'A Universe From Nothing' by Lawrence Krauss, AAI 2009

"I confess that something in me tightens whenever I hear a scientist pontificating on issues that belong to the arena of philosophy or metaphysics. I will gladly listen to Stephen Hawking when he holds forth on matters of theoretical physics, but he’s as qualified to talk about philosophical and religious issues as any college freshman." The existence of the universe is very much a matter of theoretical physics and Steven Hawking, understanding this, is surely more qualified to talk about such issues than Rev. Robert Barron regardless of his opinion that they are philosophical or religious. I don't know what prompted Steven Hawking's appearance in the media with this opinion, but here is a lecture on one explanation for why the universe does not need any first cause, [this video]

Slightly off-topic, but—how mercilessly correct he is about physics of our space-time. We all know the universe is expanding, but many consequences of this phenomenon are not obvious—such as that after some time we'll be unable to see (and therefore ever reach) even nearby galaxies, since they're constantly getting farther and farther away. We'll be completely alone forever, and future scientists would have completely wrong picture about universe in such an absence of information. Thinking about that, we already miss a lot of information because of red shift… There're facts potentially explaining the eternal question ‘about universe and everything’, but they are slipping away from us, crossing the event horizon never ever to be learned about. Not a fun thing to know. Personally for me that was a discovery thanks to the explanation by Lawrence Krauss in his ‘A Universe From Nothing’ popular talk ( [this video] ).

In his famous talk "A Universe from Nothing", Lawrence Krauss makes the same point, if slightly less definitively. ("We may never know", and that's okay - [this video] ) By analogy he describes how, due to the expansion of the universe, Milky Way residents 100 billion years from now will be unable to observe the cosmic background radiation or any galaxy but our own. Civilizations wil evolve, invent science, use the best tools possible, and incorrectly conclude that the universe consists of one single galaxy alone in a vast sea of empty space. When we triply rewrite hard drives, we understand that information can be destroyed. Sometimes the universe does the samething. Sometimes information is irretrievably lost.