Metric System and Distances
Vastness emptiness of space
Filaments and voids
"The longest journey begins with a single (first) step". Confucius
"Little drops of water, little grains of sand makes the mighty ocean and land".
Think of a girl sitting on a campus bench studying Astronomy. We begin with this picture of a scene 50 feet in diameter (size of a basketball field).
If we increase the field of view by 100 times we will see an area 1 mile in diameter, (half the size of Potsdam Village from this Campus to the Hospital). Keeping the size of the picture card same, the individual people, trees and sidewalks have vanished. In such a situation, we expect only to see Potsdam College campus, parts of Racquette river and some of the Church buildings.
This 2nd picture has a field of view one mile is actually 1.6 km. JUST CROSS THE BORDER, INTO CANADA, THEY USE METRIC SYSTEM LIKE MOST PEOPLE IN THE WORLD, Americans and British people are exceptions. For now on, we will use kilometers in this course in solidarity with the rest of the world.
3rd picture card of same length, includes distances 100 times greater than the second card (that is, 100 miles wide). In such a picture card, we will see most of the Adirondack Mountain Forests with Lake placid in the middle, the St Lawrence river, Lake Champlain and parts of Lake Ontario.
These are the 12 steps to the size of our known Universe. If we go further to look at the heavens, Super clusters are joined in filament like long structures, separated by what seemed like immense empty space (voids).
In the universe, each of the billions of galaxies contain billions of stars, and our sun is a single average star. Universe may span vast amount of space, but the laws governing its administration seem to be "only a handful", the natural laws of physics.
The laws have tremendous power to simplify the vastness of space, motion and energy. For example, Newton's law of gravity is at the heart of all kinds of heavenly motion, everything from the phases of the moon, seasons of the year and drifting of the stars and galaxies. The nice thing about Astronomy, that it explains the subject in simple terms about the vast universe.
Sun is one of 100 billion stars in our galaxy called the Milky way.