3

Earth rotates around the sun.

Is rotate an acceptable word in that context or should I use words such as orbit or revolve instead?

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    There are "official" definitions of the two terms "rotate" and "revolve" that an astronomer would insist on, but they tend to be used interchangeably by the general public. However, it's a bit more idiomatic to say a planet rotates around its own axis and revolves around its star. And "orbit" is a "safer" term, as it's unambiguous. – Hot Licks Feb 21 '16 at 14:22
  • How things move "around" is an interesting question. There should be a glossy for such things. I've always struggled with descriptions of bearing failures. – user116032 Feb 21 '16 at 21:25
  • I've always said that the Earth 'revolves about' the Sun. – ifly6 Feb 23 '16 at 20:54
10

I disagree with the choice of the word "rotate," which is most properly used to describe angular motion around the Earth's own axis. "Orbit" is more proper, because it denotes angular motion of the line joining the axes of the Earth and the Sun around the axis of the Sun.

The Earth rotates around its poles and orbits around the Sun.

5

Here is a Google Ngram chart comparing the frequency of occurrence in the Google Books database of "rotates around the sun" (blue line) versus "revolves around the sun" (red line) versus "orbits the sun" (green line) for the years 1868–2008:

And here is the Ngram chart for "rotation around the sun" (blue line) versus "revolution around the sun" (red line) versus "orbit around the sun" (green line) for the same time period:

From these charts, it appears that the "rotates around the sun"/"rotation around the sun" pair is much less common in published writing than either "revolves around the sun"/"revolution around the sun" or "orbits the sun"/"orbit around the sun." Taking into account this strong preference in written usage, I can't think of any reason to prefer the "rotates"/"rotation" wording when describing a planet that is proceeding on its elliptical circuit around a star.

1

"Rotate" is fine, for plain English or scientist, unless the subject is the detail of the elliptical trajectory...

1

There is no problem with "the Earth rotates around the Sun" on its own. But confusion creeps in if you also want to refer to how the Earth is spinning around its own axis. In that case I would use orbit to refer to the motion around the sun and rotation or revolution to refer to the spin.

1

The distinction between rotate and revolve is taught to all students. I would mark the misuse in people older than 6th graders (see the link for 6th grade education std. below). For what ever reason, this has been a sort of litmus test in the scientific community for a long time, and it may as well be public knowledge.

See objective 2a in the link below.

Objective 2 Demonstrate how the relative positions of Earth, the moon, and the sun create the appearance of the moon’s phases.

a. Identify the difference between the motion of an object rotating on its axis and an object revolving in orbit.

http://www.uen.org/core/core.do?courseNum=3060

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    It's plenty acceptable in a non-scientific context no matter what your age. – curiousdannii Feb 22 '16 at 13:06
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    -1 for first sentence. – dwjohnston Feb 23 '16 at 21:18
  • @dwjohnson. It wasn't meant to be derogatory. The age of 12 is the 6th grade, when the distinction is taught in school. Whether people agree or not, it is a litmus test of basic mechanical apprehension and has been for quite some time. It's misuse in anyone over 12 years old will be marked, and the offender may be also. I would answer a question about planetary motion very differently depending on whether the correct or incorrect term were used. It is the risk of it being marked that I want to draw attention to. – Phil Sweet Feb 25 '16 at 3:12
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    @dwjohnson. I'm new here. I've been told it is OK to edit answers in response to downvotes. This is different from the policy of other forums I'm on. I have removed the first sentence and replaced it with something I hope is more acceptable. If there is more I need to do, please let me know. – Phil Sweet Feb 26 '16 at 15:14
  • @PhilSweet - Much improved, good edit. But please don't put thing like "Large edit, see comments" in the answer itself; and answer should make sense to someone who hasn't seen the previous versions. I've removed it for you. – AndyT Feb 26 '16 at 16:13

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