Human history has been characterized by an accelerating rate of
technological progress. It is caused by a positive feedback loop.
A new technology, such as agriculture, allows an increase in population.
A larger population has more brains at work, so the next technology
is developed or discovered more quickly. In more recent times,
larger numbers of people are liberated from peasant-level agriculture
into professions that entail more education. So not only are there
more brains to think, but those brains have more knowledge to work
with, and more time to spend on coming up with new ideas.
We are still in the transition from mostly peasant-level agriculture
(most of the world's population is in un-developed countries), but the
fraction of the world considered 'developed' is constantly expanding.
So we expect the rate of technological progress to continue to accelerate
because there are more and more scientists and engineers at work.
Assume that there are fundamental limits to how far technology
can progress. These limits are set by physical constants such as
the speed of light and Planck's constant. Then we would expect that
the rate of progress in technology will slow down as these limits are
approached. From this we can deduce that there will be some time
(probably in the future) at which technological progress will be at
it's most rapid. This is a singular event in the sense that it happens
once in human history, hence the name 'Singularity'.
This is my definition of the concept. Vernor Vinge, in his series
of stories 'The Peace War' and 'Marooned in Real Time' had a different
definition. He implicitly assumed that there was no limit to how
far technology could progress, or that the limit was very very high.
The pace of progress became very rapid, and then at some point
mankind simply disappeared in some mysterious way. It is implied that
they ascended to the next level of existence or something. From the
point of view of the 20th century, mankind had become incomprehensively
different. So that time horizon when we can no longer say anything
useful about the future is Vinge's Singularity. One would expect
that his version of the Singularity would recede in time as time
goes by, i.e. the horizon moves with us.
I'm more inclined to agree with Venge here, not that we will disappear or ascend perhaps but that we will reach a point where even death is just like blinking, no longer held in fear, we live in light and love. perhaps this will happen in 2012, i don't know and it would be crazy to say that it's a certainty but it certainly feels like humanity is preparing for something. and it's a good an ideal to aim for as say, walking on mars. as events around us spiral out of control, our inner minds must be empty of fear.