Survey says...

[asterroc]

A few questions about terminology in astronomy... For any of the "Something else"s, I encourage you to comment. Or just in general, feel free to comment, though I'd appreciate it if you filled out the survey before you read the comments.

NOTE: third question didn't come out right, it's supposed to read "Are either the words 'size' or 'bigger' ambiguous to you?" If you care to add this in the comments, I'd love to know. :)

[Poll #1929305]

Comments

[hrafn.livejournal.com]

I realized looking at the lists of options that I do not think about this, generally, in that kind of specificity. I mean, if someone talks about diameter that also implies radius, and vice versa, right?

What does "physical size" even mean? Given how volume doesn't imply mass and vice versa. D: That /was/ my pick, for what I think, but now I realize I maybe don't know what -I- mean by that. >.<

I confess I rarely think about -mass- when people talk about size/bigness of planets. And so now I'm not sure how to mark the survey. Especially in the "one is bigger" category, since a planet can be bigger in volume but smaller in mass. *cries*

Ambiguous words are ambiguous.

I also haven't finished eating breakfast yet.

ETA: Having now read the other comments, I feel better about being confused/frustrated. I've definitely noticed that if people are talking -mass- (or weight) for an object, generally they make it clear, since in my experience, the only people talking about mass are talking within a scientific context, and so they are specific about that.

[zandperl.livejournal.com]

"Physical size" is a vague term that encompasses radius/diameter/volume (and therefore also surface area/cross-sectional area, though we don't particularly think about that when we use the term).

In most of astronomy physical size scales with mass - you don't often get two objects of the same type where one is bigger but the other is more massive. Astronomers don't use "weight" to describe things since "weight" means "force of gravity while on the surface of the Earth", which just isn't relevant.