2009, February 26 - Collaborative Tools/Platform 2: Weblogs
You overheard the following conversation.
Identify some of the "facts" that are not scientifically correct.
why not saw it done in Chiang mai - basic principle of hot air is less dense - super cool
Molecules cannot expand lah!
Use helium instead?
very confusing but may be new discovery!!!
Cold air should be denser. Cold air sinks.
I don't think Lantern will catch fire because all the oxygen inside has been used to lit the flame.
no more fuel, so how to catch fire and get burnt?
ErrorSlide 2 - Hot air doesn't make lantern move.Slide 3 - Air molecules do not become bigger in size with more energy, but gain energy to more faster and collide more frequently.Hot air is less dense than cold air, hence will rise upwards, causing the lantern to move.Slide 4 - When the hot air cools down in the higher atmosphere, it loses energy and will fall down onto earth.
teacher pls look at this http://www.youtube.com/watch?v=_fBc5UaQK7E