On this day in 1618, Johannes Kepler confirmed his Third Law of Planetary Motion: The square of a planet’s orbital period (T²) is proportional to the cube of the semi-major axis of its orbit (a³). The modern Newtonian derivation: > Equating gravitational force to centripetal force > Substituting orbital velocity v = 2πr/T > Resulting in T² / r³ = 4π² / (GM) The log-log graph confirms the relationship holds for planets in our Solar System. A foundational law that bridged empirical observation with gravitational physics.

Maryna Viazovska (Ukraine/Switzerland) She solved the sphere-packing problem in 8 dimensions. What’s the densest way to pack identical spheres? In 8D, the E₈ lattice is optimal. Her proof used modular forms with Fourier analysis. (Kepler’s 3D version took 400 years!)

NEWS: The FCC upheld exclusive rights for established satellite companies in key radio frequencies and rejected applications from SpaceX, Kepler, Sateliot, and AST SpaceMobile. The bands in question (Big LEO at 1.6/2.4 GHz, 2 GHz, and L-band) have long been reserved for traditional satellite phones. Companies like Globalstar and Iridium have invested about 28 billion dollars building systems there. The FCC ruled these lanes stay exclusive to the current owners for now, citing interference risks as satellite-to-phone technology grows. The decision blocks part of SpaceX’s plans to use those same frequencies for independent Starlink direct-to-cell service. SpaceX’s main U.S. partnership with T-Mobile uses entirely different spectrum and remains fully on track.​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​