There may be another way for the universe to cause itself to begin to exist, but this way will be found dubious by many since it involves backward causation. None the less, some cosmologists, such as John Wheeler, claimed that the big bang, the first state of the universe, is backwardly caused by cosmologists observing the big bang. Wheeler’s theory makes little sense to me, unless we presuppose some sort of subjective idealism where past time and the universe itself is a creation of the human mind.
But we can have a universe that is backwardly caused to begin to exist on a theory of metaphysical realism… The atheist need not repose too much weight on the assumption that backward causation is really possible, since she can always deny its possibility and say the universe caused itself to begin to exist in the first way (via a simultaneous causal loop) or in the second way (via a half-open interval of instantaneous and causally connected states of the universe). 
- http://www.qsmithwmu.com/the_reason_the_universe_exists_is_because_it_caused_itself_to_exist.htm [↩]