Deutsch English
Counter:502 (since 2001)

Gravitation Lense

The Gravitation Lense Applet could not be loaded.

  • Is Java activated in the browser? Or is Java blocked for this web site?
  • Is the Java plugin installed? To do that, you can download and install the Java Runtime Environment (JRE) (15.67 MB).

With the top left menu you can select from a list of images. With the mouse you can position a gravitation lense in form of a black hole. With the sliding widgets you can additionally adjust various parameters:

If you change one or more parameters without changing the position of the black hole, you have to click on re-calculate ("Neu berechnen"). For speeding up the calculation it is recommended to use a web browser that supports at least Java 1.3.

Project "Computer Applications in Astronomy"

The project "Computer Applications in Astronomy" took place in Winter Semester 2000/2001 at Hamburg Observatory. The instructor was Thomas Berghöfer; it was a first-time project that was initiated by the observatory.
Our goal was to simulate the effect of a gravitational lense. Taken an arbitrary night sky photograph as a basis, the lense should be placed between the stars and the observer so that the observed image is manipulated. As a programming language Java should be taken, and the program should be run from any web browser as a Java applet. We used VisualAge as a software development environment.
The result is the Gravitation Lense Applet "GRALE" (GRAvitationLEnser), which you also find on the GRALE site in the Astrolab of Hamburg Observatory. The source code is also available. The class diagram is also provided.