Having been away for the morning, we felt the need to be outside. We departed together and within a hundred yards I stooped to look, like a kid hunting for seashells among the flotsam deposited by the tide’s last reach. Joanna walked on without me.

Although we call it Avogadro’s Number, after Amedeo Avogadro, its discovery resulted from the work of others (notably Brown (of Motion fame) and Millikan (of Oil Drop fame)). The findings of all of these scientists revealed that a mole quantity of a chemical substance is comprised of  6.02 X 10 23 molecules. Would it surprise you to know that a single drop of water contains 1.39 X 10 21 molecules? Although that’s an impressive number, I derive more satisfaction from knowing how it is that liquid water may form a solid. The liquid is able to make this remarkable transformation because of the way in which its component molecules interact and pack together, especially at low temperature. When temperature declines, so too does the energy of an individual water molecule and, as a result, each moves about less rapidly. As motion slows, the molecules are less able to resist the magnetic attraction they have for their neighbors. [I could wax poetic about the nature of the water’s polar covalent bond, but will spare you, dear reader.] As temperature continues to fall, the attraction between molecules increases and eventually they become linked by hydrogen bonds. The fascinating thing about water is that its molecules pack together less closely (because of limitations imposed by the hydrogen bonds themselves) at temperatures which lead to the formation of ice than they do at temperatures which allow for the formation of liquid water. And that is why ice is less dense than liquid water. And that is why ponds freeze from the top down, rather than the other way around. But, I digress.

What intrigue me about both of the images obtained on this particular day are the incidental elements found in them. The first demonstrates the phenomenon of interference, and the second records the movements of light as it reflects from the surface of the water. The interference pattern reminds me of workbook exercises from high school physics class, while the patterns of reflected light remind me of the adhesive byssus threads of marine bivalve molluscs. I was tempted to present a third image, but thought better of it. If you’re interested, click here to view a tightly cropped and highly modified version of another photo captured in a series which includes the second shown here. The result reminds me of plasma exploding off the surface of the sun and then streaming out and back, along magnetic fields, to create a solar flare.



15 thoughts on “Incidentals

  1. I’m perhaps too given to anthropomorphizing, but a little imagination can help a lesson to stick. You wrote, “When temperature declines, so too does the energy of an individual water molecule and, as a result, each moves about less rapidly. As motion slows, the molecules are less able to resist the magnetic attraction they have for their neighbors.”

    It struck me that’s exactly why people tend to congregate in pubs during cold weather. As the temperature declines, so does the energy of individuals. They move more slowly, and develop an attraction for their neighbors.

    If I can play, just a bit more: As temperature continues to fall, the attraction between the pub-goers increases: eventually, they link arms, and may even sing.

    To turn back to science for a moment, it is fun to finally understand why ice cubes float in a glass of water, and why the top of my birdbath freezes first. Not only that, your photos are lovely.

  2. You can wax poetic all you wish, as far as I am concerned. The more knowledge shared the better and especially when it is accompanied by enthusiasm for the subject. I especially like the linked image. The cold this morning kept me indoors. Tomorrow morning shall be much worse although it sounds like Ithaca may be even colder. It is quite tempting to try to shoot in such a rare condition, but the -30° wind chill says it may not be worth the risk.

    • Eighty! We’re in Ithaca, NY this evening and we have been promised overnight temperatures eighty degrees, or more, COLDER than those you’ve got there! I’m very much looking forward to spring. D

      • I lived for the first half of 1971 in Union Springs, just a bit up the road from Ithaca. I made sure to rent a place within walking distance of where I taught because my car wouldn’t start whenever the overnight temperature dropped anywhere close to where you’re talking about. If Taughannock Falls State Park is open, I recommend a visit.

  3. Glad I never took Physics. Even your lay-men’s description seems complicated to my mind. Your images could definitely be comfortable in some textbook! Could definitely related to the stooping for sea shells!

  4. I always enjoy your prose not just for the quality of the word crafting, but also for the subject material. It seems that your posts are always timely, too. Just yesterday I was showing videos of Brownian motion and explaining how temperature is a measure of the average energy of molecules. This was accompanied by a good bit of arm flailing, of course, in front of a roomful of glassy-eyed students. Apparently, I am the most excited person in the room. How can they not be excited??? This is the science of LIFE! Oh well. The students in my morning class actually cheered up when I asked them about alternation of generations, though, and laughed at my analogies to explain plant biology, so perhaps some of my enthusiasm is not wasted.

    Thank you for also being excited about polar covalent bonds. 🙂

    • Renee! How nice to see your name in my comments section. Have you heard about my recent goings-on? I quit! Not retired, mind you … just up and left. We put the farm up for sale and are now living in Vermont. I enjoyed your comment, very much. I know, deep down, that I had little to do with your love and enjoyment of teaching, but if I bend the truth, just a bit, I like to think that maybe I did. Thank you also for the kind words concerning my writing. I have never fancied myself a writer of anything but the highly technical. I find, however, and much to my surprise, that I enjoy the genre in which I now operate. It’s something of a challenge to make what I find so interesting, sound interesting to others who might think differently than I do about science. Bringing science into the realm of the poetic has been fun. I’m glad you find excitement in thinking about polar covalents. This says lots about you and tells me that you will go far in your chosen profession. Thanks again for taking the time to touch base. By the way, the very day I departed the University it removed my electronic permissions. If you should want to get in touch, you’ll need to do so via the gmail account associated with this blog site. D

      • Good for you! I did see that the University was hiring a zoologist and thought you had finally made your escape. I hope it was satisfying and with dramatic flair. You certainly had an impact on my love of teaching! I distinctly remember you using all sorts of glorious biology terms and thinking to myself how wonderful it would be to string together as much biology jargon as possible – to one day stand at the front of the room and speak the language of science. It’s probably not good to enjoy confusing students, but I just really love the words – arbuscular, thigmotropism, parenchyma, apoplastic – I’m always learning new ones. I also admire your ability to have a life apart from academia. This academic machine seems to suck away energy and enthusiasm (how can I be so bitter so soon???). For me, it is important to be reminded that the many flaming hoops and games of the tenure process should not define my entire existence. So, cheers to you, for doing what you enjoy!

        • Thanks for your support Renee and for using the word ‘escape’ in talking about my departure. I am pleased that you have got all things in perspective. Always remember that you are Renee first and Dr. Rosier only second (or third, perhaps). How unfortunate it would be to allow one’s self to be so myopically defined. Thanks also for the kind words regarding my own efforts to define myself in more than a single dimension.

Respond to this post if you'd like.

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: