Wednesday, September 28, 2011

Google Blogger Dynamic view of my applets on measurement physics

http://weelookang.blogspot.com/search/label/MEASUREMENT

Google Blogger Dynamic view of my applets on measurement physics http://weelookang.blogspot.com/search/label/MEASUREMENT

Google Blogger Dynamic view of my applets on measurement physics.

A new experience to explore my posts on simulations i remixed.
Select Flip-card, Label choose MEASUREMENT ( i especially relabel them to work)

Feedback to Google about the ability to add LABELS quickly as it is a good way to organize the Dynamics view content/blog posts


Can add the ability to add/edit/mass change LABELS quickly in the new Dynamic view?

Wonder if Google can add it soon?

Update
Tried it on the mobile iPhone and iPad and the it seems to be unsupported for the moment.

I remember trying it earlier the result is kind of buggy but it definitely works.Google probably need more time to make it work seamlessly on mobile platforms like the iOS and Android.



Oh, if you continue unsupported, the dynamic view works but it does not have the scroll down capability

This is a view on the iPad, pretty isn't it.
Great work Google!!

Show this!

Easy Java Simulation FanPage

http://www.facebook.com/pages/Easy-Java-Simulation-Official/132622246810575
I started this FanPage to help Easy Java Simulation get more users.



I also made a Facebook Badge Easy Java Simulation (Official)

Easy Java Simulation

Promote Your Page Too

Google Supercharges Blogger With Dynamic Views

Google new Blogger Dynamic Views on Open Source Physics by lookang
Google Supercharges Blogger With Dynamic View. You can read more about it here http://www.itproportal.com/2011/09/28/google-supercharges-blogger-dynamic-views/

Looks awesome, i tested the pages it all works out.
Just need to create more labels to posts and perhaps a clever to optimize the dynamics view so that my interactive simulations can be found more easily.

Time to go to work on that!

Google Youtube

Sunday, September 25, 2011

Auto Post to twitter / facebook

example of how it looks like to use twitter feed


RSS feed address
http://weelookang.blogspot.com/feeds/posts/default

Check out http://twitterfeed.com/

It appears the way to auto post to twitter and facebook and linkedin as well.
let's check it out :)

Thursday, September 22, 2011

Talk: Aligning Simulations with US Teaching Standards

Talk: Aligning Simulations with US Teaching Standards written by Mario Belloni, Wolfgang Christian, and Francisco Esquembre
http://www.compadre.org/OSP/items/detail.cfm?ID=11476
For the past thirty years, U.S. high school science instruction has evolved toward common teaching standards. Despite this trend, consistent, well organized multimedia-based curricular materials aligned to these standards are not available. In order to address this need, we are creating a suite of interactive simulations using Easy Java Simulations with associated curricular materials and teacher resources. These materials are freely available on the ComPADRE Digital Library and indexed to educational content standards making the materials easy for teachers to find, access, and use.
MPTL 16 and HSCI 2011
Ljubljana, Slovenia: Sept 15-17, 2011
http://www.compadre.org/OSP/document/ServeFile.cfm?ID=11476&DocID=2440&Attachment=1

OSP Non-US Collaborators
As an add-on to page 3/35, the picture on Fu-Kwun Hwang is in part remixed by me :)
as a matter of remxing, the version in OSP is great, but the NTNUJAVA version has undergo slightly more attention from me due to improved coding skills, other teachers' requests and thanks to Open Source Physics & Easy Java Simulations, i was able to refine it even further after it was accepted into OSP http://www.compadre.org/OsP/items/detail.cfm?ID=9707

Do check out Ejs open source Vernier calipers java applet with objects, help & 0-error logic for the latest remixed version by lookang. :)
i also blog about it here for Google to crawl the simulation
http://weelookang.blogspot.com/2010/06/ejs-open-source-vernier-calipers-java.html

Hope to be an official OSP Non-US Collaborators one day too! :)
prof Mario explains it was to credit others who were present at MPTL16. Gonna be at MPTL17 hopefully when family commitments are more manageable :)

Micrometer with external measurement

Micrometer with internal measurement

Micrometer with depth measurement



Full screen applet

Java Simulation above is kindly hosted by NTNUJAVA Virtual Physics Laboratory by Professor Fu-Kwun Hwang
http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=684.0
alternatively, go direct to http://www.phy.ntnu.edu.tw/ntnujava/index.php?board=28.0
Collaborative Community of EJS (Moderator: lookang) and register , login and download all of them for free :)
Author: Fu-Kwun and lookang (this remix version)

on Page 6/35 and i do agree that even in my context, schooling continue to be like this too much teacher talk without much opportunity for self directed learning in inquiry of physics, though it is it is not that bad.

enjoy the YouTube from Ferris Buehler one of the great clips of bad teaching



on page 13/35 i reproduced this because i will refer to them regularly in my own self study.

Principles of Learning

  1. Principled Conceptual Knowledge. Learning with understanding is facilitated when new and existing knowledge is structured around the major concepts and principles of the discipline.
  2. Prior Knowledge. Learners use what they already know to construct new understandings.
  3. Metacognition. Learning is facilitated through the use of meta-cognitive strategies that identify,monitor,and regulate cognitive processes.
  4. Differences Among Learners. Learners have different strategies, approaches, patterns of abilities, and learning styles that area function of the interaction between their heredity and their prior experiences.
  5. Situated Learning. The practices and activities in which people engage while learning shape what is learned.

Page 20 to 21 has a fantastic Moon Phases simulation http://www.compadre.org/OSP/items/detail.cfm?ID=9308 by Todd Timberlake
picture from Phases of Moon Model written by Todd Timberlake
download 923kb .jar
Last Modified: April 14, 2010

which i also remixed on http://weelookang.blogspot.com/2010/08/ejs-open-source-moon-phases-java-applet.html

remixed version by lookang Ejs Open Source Moon Phases Java Applet


Full screen applet
kindly hosted in NTNUJAVA Virtual Physics Laboratory by Professor Fu-Kwun Hwang
http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1927.0
alternatively, go direct to http://www.phy.ntnu.edu.tw/ntnujava/index.php?board=28.0
Collaborative Community of EJS (Moderator: lookang) and register , login and download all of them for free :) This work is licensed under a Creative Commons Attribution 3.0 Singapore License
Author: Todd Timberlake and lookang
prof Mario has asked for the simulation to supplement the original simulation, hope he finds a way to add my remixed soon.

It has a lot of other simulations, i should find time to look at them more close to learn how they are made.
finally, to end off
Visit Open Source Physics at:
www.compadre.org/osp
www.um.es/fem/Ejs/
www.cabrillo.edu/~dbrown/tracker/

Oh yes, i read this http://www.compadre.org/OSP/items/detail.cfm?ID=11477
on Page 2 of Belloni, M., Christian, W., & Esquembre, F. (2011, Sept 15-17). Aligning Simulations with US Teaching Standards. Paper presented at MPTL 16 and HSCI 2011, Ljubljana, Slovenia. Retrieved September 21, 2011, from http://www.compadre.org/Repository/document/ServeFile.cfm?ID=11477&DocID=2441
EJS also allows teachers to quickly adapt existing simulations for any level of physical science and physics instruction. It is this flexibility, in combination with electronic distribution using digital libraries that allows us to determine the effectiveness of our materials and quickly, efficiently, and cost effectively create and improve the materials.
Perhaps i can testify to the validity of this statement, indeed i am one of the many teachers that Mario Belloni, Wolfgang Christian, and Francisco Esquembre argued in their paper.
They should have cited my papers like this one to support their claim. :)

Wee, L. K., & Mak, W. K. (2009, 02 June). Leveraging on Easy Java Simulation tool and open source computer simulation library to create interactive digital media for mass customization of high school physics curriculum. Paper presented at the 3rd Redesigning Pedagogy International Conference, Singapore. [PDF] from nie.edu.sg...Related articles - View as HTML - Import into EndNote

And lastly, i posted on comments to OSP to thank them.



i shared some of my thoughts here
http://weelookang.blogspot.com/2011/09/talk-aligning-simulations-with-us.html

OSP and EJS together has helped many education system make learning more active, inquiry based and for advanced learners, enabled the pedagogy of constructionism through creating, remixing or correcting incorrect physics models.

thank you OSP and CoLos.

Awesome people (OSP and CoLos community) who are agents of change making the world of learning more real world like, as oppose to reading, listening and solving word problems that i argue has little to do with living in the real world.

Wednesday, September 21, 2011

OSP-CoLoS Collaboration page 15

A History of The OSP-CoLoS Collaboration http://www.compadre.org/OSP/items/detail.cfm?ID=11474 written by Wolfgang Christian, Mario Belloni, Francisco Esquembre, Fu-Kwun Hwang, and Sasa Divjak
Over the past ten years, Open Source Physics (OSP) and Conceptual Learning of Science (CoLoS) members have worked together to produce the world's largest collection of interactive computer-based curricular materials for the teaching of physics. These materials are based on Java-based OSP programs and authoring tools such as Easy Java Simulations and Tracker and are available for free on various sites including the ComPADRE OSP. This poster describes the OSP-CoLoS partnership.
MPTL 16 and HSCI 2011
Ljubljana, Slovenia: Sept 15-17, 2011

I found me in the NTNUJAVA forum in the presentation on page 15.

The pictures are not clear thus recaptured on iPad blogger app to test the ease of using the blogger app.

The photos could not be rotated on the app.

I downloaded Photoshop express from app store to rotate the screen capture.

Enjoy!

http://www.compadre.org/OSP/document/ServeFile.cfm?ID=11474&DocID=2438&Attachment=1 page 15
Top starter in NTNUJAVA
Top Board in NTNUJAVA http://www.phy.ntnu.edu.tw/ntnujava/index.php?board=28.0  Collaborative Community of EJS (Moderator: lookang)
Top posters in NTNUJAVA
Most Online in NTNUJAVA
Top 10 Topics with http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=831.0 Ejs open source java applet 1D collision carts Elastic and Inelastic Collision

Monday, September 19, 2011

Creative Commons Attribution-Share Alike as oppose to All Rights Reserved.

MOE started a new portal http://www.ethos.moe.gov.sg/ethos/site/detail_story/57
The website has good content like:
Title: Ethos of the teaching profession.
Definition: "A strong professional ethos is important in fostering a culture of professional excellence as it establishes a shared understanding of professionalism among teachers. The Academy of Singapore Teachers will lead in strengthening the professional ethos and building a strong commitment to the beliefs and values owned by the fraternity".

Below is my own teacher story to share.
Education tools and research insights need to be sharable across the world in order to benefit humankind. Do it with Creative Commons Attribution-Share Alike as oppose to All Rights Reserved.

picture of YouTube http://www.youtube.com/watch?v=cuYJsnhWXOw 


By licensing teacher created video and worksheets etc under Creative Commons Attribution-Share Alike 3.0 Singapore, we made it clear what other people can do will these materials. Permission to use these works in your classrooms is already given, even before you asked for it. So don't let those none the wiser people tell you "Did you ask for permission to use this video or worksheet for your own classroom practices?"

There are now cleverer ideas like Creative Commons Attribution-Share Alike 3.0 that lower the barriers that teachers faced in their professional quest to liven and enrich the learning environment in their classrooms.

I have been sharing with other teachers when i conduct workshops to use technology tools for physics education and everyone knows and thinks it is a great idea to share freely educational tools and self created curriculum materials.

So join the creative commons movement in the world and license your creative works under creative commons attribution and be a citizen of the world today.

Saturday, September 17, 2011

MID811: Learning, Cognition, & Technology Reflection (08 November 2006)

http://lsl.nie.edu.sg/people/researchers/chee-yam-san
Found this amazing reflection to serve as a sign post for me whether i have progressed as what i reflected in Dr Yam San CHEE 's class, an amazing and great teacher.

MID811: Learning, Cognition, & Technology Reflection (08 November 2006) by Loo Kang WEE (050029D43) MA(IDT)
Course DescriptionThis course introduces students to current perspectives on the nature of human learning and cognition, including situated learning, distributed cognition, and other constructivist approaches. An understanding of these perspectives is used to address the design of technology enhanced learning, including multimedia learning environments and e-learning. The emphasis of the course is on pedagogy and learning design.

This one page reflection is about realizing the big ideas and big visions on what learning is about, and what is worth learning to people in general.

I have learnt a lot from Dr. CHEE lessons and I am saying this because it is the “truth” as far as what I experienced in the way I think about “what meaningful learning is about?”, “who am I?” and other big ideas revolving education in achieving deep understanding of complex ideas that are relevant to learners’ lives.

I realized to develop any lesson or learning environment, starts with a topic that is worth pursuing. What I mean is, it is basically less meaningful to develop and design lessons that are school based, compartmentalized in knowledge and skills acquiring, typically not achieving the aims of empowering the targeted learners to do meaningful tasks in their future lives.

This question is particularly useful in enriching my understanding of meaningful learning. From Dr. CHEE, “Why would our learners want to learn this?” which I loosely translated to my learners saying “Why should I learn this, what is in it for me?” The more I invest in this line of question, the more successful I am as an instructional designer.

Our group’s project journey of a learning environment from

1. learning projectile motion in simulated learning by doing with many sound pedagogy and instructional ideas,
2. to a 3 - dimensional tank simulation game environment using it to allow learners develop a deeper and engaging experience in understanding projectile motion
3. to our current airplane design e-learning framework in a rich and complex learning, contextual, authentic and immersive, with distributed and collaborative learning, accurate simulations as cognitive tools, allowing learners to study the patterns and formulate hypothesis and challenge conceptual knowledge, which I would argue is some form of activity worth doing and learning from, instead of the first 2 designs.

David Jonassen, meaningful learning that is Active, Constructive, Intentional, Authentic and Cooperative and Roger Schank FREEDOM of Failure expectation, Reasoning, Emotionality, Exploration, Doing, Observing and Motivation, have given me very effective framework for designing learner centered engaging e-learning environment.

I will apply these design principles to not school based lessons but to real life learning, bringing the usage of these principles to a higher level of meaning and justify why the learners will gain from it, significant from a student’s perspective and use it in life.

In essence, I aim to unshackle myself from design e-learning systems for academic school based forms of learning to real life learning, where it is reflective of what real life is kind of like, and prepare people to do some meaningful work or activity in life and reflect the complexity involved because people want to learn when it is real life like.

I also realize that great teaching is social, meaning the interaction between teacher and students, so a teacher need to have a personal interest in helping the students to learn. Students when they feel that genuine care and concern for their well being as a human being and passion for their learning development, they automatically response better to learning. I also found that technology is a tool; it can effectively use, misused or abused.

This project as well as this module, has also not only been about the how, but also the WHY design, to bring the meaningfulness of learning. I will remember to apply instructional design strategies to SOMETHING that is meaningful to my learners. I have attained a greater sense of deep purpose and insight into learning; eagerly anticipate for the school of the future, so that I too, like Dr. CHEE, am an agent of change.

Thursday, September 15, 2011

Mobile iPhone app blogger

Google release an app to allow blogging on the iPhone :)
Go get it it's free
picture of myself on my phone
picture captured and uploaded from iPhone 3GS
picture captured and uploaded from iPhone 3GS, once done click publish

Video Tracker Course in RGS 15 september 2011 1500-1700hrs

contact:
yixian.lim@rgs.edu.sg
cherkuan.thio@rgs.edu.sg
tzekwang.leong@rgs.edu.sg
weelookang@moe.gov.sg
samuel_tan@moe.gov.sg
http://www.cabrillo.edu/~dbrown/tracker/

Tracker on BallTossOut-main.gif showing the velocity and acceleration vectors as alternative means to self talk that ay always vertically downwards


Aim: to experience a Tracker workshop to enable teachers to conduct a lesson (kinematics, likely falling ball?, bouncing ball?, projectile motion?) using Tracker.
Results for MOEHQ: at least one lesson to be share at ICT connection ?
Results for RGS: better student engagement, improve student centered learning, teacher capability improved ?
Level of self directness learning (SDL)
basic SDL: Learning Physics of Projectile through Video Analysis and Modeling
Jimmy Goh / Yishun Junior College
advanced SDL: Learning Physics of Sport Science through Video Analysis and Modeling
LEE Tat Leong / River Valley High Sch
Title: Learning Physics of Sport through Video Analysis and Modeling
Venue: RGS Raffles Girls School, Computer Lab
Date: 15 September 2011
Time: 1500-1700hrs
Download:
· Tracker Mac version http://www.cabrillo.edu/~dbrown/tracker/installers/Tracker-4.05-osx-installer.zip
latest: http://www.cabrillo.edu/~dbrown/tracker/installers/Tracker-4.50-osx-installer.zip
The sharing had a problem where the Mac computer cannot open the video files
Solution:
Shorten the path of the video folders in the MacOSX
for example the path could be shorten by removing the initial path folder name
Took a while to trouble shoot
the other work around is to open from the OSP web library which automatically save the video is a shorten path that should be fine.



· Lesson resources from:
· basic SDL: Learning Physics of Projectile through Video Analysis and Modeling Jimmy Goh / Yishun Junior College http://ictconnection.edumall.sg/cos/o.x?ptid=711&c=/ictconnection/ictlib&func=view&rid=533
· advanced SDL: Learning Physics of Sport Science through Video Analysis and Modeling
LEE Tat Leong / River Valley High Sch http://ictconnection.edumall.sg/cos/o.x?ptid=711&c=/ictconnection/ictlib&func=view&rid=82

Participants: all physics teachers in RGS, lead by the Mr Thio Cher Kuan (RGS SH/Physics) and Lim Yi Xian (Ms) who attended my sharing during
· Wee,L.K. Lak Y.H. (2011,07 July) Blended Learning Workshop @National Junior College NJC, Bytz Room, Singapore
· Charles Chew, Wee,L.K. and Kam Y.H.(2011,07 July) Hybrid Learning Model for Meaningful Blended Learning: An Electromagnetic Induction Exemplar for transforming science instruction in Today’s “Classroom”, Blended Learning Workshop @National Junior College NJC, Bytz Room, Singapore

sharing guide
Samuel Tan on (Plan A) analysis of a projectile motion
Plan B Samuel decides maybe on a kinematics of a falling ball




Lawrence Wee on (Plan A) modeling of a projectile motion





sharing at RGS analysis workshop by Samuel
sharing at RGS analysis workshop by Samuel

sharing at RGS analysis workshop to a total of 6 RGS teachers


sharing at RGS analysis workshop to a total of 6 RGS teachers

card from the RGS teachers

envelope with a CD

envelope with a CD

Gifts from RGS containing Lee Chin CD

Gifts from RGS containing Lee Chin CD

Three reasons why teachers should blog

Title: Three reasons why teachers should blog
Title: Three reasons why educators should blog

http://www.chandymorganonline.com/wp-content/uploads/2011/05/blog_use-this-onejpg.jpg
1) Blogging is educational and fun. 
  • reflection on
  • crystallize thinking
  • widens your horizons
  • shifts your perspective
  • creative expressions
I been blogging for a while, i tend to agree with Jenny, Steve and Tat Leong that it does helps reflection and crystallize thinking. "Blogging can help with this process, enabling teachers to keep an ongoing personal record of their actions, decisions, though processes, successes and failures, and issues they have to deal with" says Steve. The fun part perhaps to me comes from knowing people does visit my blog to learn about the stuffs i blog like the physics simulations i remixed. The greater fun is also in the activity of  remixing open source physics simulations that i learn from redesigning new features in the simulations, and knowing that many would use them for educational purposes.



http://davishomesblog.com/image_store/uploads/6/7/9/5/3/ar126594678835976.jpg
2) Blogging can open up new audiences. 
  • connects community, friends, students 
  • spreads the word, sharing info
  • archive of events, achievement, awards, academic papers workshops 
I agree that i can become a teacher within an infinitely larger classroom, and as you blog on physics simulations subjects that interest me, you will discover that there are plenty of other education professionals ‘out there’ who are also interested. People who are interested will eventually find your blog and visit it regularly to see if they can learn something new from you.

http://www.biziki.com/wp-content/uploads/2008/02/momentum.jpg
3) Blogging can create personal momentum.
  •  raise your game
  •  motivates and inspires 
  • can give you valuable feedback. 
  • a way to share your expertise 
  • ease of access to your knowledge  
yes, I have started blogging, and it can be time consuming and so is learning to remix physics simulations that is customized to my local curriculum, student context and national syllabus. But i wouldn't go so far to say it is "ultimately worth it" because the rewards are intrinsic (benefits are inside the blogger and perhaps the blogs post can reflect some of these improvement in understanding). I did manage to motivate not only myself but others who visit my blog, and some more active online users do bother to give their feedback. I blogged also because the Ejs simulations and its associated curriculum and animated gif ( you would noticed in the latest posts on Ejs simulation, i have taken some useful animated gif and post them in Wikipedia, that i argue is a form of active citizenship to benefit the world at large. As for feedback, through some bloggers claim valuable feedback can be given, i suppose it will even be more helpful to also Facebook and Twitter about the blog post to get more people to look at what you have blogged. The personal momentum for me comes in the remixing and redesigning some of the physics simulations, you can see the menu on the left is slowly growing but there are still lots of possibilities and great simulations not customized to my needs. Knowing that menu is growing and relatively empty still help me to create personal momentum, despite my impossible family ( 2 young babies) commitments.   




Reference:
http://leetl.wordpress.com/2011/09/10/seven-reasons-teachers-should-blog/
http://steve-wheeler.blogspot.com/2011/07/seven-reasons-teachers-should-blog.html
http://progressiveearlychildhoodeducation.blogspot.com/2011/06/10-good-reasons-why-teachers-should.html
Lily's comment below

Friday, September 9, 2011

Ejs Open Source 1 Dimension Doppler Effect Sound Wave Java Applet

Ejs Open Source 1 Dimension Doppler Effect Sound Wave Java Applet

update: 26 November 2013: bug fixed

Ejs Open Source 1 Dimension Doppler Effect Sound Wave Java Applet with features like f = \left( \frac{c \pm v_r}{c \mp v_{s}} \right) f_0 \,, counters for waves emitted and detected
http://weelookang.blogspot.sg/2011/09/ejs-open-source-1-dimension-doppler.html
author: lookang based on the works on Fu-Kwun Hwang, Juan M. Aguirregabiria and Andrew Duffy
https://dl.dropboxusercontent.com/u/44365627/lookangEJSS/export/ejs_model_dopplerxywee01.jar
https://dl.dropboxusercontent.com/u/44365627/lookangEJSworkspace/export/ejs_model_dopplerxywee01.jar
https://dl.dropbox.com/u/44365627/lookangEJSworkspace/export/ejs_users_sgeducation_lookang_dopplerxywee.jar


Ejs Open Source 1 Dimension Doppler Effect Sound Wave Java Applet with features like f = \left( \frac{c \pm v_r}{c \mp v_{s}} \right) f_0 \,, counters for waves emitted and detected
http://weelookang.blogspot.sg/2011/09/ejs-open-source-1-dimension-doppler.html
author: lookang based on the works on Fu-Kwun Hwang, Juan M. Aguirregabiria and Andrew Duffy
https://dl.dropbox.com/u/44365627/lookangEJSworkspace/export/ejs_users_sgeducation_lookang_dopplerxywee.jar


Ejs Open Source 1 Dimension Doppler Effect Sound Wave Java Applet




Full screen applet
kindly hosted in NTNUJAVA Virtual Physics Laboratory by Professor Fu-Kwun Hwang
http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1997.0
alternatively, go direct to http://www.phy.ntnu.edu.tw/ntnujava/index.php?board=28.0
Collaborative Community of EJS (Moderator: lookang) and register , login and download all of them for free :) This work is licensed under a Creative Commons Attribution 3.0 Singapore License
Author: Fu-Kwun Hwang and lookang with ideas by Juan Aguirregabiria and Andrew Duffy
lookang thanks all of them (Fu-Kwun Hwang, Juan M. Aguirregabiria and Andrew Duffy) these are great physics teachers :)


The Doppler effect
The Doppler effect describes the shift in frequency of a wave that is produced by the motion of either the wave source or the observer of the wave (or both).
A sound source is moving with velocity v along the horizontal axis. Every period T a wave front leaves the source and travels with velocity c with respect to a medium (say air), assuming no air motion. A detector is located at position (x, y) and may move with velocity (dx/dt, dy/dt). To promote ease of learning, only the x direction is enabled, thus, making exploration confined to 1 Dimension.
You may change via sliders and edit the values of the aforementioned quantities, as well as the time interval dt between animation frames.
The source and detector position may also be chosen by means of the sliders.
Press Initial to set t = 0 and the source at its initial position.
Press Continue to start or continue the animation.
Press Stop to pause the animation, and Reset to recover the default settings.
In the graphics window below the animation a vertical red (green) bar is displayed each time a wave front leaves the source (reaches the detector).


Activities
Note that the velocities are specified in terms of the wave velocity, where positive is directed right. Thus, a source speed of 1 means that the observer moves at the speed of the waves.

1 Start with the source at rest and the observer at rest, and observe the pattern produced when you press the Play button. Describe the pattern also in terms of the relationship of f and f'. Hint: f = f'
2 Now, keep the source at rest, and give the observer an initial velocity. Explore how the frequency of the waves reaching the observer changes as you vary the observer's velocity. Does this depend on whether the observer is moving toward the source or away from the source? Does the motion of the observer effectively change the speed of the waves or the wavelength?
3 Now, keep the observer at rest and explore the effect of the motion of the source. How does the frequency of the waves reaching the observer depend on the source velocity? Does the frequency shift depend on whether the motion of the source is toward or away from the observer? Does the motion of the source effectively change the speed of the waves or the wavelength?
4 Now that you are more familiar with the simulations terms, objects and quantities, design and experiment to deduce the relationship between f' and f. Hint: a table with your inquiry quantities will be useful in your self directed science discovery.
5 What happens when the source travels at the same speed of the waves? Hint: your explanation should include/ make reference to terms like Mach, Shock-wave, Sound Barrier and Sonic Boom.
6 What happens when the source travels faster than the wave speed? Hint: your explanation should include terms/make reference to Mach, Shock-wave and Supersonic.

Advanced learners! pedagogy of constructionism
7 Use EJs and change the simulation to include 2 dimensions hint: Fu-Kwun Hwang http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=873.0
8. Use EJs and change the simulation to include the reference frame, hint:Andrew Duffy http://www.compadre.org/osp/items/detail.cfm?ID=9982
9 Use EJs and change the simulation to include the effect of wind hint: Juan Aguirregabiria edited by Wolfgang Christian http://www.compadre.org/osp/items/detail.cfm?ID=7902

other Doppler effect ejs applets
EJS version of Doppler effect (You can hear sound) by Fu-Kwun Hwang http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=873.0
Ejs Doppler Effect Model written by Juan Aguirregabiria edited by Wolfgang Christian http://www.compadre.org/osp/items/detail.cfm?ID=7902
Doppler Effect Model written by Andrew Duffy http://www.compadre.org/osp/items/detail.cfm?ID=9982


changes.

add new controls fit my usual design
redrawn for customization to sound Doppler effect v =330 m/s instead of the older 25 m/s
customized to 1 Dimension only
redo the applet on Fu-Kwun Hwang http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=873.0
added visualization of detected and emitted with reference to Ejs Doppler Effect Model written by Juan Aguirregabiria edited by Wolfgang Christian http://www.compadre.org/osp/items/detail.cfm?ID=7902
add sound from Toolkit.getDefaultToolkit().beep(); // taken from http://www.compadre.org/OSP/items/detail.cfm?ID=8385&Attached=1
//Ceiling Bounce Model written by Wolfgang Christian
made the initial v = 170 m/s
made T = 2 s

enjoy!

reference: http://www.physicsclassroom.com/class/waves/u10l3d.cfm
The Doppler effect is observed whenever the source of waves is moving with respect to an observer. The Doppler effect can be described as the effect produced by a moving source of waves in which there is an apparent upward shift in frequency for observers towards whom the source is approaching and an apparent downward shift in frequency for observers from whom the source is receding. It is important to note that the effect does not result because of an actual change in the frequency of the source. Using the simulation above, the source is still producing disturbances such as sound at a rate of f = 0.5 disturbances per second (select T period as 2 second); it just appears to the observer that the source of the wave is approaching say vsource = 170 m/s that the disturbances are being produced at a frequency greater than 0.5 disturbances/second. using the formula f' = f ( c+vobserver) / (c - vsource) = 0.5* ( 330+0)/(330-170) = 1.03 Hz.
when the source is traveling away from the observer, the formula is now formula f' = f ( c-vobserver) / (c + vsource) = 0.5* ( 330-0)/(330+170) = 0.33 Hz.

http://www.physicsclassroom.com/class/waves/u10l3d3.gif
The Doppler effect can be observed for any type of wave - water wave, sound wave, light wave, etc. We are most familiar with the Doppler effect because of our experiences with sound waves. Perhaps you recall an instance in which a police car or emergency vehicle was traveling towards you on the highway. As the car approached with its siren blasting, the pitch of the siren sound (a measure of the siren's frequency) was high; and then suddenly after the car passed by, the pitch of the siren sound was low. That was the Doppler effect - an apparent shift in frequency for a sound wave produced by a moving source.[img][/img]

The Doppler effect is of intense interest to astronomers who use the information about the shift in frequency of electromagnetic waves produced by moving stars in our galaxy and beyond in order to derive information about those stars and galaxies. The belief that the universe is expanding is based in part upon observations of electromagnetic waves emitted by stars in distant galaxies. Furthermore, specific information about stars within galaxies can be determined by application of the Doppler effect. Galaxies are clusters of stars that typically rotate about some center of mass point. Electromagnetic radiation emitted by such stars in a distant galaxy would appear to be shifted downward in frequency (a red shift) if the star is rotating in its cluster in a direction that is away from the Earth. On the other hand, there is an upward shift in frequency (a blue shift) of such observed radiation if the star is rotating in a direction that is towards the Earth.

reference http://www.kettering.edu/physics/drussell/Demos/doppler/doppler.html

f prime = f ( c + vobserver ) / ( c - vsource) for towards each other (approaching)
f prime = f ( c - vobserver ) / ( c + vsource) for moving away from each other (separating)
codes are:
frequencyemitted = 1/T;
if ((x-xe)*(v0-vobserver) >0){ // towards each other

frequencydetected = frequencyemitted*( v0+ vobserver)/( v0+ vs);
}
else {
frequencydetected = frequencyemitted*( v0- vobserver)/( v0- vs);
}
Or as in Wikipedia,
In classical physics, where the speeds of source and the receiver relative to the medium are lower than the velocity of waves in the medium, the relationship between observed frequency f and emitted frequency f0 is given by:[3]

f = \left( \frac{c \pm v_r}{c \mp v_{s}} \right) f_0 \,
where
c \; is the velocity of waves in the medium
v_{r} \, is the velocity of the receiver relative to the medium; positive if the receiver is moving towards the source.
v_{s} \, is the velocity of the source relative to the medium; positive if the source is moving away from the receiver.
Read the top signs to use when approaching and bottom signs when separating

Stationary Sound Source

Stationary Sound Source

 Pasco ripple tank. A small 650W incandescent light source was mounted about one meter above the tank, and the ripples projected on the screen were photographed from the side (see lower picture on the right) using a high-speed video camera by http://livephoto.rit.edu/LPVideos/ripple/ 
http://livephoto.rit.edu/LPVideos/ripple/Ripple_Tank_Waves_1.mov
click on the link to view the video


Stationary sound source produces sound waves at a constant frequency f, and the wave-fronts propagate symmetrically away from the source at a constant speed c (assuming speed of sound, c = 330 m/s), which is the speed of sound in the medium. The distance between wave-fronts is the wavelength. All observers will hear the same frequency, which will be equal to the actual frequency of the source where f = f0.

Source moving with vsource = 0.7*vsound ( Mach 0.7 )
Source moving with vsource = 0.7*vsound ( Mach 0.7 )


http://livephoto.rit.edu/LPVideos/ripple/Ripple_Tank_Waves_1.mov
click on the link to view the video on a Doppler effect in ripple tank case by http://livephoto.rit.edu/LPVideos/ripple/


The same sound source is radiating sound waves at a constant frequency in the same medium. However, now the sound source is moving to the right with a speed vs = 0.7 c (Mach 0.7). The wave-fronts are produced with the same frequency as before. However, since the source is moving, the center of each new wavefront is now slightly displaced to the right. As a result, the wave-fronts begin to bunch up on the right side (in front of) and spread further apart on the left side (behind) of the source. An observer in front of the source will hear a higher frequency f = \left( \frac{c + v_r}{c - v_{s}} \right) f_0 = 3.33f_0\,, and an observer behind the source will hear a lower frequency f = \left( \frac{c - v_r}{c + v_{s}} \right) f_0 = 0.59f_0\,

Source moving with vsource = vsound ( Mach 1 , breaking the sound barrier )


Source moving with vsource = vsound ( Mach 1 , breaking the sound barrier )



Now the source is moving at the speed of sound in the medium (vs = c, or Mach 1). assuming the speed of sound in air at sea level is about 330 m/s . The wave fronts in front of the source are now all bunched up at the same point. As a result, an observer in front of the source will detect nothing until the source arrives where f = \left( \frac{c + v_r}{c - v_{s}} \right) f_0 = infinity Hz\,. An observer behind of the source f = \left( \frac{c - v_r}{c + v_{s}} \right) f_0 = 0.5f_0\,. The pressure front will be quite intense (a shock wave), due to all the wavefronts adding together, and will not be percieved as a pitch but as a "thump" of sound as the pressure wall passes by. The figure at right shows a bullet travelling at Mach 1.01. You can see the shock wave front just ahead of the bullet.

US Navy Photo F/A-18 Hornet passing through the sound barrier. Navy Ensign John Gay made this phenomenal photograph on July 7, 1999 while aboard the carrier USS Constallation as Navy Lt. Ron Candiloro flew by. An MPEG movie of the flyby is also available. http://www.kettering.edu/physics/drussell/Demos/doppler/mach1.html
Every so often, just the right combination of conditions and events occur to create an unbelievable event -- in this case an F/A-18 Hornet passing through the sound barrier. Not only were the water vapor, density and temperature just right, but there just happened to be a camera in the vicinity to capture the moment. Navy Ensign John Gay made this phenomenal photograph on July 7, 1999 while aboard the carrier USS Constallation as Navy Lt. Ron Candiloro flew by.
The plane is actually in transonic flight, with normal shock waves emanating from behind the canopy and across the wings and fuselage. The condition will last for only an instant, and once supersonic flow exists completely around the aircraft, sharp-angled sonic cones replace the normal shock waves.

Source moving with vsource = 1.4*vsound (Mach 1.4 , supersonic)
Source moving with vsource = 1.4*vsound (Mach 1.4 , supersonic)

The sound source has now broken through the sound speed barrier, and is traveling at 1.4 times the speed of sound, c (Mach 1.4). Since the source is moving faster than the sound waves it creates, it actually leads the advancing wavefront. The sound source will pass by a stationary observer before the observer actually hears the sound it creates. As a result, an observer in front of the source will detect f = \left( \frac{c + v_r}{c - v_{s}} \right) f_0 = infinity Hz\, and an observer behind the source f = \left( \frac{c - v_r}{c + v_{s}} \right) f_0 = 0.42f_0\,.

As you watch the animation, notice the clear formation of the Mach cone, the angle of which depends on the ratio of source speed to sound speed. It is this intense pressure front on the Mach cone that causes the shock wave known as a sonic boom as a supersonic aircraft passes overhead. The shock wave advances at the speed of sound v, and since it is built up from all of the combined wave fronts, the sound heard by an observer will be quite intense. A supersonic aircraft usually produces two sonic booms, one from the aircraft's nose and the other from its tail, resulting in a double thump.
bullet traveling at Mach 2.45. http://www.kettering.edu/physics/drussell/Demos/doppler/bullet-3.gif

The figure at right shows a bullet traveling at Mach 2.45. The mach cone and shock wave-fronts are very noticeable.

slow motion of a hypersonic motion Mach = 5.0



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15:44, 24 September 2011Dopplereffectsourcemovingrightatmach1.4.gif (file)Lookang214 KB(supersonic text, dt =0.5)
15:36, 24 September 2011Dopplereffectsourcemovingrightatmach1.0.gif (file)Lookang332 KB(dt = 0.5)
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