I was thinking to set up an Ethereum full node, but have some questions I can’t find the answers to.
Does my node have to execute every smart contract that was put in the blockchain over the past years to verify if the outcome was the same? If so, doesn’t that make the electricity cost add up a lot over time, also for the nodes in the future? From what I understand only the miner gets paid for a smart contract, but my node would have to do work too.
If I don't have to execute all those smart contracts, how does my node know what happened in the past and what the blockchain looks like now?
What happens if the data input of a smart contract was changed or isn’t available anymore? How does my node still get in sync with the rest of the network?
Thanks in advance