Ask anyone to list any number of technological developments; chances are that they won't list developments that haven't actually occurred yet.
The problem with looking into the future is not that the future is distant or as-of-yet unexperienced, but that it's genuinely inconceivable. We can't really predict the unlikely events that will snowball into large changes or the technological developments that will come into being. We don't know what kind of devices will be invented, because if we did, we would have already invented them!
This is the gap in reasoning among people who question the economics of supporting public science research or space initiatives. Quite often, such programs are so valuable because they encourage general research that spills over into a wide array of new inventions discovered seemingly accidentally. No one planned that the funding of a space program would bring into existence cochlear implants, Dustbusters or memory foam; no one ever established a research program looking for a cosmic microwave background that no one knew was there, and no one ever asked a chemist to combine and taste random chemicals until he found our now expansive variety of artificial sweeteners.
Most scientific
discoveries are frankly accidental, or to put it more nicely
"unplanned." But in a sense, it being otherwise would be impossible as
that would imply that we already knew the about the discovery before it
happened. So dealing with future research is an issue of uncertainty,
but the pattern is that controlled tinkering with reality produces a
deeper understanding of the nature of the universe and thus a wider
plane of knowledge on which to base new inconceivable developments; many
of these leaps in knowledge consist in something unexpected and
earth-shattering that simply can't be predicted and previsionally added
to a cost-benefit analysis of research funding.
Because future developments are simply out of our awareness, it's natural that all people at all times would mistakenly think that there are no more inventions to invent or improvements to make to society or our knowledge of science. Our view of the universe has expanded from a solar system to a whole galaxy to a seemingly endless universe with commentators at every step of the way saying, "Well we got it all figured out now!" It's reminiscent of the story of the US patent officer who allegedly resigned because he felt that "there was nothing left to invent;" it's not really a true story, but it does reflect our constant inability to preview our own development.
Strangely enough, although development seems to be due to many unforeseeable and random occurrences, some kinds of technological and economic changes seem relatively stable in their capriciousness. Moore's Law is a good example; the law predicts that integrated circuits will be able to manage twice as many transistors every two years or so, a prediction that has been stable for the past 40 years thanks to a variety of unpredictable developments. Plotted logarithmically, a fairly straight trend line can be observed. Of course, even this kind of technological trend may not be a perpetual development; many are foretelling its demise within the next decade, but there always looms the possibility of new inconceivable developments that will keep the trendline straight.
In the economic sphere, disaster has always been on the tip of many tongues and the idea is always present that innovation will cease and we will be unable to sustain continuing growth. These feelings ran even higher during the Great Depression, when a seemingly mad Joseph Schumpeter confidently predicted that the capitalist engine of production would continue an average GDP growth of 2% every year for the next 50 years (not without short-term variation). He was betting on the continuation of innovation and invention that he couldn't conceive of, but as it ended up, his 2% projection wasn't bold enough to match the growth we've actually realized.
It's suiting that Schumpeter was the economist to make this prediction as most of his work in economics was focused on the fundamentally unpredictable yet inevitable improvements in economic efficiency and production. Granted he or anyone else couldn't have known the precise nature of new development as it's difficult to explain our new technology to anyone only several decades in the past, even if the trends may seem smooth.
In popular culture, there's frankly a lack
of reasoned faith in development and discovery. We can reasonably
expect in the future that there will be more inconceivable technological
innovations and more bold and efficient economic ventures. It doesn't
appeal too much to our critical pessimism, but society is in a flux of
improvement, seemingly frightening scientific studies bring us closer to
a better standard of living, our use of fuel is ever more efficient,
our technology ever more accurate and at some level we should
acknowledge this.