Quotes from Henry Petroski

Yet the bookshelf is also conspicuous in its absence. When we enter a living room without books or bookshelves, we wonder if the people in the house do nothing but watch television.

That decision falls to scientists, engineers, and managers—with at least the tacit approval of company officers and boards of directors. All complex technology is inseparably coupled to an equally complex team of people and systems of people who should interact with one another as smoothly and with as clear a purpose as a set of well-meshed gears.

Some positive persisting fops we know, Who, if once wrong, will needs be always so; But you, with pleasure own your errors past, And make each day a critic on the last. —Alexander Pope, An Essay on Criticism

Yet the bookshelf us also conspicuous in its absence. When we enter a living room without books or bookshelves, we wonder if the people in the house do nothing but watch television.

Engineers ... are not superhuman. They make mistakes in their assumptions, in their calculations, in their conclusions. That they make mistakes is forgivable; that they catch them is imperative. Thus it is the essence of modern engineering not only to be able to check one's own work but also to have one's work checked and to be able to check the work of others.

Failure analysis is as easy as Monday-morning quarterbacking' design is more akin to coaching. However, the design engineer must do better than any coach, for he is expected to win every game he plays. That is a tough assignment when one mistake can often mean a loss. And when defeat occurs, all one can hope is to analyze the game films and learn from the mistakes so that they are less likely to be repeated the next time out.

This cartoon scientist wants to look, act, and think like Einstein: casually and comfortably dressed, if not somewhat unkempt and disheveled; unconventional, but in a curiously impish and self-conscious way; irreverent and individualistic, except when it comes to dressing in a nonuniform uniform and championing his specialty.

It is the process of design, in which diverse parts of the "given-world" of the scientist and the "made-world" of the engineer are reformed and assembled into something the likes of which Nature had not dreamed, that divorces engineering from science and marries it to art.

Galileo's analysis of the cantilever beam illustrates an extremely important point for understanding how structural accidents can occur: he arrived at what is basically the right qualitative answer to the question he posed himself about the strength of the beam, but his answer was not absolutely correct in a quantitative way. He got the right qualitative answer for the wrong quantitative reason.

Betting on the success of innovative technologies in the marketplace can carry all the uncertainty and risk that betting on the next card in the deck does at a blackjack table in Las Vegas. There is a factor of randomness that must be factored in, but precisely how to do so is anyone's guess.

The space shuttle was designed, at least in part, to broaden our knowledge of the universe. To scientists, the vehicle was a tool; to engineers, it was their creation.

As engineers, we were going to be in a position to change the world - not just study it.

Typically, highway bridges have about 50 years. But over in England, they have iron bridges approaching 250 years. In France, there are Roman aqueducts that are approaching 2,000 years old. So a bridge can last a very long time if it's built properly in the first place and then maintained properly.