This document outlines four principles of open science: (1) open access to literature from funded research, (2) access to research tools from funded research, (3) putting data from funded research in the public domain, and (4) investing in open cyberinfrastructure. The principles aim to make more scientific knowledge accessible and reusable by removing legal and technical barriers to accessing and sharing published literature, research materials, data, and infrastructure. Adopting these open science principles could help advance new discoveries by allowing ideas and information to flow more freely between researchers.