||The planet Vulcan orbits a red star sixteen light years from the Sol system.3 The climate is generally harsh, with much of the surface consisting of large deserts4 or mountain ranges.5 Vulcan has a considerably higher gravity and thinner atmosphere than Earth.6 This gives Vulcans three times the strength of a Human.7 While externally similar to Humans, Vulcan anatomy differs radically - for instance, their heart is where a Human's liver would normally be, and beats several hundred times per minute,8 while their blood is distinctly green in colour.9 Vulcans have very sensitive ears, and their eyes have an inner eyelid which has evolved as a defence against the harsh Vulcan sun.10
Perhaps the most interesting aspect of the Vulcan physiology is the brain. The Vulcan brain is in direct control of most of the bodily functions, acting as a control unit for many organs. Vulcans have learned to gain concious control of many of these functions, allowing them to regulate their bodies to a high degree by simple willpower.11 When injured a Vulcan can go into a trance-like state, using this ability to concentrate all of his or her energy onto repairing the injury.8 Most Vulcans also have almost complete control of automatic responses such as generated by intense pain.12 The Vulcan immune system is highly developed and enables them to resist most known forms of infection or illness.
Of course the most famous aspect of the Vulcan brain is the inherent telepathic ability. Many Vulcans are natural touch-telepaths, while stronger minds are capable of non-contact telepathy, usually over short distances and in a limited fashion;13 occasionally Vulcans have emerged whose telepathic abilities are far stronger than the norm. The rigorous mental training all Vulcans are given often allows such individuals to develop such abilities as emotional compulsion and psychic image projection.14
Culturally one of the most fascinating species in the Beta Quadrant, the Vulcans were once an extremely violent and emotive people who waged almost constant warfare on one another.15 As their level of technology improved, the Vulcans eventually reached a point where their violent nature threatened species extinction. In an effort to avoid this fate, a Vulcan named Surak developed a new philosophy; Surak maintained that the root cause of all the problems on Vulcan lay in the uncontrolled outpouring of the peoples emotions. His followers swore to live their lives by an ethical system devised devised by Surak and based purely on logical principles. All expression of emotions, negative or positive, was completely forbidden.16 Although this new philosophy spread rapidly across Vulcan, a minority rejected Surak's ideals. They left Vulcan and founded colonies elsewhere - most notably on the planet Romulus, where they founded what eventually became the Romulan Star Empire.17
One of the first of the current powers to discover warp drive, the Vulcans conducted a series of survey missions in the mid 2000's. First Contact between Vulcans and Humans came in 2063 when a Vulcan survey ship detected the warp flight of Zefram Cochrane. The Vulcans met with Cochrane at his launch site on the day following the flight, and a strong relationship was quickly built up between the two species.18 Vulcan has a long history of enmity with Andoria, though the two achieved peace in 2152 thanks to Captain Archer's mediation.19 Although the Vulcans almost launched a full scale war against Andoria in 2154 the situation was again resolved in large part thanks to the efforts of Captain Archer and the NX-01 crew.20 Cooperation was furthered when Vulcan joined with the Human, Andorian and Tellarite fleets to counter a drone ship which was targeting shipping from all four species in 2154.21 In early 2155 the Vulcans were amongst those who attended an inter-species conference held on Earth with the aim of building a true alliance between the many different species.22 After the Earth-Romulan war, the Vulcans joined with their allies to form an alliance - the United Federation of Planets. The Federation was formed in 2161,23 with Vulcans, Humans, Andorians and Tellarites as the founding members.24
Today Vulcan remains one of the principal Federation members, and is deeply involved in all levels of that society.25 Despite the enmity between the Federation and the Romulan Empire, Vulcans have been attempting to forge a more cordial relationship with their cousins - ultimately hoping to reunify the two cultures. So far these efforts have met with little success.26
The Borg designation for Vulcans is Species 3259. The Borg considered their superior analytical capabilities to be a result of an enlarged neocortex.1
In the Mirror universe the first contact between Humans and Vulcans was also initiated when a Vulcan ship detected Zefram Cochrane's warp flight and landed the shortly afterwards. However, Cochrane and his accomplices immediately murdered the crew and seized the ship. Access to Vulcan equipment helped Humanity to gain a significant technological leap, conquering both the Vulcans and Tellarites within less than a century. Vulcans were treated as second class citizens in the Empire but had more freedom than simple slaves27, for instance they were still allowed to design their own ships. Vulcans were involved in the rebellion which threatened the Empire in 2155. The tide was turned when the Empire acquired the USS Defiant from our own universe.28