The chemistry professor in my dad's first year of college started off the first day of school in a memorable way. He filled a large red balloon with hydrogen until it was a bit less than a meter in diameter. There was a sparkplug attached, with a wire leading to the supply closet nearby where the professor was hiding.
As everyone sat down, current was applied to the sparkplug and a massive BOOM accompanied by a fireball quieted the class very efffectively. Stepping into the classroom, the professor introduced himself.
@Setcho pictures would be appreciated. Congratulations?