science and meaning
Of course we have to be careful about replacing religion as our way of understanding the world with science as our way of understanding the world, b/c so far, science does not provide mass meaning.
Some book I read did an outstanding job of eloquating just how seriously science had failed to provide the modern era with any sense of purpose and context in the way religion does. So for the many in which science has become an obstacle to faith rather than a complement of it, there is often an increased sense of randomness and a decreased sense of meaning.
Meaning may be there for the individual scientist in so far as her life has purpose, namely she is able to serve many others through her science. But the idea that a life of service is a meaningful life is a philosophical / religious idea, not a scientific one. One could just as easily use science to obliterate others. And for those of us that enjoy the benefits of science but do not engage in it directly, we must find our meaning elsewhere, that is, if we are inclined to need a meaning for our life. (This may be a peculiar trait of some/most humans, and not necessarily an absolute in the human condition).
One principal of Christianity that I particularly admire is that a life of service is meaningful. There are many things in the faith that I cannot cling to, but this remains.