What Does t Represent in Interference Without a Lens?

[mahmoodu]

Homework Statement

A source S of monochromatic light and a detector D are both located in air a distance of h above a horizontal plane sheet of glass, and are separated by a horizontal distance of x. Waves reaching D directly from S interfere with waves that reflect off the glass. The distance x is small enough compared to h so that the reflection is at close to normal incidence.

Homework Equations

2t = (m+1/2) lambda

The Attempt at a Solution

I know how to solve this problem if I understand one concept. That is, what does the "t" value exactly refer to? I understand that when using thin lens, it refers to the thickness of a lens. But in the scenario above, what does the t value exactly refer to when there is no physical presence of a lens?

Is it the distance b/w the two sources?

 

[lippyka]

Or is it the distance of the reflected ray from the point of incidence? Or is it something else altogether? Please help.

 

[m2003]

In this scenario, the "t" value refers to the distance traveled by the waves that reflect off the glass before reaching the detector D. It is not necessarily the distance between the two sources, but rather the path length difference between the two waves that interfere with each other. This distance is important in determining the interference pattern observed at the detector.