relationship between bitcoin miner and verification of transactions Bitcoin miner mines a block, which can't be submitted to the network without proof of work. And the new block contains all of the new transactions. Hence the new block acts as a security measure, and authority. 

My puzzle is following:
In the scenario I just described, the miner of the new block, in some sense, authorized the new transactions to be true. Yet the miner has never looked into the new transaction he just authorized.

This somehow relates to orphaned blocks, and longest chain(?)

Links I found useful to help me understand:


How do nodes verify Bitcoin Transactions?
http://timothyblee.com/2011/04/19/bitcoins-collusion-problem/
http://spectrum.ieee.org/img/06Bitcoin-1338412974774.jpg
Why is blockchain necessary?
Which is the relation between transactions and blocks?
A miner can either verify transactions itself or assume that a transaction is valid as some nodes let him know they verified it.

In either case, the miner can enter the transaction in the block he is working on. Note that in pool mining the pool decides what transactions are included, while in solo mining your own bitcoind client does so.

An important thing to know is that miners only try to make a successor block for a block they think is valid. This means that when a miner generates a block with an invalid transaction on top of a valid block, other miners will not accept the new block. They will ignore it and continue trying to build a block on top of the last block they think is valid.

This way of working results a situation in which accepting invalid transactions and broadcasting invalid blocks is a waste of resources because your blocks will be orphaned and you will have to start all over.