Dr. Stephen Hawking was born in 1942 in England and spent most of his life without being disabled. He received a Ph.D. in physics after studying math and physics. At the age of 21, Dr. Hawking was diagnosed with Amyotrophic Lateral Sclerosis (ALS), also known as Lou Gehrig's disease in the United States. The loss of motor neurons in the brain causes messages to muscles in the body to be disrupted as ALS advances. Muscles atrophy over time and voluntary control of muscles is lost. As a result of ALS, Dr. Hawking received assistance for most movement and was unable to speak without the aid of a computer. This presented a problem because as a researcher and scientist Dr. Hawking was regularly asked to speak at meetings and conferences and had to develop and publish new ideas to maintain a place at the forefront of academia. Dr. Hawking used assistive technology to compensate for mobility and speech difficulties. He used a thumb switch and a blink switch attached to his glasses to control his computer. By squeezing his cheek muscles and "blinking" an infra-red switch was activated and he was able to scan and select characters on the screen in order to compose speeches, surf the Internet, send e-mails, and "speak" through a voice synthesizer.