The document discusses several dangers that could threaten life on Earth over different timescales, ranging from hundreds to billions of years in the future. Some of the potential dangers mentioned include an asteroid impact in Washington D.C. in 32 years, Mercury colliding with Earth in 132 years, the Sun going supernova in 929 years, Earth's temperature rising to 477 degrees Fahrenheit in 677 years, the Andromeda galaxy colliding with the Milky Way in 1.2 million years, and the universe undergoing deflation in 13.7 billion years. The document encourages the reader to learn more about each of these potential future dangers by clicking on the corresponding links.