Thread by @mcclure111

@AxiomVerge This might take a couple tweets to reply to.

Here is a screencap from my GDC soapbox talk this year:

@AxiomVerge A blockchain is technically just a data structure. "Git" is a blockchain.

When used in this context (fintech), "blockchain" is usually used as a misnomer for append-only ledgers. The blockchain data structure is one type of append-only ledger.

Because at some point…

@AxiomVerge "blockchain" got some sort of reputation of being vaguely magical, people looking for investment funding find any excuse to add "blockchains". Not just ledger systems but potentially any distributed system, or even any kind of database, are at risk of being called blockchains.

@AxiomVerge Blockchains do not cause global warming. However, to use a ledger, you must have some method of adjudicating the "head" of the blockchain. The most popular method of doing this, mostly due to lack of imagination, is "proof of work". This is the thing that has a climate impact.

@AxiomVerge NFTs, and currencies, like to use ledgers because ledgers are a way of getting consensus. Ledgers associate the history of a system at a given point in time with a single cryptographic ID, and come packaged with some way of getting agreement on the "true" state of the ledger.

@AxiomVerge NFTs are a mapping of "X person owns Y resource" that a group of people has agreed on as meaningful. So they use blockchains. NFT people especially like using chains with "smart contracts" (Ethereum, Tezos) because smart contracts give you a way of "selling" your NFTs.

@AxiomVerge You COULD have a ledger that just marks "A transferred NFT X to B, C transferred NFT Y to D..." and so on. But smart contracts let you say "E transferred NFT Z to F *if* F pays E $N in currency Q" and then that becomes true only if the currency is actually paid. Obviously useful

@AxiomVerge "Clean NFTs" come in two flavors. The first flavor is POW-chain (carbon-emitting) NFTs where the vendor is simply lying. Popular lies: Emit the carbon then buy "offsets"; the Ethereum trick, where you *claim* you're clean because you're *about* to switch away from POW (but don't)

@AxiomVerge There are also clean NFTs that are not, directly, lying. "hic et nunc" is based on tezos, which is POS not POW, so it is not a carbon emitter in the same way Bitcoin is. This is the site of choice for "green NFT" folks who have put *some* thought into it.

But there's a problem.

@AxiomVerge Switching here from describing facts to stating my opinion:

When you buy an NFT, you have to buy it "with" something. Because NFT chains grew out of (or are hosted on) currency chains, the natural way to do this is to exchange them for the underlying currency the chain sells.

@AxiomVerge "Smart contracts" tend to get executed as an incidental byproduct of currency blockchains. Ethereum for example is basically a big shared VM that runs as part of the "work" of a POW currency chain, and if you pay-per-cycle with ETH currency ("gas fees") the VM runs your script.

@AxiomVerge So, how do you actually *pay* for an NFT?

Here you hit a problem. Blockchain currencies aren't *currencies*. That didn't work out. You can't buy pizza with it anymore. They're used to buy chain-based assets like NFTs, or they're used as speculative investment vehicles.

@AxiomVerge So say you buy that green nft on the green tezos chain. You probably bought tezos directly just for this purpose. But now the artist who you just paid has to turn that into money. This can happen in one of two ways, and *both likely go through bitcoin, the dirtiest chain of all*.

@AxiomVerge One way is a "cross chain transaction". You can pay for a green nft on the green tezos chain directly using dirty bitcoin, using code techniques where a smart contract executes dependent on something happening on a different blockchain.

@AxiomVerge But the more likely way is they either exchange the tezos you paid them for a more cash-transferrable coin, or they go to a broker who pays them cash—which is ultimately doing lots of trading tezos for more cash-transferrable coins.

@AxiomVerge The ultimate problem is the zoo of cryptocoins constitutes its own little minieconomy, & *bitcoin is its reserve currency*. It's easy to transfer back and forth between cryptocoins, hard to transfer back and forth with cash. Ultimately bitcoin acts as the fundamental value store.

@AxiomVerge So based on my understanding of the system, I don't believe it's currently possible to do transactions on one of the clean chains without generating traffic— and thus carbon burn— on one of the dirty chains.

@AxiomVerge And it will stay this way until we have a "value store" currency— maybe ethereum, if it ever does its POS changeover it's been promising for years— where you can plausibly go dollars, [reserve currency], [niche nft currency] and back again without touching Bitcoin.

@AxiomVerge Re Holochain: I don't know what this is, I'd have to look into it for a bit to say what it is. My cursory impression is it looks fake-ish. At the least, it appears "a holochain" is not a thing. Holochain appears to be a trademark of a particular company for a particular product.

@AxiomVerge From a 10,000 foot view it looks like they have a bag of technologies including a blockchain and possibly some other distributed computing primitives like an DHT? So some kinda hybrid does-everything system like the Facebook "Libra" thing that never shipped.

@AxiomVerge However, there are several competing systems trying to be this same thing and none I've seen obviously have *either* real-world use cases *or* a healthy, self-sustaining ecosystem like BTC and ETH have. Some never reall shipped. So I'd be skeptical they've achieved any different.

@AxiomVerge To me, it is extremely exciting to imagine something like a big shared distributed global-scale meta-cloud VM that you can rent time on to run cloud apps, and add computing power to and get paid for it. I don't think "blockchain" solutions are headed toward this...

@AxiomVerge …and successful applications toward that end seem to be coming from traditional P2P/distributed research, things like IPFS, than the fintech community.

Probably any "does everything" system like this has ledger capability at some point because consensus is sometimes useful, but

@AxiomVerge I assume any system that has a currency as part of it is probably poisoned forever, because the currencies at worst incentivize structuring the entire system as a scam and at best can create bubble effects that distort the intended functioning of the system.

@AxiomVerge I apologize if this was more detail than you needed.