2023-11-08
Globe
If you don't see a globe above, see Globe in Javascript.
Globe is an applet that draws a picture of the Earth. Click the Rotate buttons and the globe will rotate 20 degrees. Type in a new value for latitude, longitude, or rotation about display center, and the picture will update. Click on the globe and it will rotate 20 degrees every 2 seconds. The image is drawn with 6048 line segments every time.
This program has a long history. The original version was written in the MAD language for CTSS by either Rob Stotz or Daniel Thornhill of MIT Research Laboratory for Electronics in the late 1960s. The data for the globe was digitized and typed in by hand by a contractor for RLE. The program was often used as a demonstration for the ARDS terminal, a graphics display based on a Tektronix storage tube.
In 1971 or so, CTSS was going away, and I was working on a user interface for the Multics graphics system. I rescued the data file and translated the MAD version to Multics PL/I, and we used it for demonstrations of Multics graphics.
Sometime in the 1980s, Multics was going away at MIT, and Mark Eichin of MIT translated the program into C with calls to the X Windows display primitives.
In 1994, I rescued globe again and made it into a C++ presentation framework application for Taligent's Pink environment, based on Mark's code.
Revision history for the current Java applet:
- 04/18/96 THVV initial conversion from C++
- 04/25/96 THVV Improved controls; added animation
- 07/31/97 THVV work around Java 1.1 bugs with Netscape 4.0.
In 2013, I recoded Globe in Javascript.
Many more nice features could be added to this program. Here are some I have though of; your suggestions are welcome.
- About box
- Stars in the background
- Plot polygons, not vectors. Make the land green, lakes blue.
- Get rotation speed and angle from the applet <PARAM>
You are welcome to the source, if you
- Share your source with others freely
- Let me know you're using it
- Give me credit, and all the other pioneers, if you use the data or algorithms
Bernie Greenberg has a much fancier 
globe program for Windows, which uses the same RLE data.
John Walker wrote a beautiful Earth Screen Saver for Windows which presents a view of the globe from space.