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Comment by ubi3921 | Hacker News Reader

> We don’t just get to share code, we get to share a running computer, and anyone anywhere can use it in an open and permissionless manner

Can someone explain what this means? Its not explained anywhere in the post.

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Bitcoin transactions, or more precisely transaction outputs, are little scripts that are executed in a VM. To spend a transaction output, you have to "solve it" by providing it an input which makes it return true. The most common transaction script checks that you possess a private key through a signature check, but it's possible to make more complex scripts like the "Pay To Multisig" script. Of course, Bitcoin scripts are quite limited and, unlike Ethereum smart contracts, they are non-Turing-complete and can't store state.

Permissionless just means anyone can create transactions because there's essentially no way to block someone from doing so, unlike say a transaction on PayPal.

You can think of the Bitcoin block chain as the state of a globally-accessible machine. The state is updated through the publication of valid blocks, each of which builds on a previous block. A block is composed of transactions, each of which incrementally advances the machine's state. Each transaction contains a small program "script" that defines the conditions for the state transition it causes.

There's this persistent misconception out there that only Ethereum works this way. It's a testament to marketing. Bitcoin has been doing "smart contracts" long before Ethereum was even a gleam in Vitalik's eye.

Bitcoin's script language is very restricted, claiming that Bitcoin has been doing "smart contracts" is disingenuous to me. I wouldn't call a bitcoin script as "smart". Ethereum was born because of this

Script is restricted, but it permits everything outlined by Nick Szabo's definition. As Wikipedia notes:

> Smart contracts were first proposed in the early 1990s by Nick Szabo, who coined the term, using it to refer to "a set of promises, specified in digital form, including protocols within which the parties perform on these promises".

https://en.wikipedia.org/wiki/Smart_contract

We don't get to decide what smart contracts are. Nick Szabo decided long ago.

Marketing vs reality has been a big problem in this space.

He links committing transactions to the blockchain to storing state in a distributed data structure... which is of course, in the case of Bitcoin, implemented in arguably the most wasteful, ham-fisted, environmentally disastrous way possible.

There's also the ethereum VM which is a slow decentralized state machine capable of executing code...

Check yourself.All progress was 'wasteful' with resources at one time. And yes, bitcoin is progress.

All progress was 'wasteful' at some point, but all 'progress' is wasteful. And yes, bitcoin is 'progress'.

I suppose Bitcoin is better than gold. Unfortunately, for BTC, we already have much more advanced financial technology.

Permissioned legacy technology is not advanced. The stronger, harder money wins. Good luck with your guess.

I am specifically thinking of fiat money, based on burrowing and fractional reserve banking. This has addressed many historical problems with fixed money/value supply that Bitcoin would have if it ever caught on.

Presumably a reference to blockchain as a distributed ledger.

He is probably referring to Ethereum, which was conceived as a "global computer", operating in an open and permissionless manner.

Ethereum extends the concept, but Bitcoin transactions are programs running on the global blockchain (well, the op codes are executed by a single node, but the result is published and verified by the network, if I understand it right)

But just wanted to make the point that Bitcoin is a global computer as much as ethereum is, Solidity is just Turing complete while (Bitcoin’s) Script is intentionally limited to a few instructions.

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