It’s that time of year again. Category: Physics
34 below zero F. Coldest reading yet on our thermometer. The sun is a muted white, beaming from the southeast. Back down below, a prism of color rises from Rocky Run, a pulsing pillar that at times is quite pronounced and at other times so indistinct as to be invisible. It springs from the earth near two pines across the way which I have never noticed before, just this side of the gravel pit. It extends quite high at times, the endpiece of a rainbow. How strange this phenomenon on a cloudless morn.
How can it be so cold out there? Where does cold come from? Absence of heat… but the sun is no further, nor nearer, than another day 50 degrees warmer.
~ Journal note, 15 January 1994
While looking through one of my journals I came across the above observations. Evidently I was attempting to describe a phenomenon that I’d never seen before coming to Minnesota, the way fog and crystal-laden moisture refracts light in the context of intense cold. Here in the Northland you can sometimes tell how cold it is by the way it squeaks when walking on the frozen snow as you go out to fetch the paper in the morning.
Water is the strangest thing. The manner in which it changes based on temperature, and not just random temps but a specific temperature, at 0 degrees Celsius. And how it vanishes (becomes vapor) when it boils. Yet it is still H20 so that when it condenses it become moisture again.
The density of water is another mystery. You would think that when water freezes, becomes a solid, that it would sink, wouldn’t you? Yet when icebergs break off from Greenland they float. This seems very strange. Yet we just take it all for granted.
I was just reading how water expands when it freezes. This, too, seems strange because the molecules are still H20, yet they re-form themselves somehow when they become crystals. My initial sense would be that frozen water would take less room, as if the fluid’s molecules were arrange themselves tighter together when they became solid. But this is not the case. In point of fact, water expands by 9% when it freezes, hence the burst water pipes some of people have experienced in very cold weather in the Northland.
Physics is the study of nature and natural phenomena in our world. I have fond memories of Mr. Dennison’s physics class my junior year in high school. A former minor league pitcher who after 7 years finally came up for a pair of games with the Red Sox at the end of a season, he was also our Junior Varsity baseball coach. I learned a lot from Mr. Dennison about many things, but never quite got an answer as to why it’s so hard to hit a knuckleball.
By the way, did you see the size of the moon last night? I find it intriguing that when the moon circles ‘round the earth its influence causes the tides to advance and recede. Because of gravity the earth’s bodies of water pull inward, or downward depending on your point of view. But when the moon passes overhead the gravitational pull of our lunar companion produces swelling seas. What’s especially interesting is how the waters on the opposite side of the earth also bulge to produce a high tide there as well. (You can read how all this works here.)
It’s also interesting that water covers about two-thirds of the earth, and that when we mature our own bodies are about two-thirds water. (The ratio changes from infancy to maturity.)
Here’s another observation. Whereas water is essential for our nourishment to survive, water is also a destructive force, causing buildings to rot, dead trees to decay, and so on.
For those who are interested in other mysteries and observations about water check out these links:
The Many Mysteries of Water
5 Weird Things About Water
Middle School Chemistry Lessons on Water and Ice
Observations on Melting and Freezing
In closing, here’s a quote to float your boat: “Human nature is like water. It takes the shape of its container.” ― Wallace Stevens
EdNote: The journal entry that started this post was scribbled during our second winter here on the outskirts of Duluth. Since that time I have twice seen 42 below zero on our thermometer. Hot tip: Keep your home fires burning.
Originally published at pioneerproductions.blogspot.com