<p><strong>L</strong>änge und <strong>B</strong>reite are the German words for longitude and latitude. Thus 'b' seems like a natural choice for latitude and 'l' for longitude. A century ago when traditional choice of variable names were chosen by vote of feet, a reasonable amount of research papers were still published in German or people with some form of fluency in German. At the same time it's distinct enough from the variable names used in other coordinate systems which also have longitude and latitude (like the terrestrial where <span class="math-container">$\lambda$</span> and <span class="math-container">$\theta$</span> are commonly used), so the cause for confusion is reduced - even when you don't know German.</p>

CC BY-SA 4.0
2021-03-18T00:35:25.513Z
Etymologically also very close to length and breadth, so even English speakers can relate.
Pierre Paquette
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2021-03-18T16:19:49.117Z
@PierrePaquette Interesting that the word for breadth is used for latitude, when it's normally shown as up/down, so the word for height would seem more natural.
Barmar
CC BY-SA 4.0
2021-03-18T16:33:57.680Z
Height would be the most inconvenient one to indicate positions on a 2D map as it's the 3rd missing coordinate for a point in 3D. Think of a parchment, a map. Especially on a scroll. The scroll has a length (longtidude), and a width (breadth). A map's rectangle has a width and a length when placed on a table.
planetmaker
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2021-03-17T17:19:44.667Z
2021-03-17T17:29:37.703Z
2021-03-17T17:29:37.703Z
planetmaker
<p>I'm not sure if this is a question that has been posted before, and I'm also not sure if the answer is really mnemonic. If that's the case, I'd like to understand why we assigned <span class="math-container">$b$</span> to latitude anyways, so my brain can remember it more easily.</p>
<p>Thanks!</p>

<history><terminology>
What is the mnemonic reason behind b being galactic latitude? (in the Galactic Coordinates frame)
nuwe
# What is the mnemonic reason behind b being galactic latitude? (in the Galactic Coordinates frame)

(Asked by: username_0 on 2021-03-17)

I'm not sure if this is a question that has been posted before, and I'm also not sure if the answer is really mnemonic. If that's the case, I'd like to understand why we assigned $b$ to latitude anyways, so my brain can remember it more easily.

Thanks!

**Tags:** history, terminology

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## 1 answers

### Answer by username_1 on 2021-03-17. Score: 12 | Accepted answer

**L**änge und **B**reite are the German words for longitude and latitude. Thus 'b' seems like a natural choice for latitude and 'l' for longitude. A century ago when traditional choice of variable names were chosen by vote of feet, a reasonable amount of research papers were still published in German or people with some form of fluency in German. At the same time it's distinct enough from the variable names used in other coordinate systems which also have longitude and latitude (like the terrestrial where $\lambda$ and $\theta$ are commonly used), so the cause for confusion is reduced - even when you don't know German.

> **Comments:**
> **username_2**: Etymologically also very close to length and breadth, so even English speakers can relate.  
> **username_3**: @PierrePaquette Interesting that the word for breadth is used for latitude, when it's normally shown as up/down, so the word for height would seem more natural.  
> **username_1**: Height would be the most inconvenient one to indicate positions on a 2D map as it's the 3rd missing coordinate for a point in 3D. Think of a parchment, a map. Especially on a scroll. The scroll has a length (longtidude), and a width (breadth). A map's rectangle has a width and a length when placed on a table.  

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