So many changes in a lifetime

Last night I finished reading Stephen Ambrose's book Nothing Like It in the World: The Men Who Built the Transcontinental Railroad, 1863-1869.  It was a bit too detailed and plodding for me to add to my recommended books category, but there were some thought-provoking passages, including this one:

[The] transcontinental railroad was called the Eighth Wonder of the World. They may have exaggerated, but for the people of 1869, especially those over 40, there was nothing to compare to it. A man whose birthday was in 1829 had been born into a world in which President Andrew Jackson traveled no faster than Julius Caesar, a world in which no thought or information could be transmitted any faster than in Alexander the Great's time. In 1869, with the railroad and the telegraph, a man could move at 60 miles per hour and transmit an idea or a statistic from coast to coast almost instantly.

In the 21st century, change is so constant as to be taken for granted. This leads to a popular question: what generation lived through the greatest change? ... For me, it is the Americans who lived through the second half of the 19th century. They saw slavery abolished and electricity put to use, the development of the telephone and the completion of the telegraph, and most of all the railroad. The locomotive was the first great triumph over time and space. After it came and after it crossed the continent, nothing could ever again be the same.

The concept of change-within-a-lifetime is recurrently brought home to me after conversations with my 93-year-old mother, who is alternately confused, bemused, and delighted with the wonders of "this modern world."  She spent her earliest years on a farm with a wood-burning stove and an outhouse, so even everyday things like barcode scanners are a source of amazement.

That's one (long) lifetime.  Now go back another one.  Someone who was 93 when she was born ("you are here" on the graph below) would have been born in 1825 - the era described above by Ambrose, when the fastest transportation was by horseback - just as it was for the Greeks and Romans.  And when the population of the entire world was less than one billion:

So what will the child born today be seeing 93 years from now?  I have no doubt the world will be profoundly different.  I'm not convinced that it will be substantially improved.