The Ethereum Foundation has announced that September 6th will be the starting date for the system-wide transition known as the Merge. The first domino will be toppled on the 6th with the activation of the Bellatrix upgrade, which will then set the rest of the Merge process in action, with a completion date expected between September 10th and 20th.
The Merge refers to the switchover of Ethereum from proof-of-work to proof-of-stake — two different methods of validating transactions on the blockchain. If you’re not particularly interested in world of crypto, then the technical differences between the two approaches are a little arcane (The Guardian has a good explainer here). But the big upshot is that the new proof-of-stake method will use far, far less energy — 99.95 percent less, according to the Ethereum Foundation’s calculations. Given widespread criticisms of cryptocurrencies as a colossal waste of power that offer the world no additional utility, this is a big deal.
As the Foundation describes, the Merge is a two-step process. The first step is the aforementioned Bellatrix upgrade, due to go live on September 6th at 11:34:47AM UTC. Once this is live it starts another counter towards a TTD threshold (terminal total difficulty) of 58750000000000000000000. TTD is hard to define succinctly, but is essentially a measure of activity on the Ethereum network. Once this threshold has been reached, another upgrade, Paris, will be triggered and the Merge will be complete. (Though only on a technical level: the tangible effects of the switchover will take a while to play out.)
As a side note: this TTD threshold is the reason the Foundation is unable to give an exact date for the switchover, as reaching that figure depends on the ebb and flow of Ethereum usage after September 6th. However, they estimate it’ll be reached around September 15th.
The Merge is by far one of the biggest events in the crypto world to date. On the one hand it’s a technological upgrade that will allow new features on the Ethereum blockchain, but it’s also something more abstract: a test of the community’s coherence and commitment. If Ethereum survives and thrives after the Merge, it’ll be a sign of confidence in the platform.
Source: https://www.theverge.com/2022/8/25/23321312/ethereum-merge-date-start-september-6-bellatrix-upgrade