I want to gently note since I see a lot of misunderstanding around Spanner and global writes: Global writes need at least one round trip to each data center, and so they're still subject to the speed of light.
It's a delicate balance based on the locations that rows are being read and written. In the case where a row being repeatedly written from only one location and not being read from different location, the writes can be significantly faster than would be naively expected.
Sure, no doubt. My point wasn't really about the particularities. It was around the mistaken idea that I see sometimes where people believe that TrueTime allows for synchronized global writes without any need for consensus.
But, yes TrueTime will not magically allow data to propagate at faster-than-light speeds.
I giggled. Good witty comment, bravo.
But when you're working on distributed systems that span the planet (say multi-master setups where ~every region can read and even write with low latency), you start thinking of the distance between your datacenters not in miles or kilometers but in milliseconds. The east coast and west coast of the US are at least 14 milliseconds apart:
% units "2680 miles" "c ms"
2680 miles = 14.386759 c ms