We'll largely skip over the author's fixation on casual nudity.

When trying to understand attitudes toward and expectations for technology in previous eras, one needs to be especially cautious about relying on science fiction writers. Though they initially appear to be the richest source on the subject, numerous factors combine to make them unreliable. Most were attracted to the field by a fascination with the more dramatic aspects of the future and these tendencies are greatly heightened by working in a genre where the object was often to out geewhiz the next guy.

That said, it's a mistake to ignore them entirely, both because of the close relationship between the scientific and the science-fiction community, and because of the influence SF has played on the way we think about technology today either directly through books, film, television and indirectly through writers who alternated between science fact and science fiction (Asimov, Clarke, and to a degree, Willy Ley and Carl Sagan).

This mid century essay by Robert Heinlein on his predictions for the year 2000 is worth a look for a number of reasons. First, people did tend to take the man seriously in the postwar era. Though his standing has arguably declined somewhat at least relative to contemporaries like Asimov, at his peak, he was the best known and best respected hard science fiction writer among mainstream audiences. (Bradberry also had significant mainstream following, but even when writing about spaceships and aliens, his work tended to fall more in the category of fantasy).

Second, this essay is of particular value because the author not only makes a great number of detailed predictions (including a notable amount of time spent on the appeal of socially acceptable nudity), he also explicitly spells out the assumptions that underlie much of the period's attitudes toward the future. He even states his axioms and provides a handy graph of human advancement.

As a serious attempt at describing the rate of progress, this picture is fatally flawed. The year 1900 came at the end of a huge technological and scientific spike. Extending it back a couple of decades would have completely thrown off the curve. (Interestingly, you actually can justify an exponential curve describing progress in the 19th century.) Furthermore, it is difficult to argue a steady acceleration from the naughts to the teens, the teens to the 20s, and the 20s to the 30s.

This graph, however, is tremendously revealing when it comes to the ways people in the 1950s thought about progress. Like the end of the 19th century, the postwar era was a period when conditions lined up to cause a number of very steep S curves to cluster together. The result was a time of explosive, ubiquitous change. There was also, as mentioned before, a tendency to look at the two world wars and the interval between (particularly the Great Depression) as anomalous. It was natural for people in the postwar era to see themselves as living on an exponential slope that was on the verge of shooting past the comprehensible.