What is the significance of breaking a coconut in Hindu rituals?
Can't find any reliable citations for this, but I have mostly heard about this from my parents and elders.
Coconut breaking is a symbolic act of submitting oneself completely to the almighty. Before starting anything good/big (ex: foundation stone of buildings, buying a new car etc), coconuts are offered.
Coconut is also known as "Sriphal", or Gods fruit. It is considered as the purest form of offering to God, since the milk and the white kernel is not polluted due to the hard outer shell. (Again, I don't have any reliable citations for this)
The coconut itself symbolizes one's own head, specifically the person's ego. In the process of breaking the coconut, the person let's go of his ego and pride which he might have achieved or is going to achieve. When the ego is broken, only then you can taste the sweet milk of success, or the fruit itself.
Update: Although I couldn't find any authentic citations, here are a few blogs and threads who have written about it. I only know this from my parents and elders.
Here's a link which talks more about coconut as an offering to gods.
Note: “The question: What is the significance of breaking a coconut in Hindu rituals?” is licensed by Stack Exchange Inc (https://hinduism.stackexchange.com/); user contributions licensed under CC BY-SA.