The author's kids (not pictured) are getting older, and he says his role as a parent is changing. emholk/Getty Images When our two kids were little, my wife and I were needed for everything. Every snack, every bedtime routine, every scraped knee, every middle-of-the-night wake-up. Our days revolved around the rhythm of theirs. Now my daughter is 11, and my son is 9, and something has changed. They still need us, of course, but not in the same constant, physical way. Increasingly, their lives exist just beyond the edges of ours. They spend more time with friends. They ride bikes around the neighborhood without us. They close their bedroom doors for alone time. Sometimes they disappear outside for hours and come back only when they're hungry (which in the age of screens and distraction, is amazing). I knew this stage was coming, but I wasn't prepared for how strange it would feel while living inside it. Parenting has become less physical and more emotional When kids are small, parenting is tangible.…