
Mathematical Jargon Failures - weinzierl
https://blog.plover.com/lang/math-jargon-failures.html
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eapriv
> That's right, ellipses are not elliptic curves, and elliptic curves are not
> elliptical. I don't know who was responsible for this idiocy, but if I ever
> meet them I'm going to kick them in the ass.

The referenced Wikipedia page contains a perfectly valid explanation for the
term "elliptic curves", and a little googling reveals that it was Legendre
who's responsible for "this idiocy".

~~~
mjd
Well, if I ever meet this Legender guy, I'm gonna kick his ass.

You can tell him I said that.

~~~
tempodox
_Legendre_

~~~
JdeBP
Not to disciples of Noah Webster. (-:

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pfortuny
The Type I and Type II errors is especially hurtful to me: I am totally unable
to remember which is which and each time I read an article containing them I
think: well, I am probably going to get it wrong again but I cannot bother to
check the definition one more time... who cares?

~~~
whooshee
Same here, and some definitions named by people's names. I totally understand
the need to attribute and respect people's work, but a more descriptive name
is almost always easier to remember and talk about.

~~~
jerf
This one at least has the justification that there often aren't any words.
When you're hip-deep in topology, grabbing graph theory with your right hand
and algebra with your left, you've left English way behind anyhow.

Now we just need to go back in time and convince Euler and Grothendieck to
pretty-please either discover fewer things, or change their names every couple
of years or something.

~~~
vharuck
How about including given names with everything named after one of the many
Bernoullis?

[https://en.m.wikipedia.org/wiki/Bernoulli_family](https://en.m.wikipedia.org/wiki/Bernoulli_family)

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rbonvall
One I hate is sin^{2}(x) meaning "sine squared" and sin^{-1}(x) meaning "the
inverse of the sine function".

~~~
grumdan
A nicer, consistent interpretation would be to take sin^2(x) to mean
sin(sin(x)) and keeping sin^{-1}(x) as an inverse.

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tempodox
I'm glad to see I'm not alone in my desperation over the fact that names in
math don't always mean what they seem to mean. Intelligent programmers have
noted more than once that naming things is one of the greatest challenges. In
hindsight, it shouldn't be too surprising that math suffers from the same
difficulty.

~~~
tempguy9999
Oh yes. I've a book on dynamic programming (Applied Dynamic Programming,
Bellman + Dreyfus, seriously over my head unfortunately) which uses
missionaries, cannibals and a boat to cross a river (page 97). The authors
talk about M cannibals and N missionaries. Note again: he used the letter M
for cannibals, not the missionaries, which I note start with that letter. And
he could have called the cannibals C but, no.

I literally can't understand what mental process led them to do this, or not
realise.

Another thing I detest is mathematician's fear of brackets. They'd rather use
a tower of unstated precedences than just bracketing the fuckers. Fine, I
suppose, if you know the subject but I was trying to learn something recently,
something with quantifiers and implications nested densely, and was left
mentally bracketing the various subexpressions to (try to!) work out what was
meant. If I have to fight the syntax I'm already being blocked from
understanding the semantics.

Mathematicians really do make things hard sometimes.

Thankfully us programmers are so much better (sarc)

~~~
jerf
Ah yes, you reminded me. There was another piece of jargon I was trying to
come up with that really stinks earlier, but I couldn't remember it. And
that's what it was: _dynamic programming_. Terrible name:

"Where did the name, dynamic programming, come from? The 1950s were not good
years for mathematical research. We had a very interesting gentleman in
Washington named Wilson. He was Secretary of Defense, and he actually had a
pathological fear and hatred of the word research. I’m not using the term
lightly; I’m using it precisely. His face would suffuse, he would turn red,
and he would get violent if people used the term research in his presence. You
can imagine how he felt, then, about the term mathematical. The RAND
Corporation was employed by the Air Force, and the Air Force had Wilson as its
boss, essentially. Hence, I felt I had to do something to shield Wilson and
the Air Force from the fact that I was really doing mathematics inside the
RAND Corporation. What title, what name, could I choose? In the first place I
was interested in planning, in decision making, in thinking. But planning, is
not a good word for various reasons. I decided therefore to use the word
“programming”. I wanted to get across the idea that this was dynamic, this was
multistage, this was time-varying. I thought, let's kill two birds with one
stone. Let's take a word that has an absolutely precise meaning, namely
dynamic, in the classical physical sense. It also has a very interesting
property as an adjective, and that is it's impossible to use the word dynamic
in a pejorative sense. Try thinking of some combination that will possibly
give it a pejorative meaning. It's impossible. Thus, I thought dynamic
programming was a good name. It was something not even a Congressman could
object to." \-
[https://en.wikipedia.org/wiki/Dynamic_programming#History](https://en.wikipedia.org/wiki/Dynamic_programming#History)

A Congressman may not be able to object, but I do! It's a particular flavor of
recursion, and perhaps a flavor of the term "recursion" would be called for,
but "dynamic programming" is essentially meaningless. Any addition meaning
that phrase may have in your head is almost certainly unrelated to what the
term refers to, since we've used "static" and "dynamic" in all sorts of ways
since the 1950s.

~~~
tempguy9999
Heh. That quote is from Richard Bellman. Same guy who was one of the authors
of that book I'm criticising.

But please allow me to disagree with you. The term programming/programme
predate programming as we know it, and he was free to use it in the sense of
'scheduling', much like a radio or TV schedule. The dynamic also makes sense
as the schedule (or whatever) picks its next state depending on a
previous/simpler state (hence a 'stage' in multistage, though I can't
understand his use of 'time-varying' here). I think it's ok.

I'd rather punch mathematicians who won't bracket over mathematicians who try
and protect themselves and their work from over-powerful, deeply stupid
people.

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knappa
"Cobordism" is actually more descriptive than he thinks, but it is French
derived. "bord" means edge or boundary and a cobordism is something which
connects two boundaries.

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MzxgckZtNqX5i
I can see the point, but I don't think it's a problem as long as the concept
is well-defined. It's only a matter of getting used to don't assume, for
example, "open" and "closed" to be mutually exclusive. There are other fields
that don't have the privilege of this formal setting: I expect the concept of
"species" to be very important in biology, but there isn't a clear definition
of that (yet) [0].

[0]
[https://en.wikipedia.org/wiki/Species#Definition](https://en.wikipedia.org/wiki/Species#Definition)

~~~
IshKebab
The problem is that it requires extra mental effort for zero benefit. For
example if I tell you that cos(x) is a symmetric function and sin(x) is
antisymmetric, the meaning is far more obvious than if I tell you one is odd
and the other is even. It costs you time looking the words up and energy
remembering them.

Species doesn't have an exactly bounded definition because it is not an
exactly bounded _thing_. It's like trying to define "life". This doesn't
really have anything to do with bad jargon though so I'm not sure why you
brought it up.

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thijsb
The referenced article, [https://blog.plover.com/lang/jargon-
failures.html](https://blog.plover.com/lang/jargon-failures.html), on jargon
failures is a nice read as well!

~~~
majewsky
IT is full of jargon as well. Where else would it make sense to cherry-pick
commits into a branch and then ask others to pull that branch into their
repository? :)

My German team has a running gag where, when a sentence turns out especially
jargon-riddled, we translate all the jargon words into German, as literally as
possible. The result is always hilarious.

~~~
roelschroeven
Sometimes IT and biology share some jargon, or at least they share the words
but not exactly the meaning.

Both in IT and biology a collection of trees is called a forest. In IT, if you
take a tree and remove the root, the result is a forest. Biologists don't
agree.

~~~
JdeBP
Don't forget the nut metaphor.

* [https://superuser.com/a/329479/38062](https://superuser.com/a/329479/38062)

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tzs
> Often brought up as an example are the topological notions of “open” and
> “closed” sets. It sounds as if they should be exclusive and exhaustive —
> surely a set that is open is not closed, and vice versa? — but no, there are
> sets that are neither open nor closed and other sets that are both

For a rant on this see "Hitler Learns Topology" [1].

[1]
[https://www.youtube.com/watch?v=SyD4p8_y8Kw](https://www.youtube.com/watch?v=SyD4p8_y8Kw)

~~~
jcranmer
That video is funnier than it had any right to be.

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Balgair
In spherical coordinates, the Physicists use Phi for the azimuthal angle, and
Theta for the equatorial angle. While the mathematicians use the opposite.
That was always fun trying to switch between for the various classes.

Additionally, the physicists use 'i' for electrical current, while the
electrical engineers use 'j'. Again, very fun trying to remember what is what
during finals week.

~~~
no_identd
>Additionally, the physicists use 'i' for electrical current, while the
electrical engineers use 'j'.

Sir William Rowan Hamilton would like to have a word with you. I think he
mumbled something about some bridge or something?

~~~
Balgair
Oh Jesus. Yes, then you have quaternions and octernions.

Never mind all the indices of Taylor Series.

The most beneficial thing that Einstein ever did was getting rid all the
Sigmas. He did other things too, of course, but nothing really compares.

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aesthesia
Even and odd functions don't form a partition of the space of all functions,
but they do span it as a vector space. What's more, the vector space of
functions is the direct sum of the even and odd functions: every function has
a unique decomposition as a sum of an even and an odd function. So the problem
there is that vector spaces don't behave the same way as sets.

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billfruit
I find the terms eigenvector and eigenvalue to be especially opaque, it does
not give any hint as to what it means at all to me.

~~~
F-0X
The general case of eigen-things has no other term to describe it. One might
want something that hints at the geometrical meaning of eigen{values,vectors}
when they learn about them in the context of multiplying vectors by matrices,
but ultimately the concept is a mainly algebraic one. Accepting this it
becomes easy to deduce what should be meant by "eigenfunction of the
differential operator". So I think, somewhat retroactively, "eigen" is the
best word to use there.

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psychometry
A field of sets is neither an algebraic field nor a collection of sets.

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ghettoimp
A wonderful related talk and discussion:
[https://news.ycombinator.com/item?id=15473199](https://news.ycombinator.com/item?id=15473199)

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man-and-laptop
The function f(x)=1/x is continuous, but its graph is not connected. It's an
interesting one to explain to people.

~~~
airstrike
Few things bother me more in life than the prevalence of Pi over Tau

~~~
mhartl
Amen, brother!

(I am the author of _The Tau Manifesto_.)

~~~
airstrike
I love you, I really do

That manifesto should be on the front page of the NY Times

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k__
lol, my cat needs clopen doors all day...

