Cave Johnson is the founder and CEO of Aperture Science.
In 1943, Aperture Science was founded by Cave Johnson, as a shower curtain manufacturer. In 1956, the Eisenhower administration signed a contract with Aperture to manufacture shower curtains to all branches of the US Military, except the Navy. That was the main activity of Aperture Science from 1957 to 1973. During that period, Johnson became a billionaire. He then found a way to make a miniature Black hole. He used it to make the Aperture Science Handheld Portal Device. He made sure that it was a convention by inventing his testing spheres (found and played through in Portal 2 Chapter 7)
In 1974, Johnson was exposed to poisons while secretly developing Gels to add different physics to his testing spheres. He was poisoned when he was developing Conversion Gel, which makes a non portable surface portable.
In 1976, both of Cave Johnson's kidneys failed. Brain damaged, dying, and incapable of realizing time was not flowing backwards (thus realizing his time would come soon), he laid out a two tiered research and development program. The results, he said, would "guarantee the continued success of Aperture Science far into the fast-approaching distant past". The two first tiers (the Heimlich Counter-Maneuver and the Take-A-Wish Foundation) were a failure. What happened to Cave Johnson afterward is unknown, although it is surmised he died.
- A call cheet confirms that he is dead, and that he has just been resurrected inside of a computer, which oversees the tests made during the game, and sometimes "contemplates the afterlife".
- Bits of Johnson's personality and skills follow: he is said to have learned to trust his gut. A big picture thinker, he does not expands on details. He apparently does not really know how science works, but he knows how people work. He is used to getting what he wants. He is extroverted, enthusiastic and opinionated. He is very energetic, and considers that life is an adventure he is happy to be on. He was born salesman, he is a leader, an evangelist. People trust him, even when his plans are clearly dangerous. He uses warm, homespun delivery to put people at their ease. He does not accept the responsibility that comes with his power. Either he does not see or chooses not to see the ramifications of his actions.
- The call sheet also states he speaks with a slight Southern/Western accent, mirrored in the text excerpts and the texts revealed during the Portal ARG.
- Through the game, he is said to go from a sidekick to the main antagonist, starting to lose his grip on his humanity as the story progresses. As he isolates himself from the people around him, he is to lose touch with reality.
- In the file dump retrieved at the BBS number (425) 822-5251 revealed during the Portal ARG, several memos seemingly written by Cave Johnson can be found. In one, he describes the three pillars on which Aperture Science is built. In another, he addresses Test Subjects who raised their concerns about the dangers of the research conducted by Aperture Science. Another consists of a rant about casualty rates, firing employees, and him practicing beekeeping in his office. In another, reusing text from the casting call sheet revealed in 2008, he apparently announces his death. One is apparently the answer to a (confidential) letter Johnson sent, titled "Human Enrichment & Testing Initiative, Resource Acquisitions". It apparently describes the four types of Test Subjects and their behavior, in a not very human way.
- On ApertureScience.com, "1978" and "1979" were originally given as the date for Johnson's poisoning and kidney failure, respectively. These dates were later retconned to 1974 and 1976, as seen in the updated Aperture Science timeline on Game Informer.
- "Johnson" is quite similar to "Johanson", the name of the original Borealis captain, Johanson. Furthermore, "Arbeit Laboratories" can be seen on some crates inside the ship. The retail Borealis belonging to Aperture Science, it is possible those names were recycled.