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I partly disagree with the author, but glancing at other articles of the same blog, it seems that nuance is often left out. On technical merits, the first poin

I partly disagree with the author, but glancing at other articles of the same blog, it seems that nuance is often left out. On technical merits, the first point is kind of invalid. You can't rewrite history in git without changing commit IDs. And the two others are the same point: git doesn't have a distributed consesus mechanism. It would be very easy to build one, though, which gets git close enough for comparison purposes. And the "blockchain" term only hints at the merkle tree aspect. Now, on rebranding: while I feel the comparison apt, it shouldn't be used as a successfull example of blockchain technology. It can to an extent, but blockchain means something different in people's mind. I'd still do the comparison while pointing out the difference. And that's something I often do, when explaining how either works. And to me, blockchain (including consensus) is still a mathematical curiosity that hasn't proven useful yet. I've seen some interesting PoW proposals, like mail anti-spam, or rate limiting/captcha.

Ajedi32 4y ago
> git doesn't have a distributed consesus mechanism It doesn't have an automated distributed consensus mechanism. It does have a manual distributed consensus mechanism; that's basically how every popular open source project works. You fork the project, make a change, and if your commit is an improvement over the project you forked people will be inclined to merge it into their repositories, eventually arriving at a consensus. In practice this process is often more centralized than distributed, but it doesn't have to be. If you want to 51% attack a popular repo, all you have to do is make constant, quality improvements to the project over time, and eventually your fork may well become the dominant one even over the objections of any centralized authorities.
- dahart 4y ago
  The argument that git can have consensus if people just agree to isn’t compelling in this context. The distinction here is that with blockchain, consensus is mandatory and has a specific technical meaning. With git, consensus is optional at best, achieved only manually, is easily broken by rogue activity, and the word consensus might not even mean the same thing and can change over time in the case of git - there are lots of examples of original projects or forks that have claimed to be the one and only place people should concentrate their efforts, only to get abandoned in favor of something else later.
knorker 4y ago
> You can't rewrite history in git without changing commit IDs. But "not changing commit IDs" isn't part of git's utility. Not inherently. This is easily proven by the fact that people do rewrite history. Because it's a useful feature to have. To say that you can't rewrite history without changing commit IDs is like saying you can't prove a certain point without using the letter 'e'. Like… why are you even bringing up such a restriction? > but blockchain means something different in people's mind Right. Blockchain means "distributed ledger", which git is not. To say that git is one too is a technicality on the level of saying it's "wrong" to say "have your cake and eat it too", when it's actually "eat your cake and have it too". It's not wrong, just not meaningful. The only reason, in my opinion, to talk about the similarities between "blockchain" and git is to do exactly what this article does: to remove confusion in the mind of the listener that they are in any way meaningfully similar. > I've seen some interesting PoW proposals, like mail anti-spam, or rate limiting/captcha. Maybe in the future you'll mine the next cryptocurrency by proof of work in the form of "help this self-driving car that's stuck at an intersection it doesn't understand".
- mikea1 4y ago
  > But "not changing commit IDs" isn't part of git's utility. How is that not a useful, intentional feature of git? Commit IDs (hashes) ensure DAG consistency as well as many other benefits. Linus explains it better than I could[0]. > This is easily proven by the fact that people do rewrite history. Because it's a useful feature to have. It depends on the context. Try to rewrite commits in a PR for any public repo and see whether others agree it's a useful feature. Anyway, I think you're proving the counter point: this is a shared feature of git and block chains - you know when history has been rewritten because the hashes changed. [0] http://www.youtube.com/watch?v=4XpnKHJAok8&t=56m16s http://www.youtube.com/watch?v=4XpnKHJAok8&t=56m16s
  - knorker 4y ago
    Sure, it's a hiccup to rewrite history. But in Bitcoin it's 100% fundamental breakage. There's a difference.

Ajedi32 4y ago

> git doesn't have a distributed consesus mechanism It doesn't have an automated distributed consensus mechanism. It does have a manual distributed consensus mechanism; that's basically how every popular open source project works. You fork the project, make a change, and if your commit is an improvement over the project you forked people will be inclined to merge it into their repositories, eventually arriving at a consensus. In practice this process is often more centralized than distributed, but it doesn't have to be. If you want to 51% attack a popular repo, all you have to do is make constant, quality improvements to the project over time, and eventually your fork may well become the dominant one even over the objections of any centralized authorities.

dahart 4y ago
The argument that git can have consensus if people just agree to isn’t compelling in this context. The distinction here is that with blockchain, consensus is mandatory and has a specific technical meaning. With git, consensus is optional at best, achieved only manually, is easily broken by rogue activity, and the word consensus might not even mean the same thing and can change over time in the case of git - there are lots of examples of original projects or forks that have claimed to be the one and only place people should concentrate their efforts, only to get abandoned in favor of something else later.

knorker 4y ago

> You can't rewrite history in git without changing commit IDs. But "not changing commit IDs" isn't part of git's utility. Not inherently. This is easily proven by the fact that people do rewrite history. Because it's a useful feature to have. To say that you can't rewrite history without changing commit IDs is like saying you can't prove a certain point without using the letter 'e'. Like… why are you even bringing up such a restriction? > but blockchain means something different in people's mind Right. Blockchain means "distributed ledger", which git is not. To say that git is one too is a technicality on the level of saying it's "wrong" to say "have your cake and eat it too", when it's actually "eat your cake and have it too". It's not wrong, just not meaningful. The only reason, in my opinion, to talk about the similarities between "blockchain" and git is to do exactly what this article does: to remove confusion in the mind of the listener that they are in any way meaningfully similar. > I've seen some interesting PoW proposals, like mail anti-spam, or rate limiting/captcha. Maybe in the future you'll mine the next cryptocurrency by proof of work in the form of "help this self-driving car that's stuck at an intersection it doesn't understand".

mikea1 4y ago
> But "not changing commit IDs" isn't part of git's utility. How is that not a useful, intentional feature of git? Commit IDs (hashes) ensure DAG consistency as well as many other benefits. Linus explains it better than I could[0]. > This is easily proven by the fact that people do rewrite history. Because it's a useful feature to have. It depends on the context. Try to rewrite commits in a PR for any public repo and see whether others agree it's a useful feature. Anyway, I think you're proving the counter point: this is a shared feature of git and block chains - you know when history has been rewritten because the hashes changed. [0] http://www.youtube.com/watch?v=4XpnKHJAok8&t=56m16s http://www.youtube.com/watch?v=4XpnKHJAok8&t=56m16s
- knorker 4y ago
  Sure, it's a hiccup to rewrite history. But in Bitcoin it's 100% fundamental breakage. There's a difference.