# Is Jill behind the times?

**URL:** <https://boards.straightdope.com/t/is-jill-behind-the-times/36482>\
**Category:** Cecil's Columns/Staff Reports\
**Created:** [October 11, 2000, 12:41am UTC](https://boards.straightdope.com/t/is-jill-behind-the-times/36482 "2000-10-11T00:41:54Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![Earl\_Snake-Hips\_Tucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/earl_snake-hips_tucker/32/3269_2.png) [@Earl\_Snake-Hips\_Tucker](https://boards.straightdope.com/u/Earl_Snake-Hips_Tucker)\
**Post date:** [October 11, 2000, 12:41am UTC](https://boards.straightdope.com/t/is-jill-behind-the-times/36482/1 "2000-10-11T00:41:54Z")

</div>

Now that we have a little better understanding of gravity, isn’t the more appropriate term “center of mass.”😃

[http://www.straightdope.com/mailbag/mcamelswim.html](http://www.straightdope.com/mailbag/mcamelswim.html)

---

<div class="post-metadata">

**Author:** ![JillGat](https://avatars.discourse-cdn.com/v4/letter/j/9fc29f/32.png) [@JillGat](https://boards.straightdope.com/u/JillGat)\
**Post date:** [October 11, 2000, 3:27am UTC](https://boards.straightdope.com/t/is-jill-behind-the-times/36482/2 "2000-10-11T03:27:19Z")

</div>

[[Now that we have a little better understanding of gravity, isn’t the more appropriate term “center of mass.”]]  
Well, yeah _of course_, but I was quoting the guy at the zoo and I don’t mess with quotes from curators.

---

<div class="post-metadata">

**Author:** ![RM\_Mentock](https://avatars.discourse-cdn.com/v4/letter/r/e274bd/32.png) [@RM\_Mentock](https://boards.straightdope.com/u/RM_Mentock)\
**Post date:** [October 12, 2000, 11:56am UTC](https://boards.straightdope.com/t/is-jill-behind-the-times/36482/3 "2000-10-12T11:56:21Z")

</div>

Clearly a mislabeled thread. 🙂

But I’m not so sure Mjollnir has a point. Why is center of mass a more appropriate term?

---

<div class="post-metadata">

**Author:** ![Beruang](https://avatars.discourse-cdn.com/v4/letter/b/77aa72/32.png) [@Beruang](https://boards.straightdope.com/u/Beruang)\
**Post date:** [October 12, 2000, 11:43pm UTC](https://boards.straightdope.com/t/is-jill-behind-the-times/36482/4 "2000-10-12T23:43:37Z")

</div>

I’ve worked with curators for ten years. I just got a nasty letter from one today. Believe me, they are NOT the source of all wisdom and knowledge in the universe.

---

<div class="post-metadata">

**Author:** ![JillGat](https://avatars.discourse-cdn.com/v4/letter/j/9fc29f/32.png) [@JillGat](https://boards.straightdope.com/u/JillGat)\
**Post date:** [October 13, 2000, 2:18am UTC](https://boards.straightdope.com/t/is-jill-behind-the-times/36482/5 "2000-10-13T02:18:36Z")

</div>

[[I’ve worked with curators for ten years. I just got a nasty letter from one today. Believe me, they are NOT the source of all wisdom and knowledge in the universe.]]

::fingers in ears, singing, “Flintstones, meet the Flintstones”::

---

<div class="post-metadata">

**Author:** ![zut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zut/32/2875_2.png) [@zut](https://boards.straightdope.com/u/zut)\
**Post date:** [October 17, 2000, 12:13pm UTC](https://boards.straightdope.com/t/is-jill-behind-the-times/36482/6 "2000-10-17T12:13:17Z")

</div>

> [@](#):
>
> \*Originally posted by RM Mentock \*  
> But I’m not so sure Mjollnir has a point. Why is center of mass a more appropriate term?

I think I agree with **Jill** (well, the _curator_, really) that “center of gravity” is a more apt term. Note, **Mjollnir** , that both “center of mass” and “center of gravity” have specific definitions _as phrases_ (as opposed to just the component words being defined).

**center of gravity** The point in or near a body at which the gravitational potential energy of the body is equal to that of a single particle of the same mass located at that point and through which the resultant of the gravitational forces on the component particles of the body acts.

**center of mass** The point about which the sum of all the linear moments of mass of the particles in a body is zero.

For all practical purposes, these two points are the same; I imagine that they would be different only as a result of the small change in the gravitational field from top to bottom of the gorilla (errr…I think). Nevertheless, since the curator was referring to the effect of gravity on a gorilla, and “center of gravity” is a defined term, I’d lean toward that term as being more correct. Although it’s just semantics anyway, I suppose.