If energy spent produces only heat, how do you explain the existence of a persistent block afterward? What physical process made that block real?
Why can every node instantly reject an invalid block ...
> Why can every node instantly reject an invalid block without redoing the work?
Because it takes a massive amount of compute to brute force the output of a hash function to have a long string of consecutive leading zeros (aka POW), and it takes very little compute to verify cryptographic signatures and hash outputs.
That's why they're sometimes referred to as "trapdoor functions."
Regarding where the energy goes, consider a solo mining rig that never finds a block. It heats the house, it doesn't magically condense the physical energy into "digital energy."
Because it takes a massive amount of compute to brute force the output of a hash function to have a long string of consecutive leading zeros (aka POW), and it takes very little compute to verify cryptographic signatures and hash outputs.
That's why they're sometimes referred to as "trapdoor functions."
Regarding where the energy goes, consider a solo mining rig that never finds a block. It heats the house, it doesn't magically condense the physical energy into "digital energy."
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