I previously posted a link to the Scale of the Universe web page where you can interactively explore the cosmos from the smallest to the largest and click on objects for more information about them.

Commentator ixtrix points out a similar site called The Cosmic Scale that’s less interactive but still worth seeing for another view.

One caution: I just noticed that some of the explanatory text on the Scale of the Universe page might reinforce a common misconception about the word “theory.” In normal speech theory often means “hypothesis” or “guess,” but in science theory more commonly means “a systematic explanation.” Hence a scientific theory can be indeed speculative (such as M-theory in physics) or even wrong (such as the phlogiston theory of combustion in chemistry), but other theories are very strongly supported by evidence, such as the germ theory of infectious disease, the theory of relativity, the theory of evolution through natural selection, and so on.

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