At the end of the presentation, Dr. Schwarcz demonstrates a reaction where he reacts calcium carbide with water to produce flammable gas- acetylene. When a burning splinter was introduced through a tiny opening, an explosion in the flask took place. However, when the same experiment was repeated, by introducing a burning splinter in a tiny opening in the flask, the flask acted as a lamp due to absence of oxygen. The moral of the whole exhibition was that the same thing used for explosion could also be used as a lamp. It completely depends on the way one uses the knowledge one possesses.
The End :)