http://en.wikipedia.org/wiki/Bit_decay
Bit rot, also known as bit decay, data rot, or data decay, is a colloquial computing term for the gradual decay of storage media or a (sometimes jocular) explanation for the degradation of a software program over time.[1]
http://en.wikipedia.org/wiki/Link_rot
Link rot (or linkrot), also known as link death or link breaking, is an informal term for the process by which increasing numbers of links (either on individual websites or the Internet in general) point to web pages, servers or other resources that have become permanently unavailable. The phrase also describes the effects of failing to update out-of-date web pages that clutter search engine results. A link that does not work anymore is called a broken link, dead link or dangling link.
http://en.wikipedia.org/wiki/Distance_decay
Distance decay is a geographical term which describes the effect of distance on cultural or spatial interactions. The distance decay effect states that the interaction between two locales declines as the distance between them increases. Once the distance is outside of the two locales' activity space, their interactions begin to decrease.
http://en.wikipedia.org/wiki/Exponential_decay
a quantity is subject to exponential decay if it decreases at a rate proportional to its value. Symbolically, this process can be expressed by the following differential equation, where N is the quantity and λ (lambda) is a positive number called the decay constant:
http://en.wikipedia.org/wiki/Network_decay
Channel drift, or network decay [1] is the gradual transition of a television network away from its original programming focus to either target a newer more lucrative audience, or to broaden their viewership by including less niche programming. Often, these results in a shift from highbrow programming aimed at more educated viewers, toward lowbrow programming aimed at a wide audience. Almost all versions of channel drift feature some sort of incorporation of infotainment and/or reality television into a channel's lineup.
http://en.wikipedia.org/wiki/Decomposition
Decomposition (or rotting) is the process by which organic substances are broken down into simpler forms of matter. The process is essential for recycling the finite matter that occupies physical space in the biome. Bodies of living organisms begin to decompose shortly after death. Although no two organisms decompose in the same way, they all undergo the same sequential stages of decomposition. The science which studies decomposition is generally referred to as taphonomy from the Greek word Τάφος taphos, meaning tomb.
http://en.wikipedia.org/wiki/Decay_theory
Decay theory proposes that memory fades due to the mere passage of time. Information is therefore less available for later retrieval as time passes and memory, as well as memory strength, wears away.[1] When we learn something new, a neurochemical “memory trace” is created. However, over time this trace slowly disintegrates. Actively rehearsing information is believed to be a major factor counteracting this temporal decline.[2] It is widely believed that neurons die off gradually as we age, yet some older memories can be stronger than most recent memories. Thus, decay theory mostly affects the short-term memory system, meaning that older memories (in long-term memory) are often more resistant to shocks or physical attacks on the brain. It is also thought that the passage of time alone cannot cause forgetting, and that Decay Theory must also take into account some processes that occur as more time passes.[1]