Shrink Pods for the Bitcoin Bus

Extending the ‘Crowded Bus’ Analogy of Bitcoin’s Block Size

The best argument for big blocks is, in my opinion, the Bus Analogy:

The (Bitcoin) Bus has a combination of qualities that has led demand for passage on it to exceed its capacity. Unfortunately, hopeful passengers outbidding each other for ever-pricier tickets can never lead to them all getting a ride.

The Bus, Full

Let’s say The Bus holds no more than 5 passengers. This is extremely frustrating for us who love riding The Bus because we want more people to also enjoy it.

Some of us are saying “More Decks!”, urging the Bus Makers to upgrade capacity to 10.

Modified for More Decks

Instead, most Bus Makers are installing racks of unusual seats. This seemingly elaborate upgrade probably only increases capacity to 8.

However, the true benefit of the new seats is that they also fit Shrink Pods. Exactly the forms these Pods will take is still being determined, but the spoon-shaped seats are there to accommodate them when they’re ready.

Each Pod will shrink a crowd of passengers into the space of a single seat, to be carried and delivered to their destination in the same condition as regular passengers.

Modified for Shrink Pods

In contrast, the “More Decks” strategy expands the bus only for regular passengers - and hinders installation of Pod seats. With each new regular seat, passenger numbers would increase at a linear rate, while the comparative advantage of using The Bus diminishes.

For a concrete example of the “More Decks” approach failing, think of Bitcoin with full 1 Terabyte blocks in the near future. Paypal, Visa, Venmo, and World of Warcraft can handle that scale of transaction load with efficient databases on hierarchical, centralized networks. Bitcoin could handle those blocks by running in data centers. It might still be better than Visa for privacy, and better than Auroracoin for marketplace acceptance, but its base layer would no longer be peer-to-peer money. We could further extend the Bus analogy and call existing centralized solutions ‘cruise ships’. A cruise ship with thousands of passengers is worse for a commuter than is our dear Bus, but it’s more generally useful than a cruise ship-sized bus!

Before The Bus becomes more cumbersome than a cruise ship, we would all cry out for Shrink Pods. But would The Bus still be receptive to that upgrade, or did we miss the opportunity?

Right now, Bus Makers can add the Pod seats and only a few disgruntled pedestrians will protest. But if the bus has 100 seats, still no Shrink Pods, and has once again reached capacity, I expect Bus Makers will choose to add yet another deck for regular passengers. Their alternative is to anger throngs of important (stability-minded) passengers while they retrofit Pods onto the increasingly colossal Bus.

Bitcoin’s Scaling Future

Shrink Pods — Segwit, Lightning, Sidechains, and other Layer 2 Solutions — are rightly a top priority for most Bus Makers. Importantly, Pods will have a multiplier effect; When The Bus expands, as it probably must, each new seat could hold a crowd.

Then everybody gets a ride.