# Walking in a straight line

by | Wednesday, June 23, 2010

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 another way of computing the shape of the earth through studying the turbulent wake of a ship.

An interesting challenge that remains has to do with how we reconcile projections of the earth with the actual shape of the earth. For instance the Mercator projection distorts what are straight lines into curves and vice versa. Of course complicating all this is the fact that what we think of as straight lines needs to be reconfigured somewhat to meet the demands of a spherical surface i.e. the whole idea of a great circle.

I recently came across a very cool web site which uses Googlemaps to map a straight walk on the surface of the earth. Check out map.talleye.com

The moment you try this out you realize just how complex a process it is to go from the Mercator projection to understanding the same path on a sphere. This also reminded me of the maps of the earth that show the demarcation of day and night on its surface. Check it out at daylightmap.com.

[More information on the Mercator projection can be found here and on great circles here.]

A few randomly selected blog posts…

## Community Design Lab at Madison

One of the greatest pleasures of my work here at ASU (with the Office of Scholarship & Innovation) has been the work we have been doing with local school districts. Essentially we collaborate with partner districts and community organizations to develop...

## Douglas Adams, technologies & anticipatory plagiarism

Image Credit Leeks As readers of the blog know, Matt Koehler and I work together quite a lot. In fact we just rotate author-order in our papers since it is hard to keep track of individual contributions. (I would like to claim that the cool ideas are mine - but again...

## Paradoxes & Ambigrams: Article 2 of 2

A few months ago I had posted about publication of the first of two articles on mathematics, visual wordplay and paradoxes. The second article (part of our series on Art and Math co-authored with my friend Gaurav Bhatnagar and published by At Right Angles) is now...

## Creativity as Resistance: New article

Image credit: tshirtgifter.com The next article in our series (Rethinking technology and creativity for the 21st century) for the journal Tech Trends is now available online. This article has an interview with Dr. Shakuntala Banaji, currently Associate Professor and...

## Is the web making us stupid?

... or just narrow? I just discovered Britannica blog, a pretty lively virtual space for intelligent discussion. How I had not come across it earlier is a mystery - but again that is the beauty of the web. Anyway, there is an ongoing discussion there about how the web...

## Protected: TE150: AT&T award submission

To view this protected post, enter the password below:

## TPACK is top story on eSchool News

I just discovered that TPACK made the Top Story of the Week for Educators on eSchool News! Written by Laura Devaney, Senior Editor of eSchoolNews the article is titled, TPACK explores effective ed-tech integration. It is a pretty comprehensive piece with quotes from...

## Pogue on design

David Pogue has couple of great examples in his latest posting about bad design in the world of software. Check out: It’s the Software, Not You. Potentially useful in CEP817/917...

## Fortunate

I had discovered the amazing poet Szymborska (on this very blog a while ago). And then today in my mailbox was another poem by her, sent in by a friend. We're extremely fortunate A poem by Wislawa Szymborska We're extremely fortunate not to know percisely the kind of...