Oct. 31 (UPI) -- A nine-day online auction of physicist Stephen Hawking's memorabilia, including his motorized wheelchair, began on Wednesday.
Twenty-two items are up for auction by Christie's auction house in London. The wheelchair has already received a bid of over $25,000 and is expected to sell for about $215,000. Also to be auctioned are Hawking's script for an appearance on The Simpsons television program, which has received a $1,800 bid, and an invitation to a 2013 "Time Traveler's Reception," one of 100 meant to unite anyone on Earth who returned from a future time. The current bid for the invitation is $4,466.
Autographed copies, featuring his thumbprint on the first page, of Hawking's celebrated book "A Brief History of Time Travel," and copies of his 1963 PhD. thesis, are also available in the auction.
Hawking, 76, died in March. He had motor neuron disease for much of his life, forcing him to use a wheelchair and voice synthesizer. Money raised from the sale of the items will go to the Stephen Hawking Foundation and Britain's Motor Neuron Disease Association.
"We are very pleased to have the assistance of Christie's to help us with the important matter of managing our beloved father's archives and his unique and precious collection of personal and professional belongings, chronicling his life and work," Hawking's daughter Lucy Hawking said.