We recently celebrated my wife’s birthday, and it made me think about what that meant in our solar system: One year means that our earth has circled the sun and is in the *same* position that it was a year ago. What that really means is the same position relative only to the sun.

Not only is every other planet in a different position than the year before, but the sun itself isn’t anywhere near where it used to be.

Watch this video: Skylight: How Does Our Solar System Move Around the Milky Way?

“As our spinning planet revolves around the sun, we’re also speeding through the galaxy at 230 kilometres per second.”

So, while here on earth we are in the same relative position to the sun that we were a year ago, the sun itself has travelled:

230km/second x 60 seconds in a minute x 60 minutes in an hour x 24 hours in a day x 365 days in a year: The sun and earth are approximately 7,253,280,000 Kilometres away from where they were a year ago. We are quite literally only in the same place we were a year ago relative to the position of the sun.

Happy birthday = Happy single rotation around the sun… while the sun is racing through the galaxy, taking us 7+ billion kilometres away from where we we a year ago!

Oh, and by the way, this just factors in the way our sun moves within the galaxy. Our galaxy is also moving through the universe… all this movement is relative.

As a final thought on the relative length of a year, a year of fighting cancer is significantly different than a year of sabbatical on a tropical island… no matter how far we may travel through the cosmos in that time.

—

This video shows us the actual travel path of the sun and planets through the galaxy: The helical model – our solar system is a vortex