Thermal image video shows how dippy birds work

The ingenious design of the dippy bird heat engine is revealed in this thermal imaging video.

The liquid inside dippy birds is called Dichloromethane. Commenters who were alarmed about the grave hazards posed by laser landscape projectors will enjoy complaining about the dangers of dippy birds. From Wikipedia: "Symptoms of acute overexposure to dichloromethane via inhalation include difficulty concentrating, dizziness, fatigue, nausea, headaches, numbness, weakness, and irritation of the upper respiratory tract and eyes. More severe consequences can include suffocation, loss of consciousness, coma, and death."