Source: https://www.youtube.com/watch?v=ookTfBP5sUU When you shine a laser beam across the surface of a lake, it is very prone to refraction, but often this is ignored, and the result is declared a victory. Laser tests are a very poor choice of a test of curvature, when much clearer (and easier) tests are available, such as looking at large objects (like mountains) over water. In the video above, I describe the problem, and answer this question: With a resounding "YES, OF COURSE". It's actually really common for conditions to exist where a low-level laser is visible to a low-level camera many miles away. In fact, we are generally seeing this type of curvature most of the time during the day when the ocean is cooler than the air. We just don't really notice the very thin strip of compression near the horizon. The laser makes it stand out.