Tributes from around the world have poured in for Stephen Hawking.
He died peacefully at his home in Cambridge on Wednesday at the age of 76.
Scientists and world leaders honored the British physicist through social media.
British Prime Minister Theresa May described him as one of the great scientists of his generation and that his legacy will not be forgotten.
American astrophysicist Neil deGrasse Tyson tweeted that Hawking's death left an intellectual vacuum in his wake.
NASA tweeted that his theories unlocked a universe of possibilities that the agency and the world are exploring.
Known for his theories on black holes and relativity, Hawking died 54 years after he was told he would only have a few years to live due to Lou Gehrig's Disease.