ASTR 101 Lecture Notes - Lecture 1: Cavendish Experiment, Weak Interaction, Electric Charge
21 Jul 2017
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Three profound implications in that "outward journey": the universe is vast. Scientists deal with great distances not found in other sciences: astronomy as a time machine. Realize that although sound can"t travel through space, if it did, it would take lots of time to reach a point (think about thunder and how you hear it after you see it). Also, realize that since light takes time to travel, if you view a distant remote object, you are actually seeing it in the past: the reach of the human mind. Discussions of the use of astronomy dates back as far as socrates, who made the argument that its intellectual enjoyment is enough. During day: motion of the sun across the sky allows us to observe passing hours, where it can be captured on a sundial (through shadow movements). During night: motion of the stars across the sky.
