The Ethereum Merge: Decoding the Complete Timeline

A tragic storm of wild crashes, insolvency crises, scams, lawsuits, and regulatory threats has had a baneful effect on the entire crypto and DeFi space since early 2022. These events shook the crypto community with terror. Sadly, there is no reset button or a forgetfulness potion to wipe those off from our memory. 

But despite all this, the crypto world now anticipates the biggest and most significant event, ‘the Ethereum Merge.’ Supposedly, this transition event appears to offer a beacon of hope amid this crypto winter.

What is The Merge about? How did this begin? When is it going to happen? And What will happen to Ethereum after this upgrade? To get to know the answers, it becomes prominent to re-learn the whole process right from its origin.

Before taking a deep dive into the Ethereum 2.0 journey, there is one crucial point that the crypto community should have in mind. That is, Ethereum 2.0, also known as The Merge, is not like a normal hard fork instead it is the transition of the Ethereum blockchain from proof-of-work (PoW) to proof-of-stake (PoS) consensus. Simply put, it’s just Ethereum’s consensus makeover. This upgrade facilitates a merger between the PoW-based Ethereum mainnet and the PoS-based Beacon Chain. 

Flashback: The Inception of Ethereum Merge

The groundwork for formulating The Merge plan began quite early. Switching from energy-intensive PoW to energy-efficient PoS was more preferred by the developers themselves way back in 2015 after the protocol’s launch. A three-phased roadmap was proposed for the Ethereum 2.0 upgrade. It began with Phase 0 with the launch of the Beacon Chain in December 2020. 

The Beacon Chain is a parallel blockchain with the proof-of-stake (PoS) consensus system and continued to co-exist with the Ethereum Mainnet. The former, Beacon Chain, was tagged as Eth1 and the latter as Eth2.

The team stated:

“The Merge represents the official switch to using the Beacon Chain as the engine of block production. Mining will no longer be the means of producing valid blocks.”

Rayonism, an R&D project solely dedicated to the Ethereum 2.0 or The Merge upgrade, began in March 2021. Under this project, a month-long hackathon named ETHGlobal Scaling Hackathon brought in all the Eth1 and Eth2 clients to build testnets to initiate the trial of the PoS system on them. These testnets mimicked the entire infrastructure of the Ethereum Mainnet and exist as the compatible PoS testing environment. Steklo, the first Ethereum 2.0 testnet was launched during the hackathon.

Kiln, Rinkeby, Ropsten, Sepolia, and Goerli were prominent testnets whose upgrade is recorded as milestones towards achieving the true PoS transition.

Furthermore, there are four forks and technical upgrades that laid a firm foundation for the Ethereum Merge. Firstly, in August 2021, the London Hard Fork, incorporated significant Ethereum Improvement Proposals (EIPs) such as EIP 1559 to update the fee mechanism on Ethereum.

Secondly, in October 2021, the Altair upgrade was the first upgrade to be implemented on the Beacon Chain. It introduced the penalties on validators nodes’ inactivity.

The third and fourth upgrades, Arrow Glacier and Gray Glacier, which took place in December 2021, and June 2022 respectively, delayed the “Difficult Bomb” before The Merge.

Notably, the difficulty bomb is responsible for the Ice Age of Ethereum’s PoW engine. This code is responsible for increasing the complexity of the mining mechanism on the PoW blockchain. Thus, the difficulty bomb is introduced within the protocol in 2015 to push miners to abandon mining and switch to staking. The developers have delayed the difficulty bomb until the completion of the transition.

The upgrades in the three major public testnets, Ropsten, Sepolia, and Goerli, commenced between June to August. With the final testnet merge, Goerli, the Ethereum protocol’s schedule is finalized.

What Happens During The Merge?

All the three prominent testnet mergers: Ropsten, Sepolia, and Goerli, made the Ethereum network advance towards the actual Merge transition. As per Ethereum’s core developers, The Merge upgrade will eventually rollout through two sequential upgrades, namely, Bellatrix and Paris. These two upgrades will commence on the two parallel layers, the Consensus, and Execution layer, of Ethereum that are soon to be merged.

Danny Ryan, Researcher at Ethereum Foundation, stated:

“Bellatrix upgrades the Beacon Chain to be ‘Merge aware.’… Paris is the Merge transition itself.”

The Bellatrix upgrade is responsible for getting the Beacon Chain, also known as the Consensus Layer, ready for The Merge. This upgrade prepares the Beacon chain for undergoing the final transition by embedding it with the Merge logic. 

The validators on the Beacon Chain, formerly known as the Eth2 layer, continue to monitor the PoW chain. Also, during this upgrade, the PoW nodes are upgraded into the “EL + CL Merge-ready nodes.” 

The Paris upgrade will be initiated on the Ethereum PoW Mainnet, also known as the Execution Layer. This upgrade represents the exact Merge transition where the PoW consensus is switched to the PoS consensus. Moreover, the Paris upgrade demands the validators network to upgrade the system configuration.

Important Ethereum client engineers held a discussion on the recent Consensus Layer Call on August 10 to estimate the schedule for the Merge and its associated criteria. When the consensus layer reaches the epoch 144896, the Bellatrix upgrade is triggered and is estimated to occur by September 6. 

When the execution layer reaches a terminal total difficulty (TTD) of 58750000000000000000000, the Paris upgrade commences and its completion marks the end of The Merge. As per the estimation, the transition is about to commence by September 15. Thus, it is the actual schedule of The Merge.

On successful completion of The Merge, the era of proof-of-work (PoW) ends for the Ethereum protocol. The existing mining pools, such as Ethermine, will eventually transition to staking pools. 

What Happens To Ethereum After The Merge?

The successful Merge upgrade will mark the start of an era of enhanced scalability and energy efficiency for the Ethereum blockchain. After The Merge, the energy consumption of the Ethereum blockchain will be cut down nearly by 99.95%.

The Merge does not focus on enhancing the transaction throughput or expanding the network capacity. Ethereum blockchain is demarcated into two layers, execution and consensus layers. Importantly, Ether (ETH) becomes a deflationary token post-merge. The developers stated the ETH issuance will drop by “roughly 0.6 million” per year. 

Shanghai Upgrade will go live following The Merge transition. This upgrade will enable stakers to withdraw their staked ether (ETH) locked in the Beacon Chain. 

According to the Ethereum development roadmap published by co-founder Vitalik Buterin, The Surge, The Verge, The Purge, and The Splurge is queued up after The Merge. It is purely a rollup-centric roadmap.