nutcroft

A birthday invitation

1 July 2023 is a totally not important date for the world but it just happened that I was born exactly 29 Earth circles around the Sun before that date.

The thing is, while the Earth is rotating around itself it also constantly changes the orientation of this axis. It takes 26 thousand years to come back to where it was, so the Earth isn’t in the same place as it was 29 years ago with respect to its axis.

The thing is, also, that the Sun itself is losing mass as it’s emitting all this energy, so the less heavy it becomes the less able it is to pull the Earth towards it. So, the Earth isn’t in the same place as it was 29 years ago with respect to the Sun, it’s a bit father away. About 43.5 cm farther.

The thing is, also, the whole solar system rotates around itself with a couple of hundred million years period, so the Earth isn’t in the same place as it was 29 years ago with respect to other solar systems.

The thing is, also, that the whole solar system moves around the center of the Milky Way galaxy, so the Earth isn’t in the same place as it was 29 years ago with respect to the local black hole.

The thing is, also, that the whole Milky Way galaxy is rotating around its center, so the Earth isn’t in the same place as it was 29 years ago with respect to other galaxies.

The thing is, also, that the whole Milky Way galaxy is moving within the Local Group, not to mention that the Andromeda Galaxy is moving head-on towards us with a speed of 110 km not per hour but per second—or else it would be weirdly close to the national motorway speed limit. So, the Andromeda galaxy will crash the Milky Way in 4.5 billion years and I can only wish the best of the luck to the people writing their birthday invitation then! For now, we can only say that the Earth will not be in the same place as it was 29 years ago with respect to the Andromeda Galaxy or within any other galaxy in the Local Group for that matter.

The thing is, also, that the Local Group itself moves around within the Virgo Supercluster, which means that the Earth isn’t in the same place as it was 29 years ago with respect to friendly neighbours such as the elliptical galaxy Messier 87.

The thing is, also, that the Virgo Supercluster moves within the Laniakea Supercluster and the Laniakea Supercluster moves towards the Great Attractor. Not to mention that the Great Attractor moves towards the Shapley Supercluster. So, yeah, the Earth isn’t in the same place as it was 29 years ago with respect to other superclusters, such as new possible friends like the Vela Supercluster (possible only because we are not sure they exist, not because we’re not keen on being amicable!).

The thing is, also, that everything is moving with respect to the cosmic microwave background. Not to mention oscillations of galactic disks or the Hubble flow (the fact that everything is moving due to the universe expanding).

But ok, yes, the Earth has moved around the sun 29 times almost approximately exactly, in a sense… in a way… with respect to… some—thing. If you’re happy with that, well, fine—let’s celebrate then!