Space Blog 2025-04-30 10:35:34.03
- Subject
- It's my birthday - How far have I travelled in my life?
- Date
- 2025-04-30_10:35:34.03
- Tags
- space, distance, birthday
- Author
- tbird20d
Every time I celebrate a birthday (either my own or someone else's) I think about the fact that we're celebrating something marked by the way the Earth moves through space. Our birthdays come around once a year, and a year is the time it takes the Earth to go around the Sun completing one orbit. So really, we are celebrating something based on the fact that the Earth has returned to a similar position in its orbit as when the person was born.
Thinking about birthdays gets me thinking about that position and movement. Sure, on a birthday the Earth is in the same place in it's orbit as when that person was born. But that's not the only way that the Earth (and an individual human on it) moves through space. So we are not really in the same place (cosmically speaking) as when we were born.
Space is unfathomably big, and we are traveling far faster than we realize.
Even when we are sitting still at some location on the Earth, because the Earth is spinning, we are actually moving quite fast, and the amount is dependent on our latitude. People at the equator are moving faster than people who are closer to the earth's north or south poles. The Earth is also moving through space in its orbit around the Sun, and the Sun is moving in its orbit around the Milky Way Galaxy. And finally, the Galaxy is moving through space towards a spot that is the gravitational center of a supercluster of galaxies that are near our own galaxy.
There is something called the Cosmic Microwave Background Radiation (CMBR), which provides a frame of reference for the entire universe. Scientists have estimated we are moving relative to the CMBR at approximately 1.34 million miles per hour (or 2.16 million kilometers per hour) That's approximately 600 kilometers per second, which is fast!!
Today is my birthday, and I've just now calculated that since I was born, I've travelled about 728,264 million miles, or about 1.17 trillion kilometers (plus or minus a few billion kilometers).
Of course this is all a very non-sentimental view of birthdays. When we celebrate someone's birthday we are actually celebrating a person's life along with their longevity or accomplishments ("Hurray! You made it another year!"). I feel like's its a nice accomplishment to have travelled over a trillion kilometers in my life. I don't know about you, but that fact also makes me feel a little bit restless.
Resources [edit section]
- https://www.businessinsider.com/earth-screaming-through-space-nasa-animated-video-2019-10
- https://nightsky.jpl.nasa.gov/media/documents/resources/HowFast.pdf
- Relative Cosmic Velocities (Youtube)
- https://www.space.com/33527-how-fast-is-earth-moving.html