How does a node verify the genesis block?
The genesis node is hardcoded in the client.
This makes no sense. The genesis node IS a checkpoint.
In computing, the definition of a checkpoint is a point
beyond the beginning. For
example, "Checkpoint restart, a method for restarting a long software process at a point beyond its beginning."
If you create an entirely new blockchain built from a different genesis block, then it's just an alt-coin. It's not even a fork.
If I create a Bitcoin clone, name it Bitcoin and the only difference is the genesis block, it is Bitcoin.
Even, if I would pump billions of GHs in that Bitcoin, no other Bitcoin node would accept my chain (even if it is longer than the first one).
Why, because the default Bitcoin software
checks the genesis block. I would call this a
checkpoint no matter what Wikipedia says and what unintuitive definition of checkpoint they use. I see no reason to exclude a fixed beginning from being a checkpoint from an abstract point of view.