The mentioned applet is very handy to help pupils to really understand lat/long coordinates in geography.

I'm a teacher on secondary school level. I'm "knitting" whatever helpful interactive items into so called "Lernselbst" lessons.

I'm producing Java applets myself, but only through Z.u.L.
(a free to download geometry tool see: )

I tried to construct an interactive geographical coordinate applet myself, but failed. All I was able to produce one can see here:

I'd really like to replace my faulty applet by your accurate one. For my students I'd need to translate teh keywords into German too.

Was it possible to get your applet in a form, I'd be able to translate the keywords? If you'd agree in doing so, I'd certainly leave a (copyright) text and a link to your homepage.

If ever something on my page could be of use to you or your students, please feel free to copy, paste and use it.

Again compliment for your self explaining applets

sincerely Yours

josef strebel

hank you. I am using Safari web browser on a Mac computer and for some reason the menu does not show up on After reading your answer to my email I looked again and I found that if I move the cursor near the upper left corner of the page then I see the choices.

Thanks for the alternate web site where I can find them easier.

Several of the applets will be very useful to me in teaching my high school physics class.
I especially like Vector Addition, Longitudinal Waves, Young's Double Slit Experiment, Single Slit Diffraction (although on this one I had to change the setting on my monitor to greater resolution or else the controls were off the page at the bottom), and Adding Transverse Waves. Wow, there are still more that I have to look at!


I m interested in your Java Applets. I am a teacher of physics in the Secondary School in a small town in Poland. I have been teaching physics for 25 years. I’m interested in the methodology of physics. I believe that Java Applets are one of the best contemporary  teaching aids. I would really like to learn how to create them, because I do not know how to do that. Is it difficult to learn?

Yours sincerely,

Jerzy Sarbiewski

These applets are wonderful. I have been using them for maybe five years now and wish I had thanked you long ago.  I teach high school physics.  Tom Cleary


I am  great fan of your applets. I teach physics in NZ and your applets really help my students in visualizing stuff.

thank you

alka rhode

I am from South Africa doing highschool physics, I just wanted to say I appreciate your applets :)

I would like to ask you for your permission to place your learning material River and Boat available on the web page, on a CD-ROM that will be included in a book Using the Internet in Teaching Physics, prepared by the publishing house CP Books.

The publication is a methodology handbook designed for the teachers in Czech primary schools, showing them in what ways interesting Internet resources can be efficiently used in their teaching. Among the referenced resources, your learning material is included. The authors of the publication are teachers Josef Duhajsky, Jitka Houfkova and Jana Buresova.

The text of the handbook will be mirrored on the web server Ceska skola (, so that its use is really easy for the teachers: after studying the printed book, which is for many more comfortable than using the computer, they can open the web mirror that saves them, for instance, the effort of copying long and complex URLs. However, at many Czech schools, the Internet connection still doesn't have sufficient quality. We therefore plan to supplement the book with a CD-ROM which will contain the selected materials downloaded for the off-line usage of those without a (good) Internet connection.

The publication has been supported by a Czech Department of Education grant project, which enables us to distribute it free to every primary school. The handbook will be followed by more titles, focusing of teaching other subjects.

I am therefore asking you to let me know by e-mail whether you agree with placing your material on this CD-ROM, and on what possible conditions.

I am looking forward for your prompt answer.

Best regards,

Vit Sebor

editor, CP Books, a.s.

nam. 28. dubna 48, 635 00 Brno-Bystrc, Czech Republic

tel.: +420 546 122 713, mobil: +420 724 669 042