Thursday, December 24, 2015

Bending Light Model by PhET

awesome #html5 stuff  from #pHET. the screenshots on my hand phone Sony C5 Ultra tells it all. Thanks #PhET Cataloged here on OSP@SG, check it out!
nice landscape view in full screen view, newly developed capability

portrait view a bit too small, didn't take advantage of the empty space ?

portrait view, looks great on non full screen view

Wednesday, December 23, 2015

EJSS astroblaster model

New #astroblaster #toy #simulation #JavaScript #html5

EJSS astroblaster model

New #astroblaster #toy #simulation #JavaScript #html5

Thursday, December 17, 2015

Rutherford Scattering by PhET

#Rutherford Scattering by #PhET. found this and therefore will not be making one myself!

cataloged here



  • Quantum Mechanics
  • Atomic Nuclei
  • Atomic Structure
  • Atoms
  • Alpha Particles
  • Electric Charges
  • Electric Force
  • Rutherford Scattering
  • Plum Pudding Model


How did Rutherford figure out the structure of the atom without being able to see it? Simulate the famous experiment in which he disproved the Plum Pudding model of the atom by observing alpha particles bouncing off atoms and determining that they must have a small core.

Sample Learning Goals

  • Describe the qualitative difference between scattering off positively charged nucleus and electrically neutral plum pudding atom.
  • For charged nucleus, describe qualitatively how angle of deflection depends on: Energy of incoming particle, Impact parameter, Charge of target

For Teachers



  Rutherford's Experiment: Nuclear Atom by uploaded by HerrPingui
    Rutherford experiment animation by owigger
  Rutherford Gold Foil Experiment - Backstage Science

Software Requirements

Microsoft Windows
Sun Java 1.5.0_15 or later
OS 10.5 or later
Sun Java 1.5.0_19 or later
Sun Java 1.5.0_15 or later


Design TeamThird-party LibrariesThanks To
  • Wendy Adams
  • Michael Dubson
  • Chris Malley (developer)
  • Sam McKagan (lead)
  • Kathy Perkins
  • Carl Wieman
  • Interviewer: Sam McKagan

Tuesday, December 15, 2015

How to translate any Open Source Physics to your language

As mention in earlier post, anyone can translate any Open Source Physics simulation to your language. This are the steps to do that.

  1. Download EJSS Easy JavsScript Simulation authoring toolkit from here. i recommend the latest version Saved the zip file into your computer. 
  2. Unzip the file using any unzipping software like winrar or winzip into the default folder location.
  3. Navigate to the folder expanded, double click to launch EjsS_5.2_151201 EjsConsole.jar file
  4. EJSS will launch with a EJSS console and EJSS editor 
  5. Select Basic Options on the EJS console and select the Programming language as "Javascript", as you would want to translate those HTML5 simulations.
  6. Click on the(fourth icon on the right panel) "Read from EJSS Digital Library" icon, in the pop up select the "EJSS models at Singapore" Digital Library
  7. For example, you are interested to translate my Micrometer Model, it can be browse and found at 01_measurement Micrometer02 file. Click download or double click it to tell EJSS to read the source codes there.
  8. For beginners, just accept the default work-space and save the downloaded source codes into the work-space area. For experts, you may want to organise your files in source/users/sgeducation/lookang as default or other folders and names you want.
  9. Agree to everything like replace duplicate files
  10. At this point, you should have the source files loaded in EJSS authoring tool, ready for translation!
  11. Click the translation icon (right bottom top 4th icon) and a panel will appear showing the texts strings for translation.
  12. How to find your language code, visit and find your language, say if you are interested in Indonesia , the code is id.
  13. key in the language field and change it to id 
  14. and press Enter on the keyboard to register the input 
  15. assuming you want to type in by yourself based on your language skills as a translator, for demo proposes i will use google translate 
  16. copy the text say "answer?=" 
  17. select English in the left panel, Translated to language as "Indonesia" for example 
  18. and paste in translate 
  19. and the translated string back to the EJSS 
  20. Success! you have just successfully translated the first English string, repeat steps 15 to 19 for the rest of the strings.
  21. click on the Ok to accept all changes made in the translation 
  22. save the file to make sure the work is saved 
  23. To test whether yo did the translation correctly, right click on bottom 3rd bottom icon and select simulation package current simulation only 
  24. save the file in the default name, it will be in the folder export 
  25. navigate to the export file, 
  26. expand it  
  27. find the folder 
  28. look for the Micrometer02_Simulation_id.xhtml file and run it 
  29. package also the source codes and send it to me at and i will upload and share with the world your translation work!
  30. found in the export folder
  31. now, you or anyone should be able to translate any Open Source Physics simulation using the method above. Enjoy and remember to email me the  ejss_src_

Composition of two functions GeoGebra

Composition of two functions #GeoGebra, this is an interesting applet on #Mathematics

Drag x to vary the input for function g.
-Suggest possible domains of g for fg to be defined. In particular, what's the Maximal domain?
-What's the corresponding range?
-Look at the green line. What's the Domain of fg?
-Are functions fg and gf the same?
My suggested Answer:
corresponding range of f is >0.2
i don't understand the rest :)
i don't understand the rest :)

Exploring Range of composite functions

-You may key in the functions f and g box to vary the functions.
-Move the segment CD to select the respective domain for the first function f.

(a) how the range of the function g changes with the change in the domain of f ?
(b) What does the green highlighted portion represent?
(c) how the output gf(x) relates to the output of g?
(compare range of gf to range of g, are the two sets necessarily the same)?

Monday, December 14, 2015

Density Flash Applet by PheT

surprisingly it runs on normal browser like chrome despite being made in Flash




Sample Learning Goals

For Teachers

Software Requirements


translate any Open Source Physics to your language

#translators Hi Friends! wanna help translate any Open Source Physics to your language? the prototype in #中文, #தமிழ், #malay, #tagalog, #bahasa #Indonesia, #español, #ภาษาไทย are available for testing here…/…/01-measurements/5-vernier-caliper

drop me a comment if you wanna help translate!

Hai teman! ingin membantu menerjemahkan setiap Open Source Fisika untuk bahasa Anda? prototipe di 中文, தமிழ், malay, tagalog, bahasa Indonesia, english, ภาษา ไทย tersedia untuk pengujian sini

¡Hola amigos! quiero ayudar a traducir cualquier Source Physics Abierto a tu idioma? el prototipo en 中文, தமிழ், malayo, tagalo, indonesio, español, ภาษา ไทย están disponibles para las pruebas aquí

Hi kawan! mahu membantu menterjemahkannya sebarang Sumber Fizik Terbuka kepada bahasa anda? prototaip dalam 中文, தமிழ், malay, tagalog, bahasa Indonesia, español, ภาษา ไทย disediakan untuk ujian sini

அதிக நண்பர்கள்! இனி உங்கள் மொழி எந்த ஓபன் சோர்ஸ் பெளதீகம் மொழிபெயர்க்க உதவி? 中文 உள்ள முன்மாதிரி, தமிழ், மலாய், Tagalog, ไทย இங்கே சோதனை உள்ளன ภาษา, இந்தோனேஷியா, ஸ்பானிஷ் Bahasa

สวัสดีเพื่อน! อยากช่วยแปลใด ๆ เปิดฟิสิกส์มาเป็นภาษาของคุณ? ต้นแบบใน中文ที่தமிழ், มาเลย์, ตากาล็อก, ภาษาอินโดนีเซีย, español, ภาษาไทยที่มีอยู่สำหรับการทดสอบที่นี่

Hi Friends! wanna makatulong na isalin ang anumang Open Source physics sa iyong wika? ang prototype sa 中文, தமிழ், malay, tagalog, Bahasa Indonesia, español, ภาษา ไทย ay magagamit para sa pagsubok dito


Thursday, December 10, 2015

Wednesday, December 9, 2015

EJSS Dice Throw Model

EJSS Dice Throw Model

Download ModelDownload SourceembedFeedback


Assume the number of radioactive nucleus is N(t) --- not yet decayed into daughter product.
Each nucleus has the same probability p (p<1) decayed into daughter product.
It means that dN(t)/dt= -p*N(t) , where dN(t) is the number of nucleus decayed into daughter product at time t.
The solution is N(t)=N0 e -pt = N0 e -(ln2/T0.5)) t where N(0) is total number of nucleus at time t.
Each box represent a nucleus.
This applet let you set the probability for a nucleus to decay and watch how the number of decayed nuclei (color changed to RED)  increased with time t.


Other Resources

  1. lookang's blogpost about this JavaScript version
  2. by Fu-Kwun Hwang original Java version
  3. by Wolfgang Christian similar Java version
end state of dice =1, stop rolling, else keep rolling

end state of dice =1 and 2, stop rolling, else keep rolling

end state of dice =1,2,3, stop rolling, else keep rolling

end state of dice =1,2,3,4 stop rolling, else keep rolling

end state of dice =1,2,3,4,5 stop rolling, else keep rolling

For N0 =1024 dice, end state of dice =1, stop rolling, else keep rolling