I’m fortunate to have met my great-grandfather. He was born in the first decade of the Twentieth Century in Galicia, Spain. By the time I met him, he was very old and losing his sight. Still, he was full of fascinating stories from a world that seemed very different from mine.

When I think of him, two images come to mind.

The first is connected to Halley’s Comet. This comet swings by the solar system every 75 years or so, and is visible to the naked eye. It last came around in 1986, and everyone was talking about it — including my great-grandfather. The Comet had last been in the news in 1910, when he was a boy. He told me about it, and an image from his story has stuck with me: him as a child sitting in an oxcart at night, seeing coastal lights shining over a mountain range. He was afraid; the villagers somehow thought the lights were either the comet itself or some kind of portent. The end of the world, perhaps?

The second image of my great-grandfather is fresher in my mind because it’s captured in visual media: a short clip from a grainy Super-8 film. It shows him laughing, riding around with my mom in one of the little racing cars in the Magic Kingdom at Walt Disney World. This must have been in the mid-1970s when the park was still new and he could still travel.

For me, these images represent bookends in his lifetime’s journey. He went from an animal-powered vehicle in a world defined by material and intellectual want, to a vehicle powered by an internal combustion engine and designed for pleasure in a world of fairytale castles, singing robot pirates, and abundance. In the span between these two conveyances he experienced much turmoil and wonder: World War I, the Spanish Civil War (and emigration to the New World,) World War II, vaccines, television, jetliners, computers, and so much more. Singing robot pirates! A world the child in the oxcart would’ve barely recognized.

I’ve already experienced many astonishing things in my life: the World Wide Web, the mapping of the human genome, smartphones, and the destruction of the World Trade Center come immediately to mind. Halley’s Comet is scheduled to return in 2061. If I’m still alive, I’ll be older than my great-grandfather was in 1986. What turmoil and wonders are yet to come?