04/11/2013 01:01 pm ET Updated Jun 11, 2013

No More Men on the Moon

It has been 40 years since a man last walked on the moon, and NASA announced this week that it had no plans to send another manned mission to the moon anytime soon. If someone had told me 40 years ago that there might not be another U.S. manned mission to the moon in my lifetime I would have scoffed at their lack of vision. Hopes were high that we would be sending a manned mission to Mars within 20 or 30 years, and the moon would be our launching pad. The sky was no longer the limit.

There is, I suspect, an important lesson to be learned from all this: Technological ability does not always translate into political or economic feasibility. Scientific and technological breakthroughs happen all the time, but those advances do not always change our lives. The mere fact that we can do something does not mean that we can all do it.

Not long ago, business leaders were routinely crossing the Atlantic in well under four hours, but it has been almost ten years since the last commercial supersonic transport (SST) flight, and there's no replacement for the Concorde in sight. Supersonic technology continues to improve, but noise, pollution, and costs make it doubtful that SST service will resume any time soon.

Progress is not always linear. Fifty years ago, I remember motoring down the Des Moines River in my uncle's amphibious car and thinking soon everyone would have one. Did not happen. I have not seen one since.

Looking to the future, scientific and technological advances will make it technically feasible to boost crop yields, drill deeper for oil, extract precious minerals from the ocean seabed, mine asteroids, desalinate more water, set new speed records, and even land a man or a woman on Mars. Exciting prospects, but will they be realized on any kind of meaningful scale? Will they change lives and improve our well-being?

It's great that Tom Cruise can seriously contemplate becoming a space traveler, and maybe someone will derive vicarious enjoyment from his floating in space, but in a resource-constrained world, maybe it is time to get... real.

Scientific and technological advances have improved the human condition, but we still live on a finite planet. The sky may not be the limit for scientists or celebrities, but it is for the great bulk of humankind. And with world population increasing by another billion every 12 to 13 years, we had better find ways of living within Earth's means. The greatest challenge we face today is not finding life on other planets, it is sustaining life on this planet.

Everyone likes to think that science and technology will ride to our rescue, but the laws of supply and demand still apply. A tiny fraction of the "major breakthroughs" that are reported every years in the popular press ever achieve commercial success. Even those that do make a profit often don't produce the kind of public benefits that we anticipate.

Extraction technologies continue to improve, allowing us to mine more of the world resources, but in the past decade the prices of most metals and minerals have more than doubled. Scarcity is trumping technology.

Improvements in energy efficiency are allowing us to get more with less, but they may not be reducing the global demand for energy. Building more energy efficient cars, homes, and appliances, also makes them more affordable for consumers, particularly for the world's emerging middle class. It's called the Jevons paradox.

Technological breakthroughs may enable us to clone a woolly mammoth someday, but meanwhile poachers are using helicopters and firearms to drive the African elephant to extinction.

No one should denigrate science or the contributions that technology can make to our well-being. It's probably a good thing, for example, that NASA plans to capture an asteroid and move it to a safe orbit. What we learn from that mission may enable us someday to avert a global catastrophe.

Technology, however, may not be able to produce enough food at affordable prices to feed the projected 9.3 billion people who will live on this planet in the year 2050, and while technology will help to meet their energy needs, the transition to a post-carbon economy could be rocky. The extraction of oil from tar sands may help to meet our global energy needs, but it's an unmitigated disaster for the planet.

Science and technology are evidenced-based. Our faith in them is not.

On April 25, when the next full moon occurs, go outside and take a look up: You may see the proverbial "man in the moon," but you won't see any men on the moon anytime soon.