Don't have a miner? You can mine BTC using your own pencil and paper!
Original article: Mining Bitcoin with pencil and paper: 0.67 hashes per day 自己親自動手挖礦！
If you know what's really going on in BTC, you must have heard of the algorithm called SHA-256. In fact, if you dig into it you will find that the algorithm is not as complex as you think, you can even actually calculate it with your own hand. Of course, the process would be very slow compared to hardware, but I think it's quite interesting to understand how the whole mining process works in this way.
最近無意間在網路上看到的神人，竟然自己試著手算SHA-256演算法。其實認真一看，發現是看得懂的，並沒有想像中那麼困難。如果真的有閒的人，我覺得這是個不錯的方法了解到底平常礦機都是怎運作的
I won't go into detail about the calculation, so if you're really interested you can read the original blog here, and take a look at the youtube video Ken made.
According to Ken, doing one round of SHA-256 by hand take about 15 minutes. With this rate, hashing a full Bitcoin block (128 rounds) would take 1.5 days, for a hash rate of 0.67 hashes per day. In comparison, current Bitcoin mining hardware does several terahashes per second, about a quintillion times faster than manual hashing.
If you really want to know the profitability, it's about 0.000000000000000055 USD per day
根據Ken的運算速度，算一個hash需要花一天半的時間，而現在的硬體設備動輒幾個Terahash per second，好玩算了一下，每天用手算SHA-256，以目前BTC的價值和難度來看，一天大概可以賺5.5 x 10^-16 美金xD
真的有興趣看計算細節的人可以參考他的本文喔！
So why not take a few minutes and do one round of SHA-256, at least you can tell your friends you actually mine bitcoin!
The actual handwriting calculating process
Youtube video here, it's really cool