By definition, there is no single source of truth for a decentralized system. The breakthrough that Satoshi Nakamoto made was that he created a system that allowed all participants to independently focus on the same facts. It is the proof of work that makes this possible.
The significance of proof-of-work is that it can create a history that cannot be overturned. If there is a conflict between two histories, the history with more workload wins. By definition, the chain with the most workload is the fact, which is what we call the Nakamoto consensus.
Why use workload as an indicator? In short, because doing work requires energy. You can’t fake, ridicule, or lie on this. The proof of workload is reflected in the results of the work.
In the Bitcoin network, work refers to computing. Not all calculations, but specifically calculations without any shortcuts: guessing. The reason why there is no shortcut is that this kind of calculation has no progress/accumulation (no progress). Every guess is a new guess.
The best part is that the workload itself is included in the calculation results. The data is self-evident: the result of the calculation is an established fact, and there is no need for an external entity to tell you the fact. Due to the probabilistic nature of guessing, the data implies the amount of work paid for it.
Other mechanisms, such as proof of rights, do not have this feature. You can never be sure that what you see is the truth, because there is no cost outside the system to create another truth.
Computing is the only bridge connecting the information world and the physical world. When processing information, all we have is the conversion of information and information: that is, calculation. Calculations require energy consumption. Energy is the bridge. Energy is real.
If you cut off the end that leads to the physical world, you will always stay in the illusion: you can’t tell what really happened. You must trust other people to tell you what happened. You cannot verify it yourself. You must rely on trust.
There are many other issues with proof of rights, such as the fairness of validator elections (who decides how to elect?), the natural centralization trend (more rights = more rewards = more rights), and the lack of attacks on timestamp manipulation Natural resistance.
Proof of work can solve these problems. It can decentralize the election process and create a physical proof of what has happened; it has real out-of-system costs and can decentralize time reporting.
Link: Bitcoin is the clock (Chinese translation)
As for whether proof of work is a waste of resources, we must first understand what problem the proof of work solves before answering this question. If you understand this problem correctly, you will know that there is no other solution without trust.
Therefore, the question becomes: What is the use of trust-free digital sound currency? Is it worth so much energy consumption?
If things like refrigerators, cars, smart phones are made, the public will think it is worth it. If it is Bitcoin, those who understand the social benefits of a censorship-resistant sound currency will also answer in the affirmative.
All in all, proof-of-work is not only useful but also vital. Without it, trust-free digital currency simply cannot work. We cannot do without an anchor connecting the physical world. Without this anchor, we cannot create a self-evident and credible history. Energy is the only thing that can act as an anchor in our hands.
Proof of work = trust physics to decide what happens
Proof of Stake = The trustee decides what happened
I sympathize with everyone who thinks Bitcoin is a waste. I thought the same before, but I changed my perspective. Like most people, I knew nothing about (sound) money.
Link: Bitcoin’s energy consumption-my perspective changes
In a potentially hostile decentralized system, the problem of how to reach a consensus on time cannot be perfectly solved, even in theory. The workload proves that this practical probability-based solution can just solve this difficult problem.
Ledgers take time, and time is a thermodynamic concept.