A virtual world is an online community that takes the form of a computer-based simulated environment through which users can interact with one another and use and create objects. The term has become largely synonymous with interactive 3D virtual environments, where the users take the form of avatars visible to others. These avatars usually appear as textual, two-dimensional, or three-dimensional representations, although other forms are possible (auditory and touch sensations for example). In general, virtual worlds allow for multiple users.

The computer accesses a computer-simulated world and presents perceptual stimuli to the user, who in turn can manipulate elements of the modeled world and thus experience a degree of telepresence. Such modeled worlds and their rules may draw from the reality or fantasy worlds. Example rules are gravity, topography, locomotion, real-time actions, and communication. Communication between users can range from text, graphical icons, visual gesture, sound, and rarely, forms using touch, voice command, and balance senses.

Stephen William Hawking, CH, CBE, FRS, FRSA (born 8 January 1942) is a British theoretical physicist, cosmologist, and author. His key scientific works to date have included providing, with Roger Penrose, theorems regarding gravitational singularities in the framework of general relativity, and the theoretical prediction that black holes should emit radiation, which is today known as Hawking radiation (or sometimes as Bekenstein–Hawking radiation).

He is an Honorary Fellow of the Royal Society of Arts, a lifetime member of the Pontifical Academy of Sciences, and in 2009 was awarded the Presidential Medal of Freedom, the highest civilian award in the United States. Hawking was the Lucasian Professor of Mathematics at the University of Cambridge between 1979 and 2009. Subsequently, he became research director at the university's Centre for Theoretical Cosmology.

Hawking has a motor neurone disease related to amyotrophic lateral sclerosis, a condition that has progressed over the years. He is now almost completely paralysed and communicates through a speech generating device. He has been married twice and has three children. Hawking has achieved success with works of popular science in which he discusses his own theories and cosmology in general; these include A Brief History of Time, which stayed on the British Sunday Times best-sellers list for a record-breaking 237 weeks.

Neil Percival Young,OC,OM (born November 12, 1945) is a Canadian singer-songwriter who is widely regarded as one of the most influential musicians of his generation.

Young began performing as a solo artist in Canada in 1960, before moving to California in 1966, where he co-founded the band Buffalo Springfield along with Stephen Stills and Richie Furay, and later joined Crosby, Stills & Nash as a fourth member in 1969. He forged a successful and acclaimed solo career, releasing his first album in 1968; his career has since spanned over 40 years and 34 studio albums, with a continual and uncompromising exploration of musical styles. The Rock and Roll Hall of Fame website describes Young as "one of rock and roll’s greatest songwriters and performers". He has been inducted into the Hall of Fame twice: first as a solo artist in 1995, and second as a member of Buffalo Springfield in 1997.

Young's work is characterized by his distinctive guitar work, deeply personal lyrics and signature alto or high tenor singing voice. Although he accompanies himself on several different instruments, including piano and harmonica, his idiosyncratic electric and clawhammer acoustic guitar playing are the defining characteristics of a varyingly ragged and melodic sound. While Young has experimented with differing music styles, including swing and electronic music throughout a varied career, his best known work usually falls into two primary styles: acoustic (folk and country rock) and electric (amplified hard rock, very often in collaboration with the band Crazy Horse). Young has also adopted elements from newer styles such as alternative rock and grunge. His influence on the latter caused some to dub him the "Godfather of Grunge".