What's a bitcoin miner

       ... or, "why does my computer fan turn on when I visit that website?"

If you're here, you probably followed a link from a website using Bitcoin Plus for websites. To find out why your computer fan turned on, first you need to know about bitcoin:

Bitcoin is a new online currency. It can be created (yes, the currency can be created) by a piece of software called a bitcoin miner.
Your computer fan turned on because generating bitcoin takes computer power. It's essentially generating money to help support the website you came from.

It's nothing to be alarmed at, it will not slow down your computer because it only uses spare computer power.
If you like, you can learn more about bitcoin.

If you're annoyed by this, feel free to complain to me at donny@bitcoinplus.com. 

How Bitcoin Works

Bitcoin is a "peer-to-peer virtual currency". That doesn't tell you much - here are the main differences of bitcoin compared to cash.

Bitcoin vs cash

• Payments are public. It's possible to look at every single payment that's been made.
• Payments are anonymous. Well, kind of anonymous. You need to give out a bitcoin address to receive a payment, but addresses are free and aren't linked to who you are.
• Payments take time to be confirmed. You can make a payment and the receiver will see it almost immediately, but you have to wait for it to be accepted by other people (this is the "peer-to-peer" part).
• Bitcoin can be created from nothing. Actually, not exactly from nothing - it's created by performing calculations in order to solve a puzzle.

Solving the puzzle

When you're a part of the bitcoin network, your computer can try to solve a kind of puzzle. When your computer solves the puzzle, you get 50 bitcoins. The puzzle difficulty keeps changing so that around 6 computers solve it per hour.

Why it has value

If bitcoin can be created by computers without you doing any work, you might wonder why it has any value. The answer is simple: it has value for the same reason the pieces of paper in your pocket (aka "cash") have value: people are willing to give you things in order to get it. There are even places where you can exchange bitcoins for cash.

What's it worth?

The price has been around $7 per bitcoin lately (as of May 17th, 2011). You can see the current price of bitcoins in US dollars at Mt Gox.

Generating 50 bitcoins

There's some good news and some bad news. The bad news is that because there's so much computing power generating bitcoin already, it would take an average computer years to generate 50 bitcoins. Instead of waiting for years, people decided to join forces. They've created pools of computing power - everyone uses their computer together, and when anyone in the pool solves the puzzle, everyone splits the profit.
You can start doing this right now. Go to the bitcoin generation page and you can put your computer to work creating bitcoins. 

Bitcoin Generation

New: you can generate bitcoin for a friend.

Stop generating

Step 1: Click "Start Generating"
Step 2: Wait while your computer works (leave this page open)
Step 3: Earn bitcoin

It's that easy. Want the explanation? Read how bitcoin works, but click "Start Generating" first so you'll earn bitcoin while you read.

New: Have your friends generate for you (or generate on multiple computers without logging in) with http://www.bitcoinplus.com/generate?

New: The bitcoin miner for websites is available.

FAQ

Can I use multiple computers to generate bitcoin

Absolutely. You can use as many computers as you like, all signed in to the same account, in order to generate bitcoin faster.

What does the speed mean?

The speed is how many times per second you are trying to generate a payout. A payout happens around every 4 billion tries.
The "Estimated time per payout" is the average time it will take you to generate a payout based on your average speed.

Will this slow down my computer?

No. The bitcoin generator only uses your spare computing time. It runs at a low priority, so if you start using other applications, it will get out of the way so that your other applications won't slow down. Try it - you should find that your computer is just as fast (or slow) as it normally is.

Do I need to keep this page open to generate bitcoin?

Yes. Your computer will only be generating bitcoin as long as you keep this page open.

I generated a payout in 5 minutes but it says it takes 2.5 hours. How did that happen?

Payouts are essentially random. It's like a lottery that happens millions of times per second, where you get an entry for every calculation you perform. In your case, you got lucky and a got a payout quickly.

Why does the payout change? Do you take a cut?

The bitcoin network adjusts the difficulty of the puzzle approximately every 2 weeks. This means it takes more computing power to get the same payout. However, instead of taking longer and longer to generate a payout on this page, I keep the difficulty the same, but adjust the payout. Yes, I do take a small fee of 3%, to keep the site going (and make a little bit of money).

I'm close to generating a payout, will I lose my progress if I turn off my computer?

No. The progress bar is an estimated progress. In reality, it's impossible to determine how long it will take to generate a payout since they are random. Try to have your computer generating all the time, but remember you won't lose your progress when you turn off your computer or stop generating.