BLOCKCHAIN & WEB3 FUNDAMENTALS - Chapter 9, Exercise 1 Solution ========================================================== Why "Just Make Blocks Bigger and Faster" Isn't a Free Fix PROBLEM ------- A colleague proposes: "Just increase Bitcoin's block size and shorten the block interval — problem solved." Using this chapter's own scalability trilemma, explain the real trade-off this proposal doesn't account for. SOLUTION -------- Making blocks bigger and coming more often really would increase raw transaction throughput - that part of the proposal is technically correct. But the trilemma this chapter describes says a design tends to strongly deliver on only two of decentralization, security, and scalability at once, and this proposal doesn't get scalability for free - it trades it against decentralization. Every full node on the network has to download, store, and verify every single block to independently participate and enforce the network's own rules (a genuinely important part of why the network doesn't need a trusted central party at all, going back to Chapter 1). Bigger blocks, arriving more frequently, mean a much larger, constantly growing amount of data that every node has to keep up with. Someone running a full node on ordinary home internet and modest hardware - exactly the kind of participant that keeps the network genuinely decentralized rather than controlled by a small number of well- resourced operators - would find it progressively harder to keep pace as blocks grow larger and arrive faster. Over time, this tends to push smaller, less-resourced participants out of running their own full nodes, concentrating the ability to fully verify the chain into fewer, larger, better-resourced operators. That's a real, direct erosion of decentralization, even though it wasn't the proposal's intent - it's a structural side effect of larger, more frequent blocks, not a mistake that better engineering alone could avoid entirely. ANSWER: Bigger, more frequent blocks would genuinely increase throughput, but at a real cost to decentralization - larger, more-frequent blocks make it progressively harder for smaller, less well-resourced participants to keep running their own full nodes, concentrating verification power into fewer hands rather than scalability being a free improvement with no trade-off at all. ---- WHY THIS WORKS AS AN ANSWER This correctly applies the trilemma's own logic - scalability isn't free, it's traded against one of the other two properties - and identifies the specific real mechanism (rising node resource requirements) through which bigger/faster blocks concretely erode decentralization.