# The Frontiers of Knowledge

- Institution: Gresham College
- Speaker: Professor Roberto Trotta
- Year: 2021
- Level: For everyone
- Language: English
- Subjects: Physics, Astronomy and space
- Source: [Gresham College](https://www.gresham.ac.uk/watch-now/series/frontiers)
- Licence: [Educational use (Gresham College's terms)](https://www.gresham.ac.uk/terms-and-conditions)
- Who can watch: Tweens profiles and older (sources give no ratings; placed by Invisible Network from the source's own words)

When Albert Einstein tweaked his newly invented equations of General Relativity in 1917, he had one goal in mind: to find a solution that described a closed, static, eternal universe. He therefore minted a new universal constant to make it work. After Hubble’s discovery of the expansion of the universe in 1929, Einstein reportedly declared it his “greatest blunder”. In 1998 observations of distant exploding stars brought Einstein’s "blunder" back into consideration: Einstein might have been right the first time around.

## Lectures

1. [Einstein’s Blunder](https://invisiblenetwork.ai/learn/gresham/series-frontiers/70a9129907fc) (YouTube)
2. [The Broken Cosmic Distance Ladder](https://invisiblenetwork.ai/learn/gresham/series-frontiers/c953e6eda807) (YouTube)
3. [The Future of Life on Earth](https://invisiblenetwork.ai/learn/gresham/series-frontiers/c165f62e9224) (YouTube)