Seeing in the dark

by | Monday, April 14, 2008

All of us have walked through a sun-dappled forest. However, few of us have noticed that underneath are feet are thousands of little perfect circles. This is often difficult to see because these little perfect circles often overlap into irregular globs of sunlight. However, if you find a single piece of sunlight within the shadows of the leaves above – you will a perfect circle of sunlight. And when I say a perfect circle, I mean exactly that, perfect! Where do these perfect little circles come from?

As it turns out, each of these circles is a little image of the sun – filtered through gaps between leaves in the trees. These gaps act as little pin-hole cameras, throwing tiny (inverted) images of the sun, onto the grass or ground beneath.

This may be difficult to believe, but there is one easy test. What if the sun were somehow converted from a circle to some other shape – a square perhaps. If what I am saying above is right, what we would see below our feet would be thousands of tiny, perfect squares.

Now, it is impossible for us to change the shape of the sun – but if we wait long enough there is one astronomical phenomenon that does change the shape of the sun (at least as perceived from earth) – and that is during an eclipse.

So if our theory is right, if we stand in the shadow of a tree during an eclipse the shadows beneath our feet would show, not circles, but rather hundreds and thousands of little eclipses.

In 1994, on the 10th of May to be exact, when I was a graduate student at the University of Illinois at Urbana-Champaign, I had a chance to observe this, and I took some pictures.

Last week I had visited some sections of CEP240 (with Father Mark Inglot) to speak about religion (or the lack thereof) and had mentioned this phenomenon, and had asked interested students to email me, if they wanted to see these pictures. One of the students took me at my word, and I took this opportunity to upload these pictures onto my Flickr site. You can see them here.

Incidentally I had first read of this in a book, Sympathetic Vibrations: Reflections on Physics As a Way of Life, by K. C. Cole, many years ago when I was a high school student in India.

Enjoy.

Topics related to this post: Fun | Photography | Religion | Representation | Science | Worth Reading

A few randomly selected blog posts…

New TPACK book chapter

New TPACK book chapter

The  Commonwealth Educational Media Centre for Asia (CEMCA), New Delhi, recently published a book titled “Resource Book on ICT Integrated Teacher Education.” Edited by Dr. Manas Ranjan Panigrahi it is available as an Open Educational Resource...

My Illusions on the web

There are a couple of websites that feature work done by me. I had written earlier about Brad Honeycutt's website An Optical Illusion at (http://www.anopticalillusion.com/). He now features four different ambigrams created by me: You can find them on this page on his...

Visualizing mathematics

I love visual proofs of mathematical theorems. One visual proof I use quite often in my design courses (CEP817 or CEP917) is a visual proof of the fact that the sum of consecutive odd numbers is a square number. In other words: 1 + 3 = 4 = 22 1 + 3 + 5 = 9 = 32 1 + 3...

Walking in a straight line

Determining the shape of the earth is something I have written about previously. For instance, see this post on seeing the shape of the earth using eclipses. (A somewhat similar effect could be seen in my photo of the moon during a lunar eclipse). On the web, I found...

Soham starts college, new ambigram,

We dropped off my eldest at the University of Michigan today. He begins the next stage of his life. We couldn't be more excited. Here is a new ambigram design to mark this occasion. Soham whichever way you look at it, with UMich colors! Mouseover the image to rotate...

Street Use

In blogging Kevin Kelly's piece on "Better than free" (read that post here), I came across another site that he maintains, titled "Street Use," self-described as follows: This site features the ways in which people modify and re-create technology. Herein a collection...

Representing networks

Facebook has a couple of apps that allow you to map your friends' network. I knew about them but hadn't really played with them till Matt Koehler asked for some ideas to use in his 956 (Mind, Media & Learning class) and I suggested trying some of these tools out. To...

Dancing with words, Good/Evil in a new ambigram context

Many years ago I constructed an ambigram for the words "good" and "evil." The idea came to me while waiting for a traffic light to turn green. The memory of it is so vivid in my mind that even today when I come to that particular intersection I remember that moment...

The Postman always rings twice: Unpacking McLuhan (3/3)

The Postman always rings twice: Unpacking McLuhan (3/3)

This is the third of three blog posts about how media influence our thinking. This is the second of three blog posts about how media influence our thinking. The first post, uses the invention of writing and print to unpack the meaning of McLuhan’s statement, “The...

0 Comments

Submit a Comment

Your email address will not be published. Required fields are marked *