Readers of a certain age can recall Christmas shopping as an almost sensual experience. City streetlights, even stoplights, blinked a bright red and green as shoppers rushed home with their treasures. The snow crunched, the kids bunched, and above all the bustle you heard silver bells.

Now, of course, all of that has been reduced to a click on your home computer. You can go shopping without going shopping, and that's just one of many things you can do without doing them.

We live at the dawn of an age in which the virtual is replacing the actual. Facebook gives us hundreds of friends we've never met. We can go to the movies without setting foot in a theater, or read a book without holding one in our hands. We can even fight wars with remote-control drones and be home in time for dinner.

One of the most intriguing things we can do is go to college without going to college. For better and worse, "massive open online courses," or MOOCs, have the potential to end campus life as we know it.

They're being offered by a growing number of the nation's top schools and being taught by some of the world's most celebrated professors. As reporter Jenna Ross pointed out in the Dec. 9 Star Tribune, it's now possible to study computer science at Harvard and mechanical engineering at Stanford from your laptop in Minneapolis.

Tuition? Not yet. These digital classes are free, at least for now, and most universities aren't yet counting them as credits toward a degree.

But the accrediting agencies are scrambling to react as MOOCs proliferate, and you can see where this is heading. Last fall, more than a million students worldwide signed up for hundreds of these online courses. Despite dropout rates that often exceed 80 percent and despite problems enforcing honor codes and evaluating student performance, the MOOC advantages are undeniable.

Start with cost, or lack of it. Even as costs rise, MOOCs are not expected to add up to the $100,000 to $200,000 price tag on a traditional college degree. Flexibility for teachers and students is another big advantage, along with the obvious productivity gain: A single professor is able to reach 150,000 students worldwide in a single lecture. Private firms are impressed by that kind of ratio, so they're busy bundling courses from top schools to create a new remote-control business model for higher education.

It's not altogether new. Correspondence courses flourished in the early 1900s, with prestigious schools like the University of Chicago promising "individual personal attention" to mail-order learners. The fad fizzled in the 1930s, but today's digital version, bolstered by interactivity, customized e-learning, cloud data storage, and social media study sessions, may have more staying power.

Not everyone is applauding. MOOCs could eventually reduce opportunities for college professors, marginalize smaller or lesser colleges, lower the overall quality of learning and eliminate the experience of college life for many. Indeed, face-to-face learning could become a luxury if MOOCs replace the traditional college experience for all but the most elite or affluent students.

In all aspects of life, difficult questions are emerging about the effect of the virtual world on the brain, on society and on human nature. Neuroscientists, economists, sociologists and philosophers are busy looking for clues.

We live at a time in which technology continues to leap far ahead of human consequences. Our own hope is that digital advances, however fabulous, will help us to hold on to the value in our analog lives -- to still hear the silver bells at holiday time and to hug our loved ones a little tighter.