Growth rings of a tree not only tell us about its age. Sometimes they can also tell us about directions. These will be introduced in the latest episode of "Cool Met Stuff".
The video is now available on the "MyObservatory" mobile application and the Observatory's website for your viewing (programme is broadcasted in Cantonese).
Observatory's "Cool Met Stuff" channel (broadcast in Cantonese):
Broadcast schedule of various TV channels: