No, this term does not belong to the realm of science fiction. Instead, it refers to the process of adjusting the difficulty of mining cryptocurrency to ensure fairness.
Bitcoin mining is a challenging task, and its difficulty is modified every 2,016 blocks. Given that each block takes approximately ten minutes to mine, adjusting the difficulty of Bitcoin can take nearly two weeks. Recognizing a potential flaw, other cryptocurrencies have devised methods to dynamically adjust their difficulties and maintain stability when significant amounts of computing power enter or exit the mining pool.
Multipools with a significant amount of computational power, like GHash.io, can significantly improve a cryptocurrency’s hashing power. The block time and the incentive system may both be affected by this abrupt rise.
The Kimoto Gravity Well was developed to address this problem by limiting the impact of multipools and other potent mining techniques on different cryptocurrencies. Instead than waiting for 2,016 blocks, it does it by changing the difficulty with each block.
Another commonly used algorithm for difficulty readjustment combines multiple exponential and simple moving averages. This approach smooths out readjustments and safeguards against potential exploits and workarounds attempted against the Kimoto Gravity Well.
Fortunately, Bitcoin itself is not susceptible to this problem because its difficulty readjustment is limited due to the vast hash power of the Bitcoin network. For instance, it would require around $3 million to increase the mining rate by a mere 10%. Consequently, Bitcoin does not require the Kimoto Gravity Well, although many smaller cryptocurrencies do rely on it to maintain fairness.