According to Merriam-Webster, the term "nuclear family" was coined first in 1947. Because of its Cold War origins, the phrase has several layers of meaning. In an atom, the nucleus is tightly packed and contains only two types of particles, which might be considered analogous to the expected male and female roles within the family.
In a solid, the atoms are rigidly structured, much like suburbia in the 1940s (and today). However, outside of the nucleus, the electrons are most likely moving in a certain area most of the time. Young, newly formed families were moving far away from their kin, much like the particle movement in an atom.
The other layer is the explosive potential demonstrated by the atomic bomb only two years before the term was coined. Here, energy is generated by a particle hitting the nucleus of an atom, which induces a change in the nucleus. More on that here. During the 1960s and 70s, social movements started challenging this newly minted convention.
Returning Vietnam veterans and war protesters deepened the generational divide, women's rights became a visible issue and the Cold War dragged on. All of these factors were like particles rushing towards a nucleus to bust it open. With all these changes, typical family structures became, well, not so typical. Thus, the post-modern family was born.
Nowadays, some believe that non-nuclear families provide unsuitable environments for childhood development. I find this generalization simplistic. It assumes both that the entire concept of home is rooted in the Rockwellian vision of the nuclear family and that the households that don't fit into this vision do not -- could not -- provide the same things. Granted, there are some parents who cannot, either by choice or circumstance, but many of my beautiful friends grew up in single parent households or are raising children as single parents. They work harder and sleep less than any other group of individuals I know, and they do it all for their kids.
There's also another component to family that hasn't even been mentioned. To quote Eustache Deschamp, "friends are the relatives you make for yourself." Both my blood relatives and friends are beautiful, messy and imperfect and have taught me that love and home come in different shapes and forms. They have supported me while I learned the difference between love that inspires growth and love that burns away the edges of what you love about yourself. They have comforted me and helped me build back the singed parts with a stronger foundation. Love is everything.
Today's title comes from Paul Simon's "Love Me Like A Rock." When my family went on car trips, my dad would spend hours beforehand making mix tapes for different parts of the drive. Because all of us knew all of the lyrics to most of Paul Simon's songs, either a song or an album usually cycled through the mix during the trip.
Full disclosure: the first part of this post was adapted from an essay on the role of "Sesame Street" as a (seriously) post-modern family structure.