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 Author Topic: Help with simulation "Feynman QED" in EJS/board:26-101-  (Read 19613 times) 0 Members and 1 Guest are viewing this topic. Click to toggle author information(expand message area).
jirischamberger
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 « Embed this message on: December 23, 2010, 02:36:57 am » posted from:BÃ­lina,Ustecky kraj,Czech Republic

Hallo, i am trying to make the simulation based on the Feynman QED (as you can see on the pictures below) in EJS, but to say the true, i dont even know how to start. My goal is : Two mirrrors, which can be changer (straight and concave), the user will click on any place in the mirrors and in the second window he will see the summation of probability amplitudes. Can anybody help me, please ?
 feynman2.jpg (38.14 KB, 496x462 - viewed 388 times.)  feynman3.png (120.32 KB, 980x430 - viewed 392 times.) Logged
Fu-Kwun Hwang
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 « Embed this message Reply #1 on: January 15, 2011, 10:21:43 pm » posted from:Taipei,T'ai-pei,Taiwan

Does the following simulation is what you need?

You can drag S,P to different location.
The red segments show the path which is shertest distance (or smallest time value).

Embed a running copy of this simulation

Embed a running copy link(show simulation in a popuped window)
Full screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
• Please feel free to post your ideas about how to use the simulation for better teaching and learning.
• Post questions to be asked to help students to think, to explore.
• Upload worksheets as attached files to share with more users.
Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!
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jirischamberger
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 « Embed this message Reply #2 on: January 23, 2011, 03:14:09 pm » posted from:BÃ­lina,Ustecky kraj,Czech Republic

Yes, that is exatly what I needed. Thank you very much
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ahmedelshfie
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 « Embed this message Reply #3 on: January 24, 2011, 08:43:52 am » posted from:SAO PAULO,SAO PAULO,BRAZIL

In my opinion is excellent applet, thanks prof Hwang for the wonderful work
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jirischamberger
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 « Embed this message Reply #4 on: February 27, 2011, 07:44:53 pm » posted from:BÃ­lina,Ustecky kraj,Czech Republic

I have tried this simulation in a different way : You can drag each point or you can generate (random or Gaussian) the points positions. But I have one problem : Somewhere I do a mistake and I cannot properly display the graphical summation of vectors. Can you help me, please ? Thank you.
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Fu-Kwun Hwang
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 « Embed this message Reply #5 on: February 27, 2011, 08:47:48 pm » posted from:Taipei,T\'ai-pei,Taiwan

I do not understand what is the problem ?
Could you create snapshot of the image for your simulation (right click mouse and select snapshot) when the problem occurs?
Explain what you want and what you have in the current program.
There is no way to help if I do not understand what is the problem.
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jirischamberger
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 « Embed this message Reply #6 on: February 28, 2011, 12:21:28 am » posted from:BÃ­lina,Ustecky kraj,Czech Republic

Hi, my problem is that i cannot display properly summation of vectors (and resultant vector). It should be looked like Cornu spiral, i think, but I cannot link vectors to each other (vetor A to B, then to C etc. and finally resultant vector), and I cannot find mistake. Thank you.
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Fu-Kwun Hwang
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 « Embed this message Reply #7 on: February 28, 2011, 08:23:13 am » posted from:Taipei,T\'ai-pei,Taiwan

Quote
d1 = Math.sqrt((x1-x2)*(x1-x2)+(y2-y1)*(y2-y1))+ Math.sqrt((x4-x2)*(x4-x2)+(y2-y1)*(y2-y1));
d2 = Math.sqrt((x1-x29)*(x1-x29)+(y2-y1)*(y2-y1))+ Math.sqrt((x4-x29)*(x4-x29)+(y2-y1)*(y2-y1));
d3 = Math.sqrt((x1-x26)*(x1-x26)+(y2-y1)*(y2-y1))+ Math.sqrt((x4-x26)*(x4-x26)+(y2-y1)*(y2-y1));
d4 = Math.sqrt((x1-x24)*(x1-x24)+(y2-y1)*(y2-y1))+ Math.sqrt((x4-x24)*(x4-x24)+(y2-y1)*(y2-y1));
d5 = Math.sqrt((x1-x22)*(x1-x22)+(y2-y1)*(y2-y1))+ Math.sqrt((x4-x22)*(x4-x22)+(y2-y1)*(y2-y1));
d6 = Math.sqrt((x1-x23)*(x1-x23)+(y2-y1)*(y2-y1))+ Math.sqrt((x4-x23)*(x4-x23)+(y2-y1)*(y2-y1));
d7 = Math.sqrt((x1-x25)*(x1-x25)+(y2-y1)*(y2-y1))+ Math.sqrt((x4-x25)*(x4-x25)+(y2-y1)*(y2-y1));
d8 = Math.sqrt((x1-x28)*(x1-x28)+(y2-y1)*(y2-y1))+ Math.sqrt((x4-x28)*(x4-x28)+(y2-y1)*(y2-y1));
d9 = Math.sqrt((x1-x32)*(x1-x32)+(y2-y1)*(y2-y1))+ Math.sqrt((x4-x32)*(x4-x32)+(y2-y1)*(y2-y1));
d10 = Math.sqrt((x1-x27)*(x1-x27)+(y2-y1)*(y2-y1))+ Math.sqrt((x4-x27)*(x4-x27)+(y2-y1)*(y2-y1));
d11 = Math.sqrt((x1-x30)*(x1-x30)+(y2-y1)*(y2-y1))+ Math.sqrt((x4-x30)*(x4-x30)+(y2-y1)*(y2-y1));
d12 = Math.sqrt((x1-x31)*(x1-x31)+(y2-y1)*(y2-y1))+ Math.sqrt((x4-x31)*(x4-x31)+(y2-y1)*(y2-y1));
The above is a copy from part of your code. It is very difficult to read or debug your code.
This is not the way to write a program.
You should have defined an array (e.g. d[12]) and do it with a for loop.
Do the same for x,y,phase, ...

You might want to check out my ejs source from the above example  to find out how to do it with a loop.
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linjin
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 « Embed this message Reply #8 on: March 03, 2011, 01:59:52 pm » posted from:Putian,Fujian,China

go off work, walk on white streets, windy, but feet from warm feeling, but didn't feel a

bit cold, I really like this pair of ugg boots, good warmth, if you want to buy, to "site"

purchase, price cheap... Wear comfortable...
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jirischamberger
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 « Embed this message Reply #9 on: April 24, 2011, 02:55:34 pm » posted from:BÃ­lina,Ustecky kraj,Czech Republic

I finally did it. You can change number of path (maximum 100), you can drag Source and Detector, you can drag the points on the mirror. Red ray is the minimum time, green rays are the closest to minimum, you can change lambda. What do you think ?
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jirischamberger
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 « Embed this message Reply #10 on: April 24, 2011, 03:00:04 pm » posted from:BÃ­lina,Ustecky kraj,Czech Republic

Sorry, i have a problem with attaching files, trying it again...
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Fu-Kwun Hwang
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 « Embed this message Reply #11 on: April 24, 2011, 10:16:13 pm » posted from:Taipei,T'ai-pei,Taiwan

You will find Upload new EJS jar file check box at the same line of "Post" button (submit button) when you edit the forum message.

Click that checkbox,  select the jar file before you submit the message.
Then, the EJS simulation in the jar file will appear as applet (part of forum message).
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jirischamberger
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 « Embed this message Reply #12 on: April 24, 2011, 10:22:37 pm » posted from:BÃ­lina,Ustecky kraj,Czech Republic

I am trying it...hope it works.
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Fu-Kwun Hwang
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 « Embed this message Reply #13 on: April 24, 2011, 11:49:17 pm » posted from:Taipei,T'ai-pei,Taiwan

Let me tried it for you!

Embed a running copy of this simulation

Embed a running copy link(show simulation in a popuped window)
Full screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
• Please feel free to post your ideas about how to use the simulation for better teaching and learning.
• Post questions to be asked to help students to think, to explore.
• Upload worksheets as attached files to share with more users.
Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!
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jirischamberger
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 « Embed this message Reply #14 on: April 25, 2011, 12:11:14 am » posted from:BÃ­lina,Ustecky kraj,Czech Republic

Thank you. I forgot one notice - distance is in micrometres. Regards
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transportation
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 « Embed this message Reply #15 on: April 26, 2011, 01:48:37 am » posted from:Dhaka,Dhaka,Bangladesh

I have tried this simulation in a different way : You can drag each point or you can generate (random or Gaussian) the points positions.
I am impressed by the quality of information on this website. There are a lot of good resources here.
I am sure I will visit this place again soon.
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Wisdom is to teach our students how to teach themselves. ...Wisdom