More relativity -
Real Relativity by Einstein
In 1995, with their forthcoming 15th anniversary issue in mind, The Face magazine approached Stephen Hawking and asked him for a time travel formula. They soon received the following response by fax.
- A Brief History of Stephen Hawking: A Video Tribute (blogs.scientificamerican.com)
- Stephen Hawking Says Settle Space to Survive (abcnews.go.com)
Einstein with Einstein
Simply - Einstein