I'm in the camp that mathematics is a language. But it's more than that.
The Embalse Nuclear Power Station in Argentina, a pressurized heavy water (PHWR), is a building. Yes, Embalse is a building, but it's more than just a building. Similarly, mathematics is a language, but it's more than that.
Mathematics is a language, but it's a very special, very precise language. It is also a tool of logic (
tool being the key word here). And in addition to those, it is an embodiment -- an abstract repository so to speak -- of a particular body of knowledge: the very logic itself of previously proven ideas.
Language:
I think it was Stephen Hawking that related an anecdote told to him by his publishers when writing one of his lay-person targeted books. They told him something to the effect that every equation he put in his book would drop the book's sales by 10% (or some-such). I guess most lay-people are scared away by equations and will put the book down if they see one.
I find that sad, because
communicating certain ideas are so much clearer in my opinion if they are communicated with equations and math. One could say, "the gravitational force between two bodies is proportional to the area of a rectangle who's length takes on the mass of one body and who's width takes on the mass of the other body; and the force is also inversely proportional to the area of a square who's sides are the distance between the two bodies." Gah! Are you kidding me? Just say,
F = G \frac{m_1 m_2}{r^2}.
That's so much more clear to me, and communicates the same idea! Then again I've taken the time to learn what that notation means, with the multiplication and the division and the squaring operation. So I understand that maybe some others less well versed in mathematical notation would prefer the former. If only they knew what they're missing!
Tool:
Egill Skallagrímsson, born in Iceland in the tenth century, in a time and place where the common person could not read a written language (paper and parchment had not been introduced to Scandinavia yet), was a famous warrior-poet. While most people couldn't read or write, Egill on the other hand had learned the "runes." He could read and write. I can imagine Egill scratching out a poem-in-progress in the dust by his feet as he's working out the details, "Hmm, that doesn't quite fit. Let me scribble that out. Ah, that word works much better here." A written language can be a wonderful tool to organize one's thoughts before speaking them.
English is a spoken language but also has a written form, and they are different from each other. Although the written form does not have the pronunciation, and the spoken form does not have the spelling, nor the same detail of punctuation. (Before arguing that the written language simply imitates the spoken form, ask yourself why the language has words with silent letters.) Try to read a book to someone out loud, and the style is noticeably different than it would be if the story was created and spoken on the spot. It becomes quite obvious that there is more to the written word than just the fact that it is written.
This is where the written form of mathematics really shines. It's able to communicate ideas and relationships that simply couldn't be clearly spoken. It aids one in organizing one's thoughts in ways that the common, non-mathematical language fails.
With only a little effort, starting with
F = G \frac{m_1 m_2}{r^2},
I can use mathematics to reorganize that idea and say,
r = \pm \sqrt{\frac{G m_1 m_2}{F}}.
That would be difficult if the only language available was English.
[Edit: And elaborating on this tool idea, sometimes when physicists and engineers use mathematics to rearrange and combine thoughts it can help lead to new, unexpected ideas. For example, when Paul Dirac reformulated the ideas of non-relativistic quantum mechanics with the principles of special relativity, it lead to hints of antimatter. The existence of antimatter "fell out of the math" so to speak (this relates to the \pm sign when you take the square root). Mathematics is not just a tool, it can be used, in part, as a predictive tool.]
Knowledge:
Pythagoras proved that for a right triangle, c^2 = a^2 + b^2. Brahmagupta derived the roots of a second order polynomial to be x = \frac{-b \ \pm \sqrt{b^2 - 4ac}}{2a}. Euler showed us that e^{ix} = \cos x + i \sin x (and yes, this is a provable relationship -- not a mere definition or "trick"). Once proven, those ideas become added to the overall body of mathematical knowledge. We don't need to re-prove them from scratch when working on other things; we can leverage the results and go from there.
So mathematics isn't just the language of logic, it also embodies the very logic itself of previously proven theorems.
---------------------------------------------------
I'll end this post with a love poem I wrote several years ago:
A love poem, by collinsmark:
The number of ounces per ton,
less a dozen times square fifty-one,
with the cube of neg-nine
together combine
to make three score, less one to the none.
32000 -(12)(51)^2 + (-9)^3 = 3(20) - 1^0