How backflow incense burners make smoke fall

We love the exciting videos produced by YouTuber Steve Mould where he shares the most entertaining and educational science experiments and explanations, portraying them in a way that is accessible and easy to understand. In this latest clip, Mould explains how backflow incense burners manage to make smoke fall, defying the laws of physics and nature.

But let's start by explaining what these devices are. Backflow incense burners serve the same purpose as regular incense burners: to equip a room with a pleasant aroma.

They are created so that the smoke from the burning incenses flows up through the device through an exit and then proceeds to fall from one section to another of the device's front layer. This is very interesting indeed as in normal conditions smoke flows upward, not downward.

How do backflow incense burners manage to achieve such a task? What kind of physics and chemistry is involved in the process? Are these types of incense burners safer than their conventional counterparts? How effective are they at infusing a room with their pleasant scent? This video answers all these questions and more.