Although not an exact replication of the layers in the atmosphere, this demonstrates how light can travel through the density layers of Earth's atmos
No, it doesn't. For the FOURTH time now, he's shooting the laser through deliberately created layers of sugar, and that's the equivalent of bouncing it through multiple layers of atmosphere, not through the same layer 1.5 meters above sea level. That's why he puts the laser way down beneath the globe, so that it can cross through multiple levels of of the sugar mixture. Nothing but lies and deceptions from the globers.
With Dr. John D's laser experiment, you'd have to have constantly increasing density gradients about 1.5 meters above sea level ... in BOTH directions, which simply isn't possible.