Let us say that you draw a vertical line and a horizontal line. Now, place three pins along the horizontal line, one at the center and the other two equal distances from the center on the horizontal line. If you attach a string that is longer than the distance between the two pins to one pin (F1 in the above view) and the other end of the string to the other pin (F2), you can then use a pencil to draw an ellipse as shown above. Now, what happens if you move the two focal points out or in? Yep the ellipse changes shape. Now, if you move both pins into the center where the lines cross, you will get a circle. A circle is an ellipse with a common focal point.
The planets' orbits are basically an ellipse but they are more like circles with the sun offset to one side. Anyway, so what causes the planets to orbit in this offset circle or ellipse? Any object coming into the gravity field of star, or black hole, or any object larger than they are and gets caught in that objects gravity will be slung into an elliptical orbit. The speed of the smaller object is highest when it is closest to the larger object and slows down enough as it gets further away to allow the gravity of the larger object to swing it back around. So, most objects start their orbits in an elliptical fashion which determines the way it travels around the main object from then on.
Alright, before I start talking in circles or ellipses, I better quit and say, you have a great day, you hear?
So are you saying that the earth orbits the sun is moving faster when it comes near the sun, and travels slower when as it gets further away from the sun? Can we notice this effect? Interesting post today, Diz.
ReplyDeleteA person weighs more at the north or south pole than they do at the equator because at the equator the rotation of the earth tries to through them off. Do they feel lighter? No. So I doubt if we people notice any difference. Of course the earth bulges at the equator so would have a little more gravity there. Animals and birds may notice these things, but don't know. Astronomers may notice the difference from observing distant objects over a long period of time, the here too, I don't know.
DeleteAll those loops, circles got me lost...
ReplyDeleteYep, they can make you run in circles. . .that is why they call me Dizzy.
DeleteHave you looked into the Testellar Orbit pattern yet?
ReplyDeleteNo I haven't. I know that our star (the sun) is located out on an arm of the Milky Way galaxy and that the galaxy is spinning. Also, binary stars orbit each other. Could you explain what you mean by Testellar Orbit?
DeleteNot really because I don't understand what it means since I made it up to bring chaos to the world.
DeleteGo Kepler!
ReplyDeleteYep, he was one of the first to figure it all out.
DeleteDizzy - my no-quite-4 year old grandson sat at lunch last Sunday and recounted all the planets in order around the sun, told me which was the heaviest and why. I can't tell the planets in order! I think he's gonna be an aeronautical engineer, but he wants to be a garbage truck driver..... Love them little 'uns.
ReplyDeletehahahaha,, love those little ones..
DeleteHey texasann, he would probably make a better living as a garbage collector. . . But it would be great for him to pursue astronomy or some other of the sciences. I wish I had.
DeleteYou sure know how to make my head spin early in the day!
ReplyDeleteMaybe, then, we should call you Dizzy instead of my. I loved your blog today. No, that couldn't have been made up.
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