This endless road

From schooldays, we were taught the familiar picture: the planets revolve around a stationary Sun, following orbits that are technically elliptical but, for most of them, close enough to circular. The moons, in turn, circle their parent planets. It was a simple, elegant model and for a long time, many of us assumed the entire solar system sat more or less fixed in the sky, unmoving except for the planets tracing their slow, predictable paths around the Sun.

Only much later, over the past three decades or so, did I begin to appreciate that this picture is incomplete. From the perspective of Earth, we look stationary except for our daily rotation that gives us day and night. The other planets spin too, each in their own way, and because everything seems regular and orderly, it’s easy to imagine the whole system as a stable “clockwork” floating in place.

But in reality, the solar system itself is on the move. The Sun and its planets are orbiting the centre of the Milky Way, completing one galactic circuit roughly every 230 million years. Once you take this into account, a very different image emerges: the planets are not moving in flat circles, but in long, elegant corkscrew paths as they follow the Sun on its galactic journey.

This can be a difficult concept to picture, so I was very happy to come across a computer-generated simulation by amateur astronomer Tony Dunn. His visualisation, covering a hypothetical 20-year period from a vantage point more than 50 astronomical units away, shows the sweeping arcs of Jupiter, Saturn, Uranus, Neptune and Pluto, while the inner planets appear as tight, rapid spirals so quick that labelling them clearly becomes impossible. Still, one can roughly identify them: grey for Mercury, light yellow for Venus, light blue for Earth and orange for Mars.

And all of this is happening at astonishing speeds. Our solar system races through the galaxy at about 230 kilometres per second or around 830,000 kilometres per hour. Meanwhile, the Milky Way itself is moving through the universe at an estimated 2.3 million kilometres per hour. As for the centre of the universe, no one knows where that might be, or whether such a centre even exists in any meaningful way.

What we do know is this: we are not standing still in space. Far from it. We are passengers on a vast journey, carried through the galaxy without ever sensing the motion. And this, in its own quiet way, echoes the Buddha’s reminder that nothing in existence is ever fixed. All things arise, change and pass away. Our lives unfold in the same manner: we board the bus of life, ride for a time and eventually step off, while new passengers climb aboard. The bus keeps moving, just as the universe keeps turning, indifferent to who comes and goes.

To reflect on this is to see the nature of samsara laid bare. A constant movement, a constant becoming. It is humbling, but also gently liberating. In a cosmos that never stops, the only true stillness is the one we cultivate within, moment by moment, as we travel together on this endless road.