SITUATION EXPLAINED: Anthropic's Tom Brown says innovation has always been bottlenecked by how many smart people we have. That's about to change. • His three opening points: there's no wall, demand is exponential rather than just fast, and the buildout is bigger than the railroads of the 1800s • The 2019 scaling laws paper is when 50-year timelines became under 10 for him. The trend held over eight orders of magnitude then, and 15 now • Lutnick asked what G20 countries need to do to share in…