10 - Turing machine and script UTXO

10 - Ethereum

Questions

2. to speed up PoW
   • use dedicated hardware that is ASICS
3. What Bitcoin names as stale blocks can matter in Ethereum as
   • ommers

Turing

• important mathematician that cracked the Enigma machine in 1939 and then in 1942
• he was a genius
• inventor of Turing machine
  • theoretical
    • it can model any computer nowadays
  • it consists of:
    • a line of cells that can be moved back and forth (tape)
    • an active element with a state (head) that can chenage the properti (color) of the active cell underneath it
• halting problem

Turing-completeness

• If a computing language is not Turing-complete, it can solve only a subset of problems that other Turing-complete languages can do
• examples TC: C, Java, Python…
• examples TNC: SQL, HTML, CSS and Script

Script

properties and limitations:

• Lack of Turing completeness
  • No loops
• Value blindness
  • No way for an UTXO script to provide fine-granular control over the amount to be withdrawn
    • Because UTXOs are “all or nothing”
• Lack of state
  • UTXOs are either spent, or unspent
    • No half-spent, on-the-way, conditionally accepted…
• Blockchain-blindness
  • UTXOs are unaware of the block they are in, the timestamp, the previous block hash, …

Withdrawal limits are not possible with Script