user19182: I am stuck in this thought for a while regarding the block generation rate. My concern is, when a payer waits for 10 minutes to confirm that her transaction is included in a block, it suggests that a new block is generated in 10 minutes, because her transaction is brand new and the block includes it. So, how does a miner do that in just 10 minutes? Isn't it supposed to be hard? The miner can then become a millionaire in months.
Does the block generation rate imply that, once a miner starts computing the proof-of-work(POW) she succeeds in getting the nonce after 10 minutes? Or is it the case that miners are computing POW at their own pace(probably for a long enough time) and 1 new block pops up every 10 minutes. If the 2nd scenario is true, how does it justify the waiting time?
Thank you.

user18227: The block difficulty is adjusted every 2016 blocks so that, on average, it takes 10 minutes for miners to generate a new block. It would take any individual miner much longer than 10 minutes to compute the proof-of-work, but all miners together should be able to compute the proof-of-work in roughly 10 minutes. 

19182: <p>I am stuck in this thought for a while regarding the block generation rate. My concern is, when a payer waits for 10 minutes to confirm that her transaction is included in a block, it suggests that a new block is generated in 10 minutes, because her transaction is brand new and the block includes it. So, how does a miner do that in just 10 minutes? Isn't it supposed to be hard? The miner can then become a millionaire in months.</p>

<p>Does the block generation rate imply that, once a miner starts computing the proof-of-work(POW) she succeeds in getting the nonce after 10 minutes? Or is it the case that miners are computing POW at their own pace(probably for a long enough time) and 1 new block pops up every 10 minutes. If the 2nd scenario is true, how does it justify the waiting time?</p>

<p>Thank you.</p>
 18227: <p>The block <a href="https://en.bitcoin.it/wiki/Difficulty" rel="nofollow">difficulty</a> is adjusted every 2016 blocks so that, on average, it takes 10 minutes for miners to generate a new block. It would take any individual miner much longer than 10 minutes to compute the proof-of-work, but all miners together should be able to compute the proof-of-work in roughly 10 minutes. </p>
