This question already has an answer here:
I'm new to this community and a Bitcoin novice.
I believe to have understood the concept and purpose of proof of work but also, that the high energy consumption of proofs of work is a major problem of the Bitcoin (and other blockchain based) systems.
The puzzle that need to be solved for the proof of work has to be complex:
- computing the cryptographic nonce (as used in the Bitcoin system)
- solving complex differential equations
- operations on dense matrices
I wonder if my impression is correct that these puzzles' only purpose is to provide authentication, esp. for the right to mine new bitcoins - and that they are otherwise "useless".
More than that I wonder if there are attempts to define complex proof of work puzzles that fulfill other purposes that are more beneficial/useful/valuable to - let's say society - which would justify the high energy consumption.
You may compare this with Google's ReCAPTCHAs that next to authentication "assist in the digitization of books or improve machine learning".