Thanks to Galileo, it's common knowledge that the Earth orbits the sun. What's not as commonly known is that the sun - and our entire solar system - is orbiting around a massive black hole at the center of the galaxy. It takes 225 million Earth years to make one loop around the Milky Way.
A small group of science enthusiasts thinks we should all stop and ponder this and other amazing facts about our place in the universe once in a while, and they’ve declared a holiday this Thursday for exactly this purpose. It’s called Galactic Tick Day.
But what's a Galactic Tick, you ask? It's just shy of three billionths of one orbit around the galaxy, or the distance that our solar system travels in approximately 1.7 years. It's not as random a number as it may seem. A full explanation does require a bit of mathematics, though.
Our galactic orbit is a circle. Circles can be divided up into 360 degrees. Each degree can be divided into sixty arc-minutes, and each minute into - you guessed it - sixty arc-seconds. With a circle as enormous as our galactic orbit, that's still a really large distance. So the creators of Galactic Tick Day divided an arc-second by 100, and declared that a Galactic Tick.
Basically, it's an arbitrary and conveniently small slice of our orbit that can be recognized and celebrated by humans on a regular basis. Of course, that raises another question, namely, when should Galactic Tick Day fall?
The creators of the holiday made another arbitrary decision and retroactively declared the first Galactic Tick Day to have been October 2nd, 1608. That's the day Hans Lippershey filed the first patent for a telescope, a technology that has opened our eyes to many of the wonders of the universe and enabled unparalleled scientific advances.
A bit more math, and it becomes apparent that September 29th, 2016, is the 235th Galactic Tick Day. Of course, it will be the first to actually be recognized. Events in the San Francisco area promise to resemble a cross between a science festival and a New Year's Eve celebration. Those who dreamed up the holiday say people everywhere can mark the occasion simply by being mindful of our place in the universe and intentional in our actions.