Lets Do The Time Warp Again. :-D

In time travel, a paradox is any combination
of events caused by a time travel event
which is counter-intuitive and appears on
some level to be impossible. The term
temporal anomaly was coined to refer to
any disruption in the normal flow of time or
of the sequencing of events within time. It
thus includes paradoxes, but is a
considerably broader term, referring to any
event in which persons, objects, or
information travel through time in a way
that disrupts time.
There is disagreement as to whether time
travel to the future creates an anomaly or
not. Some maintain that travel to the
future is not different from the same object
or traveler being dormant or inactive for
the period of time skipped, except that it
does not age. Others observe that the total
mass of the universe must decrease during
that time, and then increase at the arrival
point, and that this coupled with the aspect
of the object not aging is sufficient to
categorize this as an anomaly. Further,
under some forms of parallel and divergent
dimension theory, the traveler to the future
leaves his own universe and enters another
even in forward time travel, and thus an
anomaly is created similar to time travel to
the past. Other forms of these theories
maintain that travel to the future does not
entail a move to another dimension,
although travel to the past always does. No
one has attached a name to such an
anomaly, and it does not threaten to create
a paradox under any theory of time. It
should be noted, however, that a return
trip to the point of origin (or any point in
the past of the traveler's temporal position)
does create an anomaly, as any other time
travel to the past would.
Under the replacement theory, there
are three major types of anomalies,
the infinity loop, the sawtooth snap,
and the N-jump. These names are
based on diagrams (reproduced to
the right) which first appeared in
Multiverser: The Game: Referee's
Rules . An infinity loop describes
usually two distinct histories which
cause each other. A sawtooth snap
refers to an unstable progression of
histories each causing the next in
sequence. An N-jump refers to any
time travel event in which the
changes to history are minimal enough that
time stabilizes into a unified sequence of
causes and effects. The term cycling
causality is sometimes used for anomalies
like infinity loops and sawtooth snaps, but
its use is not consistent.
Other anomalies include the predestination
paradox or uncaused cause, in which a
chain of events is self-sustaining because
events in the future are necessary causes
for events in the past which in turn are
necessary causes for those same future
events; and the two grandfather paradoxes
in which events in the future interfere with
necessary events in the past.
Temporal doppelgangers also occur, which
may also be called temporal duplicates,
parallel or divergent selves, or former and
future selves, depending on how they are
related to the traveler under the presumed
theory of time.