Muir Glacier: Ethereum hard forks for second time in one month

Ethereum completed the Muir Glacier hard fork which delayed the difficulty bomb, a measure to increase block times in order to push the network to upgrade to proof-of-stake, approximately 611 days. Had this not been implemented, block times would have increased 2x-3x longer than normal. This was the second hard fork for Ethereum in the past month, the first being Istanbul which optimized opcode computational costs to enhance the performance of layer-2 solutions. The upgrades were not combined into one fork because developers originally estimated the difficulty bomb to not become noticeable until much later in 2020, however, their estimates proved to be wrong.

Why this matters

• Hard forks require node operators to upgrade their software due to the backward incompatibility, so they are typically avoided if possible. Given there was one recently, many in the community were upset the upgrades couldn't have been implemented in one. It appears to have been an honest mistake as a result of a miscalculation.
• This is the third time the Ice Age has been pushed back and is only a temporary fix to the underlying problem, demonstrating the difficulty in coordinating to make the eventual switch to proof-of-stake.