I needed a diagram for an article on noctilucent clouds. They range from pretty (and copyrighted) to pretty ugly online so I had a go at making my own. As usual this was done with LaTeX (via LyX) and PSTRICKS.
Here's the finished picture:
The diagram is simple: part of a circle, some tangent lines, cloud symbols and labels. Then shade between the various curves and lines. Finally, a multi-do loop to draw the Sun.
Details below the fold.
Just put the finishing touches to a planetary elongation chart. Here it is in all of its glory:
A high quality PDF can be downloaded here.
This chart shows the positions of the naked-eye planets to the east (left) or west (right) of the Sun. The vertical axis represents the days and months of the year. The diagonal bands represent constellation boundaries. The wavy yellow band is a region close to the Sun in which it would be difficult to observe the planets. This chart behaves like a game of PacMan; any planets reaching opposition 180 degrees west of the Sun wrap straight over to the evening sky on the far left. Think of this as being like an unwrapped cylinder!
The places where the paths of the planets intersect represent conjunctions. These are visually striking opportunities to see bright planets shining together in the sky. In 2015 there are at least 12 such opportunities.
There's a particularly striking gathering of the planets in the morning sky during October 2015. The planets Mercury, Venus, Mars and Jupiter will all appear together before sunrise on many of those autumn mornings.
I was introduced to the joys of LaTeX (and TeX) by my PhD supervisor about 13 years ago. When it came to writing up scientific reports and documents Microsoft Word just didn't cut it; documents with inline equations in Word just looked bad. Things may have improved since then (I'm not convinced) but polished, beautifully typeset documents come from LaTeX.
However, LaTeX has a steep learning curve. You have to write code in LaTeX (to produce everything from headers, footnotes, bold text, equations, etc) and then compile the document to see how it looks. LaTeX is best described as WYSIWYM (What You See Is What You Mean). LaTeX's internal algorithms deal with the best places for page breaks, positioning diagrams, equations, footnotes and so on. This is not the same as Word (or equivalent), with its WYSIWYG (What You See Is What You Get) interface and bewildering choices of styles for everything.
Now to the point.
LaTeX has a steep learning curve - no doubt about it. In recent years there have been attempts to put a nice front end on it. Something between Word (with it's shortcuts and buttons) and raw LaTeX (with the actual coding hidden from view but not inaccessible and still easily customisable).
My favourite editor - by a mile - is called LyX. I like it because it's free and easy to use. I wrote my mathematics textbook using LyX. All of my course notes were produced with it. Any time I need a diagram or figure for an exam paper....I write the code to produce it. Just to give you an idea how I use it, here's an example: a slab of graph paper with an irregular shaded region. This was part of a question about using Simpson's rule to compute areas.
To produce this diagram I called the package "pst-plot" in the LaTeX preamble within LyX:
and in the document window I placed some ERT (evil red text - raw LaTeX!)
...and LyX outputs a hires plot to the exact specifications I need.
It's easy to get started - just go to the LyX website and download the latest stable version (currently 2.10).
Welcome to my blog!
Dr Adrian Jannetta. Amateur astronomer, maths teacher and science enthusiast.