Why is ether divisible to 18 decimal places?

Vitalik had the foresight to realize one day, most financial institutions, corporations and people would utilize Ethereum. To a further extent, alien races and far away worlds may also want to utilize Ethereum.

While the current financial market cap of all value including derivatives in the financial world are in the trillions if not, hundreds of trillions or more. Our total population in the billions. Accounting for additional neighboring planets and yet to be discovered M-class planets, the only rational thing to do was provide ether the room to grow to it's true potential.

Allowing for 18 decimal places was the only way to move forward. This will allow Ethereum to one day achieve it's true market cap and be utilized within our known universe by all species capable of building a computer and communicating through the inter-web to participate in universal-commerce without fear of being scammed.