Revision as of 19:28, 6 May 2025

Feynman's Path-Integral Formulation (QED)

YouTube video: Richard P. Feynman's 1979 Lectures at the University of Auckland, NZ	YouTube video: Physics With Elliot

Book resulting from Auckland lectures QED: The Strange Theory of Light and Matter

Here are a few figures that we generated (in Excel) to explain Fig. 24 of Feynmann's Book

Figure 1

Figure 2

Panel a: Same as Figure 1, but with fewer photon trajectories displayed.
Panel b: Positions of detector and source modified from Panel a.	Panel c: Mirror replaced by slit; position of source flipped to position such that light passes through the slit rather than bouncing off of mirror.	Panel d: If the source is a laser, then photon trajectories between the source and the slit are all in phase with, and parallel to one another.

@@ Line 43: / Line 43: @@
 ==Slit Aperture Instead of Mirror==
-<table border="1" align="center" cellpadding="8">
+<div align="center">
+<b>Figure 2</b>
+</div>
+<table border="1" align="center" width="85%" cellpadding="8">
 <tr>
-   <td align="center" colspan="3">[[File:QEDfig24TrajectoriesPPT.png|700px|Fig24 Trajectories]]</td>
+   <td align="center" colspan="3">
+[[File:QEDfig24TrajectoriesPPT.png|700px|Fig24 Trajectories]]<br />
+<b>Panel a:</b>  &nbsp; Same as Figure 1, but with fewer photon trajectories displayed.
+  </td>
 </tr>
 <tr>
-   <td align="center">[[File:QEDmirror02PPT.png|300px|Mirror02]]</td>
+   <td align="center" width="33%">
-   <td align="center">[[File:QEDslit02PPT.png|300px|Slit02]]</td>
+[[File:QEDmirror02PPT.png|300px|Mirror02]]<br />
-   <td align="center">[[File:QEDslit03PPT.png|300px|Slit03]]</td>
+<b>Panel b:</b> &nbsp; Positions of detector and source modified from Panel a.
+</td>
+   <td align="center" width="33%">[[File:QEDslit02PPT.png|300px|Slit02]]<br />
+<b>Panel c:</b> &nbsp; Mirror replaced by slit; position of source flipped to position such that light passes through the slit rather than bouncing off of mirror.
+  </td>
+   <td align="center">
+[[File:QEDslit03PPT.png|300px|Slit03]]<br />
+<b>Panel d:</b>&nbsp; If the source is a laser, then photon trajectories between the source and the slit are all <i>in phase with</i>, and parallel to one another.
+  </td>
 </tr>
 <tr>