October Update

Bought a standard poodle puppy.  Bringing him home October 5, so October will be full of housebreaking, and FUN.

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WONDER OF THE MOMENT

Entries in atmosphere (3)

Tuesday
Jul202010

Reflections on Mylar, Helium, and the Atmosphere, Part 3

The Mylar balloon I wrote about in my last two posts (July 13 & 15) descended to earth because it no longer was full of helium.  All balloons have microscopic holes and imperfectly sealed entryways.

         The atoms or molecules that make up a gas are constantly zipping this way and that, changing direction whenever they collide with one another or with the sides of a container, like scattering pool balls. And helium atoms are the second tiniest of all atoms, right after hydrogen.  So it’s highly probable that in a matter of days, the majority of the helium atoms in a balloon will hit a hole, easily slip through it, and escape.         

         Meanwhile, air molecules, mostly nitrogen and oxygen, are bouncing against the balloon from the outside.  Many of these may make their way into the balloon.  In this way, air replaces some of the helium, though the overall pressure inside lessens.

         But the result of this dynamic is that eventually all the helium, from all the helium balloons, escapes and disperses into the high levels of earth’s atmosphere.  Meaning helium is not a renewable resource.  So we have to keep finding more helium somewhere. 

         Right now, there’s plenty of helium on earth.  But it’s expensive to isolate from air or from natural gas deposits.  There is also helium on the moon that we might eventually exploit.  (What a concept!  And what an expensive concept!)

         The place with the most helium in our solar system is the sun itself.  All that solar radiation results from fusion, a nuclear reaction in which hydrogen nuclei fuse to form helium and give off a lot of energy in the process.  This is the energy Einstein was talking about in his famous equation: E = mc2.

         Our sun is one of the billions of stars in our Milky Way Galaxy.  And there are billions of galaxies.  So helium is abundant in the universe.  From floating balloons to the myriad stars in the night sky: helium is part of the magic of the cosmos.  Don't you agree?



Thursday
Jul152010

Reflections on Mylar, Helium, and the Atmosphere, Part 2

The Mylar balloon I wrote about in my last post (July 13) reminded me of the rare helium balloons in my childhood.  I grew up in Cleveland, and once each summer, my family went to an amusement park called Euclid Beach.  It was the absolute most magical of all possible family jaunts.

         To a young child, the rides seemed hatched directly out of imagination.  Holding on for dear life in shallow, shiny chrome cars, we jerked up and down and side to side in wild, unpredictable zigzags.  Or we rose higher and higher in stately silver rocket ships, sailing in serene circles far above the ground.  Or, bathed in celestially bright light, we rode merry-go-round horses up and down and round and round to a hurdy-gurdy that took complete possession of our senses.

         All nourishment rules were suspended.  We chewed on Euclid Beach taffy, ten times more delicious than the saltwater stuff relatives sent from the East Coast.  We consumed cotton candy, popcorn balls, and ice cream.  Last of all, before we left, came a helium balloon for each child.

         As we drove back home, we were still full of the excitement we had experienced all day long.  But back in our workaday, ordinary house, the one bit of magic that remained, to prove it hadn’t all been a dream, was that balloon up on the ceiling, defying gravity.

         Maybe it was my child’s eye view, but I seem to recall those helium balloons staying up for days.  Or maybe the helium was purer, and they really did stay up longer.

         As an adult, I love the way helium balloons illustrate that we live at the bottom of an ocean of air.  Just as a beach ball floats on water because the air it’s full of is less dense than water, so a helium balloon floats on air because the helium it’s full of is less dense than air.  The reason is that helium atoms weigh much less than the nitrogen and oxygen molecules that make up most of our atmosphere.        

         Reflecting on this, I was startled when I realized that if we filled a balloon with helium on the moon, it would just drop to the ground!  No atmosphere on the moon for a helium balloon to float on.

         But that tendency of helium to rise to the top of the atmosphere here on earth means that once it gets loose, helium is always leaving.  Eventually, we may run out of helium, a disappointing thought.  More on this next time. 

Tuesday
Jul132010

Reflections on Mylar, Helium, and the Atmosphere, Part 1

My morning power walk takes me near the Sydney R. Marovitz municipal golf course, part of the Chicago Park District.  The course stretches between the bike path and Montrose Harbor, a scenic spot for golfers, bikers, joggers, walkers, and dog exercisers.  The chain link fence that separates the golf course from other traffic is painted black, so it’s barely visible; and this time of year, it’s draped with a cheery, orange-flowering vine I haven’t been able to identify (but which might be orange trumpet creeper)

         Occasionally golfers appear by 6:00 AM, as early as the rest of us.  I can watch or at least listen to them tee off as I walk along, though I’m rarely in the right position to follow the ball’s trajectory.  Mowers appear also, roaring back and forth annoyingly.  But mostly the golf course simply presents a lush green savannah (though with short grass)—scenic and peaceful.

         However, yesterday, as I walked swiftly northward on my return trip, I spied, through the vine-draped fence, a shiny purple something lying on the bright green grass.  At first glance, it looked like a cast off backpack, or a down vest.  My mind struggled to match either object with golfers or grass trimmers.  But as I drew nearer, I recognized a purple, Mylar balloon, it’s “Happy Birthday” side down, its gleaming, blank purple back on display.

         Certainly, this balloon must have escaped its owner somewhere far away.  It must have risen high, high into the atmosphere, floated along, propelled by the wind.  Then, gradually exchanging its helium for plain old air, it must have drifted down, bouncing here and there among the tree tops, until it came to rest in the Marovitz municipal golf course in time for my Monday morning walk.

         I reflected on the difference between my childhood, when helium balloons (rubber, not Mylar) were a rare, magical treasure once a summer, and today’s dime-a-dozen ones.  I reflected on helium, the element, and on the earth’s atmosphere and the moon’s non-atmosphere, all which I will write about in my next couple of posts.