In considering the origin of the universe there are basically two possibilities; at some point either something came out of nothing or something has always existed.
The standard model holds that time did not exist before the origin of the universe. Even if we do not accept this, there is no way to limit our options to the two you suggest:
1) Time, whether expressed as the distance traversed by light or as some unit like seconds or light-years, cannot always be expressed in terms of points. In particular, a nonlinear view of "time" relative to an observer, either within our own spacetime coordinates or in some pocket universe, renders meaningless the notion that there exists a "point" in time at all or ever.
2) You note later that Krauss' abominable popular book questions the meaningfulness of "nothing". The real issue is what we mean by something, or rather what being a thing entails relative to the absence of any and all things.
3) If the universe came out of nothing, then our colloquial sense of "nothing is utterly irrelevant. To "come out of nothing" means that there is something we are either incapable or currently unable to conceptualize as that which is not "nothing" while neither being what we call "something".
It happens frequently.Fact one
Believing that something could have come out of nothing is naturally inconceivable
And these laws belong to the 19th century.because of the law of conservation of energy and the logically simple and obvious statement something cannot come from nothing
There is no real "law of cause and effect". We model causation by naively or scientifically selecting initial states and seeing what happens. In many cases, we could reverse the set of "causes" and make them "effects. Classical causality wasn't just challenged, It was completely eradicated by the removal of any absolute frame of reference, circular causality in complex systems, self-organized systems and emergence, and quantum physics.Fact two
Believing that something could have always existed is naturally inconceivable because of the law of cause and effect.
We can describe everything this way. I've addressed this before:Everything we know of works within the bounds of cause and effect
Causality is inconsistent with modern physics
and in this post I linked to several other posts on this issue I've written on this forum.
If there were any physical laws that operate at all, something must exist.Conclusion
According to the physical laws that operate in our universe and in which we live - it should be completely impossible that anything exists