#1

Vintage Shaver
Seattle, WA
Usually my daily shave feels pretty restful, especially when I take my time. However, I'm not really at rest then...

From the astrosociety.org site:

When we are on a smoothly moving train, we sometimes get the illusion that the train is standing still and the trees or buildings are moving backwards. In the same way, because we "ride" with the spinning earth, it appears to us that the sun and the stars are the ones doing the moving as day and night alternate. But it is our planet that turns on its axis once a day -- and all of us who live on the earth's surface are moving with it. How fast do we turn? To make one complete rotation in 24 hours, a point near the equator of the earth must move at close to 1000 miles per hour (1600 km/hr). The speed gets less as you move north from the equator, but it's still a good clip throughout the United States. Because gravity holds us tight to the surface of our planet, we move with the earth and don't notice its rotation in everyday life.

In addition to spinning on its axis, the earth also revolves around the sun. We are approximately 93 million miles (150 million km) from the sun, and at that distance, it takes us one year (365 days) to go around once. The full path of the earth's orbit is close to 600 million miles (970 million km). To go around this immense circle in one year takes a speed of 66,000 miles per hour (107,000 km/hr).

Our sun is just one star among several hundred billion others that together make up the Milky Way galaxy. This is our immense "island of stars," and within it each star is itself moving. Any planet orbiting a star will share its motion through the galaxy with it. Stars can be moving in a random way, just "milling about" in their neighborhoods, and also in organized ways, moving around the center of the galaxy.

Astronomers define a "local standard of rest" in our section of the galaxy by the average motion of all the stars in our neighborhood. Relative to the local standard of rest, our sun and the earth are moving at about 43,000 miles per hour (70,000 km/hr), roughly in the direction of the bright star Vega in the constellation of Lyra. This speed is not unusual for the stars around us and is our "milling around" speed in our suburban part of the galaxy.

It takes our sun approximately 225 million years to make one trip around our galaxy. This is sometimes called our "galactic year." Since the sun and the earth first formed, about 20 galactic years have passed; the sun and earth have been around the galaxy 20 times. How fast do we have to move to make it around the Milky Way in one galactic year? It's a huge circle, and the speed with which the sun has to move is an astounding 483,000 miles per hour (792,000 km/hr)! The earth, anchored to the sun by gravity, follows along at the same fantastic speed.

And how fast is the Milky Way galaxy itself moving? The speed turns out to be an astounding 1.3 million miles per hour (2.1 million km/hr)! We and the whole galaxy are moving roughly in the direction of the sky that is defined by the constellations of Leo and Virgo. Although the reasons for this motion are not fully understood, astronomers believe that there is a huge concentration of matter in this direction. Some people call it The Great Attractor, although we now know that the pull is probably not due to one group of galaxies but many. Still the extra gravity in this direction pulls the Milky Way (and many neighbor galaxies) in that direction.

Lipripper660 likes this post
John
#2
(This post was last modified: 11-15-2018, 04:59 AM by celestino.)
Wow! My head is spinning just imagining how fast everything is moving, at the moment. Smile
Thanks for the insightful info, John.
Celestino
Love, Laughter & Shaving  Heart
#3

Super Moderator
Yes, gravity sucks. Or pulls, whichever you like.


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