I'm two chapters into this story and strangely enough, it appears to be an appropriate submission to HN. Petunia ends up marrying a scientist (not that he or she or all the relationships are perfect or even great), and a "
rationalist!Harry enters the wizarding world armed with Enlightenment ideals and the experimental spirit".
And it's funny (ADDED: very funny). A few too many slightly long digressions on "rationality", but worth a look, I think.