Disability
Hawking had a rare early-onset, slow-progressing form of MND, which gradually paralysed him over decades. During his final year at Oxford, he had experienced increasing clumsiness, including a fall on some stairs and difficulties when rowing. The problems worsened, and his speech became slightly slurred. His family noticed the changes when he returned home for Christmas, and medical investigations were begun. He was diagnosed with MND at age 21, in 1963; doctors gave him a life expectancy of two years.
In the late 1960s, Hawking's physical abilities declined: he began to use crutches and could no longer give lectures regularly. As he slowly lost the ability to write, he developed compensatory visual methods, including seeing equations in terms of geometry. Werner Israel later compared the achievements to Mozart composing an entire symphony in his head. Hawking was unwilling to accept help or make concessions for his disabilities. He preferred to be regarded as "a scientist first, popular science writer second, and, in all the ways that matter, a normal human being with the same desires, drives, dreams, and ambitions as the next person". Jane Hawking later noted: "Some people would call it determination, some obstinacy. I've called it both at one time or another." He required much persuasion to accept the use of a wheelchair at the end of the 1960s, but ultimately became notorious for the wildness of his wheelchair driving. Hawking was popular among his colleagues, but his illness, as well as his reputation for brashness, distanced him from some.
When Hawking first began using a wheelchair he was using standard motorised models, or "powerchairs". The earliest surviving example of these chairs was made by BEC Mobility and sold by Christie's in November 2018 for £296,750. Hawking continued to use this type of chair until the early 1990s, at which time his ability to use his hands to drive a wheelchair deteriorated. Hawking used a variety of different chairs from that time, including a DragonMobility Dragon elevating powerchair from 2007; a Permobil C350 from 2014; and then a Permobil F3 from 2016.
Hawking's speech deteriorated, and by the late 1970s he could be understood by only his family and closest friends. To communicate with others, someone who knew him well would interpret his speech into intelligible speech. Spurred by a dispute with the university over who would pay for the ramp needed for him to enter his workplace, Hawking and his wife campaigned for improved access and support for those with disabilities in Cambridge, including adapted student housing at the university. In general, Hawking had ambivalent feelings about his role as a disability rights champion: while wanting to help others, he also sought to detach himself from his illness and its challenges. His lack of engagement in this area led to some critics saying he was not doing enough, although White and Gribbin noted: "just by staying alive and continuing to work at the intense rate he and the world have grown used to, he is an inspiration to handicapped people everywhere".
During a visit to CERN on the border of France and Switzerland in mid-1985, Hawking contracted pneumonia, which in his condition was life-threatening; he was so ill that Jane was asked if life support should be terminated. She refused, but the consequence was a tracheotomy, which required round-the-clock nursing care and caused the loss of what remained of his speech. The NHS was ready to pay for a nursing home, but Jane was determined that he would live at home. The cost of the care was funded by an American foundation. Nurses were hired for the three shifts required to provide the round-the-clock support he required. One of those employed was Elaine Mason, who was to become Hawking's second wife.
For his communication, Hawking initially raised his eyebrows to choose letters on a spelling card, but in 1986 he received a computer program called the "Equalizer" from Walter Woltosz, CEO of Words Plus, who had developed an earlier version of the software to help his mother-in-law, who also had ALS and had lost her ability to speak and write. In a method he used for the rest of his life, Hawking could now simply press a switch to select phrases, words or letters from a bank of about 2,500–3,000 that were scanned. The program was originally run on a desktop computer. Elaine Mason's husband, David, a computer engineer, adapted a small computer and attached it to his wheelchair.
Released from the need to use somebody to interpret his speech, Hawking commented that "I can communicate better now than before I lost my voice." The voice he used had an American accent and is no longer produced. Despite the later availability of other voices, Hawking retained this original voice, saying that he preferred it and identified with it. Originally, Hawking activated a switch using his hand and could produce up to 15 words per minute. Lectures were prepared in advance and were sent to the speech synthesiser in short sections to be delivered.
Hawking gradually lost the use of his hand, and in 2005 he began to control his communication device with movements of his cheek muscles, with a rate of about one word per minute. With this decline there was a risk of him developing locked-in syndrome, so Hawking worked with Intel researchers on systems that could translate his brain patterns or facial expressions into switch activations. After several prototypes did not perform as planned, they settled on an adaptive word predictor made by the London-based startup SwiftKey, which used a system similar to his original technology. Hawking had an easier time adapting to the new system, which was further developed after inputting large amounts of Hawking's papers and other written materials and uses predictive software similar to other smartphone keyboards.
By 2009, he could no longer drive his wheelchair independently, but the same people who created his new typing mechanics were working on a method to drive his chair using movements made by his chin. This proved difficult, since Hawking could not move his neck, and trials showed that while he could indeed drive the chair, the movement was sporadic and jumpy. Near the end of his life, Hawking experienced increased breathing difficulties, often resulting in his requiring the usage of a ventilator, and being regularly hospitalised.
Hawking continued to travel widely, including trips to Chile, Easter Island, South Africa, Spain (to receive the Fonseca Prize in 2008), Canada, and numerous trips to the U.S. For practical reasons related to his disability, Hawking increasingly travelled by private jet, and by 2011, that had become his only mode of international travel.
Starting in the 1990s, Hawking accepted the mantle of role model for disabled people, lecturing and participating in fundraising activities. At the turn of the century, he and eleven other humanitarians signed the Charter for the Third Millennium on Disability, which called on governments to prevent disability and protect the rights of disabled people. In 1999, Hawking was awarded the Julius Edgar Lilienfeld Prize of the American Physical Society.
In August 2012, Hawking narrated part of the opening ceremony of the 2012 Summer Paralympics in London. In September 2013, he expressed support for the legalisation of assisted suicide for the terminally ill. In August 2014, Hawking was given the Ice Bucket Challenge—in which someone pours a bucket of ice water over their head on video, before challenging someone else—to promote ALS/MND awareness and research funding; as he had pneumonia in 2013, he did not have ice poured over him, but his children accepted the challenge on his behalf.