Hacker News on 31 July 2019

• Advertising Is a Cancer on Society
• A Raspberry Pi-powered live train station sign
• LightSail 2 Spacecraft Successfully Demonstrates Flight by Light
• Equifax removed the $125 claim payout option after millions submitted claims
• Filling hospitals with art reduces patient stress, anxiety and pain
• Tree planting: Where can I do it and which type is best?
• Kriegspiel
• Launch HN: Hatchways (YC S19) – Internships Instead of Interviews
• A Brief Guide to a Few Algebraic Structures
• Tokyo's audiophile venues (2016)