In section 1-2, there’s a “comic zoom-out” starting with a person sitting on a bench, this could be found in figures 1-2 through 1-13 (page 2-4). These photos are there to show us the proportion of objects in our everyday lives, in comparison to the size of earth, so that we can compare our earth to the size of the enormous universe. We notice that with each photo, the previous photo seems to be getting smaller and smaller until it is no longer visible.
The field of view refers to the region you can see in the image.
The angular distance is a measurement used by astronomers to tell the distance between two objects in the sky. For example, an astronomer might say, “the star was two degrees from the moon”. The ways this works is that; pretend there’s an imaginary line between your eyes and a star in the sky, then pretend there’s another imaginary line from your eyes to the moon. The distance between these two imaginary lines is the angular distance between two objects (view photo on page19).
Units of angular distance: astronomers measure distances in degrees called
-Arc minutes: 1/60th of a degree
-Arc seconds: 1/60th of an arc minute
The angular size/diameter of an object is the angular distance from one edge of the object to the other. The sun and moon are about half a degree in diameter, while the “bowl” of the big dipper is about 10 degrees wide.
-The angular size of something is NOT equal to its true size.
Astronomical unit (AU): is a unit of measurement, which in length is the average distance from earth to the sun. For example, the distance between the earth and the sun would be 1 AU, & the average distance from mercury to the sun is about 0.39 Au.
The Solar system: the motha-fuckin solar system consists of the sun, its family of planets, and smaller bodies such as moons and comets. You’ve got me fucked up if you believe that “our solar system” is the only solar system in the fat ass universe.
A light year: is the distance that light travels in one year, which is approximately 63,000 AU. It’s a measure of distance, not time.
Important facts to know about light years:
- A light year is a shitload bigger than an astronomical unit, about 63,000 times larger.
- A light year is a unit of distance NOT time.
- A light year is the distance you’ll reach traveling somewhere at the speed of light, given a years time.
A galaxy is a great cloud of stars, gas, and dust held together by the combined gravity of all of its matter. It contains a lot of solar systems within it.
The galaxy in which we live is known as the Milky way.
The Universe includes everything: all of the galaxies, planets, stars, including our own galaxy, and a very small part of that…our solar system.
A hypothesis is a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation. The hypothesis is then tested time after time again; many experiments are then conducted to confirm the validity of the hypothesis.