5 ms·

Bitcoin transactions are worthless unless put into blocks, and blocks have a cap for transactions.

jude- 6y ago
The parent was talking about the cost per transaction being high. In reality, that number is basically 0. The entire cost of Bitcoin mining is in block production, no matter how many or few transactions there are. If you're going to get mad about the energy use, at least direct it towards the right target.
- kaba0 6y ago
  As others have written, a block can handle at most (I think 100, but the exact number doesn’t matter) transactions, so to get an lower bound on consumption per transaction we could divide the block’s energy requirements by this number.
  - jude- 6y ago
    If there were _zero_ transactions, Bitcoin would take the same amount of energy. The proof-of-work calculation is _completely decoupled_ from how many transactions there are.
    - minsc__and__boo 6y ago
      You're missing the point. The point isn't that there are zero transactions, it's that there is an upper limit to the transactions allowed on blocks (a very famous limit) which allows for these types cost calculations.
      - jude- 6y ago
        OP was arguing that transactions in Bitcoin take a lot of energy. I'm pointing out that this simply isn't true -- all the energy use in Bitcoin is in solving the PoW puzzle, which is unrelated to transactions. It's not like this is a secret -- read Bitcoin's source code if you don't believe me.
        minsc__and__boo 6y ago
        Nobody is saying that PoW doesn't exist, so no, I'm not going to read Bitcoin's source code. That is such an odd thing to say. You can calculate cost per transaction because each block has a maximum number of transactions, irregardless of the current PoW difficulty. I don't know why you're so fixated on this. You can take 10 minutes of electricity costs and project it onto the number of transactions in the last block.
        jude- 6y ago
        It's now an odd thing to recommend reading the source code to a skeptic on a tech site that focuses on software development? You've come to the wrong place if you believe that reading the comments section will be more informative than studying the software artifact being discussed. You and the OP commit a category error in thinking that transactions contribute to Bitcoin's energy expenditure. Transactions are no more a source of Bitcoin's energy usage than solar panels are a source of the Sun's energy usage. The sun produces energy on a schedule that is independent of the number of solar panels around to collect it. Similarly, Bitcoin consumes energy on a schedule that is independent of the number of transactions around to be mined.
        kaba0 6y ago
        It’s like arguing that the heating in a car is energetically free because when the motor is on, it will generate heat. Just because PoW have to happen regardless of transactions doesn’t make transactions decoupled from it - and thus they have a ‘price’.
        jude- 6y ago
        Miners are selling you space in the block they're building, which you pay for with a transaction fee. But that block is getting built either way as long as it is profitable. Putting this in terms of distributed systems, we would say that the act of mining a block is the act of executing a view change (or a leader election). We would say that transactions are the messages sent to all nodes during the epoch. Obviously a system that only executes view-changes is not an interesting system, and nor is a system that just transmits messages but cannot order them or decide which are accepted by other nodes. But my original point is, these are separate operations, and only one of them is energy-intensive. Trying to say that both view-changes and message transmission are energy intensive because just one of them is not only belies a fundamental lack of understanding of how the system operates, but also hinders an effective regulatory response to stopping the real problem: pollution from fossil fuels.

The parent was talking about the cost per transaction being high. In reality, that number is basically 0. The entire cost of Bitcoin mining is in block production, no matter how many or few transactions there are. If you're going to get mad about the energy use, at least direct it towards the right target.

kaba0 6y ago
As others have written, a block can handle at most (I think 100, but the exact number doesn’t matter) transactions, so to get an lower bound on consumption per transaction we could divide the block’s energy requirements by this number.
- jude- 6y ago
  If there were _zero_ transactions, Bitcoin would take the same amount of energy. The proof-of-work calculation is _completely decoupled_ from how many transactions there are.
  - minsc__and__boo 6y ago
    You're missing the point. The point isn't that there are zero transactions, it's that there is an upper limit to the transactions allowed on blocks (a very famous limit) which allows for these types cost calculations.
    - jude- 6y ago
      OP was arguing that transactions in Bitcoin take a lot of energy. I'm pointing out that this simply isn't true -- all the energy use in Bitcoin is in solving the PoW puzzle, which is unrelated to transactions. It's not like this is a secret -- read Bitcoin's source code if you don't believe me.
      - minsc__and__boo 6y ago
        Nobody is saying that PoW doesn't exist, so no, I'm not going to read Bitcoin's source code. That is such an odd thing to say. You can calculate cost per transaction because each block has a maximum number of transactions, irregardless of the current PoW difficulty. I don't know why you're so fixated on this. You can take 10 minutes of electricity costs and project it onto the number of transactions in the last block.
        jude- 6y ago
        It's now an odd thing to recommend reading the source code to a skeptic on a tech site that focuses on software development? You've come to the wrong place if you believe that reading the comments section will be more informative than studying the software artifact being discussed. You and the OP commit a category error in thinking that transactions contribute to Bitcoin's energy expenditure. Transactions are no more a source of Bitcoin's energy usage than solar panels are a source of the Sun's energy usage. The sun produces energy on a schedule that is independent of the number of solar panels around to collect it. Similarly, Bitcoin consumes energy on a schedule that is independent of the number of transactions around to be mined.
        kaba0 6y ago
        It’s like arguing that the heating in a car is energetically free because when the motor is on, it will generate heat. Just because PoW have to happen regardless of transactions doesn’t make transactions decoupled from it - and thus they have a ‘price’.
        jude- 6y ago
        Miners are selling you space in the block they're building, which you pay for with a transaction fee. But that block is getting built either way as long as it is profitable. Putting this in terms of distributed systems, we would say that the act of mining a block is the act of executing a view change (or a leader election). We would say that transactions are the messages sent to all nodes during the epoch. Obviously a system that only executes view-changes is not an interesting system, and nor is a system that just transmits messages but cannot order them or decide which are accepted by other nodes. But my original point is, these are separate operations, and only one of them is energy-intensive. Trying to say that both view-changes and message transmission are energy intensive because just one of them is not only belies a fundamental lack of understanding of how the system operates, but also hinders an effective regulatory response to stopping the real problem: pollution from fossil fuels.