2 9 8 D O C . 2 7 8 I N T E R F E R E N C E O F C A N A L R A Y L I G H T Therefore, in the latter case, no interferences are visible. In the former case the relative strength of the interferences toward the non-interfering portion is given by the linear function . Thus the relative interference strength drops linearly to 0 with an increasing differ- ence in path. This result is based substantially on the diffraction at the slit. If our statement is right that there is no influence of a parallel shift of the light source on the interference phenomenon, then this result is also valid for the emis- sion of canal ray particles that pass by directly behind the slit, contrary to my orig- inal expectation.[14] I would now like to show that this result corresponds exactly to the expectations of the wave theory, according to which the canal ray particle emits light like a Hertz oscillator. According to this, the individual canal ray particle sends a wave train through the slit as it is passing by it at the frequency in the positive x-direction. is the duration of the emission. From this one wave train, the interference appa- ratus produces two of the same amplitude, which are shifted in time against each other by . Thus, the two wave trains interfere only during a time at a se- lected place, and also at such a small d that this quantity is positive. In this case, the time integral of the square of the excitation at a point on the X-axis is proportional to . Because this is proportional to the total intensity at the selected point, one again ob- tains for this, by calculating up to an insignificant proportionality factor, the value , which fully agrees with the above result. The analogous examination of a regular grating would have yielded a periodi- cally linear drop and growth in the interference strength with d instead of a one- time linear drop. If means the thickness of the grating rods as well as the grating 1 v-d bc ----- – ν0 b v -- - d v -- - b v -- - v -- -–d [p. 340] 2 2πν0t)dt 2πν0t) 2πν0© t d·· v -–--¹¹ § § cos© + cos( 2 td 0 b v -- - d c -–-- ³ + 0 d c -- - ³cos2( 1 1 dv· bc¹ -- - -- – © § π d λ0¹ ----- § · cos© + b d -- -