My life span has embraced the change from buggy whips to spaceships. Speaking of life spans and change, it would require the life spans of nearly 770 people to span the last 50,000 years of human existence, assuming that a typical life span during that time was 65 years. Of those 770 people, 600 would have spent their lives in caves or something less. Only the last 68 had any effective means of communicating with each other. Only the last six ever saw a printed word. Only the last four could measure time with precision. Only the last two used electric motors. Almost everything that makes up our material world today has been developed during the life span of the 770th person. Futurists tell us that in the world of tomorrow well vacation in resorts under the sea or on a distant planet, medical specialists will examine patients by "phon-o-vision," and well heat our homes with the energy of the sun or the power of the peaceful atom. It will be an exciting and fascinating tomorrow -- one in which many of you and your companies will not share because you refused to accept the challenge of change. Pessimists tell us that in the world of tomorrow well have to address and solve the almost impossible sociological and psychological problems of a mushrooming population. Well have to cope with the economic needs of the have-not nations. Well have to feed the bellies of billions and cultivate the minds of millions. Well have to create more jobs for more people. Well have to cope with clashes among cultures, the dangers in diversity, and the unholiness of holy differences. It will be a hectic and frightening tomorrow -- one in which many of you and your companies will not exist because you refused to accept the challenge of change. The challenge of change will make great demands on chief executives. It will demand fewer chief executives who are imitators and more who are innovators. It will demand chief executives with less glitter and more glow, with less blow and more know, with fewer buts and more guts. Chief executives will have to sharpen their ultrapreneurial vision in the world of tomorrow. They must be able to see what others cant and take risks that others wont. Their challenge will be to grasp new concepts instead of old straws. That is what will separate those who survive from those who become obsolete. When a product or a company or an industry dies, the bereaved often wonder what happened. It was only yesterday that some CEO leaned back in his genuine leather swivel chair and said something like this: "If you think Im going to change the way Ive been running this business, youve got another think coming. Ive got a healthy company and a healthy bottom line. And we owe our success to an excellent product line and my insistence on tried-and-true methods." Stupid thinking yesterday. Stupid thinking today. And stupid thinking tomorrow! Stupid because it ignores the reality that the only constant in an inconstant business world is change. Tomorrow inevitably will be different from today. With each dawn, we emerge into a new business world -- a competitive business world that forces us to adapt, keep up, or die. As we watch the panorama of change pass before us, some of us will see more than others. Some of us will have better depth perception. And some of us will scramble up to a better vantage point. Seeing the future -- and where our companies fit -- is the chief responsibility of the chief executive. Well need chief executives with 20/20 foresight seasoned by 20/20 hindsight. They should also have 20/20 insight, as well. And while theyre studying, thinking and planning, good chief executives always remember to share the credit with the employees who did the more difficult work of translating their visions into reality. Lots of people think. And lots more think they think. But thinking is only the beginning of the process. Thinking must be followed by executive execution. One way or the other. Sal F. Marino is chairman emeritus of Penton Publishing Inc. and an IW contributing editor. His e-mail address is [email protected].