Quote Origin: I Don’t Think the Human Race Will Survive the Next Thousand Years, Unless We Spread Into Space

Stephen Hawking? Alvin Toffler? David Deutsch? Apocryphal? Question for Quote Investigator: Humankind currently inhabits only one small fragile planet, and the perils on Earth continue to grow. A prominent physicist once insisted that humankind must expand into space in order to survive the next thousand years. I am not sure of the exact phrasing. Would …