Sheesh. I can point out a few discrepancies in that correspondence with the 'Young Girl'. She obviously has no working knowledge of science, and is still trying to bring it in. Albert Einstein never said 'every action has an equal and/or opposite reaction'. Newton did. And it's not and/or it is and. Also, opposite reaction does not mean 'less reaction' as she says. Plus, Newtonian physics does not include all circumstances. And Newtonian physics is for particles, chemistry is different.

Apart from that, the statement 'energy can neither be created nor be destroyed' is only true in 'classical' physics; E=mc^2 talks about exactly this, and this is how nuclear reactions take place.

Also, eminent physicist Sir Stephen Hawking HAS talked about effects before causes.

There was no time before Big Bang, she obviously doesn't know that. And mention cosmic background radiation to her, in relation to Big Bang.

And you went wrong at a point saying Stephen Hawking says Univerese has no origin. His life's work is based on Big Bang. Please read his 'Brief History of Time' carefully. BTW, for that girl, tell her to hang on until 2007-08, because Sir Stephen will publish a book for kids (with help from his daughter) about the origin of the universe.

Universe is infinite was chucked out of the window long ago. Point out to her that this was first done by a Christian priest, later taken up by Edwin Hubble (universe is expanding...)

Did I mention I'm an atheist?

I guessed that you are an atheist.

In fact, though I don't mean this to sound as harsh as it does, I feel that letters like yours are part of the reason that theists have such a resistance to discussion with atheists. You come across as very condescending as self congratulating. Your statement that the correspondent has "no working knowledge of science" sounds nasty both because it is untrue (much of her knowledge of science is just very basic and outdated) and because it ignores the fact that, despite her ignorance on this topic, she is apparently making a sincere effort to increase her knowledge.

I agree with most of your points about the science of the correspondent -- in fact, I pointed out most of these things in my responses. Other inaccuracies I didn't think worth pointing out as they were not germane to the conversation. Our disagreement about Stephen Hawking may be one of vocabulary, in that he speaks of a finite unbounded space in which our universe exists, and that space can also be referred to as the universe. This allows for the big bang to occur within a universe that does not require anything outside of it. The statement "there was no time before the big bang" is also a very complex one, so I'd say that your seemingly condescending statement about her "not knowing that" is misplaced.

My point here is that yes, it's fun to be able to pick apart the arguments of uninformed theists, but that should not be a goal of atheism. Discussions of this sort should be conducted in a way that helps others see why atheism makes sense, not in a way that makes them feel attacked or badgered, or that makes them want to avoid atheists in the future.