Newspaper circulation and magazine subscriptions have been declining for years. Why would I want to read a printed paper or magazine when I can instantly get access to whatever news they provide from thousands of sources on the Web? In fact, on the Web I can tailor my own presentation to see only the news of interest to me.

Ah, there's the rub! Our under-30 population is self-limiting the information they see to only those things they currently are interested in, be it sports, celebrity news, music or videos. I understand why this is empowering, but at the same time it is enfeebling.

They are eliminating the possibility of ah-ha! moments, when you stumble across some story on page 5 of the paper, or in one of the small sections of a magazine. When you find something you would never search for, because it's way outside your sphere of interest, or you didn't know it existed -- until you saw a compelling headline and just had to read what followed.

Here are a couple of recent examples I've experienced.

Did you know that Craig Ventner, he of decoding-the-genome fame, is working on a designer microbe that will ingest CO2 and create burnable fuel? Or that intrepid shipwreck hunters, after decades of effort, have found, deep in Lake Ontario and miraculously intact, a British war ship sunk in a storm in 1780?

The first item could portend a revolutionary approach to climate change and a possible solution to our energy crisis. The second isn't going to advance anything but makes me fell enriched just knowing about it.

I would not have known about either one of these things, or thousands of others, if I didn't take the time to read and scan newspapers and magazines. I know I'm more knowledgeable, and feel I'm a better conversationalist, because I continually encounter new information and different perspectives.

Those living online miss most if not all of these insightful encounters. Even those who do learn about current events filter the news through a prism of like-minded Web sites. They rarely see dissent to their preconceived views so they have no understanding of differing outlooks. "Hey, everyone I know thinks this way, so those who don't are ignorant subversives!"

My fear is that it will become harder to form anything even remotely like consensus on a broad array of issues. Bi-partnership, which is critical to a functional government, will become almost impossible. We already are somewhat in this situation; many people have put themselves into cocoons with self-built funnels that allow in only similar viewpoints.

So we are going at light speed (literally, since most Internet traffic moves via fiber) toward a world where we consciously decide to create millions of virtual tribes. But the movement of civilization, until this decade, was into ever larger groupings (from tribes, to city-states, to countries, to alliances), which provided leavening to help keep us from veering toward one extreme or another. The "wisdom of the group" has kept us moving forward to the betterment of everyone, but now we are splintering into tiny, restrictive groupings that refuse to let opposing information cloud their reality.

I hope our education system will respond to this challenge to a free and open society, but I have my doubts. Educators may see what needs to be done, but will their communities let them act appropriately? We instead could see a modern-day version of the Scopes monkey trial, where locals decide reality does not fit their dogma so they try to create an alternative version.

In our all-about-me world, I don't know how to put the technology genie back in the bottle. I can foresee the mythical middle of political and social moderates eroding and disappearing, with everyone polarized in one camp or another. That's not a welcome prospect.

The middle is what rights our ship and ensures the progress of civilization while the extremes promote their own narrow agendas. We must ensure the middle-ground is never lost -- by encouraging people to remain open to all points of view instead of locking themselves into echo chambers of thoughts exactly like their own.

Cartoonist Rob Rogers does "Rob's Rough," an early look at his work and his creative process, exclusively at PG+, a members-only web site of the Pittsburgh Post-Gazette. Our introduction to PG+ gives you all the details.