Well, from science books i read the sun is 149,597,900 km from Planet Earth. I would like to know what types of forces puts the sun in a fixed position and if possible what does science put forward to explain the sources of these forces ?
Any one out there to give me facts so i can explain well to the children i teach at our school. Thanks.
That's probably a bit too much for kids, George (even though it's accurate). ;-)
Sol's given distance from Earth is the mean (average) but Earth's orbit is elliptical but it averages out at roughly 93 million miles or about eight light minutes.
Things orbit other things because they are attracted by gravity which is a very weak force - so you need a very large something before it can exert a noticeable force on something much smaller. Earth has man-made satellites and our moon, other planets may have moons and many stars are orbited by planets.
Our solar system orbits around (it's thought) a black hole at the centre of our galaxy... and so on. Black holes have immense gravity, you'll recall.
Crucially, to orbit something you have to be at a distance where you are constantly attracted to it but keep falling because you miss! Too close and you fall to the surface, too far away and you fly off into space.
This isn't actually true. I found it much easier to understand gravity when it was explained to me like above, where a bowling ball was put on a stretchy surface and I could see the bend. It's also extremely EASY to explain four dimensional space to a child. In fact, understanding all of these things is MUCH easier than trying to get them to understand that 'a bigger object attracts a smaller object'. These explanations were very hollow and vague to me as a kid in science class and led to questions like 'So why don't we attract each other into orbit?', whereas with the visual of warped space time fabric, I could see that we obviously weren't big enough to make a dent in the fabric, like a bead compared to a bowling ball.
As far as explaining four dimensional space, the easiest way to explain it to a child is to explain it with the 'appointment' analogy. When you have a doctor's appointment, the dimensions of life are completely illustrated in the instructions.
The address / building is a place, which has three dimensions-- your length, width, and the height (the floor you're visiting for your appointment, for instance), and you have to be in the right mix of those three dimensions (i.e.: in the right place) in combination with the fourth dimension, time, in order to make your appointment. In this instance, time and place go directly hand in hand and illustrate how time is a cooperative dimension and not its own separate idea. Because if you're at your house during the time of your appointment, you've missed your appointment. You've also missed your appointment if you're in the right place at the wrong time. In either case, time is essential in the situation and it's something that kids, who have gone to the doctors many times by the time they're talking about space science in school, can understand easily--- especially with drawings.
Our solar system acts as one unit as it moves through our milky way galaxy. Earth is one of the satellites orbiting the sun, our moon is a satellite to earth. It is all about Gravity. No one mentioned this, but this might be a good place to explain how the universe is expanding and even our milky way galaxy is not fixed in the universe. In summary, the movements involve the earth moving around the sun, our solar system moving within our milky way galaxy, and our galaxy moving within a larger framework of the expanding universe. The big question would be is our universe moving within some larger context? That question would take us outside the realm of our common preception of space and time. For the record, I like snickers better than milky way.