APOD: Polar Ring Galaxy NGC 2685 (2014 Mar 14)

[bystander]

I still think there is very little confusion over what is meant by "football shaped."
I doubt seriously anybody would call a spherical galaxy "football shaped."

What confuses me is why anyone would want to call soccer football.

[Nitpicker]

I was actually annoyed by BillBixby's post. This happened multiple times before at Asterisk prior to your arrival, Nit. I will be sure to reference Ctenophora next time it happens.

Oh well, to finally resolve the earlier shape discussion revived by Bill, "football" is a vague and unsophisticated name for a shape, but fine for the name of a galaxy or nebula (which is only a nickname anyway).

Does Ctenophora have a silent "C" or "t" or something else entirely? I don't see it getting past the marketing department.

[Nitpicker]

I still think there is very little confusion over what is meant by "football shaped."
I doubt seriously anybody would call a spherical galaxy "football shaped."

What confuses me is why anyone would want to call soccer football.

You are right that "football shaped" is not confusing. And a very good point that something spherical would never be described as "football shaped". But "football shaped" is contentious, as it does appear to upset those emotionally charged people who argue that greater worldwide popularity is a virtue, and therefore Soccer/Association Football is the real "football". So, if for no other reason than to avoid a tiresome argument, the term "football shaped" should perhaps be avoided.

Now that I think of it "ovoid" seems to cover all non-spherical football shapes quite nicely.

[Ann]

What confuses me is why anyone would want to call soccer football.

Because you use your feet to transport the ball.

What confuses me is why anyone would call a game "football" when you spend most of the time carrying the ball around in your hands.

Ann

[Nitpicker]

What confuses me is why anyone would want to call soccer football.

Because you you use your feet to transport the ball.

What confuses me is why anyone would call a game "football" when you spend most of the time carrying the ball around in your hands.

Ann

All the different kinds of football are football. The modern codes all have a common origin. You use your feet in all of them. Yet the ball is not conveyed with the just the foot in any of them. The only real problem that arises is when someone tries to say that one code is football and another isn't.

[geckzilla]

Also, Bystander was pretty clearly cracking a joke. When have you ever seen him use three emoticons before?

[Nitpicker]

But one of them was a "razz" emoticon. It is less offensive to foreign tribes if you refer to all football codes as a kind of football, before slagging off the rubbish ones.

[owlice]

I still think there is very little confusion over what is meant by "football shaped."

You are right that "football shaped" is not confusing. ...
if for no other reason than to avoid a tiresome argument, the term "football shaped" should perhaps be avoided.

Since "football shaped" is not confusing and very well describes the shape of various objects, why should it be avoided? I believe to the depths of my hard little stone heart that the vast majority of APOD's audience can figure out "football shaped"; those who don't will have learned something new when they ask about or research the term. APOD increases my vocabulary; that it does so is part of its value. Why would you want to take that away from someone else?

[Nitpicker]

I still think there is very little confusion over what is meant by "football shaped."

You are right that "football shaped" is not confusing. ...
if for no other reason than to avoid a tiresome argument, the term "football shaped" should perhaps be avoided.

Since "football shaped" is not confusing and very well describes the shape of various objects, why should it be avoided? I believe to the depths of my hard little stone heart that the vast majority of APOD's audience can figure out "football shaped"; those who don't will have learned something new when they ask about or research the term. APOD increases my vocabulary; that it does so is part of its value. Why would you want to take that away from someone else?

Well, you kinda sorta clipped out the answer to your question when you quoted me. Whilst the term "football shaped" is not confusing, it can be contentious, and hence distracting. As ridiculous as it sounds, this is simply because some people have perhaps too much emotion wrapped up into what the word "football" means to them. Yes, everybody knows what "football shaped" means, but some just don't like the use of the term. My comment was a general one, not specific to APOD, and not particularly critical or important.

It may sound silly, but it is quite similar to how the use of the word "faith" can upset some people on this forum, even when used in a non-religious and non-spiritual way.

[geckzilla]

I have faith that the non-planet Pluto is football shaped.

[Nitpicker]

From now on, as the FSM is my witness, I vow to ovoid the term "football shaped". Ramen.

[Nitpicker]

A forum member kindly PM'ed me with links to the previous discussions of "football shaped", before my time. I think my issues with the term are twofold and different from those stated previously by others. They are:

1) When one thinks of everyday shapes: triangle, square, oblong, circle, etc, it becomes immediately apparent that "football shaped" does not fit well in the list, and "American football shaped" is even worse. Both look clumsy, ridiculous and are ripe for criticism and parody. The word "oval" is the best fit. "Oval" is not as precise a word as "ellipse", and covers anything somewhat egg shaped, whether one end is fatter than the other, or not. The 3-D variant of an oval is an ovoid, and for an ellipse it is prolate spheroid (when rotated about the major axis), and oblate spheroid (when rotated about the minor axis). For all non-spherical footballs, "ovoid" is the best general description of the 3-D shape. But "oval" would do too, and is less esoteric, and so perhaps better. The word "oval" must be just as well understood as "football shaped", if not more, throughout the English speaking world (and beyond).

2) People who insist that "football", without qualification, can only mean Soccer or Association Football, are surely a little bit up themselves, and are another big part of this small problem. I live in a country where there are four codes of football played professionally on a significant scale. They are all commonly referred to as football, often without qualification. And the three most established are played with oval balls, none of which would ever be described as "American football shaped". Yet it is futile to confront this problem by continuing to use the term "football shaped", with insistence that there is no problem. It simply leads to discussions that go off on stupid tangents, like we see here. Better to avoid the issue with the term "oval".

[geckzilla]

And yet, it is not oval. It is more like two intersecting circles. The center of a Venn diagram.

[Nitpicker]

What is not oval? Oval does not have an exact definition, in all but a few contrived contexts.

All non-spherical footballs and this galaxy could be well described as oval.

[geckzilla]

Well, the sides of an oval are squished so they don't fit very well. The side of a football (viewed lengthwise) is an arc of a circle.

[Nitpicker]

Well, the sides of an oval are squished so they don't fit very well. The side of a football (viewed lengthwise) is an arc of a circle.

Footballs are not so precise. All non-spherical footballs have rounded ends to some degree. The ends of an American football are less rounded and more pointy than the others, but still not sharp to a point. They are all oval.

[geckzilla]

I don't think you get what I mean, really. It's a very specific shape. Of course the balls themselves are imperfect but when referring to the shape itself we are talking about two intersecting circles rather than a single oval, otherwise it would just be called an oval.

[owlice]

The only reason using the term "football shaped" leads to discussions that "go off on stupid tangents" is because some just will not reconcile themselves to the use of this perfectly understandable term in the text of a US site written by US astronomers!

[geckzilla]

I'll be damned, this shape has a name.
https://en.wikipedia.org/wiki/Vesica_piscis

(Although apparently this is a very specific ratio of intersection, so it doesn't quite fit what I mean)

[owlice]

Oh, that clears things up right smart; let's see APOD use that!

[geckzilla]

This isn't even a matter of words used in APOD descriptions anymore. This is a matter of a simple geometric object not having a name. "Lens" is more generalized and I had not thought of it quite that way before. What when the lens shape is very fat when the two intersecting circles approach overlapping?

[Nitpicker]

... a touch late, but:

when referring to the shape itself we are talking about two intersecting circles

If you need to be as precise as that, then you have vesica piscis lens:
http://en.wikipedia.org/wiki/Vesica_piscis
http://en.wikipedia.org/wiki/Lens_(geometry)

Less formally and less precisely, one could say cigar shaped, almond shaped, or simply a pointy oval. These are all better than "football shaped" in my opinion. I would have never associated the shape of any non-spherical football to be the same as a vesica piscis lens, as the sides of these footballs all have a variable radius. But then again, I am somewhat particular about geometry.

In the case of this galaxy, "oval" is sufficiently precise. One doesn't even need to say "pointy". (But "Football Galaxy" is still a fine nickname.)

[geckzilla]

A football is more closely represented by two intersecting circles than it is an oval. The oval only matches the shape of a football at four points while the shape of two intersecting circles only fail to outline it at the very ends where the pieces must be bound together in a way which will not gouge eyeballs from players' sockets.

Left, oval. Right, intersecting circles.

[Nitpicker]

A football is more closely represented by two intersecting circles than it is an oval. The oval only matches the shape of a football at four points while the shape of two intersecting circles only fail to outline it at the very ends where the pieces must be bound together in a way which will not gouge eyeballs from players' sockets.

The attachment football.jpg is no longer available

You appear to have assigned the definition of an ellipse (with a continually varying radius) to the oval you have drawn. But an oval is more generic than that.

I take your point that the vesica piscis lens is a good approximation to an American football -- better than I thought. In technical drawing, the "standard" way to define an oval is with two pairs of arcs with different diameters. This kind of oval gives the best approximation to an American football:

[Nitpicker]

It does go to show though, just for the different non-spherical footballs (American, Canadian, Australian, Rugby Union, Rugby League) that "football shaped" all made us think of slightly different geometry.

The only reason using the term "football shaped" leads to discussions that "go off on stupid tangents" is because some just will not reconcile themselves to the use of this perfectly understandable term in the text of a US site written by US astronomers!

That is still a reason, and it is not the only reason. Another was my point 1) above. But by all means, it you have no particular wish to discourage people going off on stupid tangents, then "football shaped" will do.