The World

[asterroc]

I'm trying to understand something. Please answer the below questions to the best of your ability.

[Poll #1397877]

What I'm trying to understand is why my students are unable to distinguish between the planet Earth and the entire universe. For example, I said "1. How is the world (the planet Earth) going to end?
2. Which of the three scenarios for the end of the universe do YOU think is most likely?" And they answered #1 with "Big Crunch, Big Rip, or Heat Death," and for #2 picked their favorite. The correct response for #1 is "When the Sun runs out of Hydrogen in its core, it will expand as a red giant and engulf the planet Earth."

This time I explicitly wrote "(the planet Earth)" in the question to try and avoid the mix-up from the colloquial usage of the word "world". I think I need to just never ever use the word "world" again in astronomy.

Comments

[calzephyr77.livejournal.com]

I really love it when you post stuff like this as it has been a very long time since I took any science classes and I never took physics in high school either. It's always so enlightening.

[zandperl.livejournal.com]

And I like it when my non-science-y friends respond, as it gives me insight into the minds of my students. Remind me later if you want my responses to these questions, I want to see more of others' responses first.

[q10.livejournal.com]

you have to remember that humans usually don't so much read the directions as skim them and haphazardly extract key phrases and general hints.

also, normal rules of conversational structure make people assume that one question is an elaboration on the previous question if at all possible.

and, unfortunately, one of the easier important words to insert or drop in misreading is ‘not’.

if you want to minimize misreading, i would:

1. avoid the word ‘world’.
and
2. not put those two questions next to each other.

[zandperl.livejournal.com]

I was hoping you'd chip in w/ your linguistics viewpoint.

1) I plan to do this in the future.

2) The problem is that I want to tease out that the students know the difference between the origins and fates of the Universe and the Earth, in an assignment with only 2 questions. I guess I could entirely rework the questions to something like "compare and contrast how the Earth and how the Universe will end," but IMO that is a meaningless question as the two don't really have anything in common.

Do you think if I just did "1. How will the planet Earth end? 2. How will the universe end?" that would be sufficient? Another option is to add in or substitute "how will life on Earth end?" - some of my readers here already interpreted the question that way.

[q10.livejournal.com]

well, i should warn you that i don't really have any special linguistics expertise on these subjects - just the results of some casual observation. i think the revised version you mention will probably diminish the effect, and if you only have two questions, so you can't space them out, it's about the best you can do. also remember that students will find some ways to screw things up no matter how good the directions are. one should do one's best to avoid making things more ambiguous or misleading than necessary, but one isn't obligated to include a little clause to specifically dispel every possible misreading (and even if one did, most people probably wouldn't read it).

[fireaphid.livejournal.com]

Neat little poll! I guess for students, you have to be very specific. . .

[q10.livejournal.com]

a few examples of cases where ‘world’ means universe:

1. in metaphysics and semantics, one sometimes talks about ‘possible worlds’ when defining notions of metaphysical necessity or discussing the kinds of alternative, unreal states of affairs that we think about when we think about possibilities and uncertainties. in these areas, nothing is special about planets - its very clear that most writers in these areas (David Lewis is a striking example) are using ‘possible world’ to mean ‘possible way that the totality of everything that is’ could be, which, in ordinary talk, is pretty close to ‘possible universe’.

2. similarly, in epistemology, writers often draw distinctions between one's own mind and the external world (that can only be perceived through the senses) - here again planets aren't special - looking up at the sky on a clear night is still taking in sensory impressions of the world.

3. in theological contexts, people frequently use ‘the world’ to mean ‘the sum of all creation’ - see e.g. Cat Faber's deist hymn The Word of God - when she writes ‘Humans wrote the Bible, God wrote the world.’, it's pretty clear she means the whole of natural reality, including at least the sky that was mentioned in a pervious verse.

4. i'm pretty sure the many worlds interpretation of QM isn't about planets being special.

[zandperl.livejournal.com]

*nods* There's definitely a colloquial usage of "world" to mean "everything" or "universe", and I expect either your #2 or #3 is where that colloquial usage comes from.

[hitchhiker.livejournal.com]

The correct response for #1 is "When the Sun runs out of Hydrogen in its core, it will expand as a red giant and engulf the planet Earth.

okay, i got that one wrong :) was sure earth was too far away to be engulfed

[zandperl.livejournal.com]

Even if the Earth were not engulfed, I am pretty sure it would still be destroyed when those outer layers were shrugged off as the Sun becomes a planetary nebula. Certainly that would destroy the gas giants (since all they are is gas, and that's what the PN is as well, so they'd be blown away), but I'm not 100% sure the PN would destroy rocky or icy bodies.

[hitchhiker.livejournal.com]

i went googling and found this, which suggests that it will likely be vapourised

[zandperl.livejournal.com]

Interesting! It didn't occur to me that the Earth's orbit might not remain at 1AU. (Begging the question of whether we will redefine the AU always be the distance from the Earth to the Sun, or to always be 1.4960E11m.) The tidal bulge part either has a major error or else a severe oversimplification - things that spin FASTER have a tidal bulge, not things that spin SLOWER, so a larger Sun (which spins slower) should have less of a tidal bulge.

[framefolly.livejournal.com]

*blushes*

I totally thought "world" meant universe. I mean, if I had taken your class I probably wouldn't have because I probably would have noted your usage, but taking your poll without clicking the answers first, I just assumed universe for some reason.

Hmm...a possible reason: world is translated as Shi4jie4 (World Journal!) in Chinese, which means basically "everywhere that people can perceive." There's another word that more specifically denotes universe or cosmos -- yu3zhou4 -- but shi4jie4 definitely doesn't necessarily end at the borders of the earth.

Of course, having lived (and been educated) here for 21 years, the "I speekee no good Engrish" defense doesn't work :P .

[zandperl.livejournal.com]

As q10 mentions above and Merriam Webster confirms, "everywhere that people can perceive" is an entirely valid interpretation of the word "world".

And I don't think of your explanation as a cop-out as you imply. You're not actually misusing an English word here, you're selecting one of multiple definitions based upon your own background, and that's what everyone does when they're reading any language. What I'm trying to figure out is why my students universally (har har) choose the same interpretation as you do. At least half of the people who responded to this survey have a science background or are science enthusiasts, so I think that has colored their responses.

[sirroxton.livejournal.com]

My understanding is that the Earth's orbit will change when the sun goes red giant, and that it won't be engulfed (at least not right away).