It is fitting that the first plane to fly around the world entirely powered by solar energy has done so almost a century after the great exploratory plane flights began.
The long-distance flying missions took place in the two decades after the end of the Great War, when flight technology was sufficiently advanced to allow big distances to be covered and when countries were sufficiently peaceful to accommodate such efforts.
The most famous such flight was by Charles Lindbergh, who in 1927 became the first person to cross the Atlantic solo.
But the long distance flights that began in 1919 typically involved multiple short flights over a long period of time. Even by 1931, when Wiley Post and a navigator circumnavigated in eight days, they had to stop more than a dozen times.
The Solar Impulse 2 flight, that made history yesterday when it landed in Abu Dhabi, was a return to that tradition. The plane made 16 stops on its 25,000-mile journey, that took more than a year.
Travel has become so easy now that we can all be on the far side of the globe, to places such as Australia or New Zealand, in under a day.
This solar powered journey has been a reminder of the vast distances that are involved in such journeys.
It has also been a thrilling illustration of the advances of science, amid so much bad news of war and terrorism and economic uncertainty and fears about fuel security.
The Swiss-engineered Solar Impulse 2 did not use a drop of fuel. It indicates the extent to which we will be able to reduce our reliance on fossil fuels in the future, and cut the harmful energy emissions that are being pumped out around the world.
The exploratory flights of the 1920s and 30s spread hope after the horror of World War I. One hundred years later, Solar Impulse 2 has been a symbol of hope and adventure and progress at a time of global turmoil.