In one of the "Ethereum for dummies" articles, I found an example of a possible "smart contract":
John is a farmer, and he is afraid the temperature will drop down zero Celsius and destroy his crops,
so instead of make an insurance with a regulated insurance company (and endless trials in a case of a disagreement),
he signs a smart contract with somebody else which may be unknown to him (did I mention "no regulation"?..) that if the temperature in his region will fall under zero between October 2017 and April 2018, he will be compensated by 1000 and if not he will pay 20 as an insurance fee. No forms, no complex procedures, just a simple rule and a code which will take a decision.
My question is - how the system can get the details about the minimum temperature?
Or another example - gambling about football: how the contract can know the results?
Does the contract include also a link to a reliable internet site, and access it automatically?
Maybe I missed something?
Thanks in advance.