Sound and Light and Ice

I am not a scientist and have zero scientific training, but I think that the way sound and light travel through solids, liquids, and gasses is fascinating.  Egocentrically, I would think that I could hear the best when unencumbered by the heavy stuff of solids and liquids.  But, have you ever been close enough to a pile driver to feel and hear it at work?  There is a muffled thump and a loud clang.  You’d think the clang would come first, followed by the thump, but it’s the other way around.  The sound you hear through the earth, the thump, arrives at your eardrum first, followed by the clang that travels through the air.  The time between them depends on your distance from the pile driver, the source of the sound.  Sound travels fastest through solids, next fastest through liquid, and slowest through gas/air.  This is why when I was diving off Hawaii, I could hear whales all around me when I was underwater, but they were never close enough to see.  I have never heard a whale song while I was sitting in a boat … except for once.  My kayak guide in Hawaii taught me to stick my paddle in the water and put my ear on the exposed end of the paddle.  Et voilà!  I could hear the whales.  But I needed a liquid and a solid to do it. 

And then there’s ice.  Water droplets fall from the sky.  If they happen to freeze along the way, they fall to the ground as snowflakes.  The snowflakes pile up, and if it’s cold enough, they do not melt.  The snowflakes fall and fall and fall until the snow is very deep and heavy and compresses until it becomes a glacier.  Bits of the glacier fall off into the ocean and become icebergs.  When they are young, the glacier and the icebergs are full of air.  Lots of light passes through them—all the various waves that make up visible light—and they look white.  The older, deeper, more compressed parts of the glacier have less air in them, and the longer light waves don’t make it through.  Eventually, only the short, blue light waves are left.  The densest parts of the glacier and the icebergs calved from those parts look blue because we can see only the blue light waves.  As every underwater photographer knows, this also happens in water.  The deeper you go, the less color you see as the light waves peter out.  The red goes first, then the orange, then the yellow, then the green, and so on until pretty soon all you have left are blue and black.  The blue light waves are the shortest.  I have no idea why it works that way. 

I’ve been told there is such a thing as black ice, ice that is so dense that almost no light at all gets through.  This ice is ancient.  I’ve also been told that black ice is black only because it contains dirt that makes it look black.  Either way, this only proves that you shouldn’t necessarily believe everything you hear.  One or the other could be correct — or both!

The thing about ice for me is that in its natural state, as calved bits of glaciers, every single chunk, large or small, is different.  The color, the shape, the size, the content—everything is different.  As it melts, quickly or over hundreds of years, it is endlessly evolving into something different and different and different, second by second.  Each chunk has a life and a life span.  Floating through a community of ice is like walking through a forest or sitting in a van in the middle of the wildebeest migration.  The life forms are phenomenal, and like any living thing, what keeps each life grounded and maturing, what allows it to be what it is, is mostly unseen.  And eventually, much like humans do, they all become something else.  

Check out some incredible ice visions from the Arctic in the Europe section. Look for “Norway.”

February 2024

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