The incentives to mine are: newly created coins and the transaction fees. Even when all coins are mined, the transaction fees still belong to the miner.
mskryxz: the algorithm behind Bitcoin (SHA256) is useless for "genome, dna, ai, weather modeling". ASICs are not reprogrammable, the algorithm in them cannot be changed.
I am asking when all 21 million coins are found though....who's going to mine then?
Blockchain is a distributed
ledger book. The blocks created by miners are
pages written to that ledger. Every block contains number of transactions and that transaction may include fee. There is a special transaction in every block, that sends newly minted coins AND the fees to the miner who found the block. The newly minted coins are now 25.0 BTC and will gradually diminish until 2040. The fees on the other hand used to be zero, but are gradually rising as more and more transactions are included in the blocks. Now the average fees per block are about 0.1 BTC. So the incentive to mine for new coins will be declining, but the incentive to mine for fees will rise. That is what miners will mine for - they will continue confirming transactions and securing the Bitcoin network for a fee built in the Bitcoin protocol.