Schrodingers Cat is a famous thought experiment in Quatum Theory. The two major interpretations of quantum theory's implications for the nature of reality are the Copenhagen interpretation and the many-worlds theory. Niels Bohr proposed the Copenhagen interpretation of quantum theory, which asserts that a particle is whatever it is measured to be (for example, a wave or a particle), but that it cannot be assumed to have specific properties, or even to exist, until it is measured. In short, Bohr was saying that objective reality does not exist. This translates to a principle called superposition
that claims that while we do not know what the state of any object is, it is actually in all possible states simultaneously, as long as we don't look to check.
To illustrate this theory, we can use the famous and somewhat cruel analogy of Schrodinger's Cat. First, we have a living cat and place it in a thick lead box. At this stage, there is no question that the cat is alive. We then throw in a vial of cyanide and seal the box. We do not know if the cat is alive or if it has broken the cyanide capsule and died. Since we do not know, the cat is both dead and alive, according to quantum law - in a superposition of states. It is only when we break open the box and see what condition the cat is that the superposition is lost, and the cat must be either alive or dead.
now.. as regards the question of Absolute Truth.
yes, i believe that there is one, as expressed in the Diamond Sutra and the PrajnaParamita Sutras, however, this is beyond or "outside" of human conception and doesn't really help to encourage one in their practice. in the Hinyana schools, this is one of the "unthinkable" questions which was generally ignored by the Buddha when he was asked about it. one thing that Buddha insisted upon was that philosophical speculation should not interfere with ones actual practice.
i suppose that the question naturally arises "if it's outside of human conception, what is the point of asserting an "absolute"?" to which i'd reply, "that's a good question, how's your practice coming?"
the Buddhist teachings are contained in a book called the Tipitaka which literally means "Three Baskets". the three baskets are the Vinya (the rules of the monastics) the Sutras (teachings of the Buddha) and the Abidharma (metaphysics). the Abidharma is where the concepts such as "absolute" and so forth are dealt with.
in the Vajrayana schools, the Absolute Truth is beyond conceptional thinking as well, however, it's not beyond experience. this is a bit tricky and i'm a bit reluctant to say much more since partial information can easily lead someone astray... with that cavet... there is something fundamental about reality.. something "intrinsic" if you will. in our tradition this is called the Clear Light sometimes called Mahamudra. it is possible to have this experience whilst still living in this existence, though that is a bit rare. this experience is beyond the discursive intellect and if conception is imupted to it, that isn't it.
as always, my answers try to be as broad as possible when explaning Buddhist thought, though some of my own schools understanding is bound to come through. as such, there will be Buddhists that disagree