edward_monahan

So is Ethereum's VM simply not Turing complete, then? :) Since by its nature it can not possibly compute every Turing-computable function. If so, why was it even advertised as such?

edit: Haha okay, so I guess I'm not the only person who stumbled on this.

https://media.consensys.net/ethereum-isnt-turing-complete-an...

> A better question is -- why are there so many currencies to begin with? Why isn't there a single currency that everybody uses?

Groups of people live in bordered countries and like to have their own currencies for their own countries. There is, it's the United States Dollar. Why everyone uses USD, either directly or as a metric, is outside of the scope of this discussion.

Your argument about communities is where this all falls apart -- as I already stated, at some level you need the threat of violence to enforce the property rights necessary for any kind of personal wealth to flourish. Cryptocurrency doesn't solve this issue, or even approach it. It just creates a new virtual asset, backed by nothing and valued by faith, on top of an established system of community and law.

The halting problem in essence states that no algorithm can exists which determines whether or not a given algorithm will terminate given some input.

Ethereum makes the assumption that given a user-defined algorithm and a user-defined input, that within the limitations of the EVM whether or not the algorithm will halt can be determined. We know that that this can not be the case due to the halting problem. It may always be possible for there to be an implementation specific EVM-escape which could result in a catastrophic failure and loss of Ethereum for the end user.

> There's a significant difference between the social consensus you use to pick Bitcoin and the social consensus that you use to resolve a proof of stake fork. With Bitcoin, you choose it once and then it's stable forever.

A government with sufficient means can freely create a new history for Bitcoin and make that history canon. The work in blocks originating earlier in the chain is exponentially less than the blocks succeeding it.

>The value of Bitcoin is that it is very difficult to manipulate. In this, we have already seen it succeed repeatedly. The inflation is the same, legacy nodes all still work, nobody has ever invalidated addresses or taken money they didn't have the keys to.

The value of Bitcoin is whatever people believe it's worth. Control of the hashing power is trivial, and actually free, for the government of China. All they have to do is march their army into the mining warehouses and seize the means of production. Then there's nothing to stop Bitcoin from becoming the PBOCoin, with blacklists, inflation, and so on.

You could argue that, "Wait, it has the most work but it's not the valid chain! People elsewhere will continue the original chain." Okay, so which is the real chain? The answer is: whatever people believe is the real chain! And it comes back to being 100% established socially and emotionally by human beings.

Fun history of Bitcoin/cryptocurrency forks: 1. Value overflow bug in Bitcoin creates two Bitcoin chains, one with a person with 2 billion Bitcoins and one without. Which chain is the real Bitcoin chain? This is the first incident where 'the code is the contract except when no wait it's not'. 2. Berkeley DB bug makes two Bitcoins, just pick one and roll with it. 3. Ethereum DAO bug fiasco inadvertently creates two socially constructed versions of Ethereum, Ethereum Spicy Rollback Edition and Ethereum Classic. Which is the real Ethereum? 4. Bitcoin people can't agree with one another on anything, so one group of Bitcoin people make 8 MB Malleable Cash Bitcoin and another group makes Segwit2X Bitcoin, but some other people don't agree with the 2X part so maybe they'll make Segwit-not-2x Bitcoin too.

Which is the 'real' cryptocurrency that merits 2000 cheeseburgers of purchasing power today? Why, whatever we believe it to be!

Here is the irony in blockchain and computerized value systems in general: value is a collective social phenomenon. There is no way to avoid social consensus when creating a value exchange system between participants. In Bitcoin, it's people who have the biggest computational power decide what happens. In proof-of-stake, it's people with the most money decide what happens. In the latter, you might as well just argue that every country's government be set up as a trusted validator proportional to their population instead of Ethereum early adopters.

Cryptocurrencies are a platform attempting to solve the very human issue that value transfer systems are social and emotional. The original concept with Bitcoin was that your money could go from A -> B and no one could stop it -- except for those people who can actually stop it because they have vast amounts of network influence for whatever reason. Notwithstanding, even if you have millions of dollars in cryptocurrency, if someone really wants it badly enough they can probably hit you with a wrench until you reveal your keys. The only thing stopping this is a strong system of property law enforced by someone capable of physically removing you from the rest of society if they deem you to be in violation of social pacts.

The only major advantage offered by cryptocurrencies is that at least you can know the numbers appearing in your bank account aren't completely made up by a bureaucrat in an office somewhere. Regardless of your feelings about fiat, you can generally rest assured of this if you buy equities, which are well tracked and actually represent a corporeal stake in some company. So, aside from being a geeky toy and new market for gambling, where has cryptocurrency actually succeeded?