and the Montreal Protocol was opened for signature just two years later.  Atmospheric CFC concentrations continued to rise until the year 2000, due to the continued use of previously produced, non-compliant refrigerators and air conditioners, but as those units have failed over time, we’ve developed the much rosier picture of our future we now see, one that’s been painted by urgent action following smart science.

spray cansmokestack

We fixed one, now let’s work on the other.  Images from howstuffworks.com and Scientific American, respectively

The furor surrounding global climate change has been different in many respects.  One of the main disparities is the speed at which the problems have become grave.  Whereas we’ve been pumping large amounts of carbon dioxide into the atmosphere since the Industrial Revolution began in the late 1700′s, with only a gradual change in temperature, it was just a decade after the mass production of CFC-containing products that their chlorine molecules were shown to pollute the atmosphere, and the titanic damage to the ozone layer was recognized.  That made it easier to pin the effect to the cause.  Unusual warming was first noticed in the United States and North Atlantic in the 1930′s, but it wasn’t until 1960 that carbon dioxide levels were proved to be rising.  But climate is a much more complex monster, and there is more than one factor at play.

Other factors affect global temperature, and we know that climate has changed over geologic history, without our influence.  Volcanic eruptions, variations in solar radiation and the Milankovitch Cycles all play roles, but that really just goes to show how delicate the whole system is and how it’s easily nudged.  We now know that solar activity has actually decreased over recent years, and ancient ice cores have shown us that the correlation between temperature and the atmospheric concentration of carbon dioxide is very strong.  Better and better computer models of the chaotic system have been implemented as technology advances, and now a consensus of 97-98% of climate scientists agrees that global climate change is real, and produced by human beings.

WHAT DOES THIS MEAN?

It took us longer to prove human-induced change to the atmosphere in the case of global warming, and now that we’ve gotten there, the people who stand to lose out if measures are taken to halt it still deny, just like DuPont did into 1987.  But even if the oil companies and others were on board, what could be done?  The worldwide economy is much more dependent on the burning of fossil fuels, the largest contributor to the problem, than it was the use of fridges and spray cans.  And then a less harmful substitute was easily found, whereas the research into alternate energy sources is splintered and slow-moving.  Could we use some sort of agreement that forces us to drastically reduce our carbon dioxide emissions, akin to the Montreal Protocol?  I mean something actually useful, unlike Kyoto?  Would it even help?  Some predictions show that even if all carbon emissions stopped today, we couldn’t naturally return to a pre-industrialization climate for a thousand years.

That all seems like a major bummer, but the ozone depletion parable has shown us that as good as we are at wrecking our future, we can also find ways to solve the problems we’ve created.  It’s no longer in dispute that puny humans can affect serious changes, and now we also know that taking stringent and serious action can swing the pendulum back.  It’ll take brilliantly creative technologies, but it’s not our ingenuity that’s questionable.  It’s our commitment.  We’ve come together to fix our screw-ups before.  We’ll have to do it again.  Do we need a “holy shit” moment to get our brains and asses into gear?  Don’t brutal heat waves and superstorms fit that bill?

Much of the history of climate change research described here was taken from the wonderful American Institute of Physics resource at this location.

Killer Sinkholes: Could It Happen to You?

The geologic term “karst” is used to refer to a characteristic type of topography in regions underlain with carbonate (typically limestone) rocks, which chemically weather to produce hilly features or depressions at the surface and sometimes spectacular caves beneath, such as Carlsbad Caverns in New Mexico and the Mammoth Cave system in Kentucky.  Beauty can turn to tragedy, however, if those chambers collapse to form sinkholes, as in the sad and surprising story of Jeffrey Bush, whose Florida home was partially swallowed by such a structure while he was sleeping on the evening of February 28th.  Mr. Bush unfortunately did not survive the experience, which may lead some to wonder, could it happen to me?  How dangerous is this phenomenon?  Well, it depends on where you live.

Sinkhole map

The above map, developed by the United States Geological Survey (USGS), shows a generalized distribution of karst features within the United States.  Why is Florida so riddled with cavities?  The state’s land mass was underwater for much of its history, so that most of its basement rock is composed of limestone (chemical formula CaCO₃), formed by the deposition and lithification of corals and the hard parts of other marine organisms.  Those limestone formations, hundreds or even thousands of feet thick, were then covered with much thinner layers of sand and clay thanks to the erosion and transportation of material from the Appalachian Mountains.

Rainwater can pick up carbon dioxide (CO₂) as it passes through the atmosphere and then the soil, forming a weak carbonic acid (H2CO3) that can act to dissolve the limestone bedrock.  The process is exacerbated by man-made acid raid, which often comes in the form of the more reactive hydrochloric acid (HCl).  Hydrochloric acid’s reaction with calcium carbonate is so violent that introductory geology students use it to help identify limestone and related rocks.

Of course the diagnostic solutions are more highly concentrated than what falls from the sky, but it can help you imagine what goes on beneath your feet.  The effects of pollution from the industrialized mid-west are felt on the east coast thanks to the jet stream.

Sinkholes are then more common after rain events, but they can be produced by droughts as well, as in the Bush case.  Florida State Geologist Jonathan Arthur notes that dry conditions can cause overlying soil to collapse.  Human extraction of groundwater can have the same effect, as 65 sinkholes appeared in Florida after overuse by strawberry farmers in 2010.

WHAT DOES THIS MEAN?

About 20% of the United States is underlain by karst terrain, making it susceptible to subsidence and sinkholes.  While they often appear quickly and without warning, basic geologic principles tell us that past is a good prediction of future.  Just as Californians know to always expect earthquakes, spots currently plagued by sinkholes will likely continue to endure the uncertainty.  Know your local geology and what potentially hazardous effects you might be able to expect.  If you live in an area prone to sinkholes, learn to note the signs, such as muddied well water, new ponds, or slumping features.

sinkhole1

More generally, we have to continue our staggeringly slow realization that what we do affects the world and environment around us.  Acid rain doesn’t just kill a few fish; it can destroy property and even take human lives.  Overuse of resources not only puts strain on the local ecology but could do irreparable damage to our neighbors.  When couched in more practical terms like that, maybe stewardship isn’t quite so hard to swallow.  And maybe something good can come from otherwise senseless deaths.

The solar system hates Russia: Chelyabinsk, Tunguska and UFOs

Remember the “other factors” pointed to by Rare Earth hypothesis proponents I mentioned in the previous post?  Things that may be necessary for the evolution of complex life that aren’t intrinsically accounted for in the Drake Equation?  One of those is the presence of a significantly large, so-called “gas giant,” like Jupiter, in the same system as a habitable planet.  The idea is that such a sturdy stalwart acts to gravitationally Hoover up enough of the biggest asteroids loitering around the neighborhood so as to allow the critters on an inner planet enough time to figure out things like civilization, technology and e-mail before they shoot cosmic craps and some big space rock slips in and ruins it for everyone.

Fat fucking lot of good it did for the residents of Chelyabinsk, Russia on Friday, February 15th.

But hey, we’ve seen our burly protector in action, through the 1994 impacts of Shoemaker-Levy 9 cometary fragments.  So we know it does its job, as least sometimes, as the largest piece of Shoemaker shrapnel was on the order of 100 times the size of the little guy that injured over 1,000 and did more than $33 million in damage last week.  Imagine a fleet of those jerks showing up on our doorstep.  Thanks for having our back, Jupes.

Our watchful big brother can’t catch ‘em all, however, and some of the smaller stuff sneaks on through.  On average we can expect an interloper the size of the Chelyabinsk object every 30-60 years.  This most recent assaulter was the largest since the then mysterious 1908 blast at Tunguska, in the Siberian region of (would you believe it?) Russia.  The solar system is obviously trying to strike at our population’s strategic vodka reserves.

WHAT DOES THIS MEAN?

Asteroid early detection is no joke.  Fortunately, NASA estimates that they’ve locked down the orbits of more than 90% of the near Earth objects large enough to wipe us out (those at least a kilometer in diameter), and none of them should come calling anytime soon.  The outlook is less rosy when considering debris with diameters in the 100 meter range, as we’ve only got a handle on about 30% of those.  To compare, Friday’s visitor was probably less than 20 meters in size.  There are hopes that new projects like ATLAS will aid in increasing our detection limits, but even that won’t spot rocks as small as the Chelyabinsk body.  Maybe it’s time to spend more than $3 million a year on such things?

Additionally, perhaps this will finally shut up the Tunguska conspiracy nuts.  Some people will try to find a mystery anywhere, and plenty claim something stranger must have happened then because no large meteorite fragments were found.  Forgetting the fact that no one bothered to look for 13 years.  And ignoring the discovery of the predicted silicate and magnetite spheres in the surrounding soil and tree resin.  Or the anomalously high amounts of iridium, an element that’s rare on Earth but more abundant in asteroids.  The first fragments of the Chelyabinsk object have been identified, but it’s probably easier to know where to look when you can see the damn hole in the ice.

The ubiquitous video footage of the meteor’s approach, thanks in part to Russia’s obsession with dash cams, has nothing but bad implications for the “UFO phenomenon,” to boot.  If interstellar snoops are constantly dropping by, why aren’t they repeatedly filmed from a myriad of different angles, as in the montage above?  And don’t tell me they know enough to avoid the former Soviet republic; I’ve seen sighting reports from less than 2 months ago.  Hell, the meteorite that struck a parked car in Peekskill, New York in 1992 was filmed by *16 different people,* in a time prior to our now inescapable cell phone preoccupation.  If aliens were around as much as the proponents claim, they’d have a weekly dedicated segment on TMZ.