# Virtual Reality > ###### Central Idea > The fact that [Virtual Reality](Virtual%20Reality.md) is possible is an important fact about the fabric of reality. It is the basis not only of computation, but of human imagination and external experience, science and mathematics, art and fiction. [Computers are Physical Objects and Computation is a Physical Process](Computation%20is%20a%20Physical%20Process.md). One of the most important concepts of the theory of computation is [Universality](Universality.md). The significance of [Universality](Universality.md) lies in the fact that [Universal Computers](Universal%20Computer.md)[^1] can actually be built, and can be used to compute not just each other's behavior, but the behavior of interesting physical and abstract entities. This is is possible due to the [Self Similarity](Self-Similarity.md) that reality exhibits. The best known physical manifestation of universality is [Virtual Reality](Virtual%20Reality.md). This refers to any situation in which a person is given the experience of being in a specified environment, such as a [Flight Simulator](Flight%20Simulator.md). Because we experience our environment through our senses, any virtual reality generator must be able to manipulate our senses, overriding their normal functioning so that we can experience the specified environment instead of our actual one[^2]. We will refer to [Image Generators](Image%20Generator.md) as devices that can generate specified sensory inputs. If Bishop Berkley or the [the Inquisition](Galileo%20vs%20the%20Inquisition.md) had known of virtual reality, they would almost certainly have seized upon it as the perfect example of the deceitfulness of the senses, backing up their arguments [against scientific reasoning](Arbitrary%20Boundaries%20Beyond%20Which%20Human%20Reason%20Cannot%20Access.md). But what would happen if the pilot of a flight simulator used [Dr Johnsons Criteria](Dr%20Johnsons%20Criteria.md) in order to determine what was real? They would see that [Even a Flight Simulator Kicks Back](Flight%20Simulator.md#Even%20a%20Flight%20Simulator%20Kicks%20Back). It responds to the throttle control with [Complex](Complexity.md) and [Autonomous](Autonomous.md) calculations, just as a real engine would. It does not matter that it is a not a real engine, just as if you attempt to kick a rock and it is actually a [Holographic Projection Disguising a Garden Gnome](Holographic%20Projection%20Disguising%20a%20Garden%20Gnome.md). You have kicked *something* that is real, that has a complex and autonomous response. The feasibility of virtual reality may seem like an uncomfortable fact for those whose world view is based on science. It seems to open us up to all sorts of new ways to be mislead. But Virtual reality does not indicate that the human capacity to understand the world is limited. On the contrary, [Virtual Reality Indicates Human Capacity to Understand the World is Unlimited](Virtual%20Reality%20Indicates%20Human%20Capacity%20to%20Understand%20the%20World%20is%20Unlimited.md). --- Date: 20241201 Links to: Tags: References: * []() [^1]: Or at least good approximations of them. [^2]: This may sound like "Feelies" from *Brave New World*, but technology to artificially control human sensory experience has existed for thousands of years - look no further than paintings of humans and long distance communication.