The famed British theoretical physicist Stephen Hawking died in the early hours of March 13 at the age of 76, a family spokesperson said.
Hawking, who was wheelchair-bound and lived most of his life with Amyotrophic Lateral Sclerosis (ALS), also known as Lou Gehrig's Disease, was best known for his work with black holes, quantum gravity and relativity, among other things.
The scientist also taught mathematics and physics and famously wrote the best-selling science book, “A Brief History of Time.”
Many celebrities have given their condolences to Hawking’s family, including actor Eddie Redmayne, who portrayed Hawking in 2014 in the movie “The Theory of Everything.”
“We have lost a truly beautiful mind, an astonishing scientist and the funniest man I have ever had the pleasure to meet. My love and thoughts are with his extraordinary family,” the actor said in a statement.
Read on for a look at other celebrity reactions.