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Hydrogen is an open source drum set that runs on your computer. We’re going to take a short look at this exciting piece of software. For those uncertain as to what a drum kit is, just imagine a virtual drum kit (drums, cymbals, etc.) on your computer, but with an interface of sliders and knobs in lieu of actual drums. Read on. You’ll see.
Hydrogen presents an approachable interface that anyone familiar with audio-visual equipment, such as equalizers, should have little trouble finding his or her way around. Hydrogen’s interface is modular and incorporates timelines, sliders, knobs, toolbars, tabs and menus to help users get the job done.
The screenshot gives you an idea of what to expect. The screen is divided into panes, each one offering something special. Some components, such as the Mixer, operate from their own window. The upper pane is where compositions are created. The lower left pane presents instruments in the drum kit. The panel in the lower right allows users to toggle between modifications for the currently selected drum set and accessing the sound library.
Hydrogen is replete with features. One of these is a Pattern-based Sequencer. Hydrogen is designed to work with patterns. To facilitate this, the developers have also included an integrated Pattern Editor. Another impressive feature is unlimited instrument tracks. That’s right. A composition created in Hydrogen can have unlimited instrument tracks. It’s almost mind-boggling.
Hydrogen offers support for QT5, MIDI and OSC file formats. Hydrogen also provides support for sound library images. If drums are not your thing, it’s possible to import different musical instruments. There is support for managing different sessions. Support for basic exportation to LilyPond is also available. Playback capabilities and menu editing are two more useful Hydrogen features. Hydrogen can be easily customized via the Preferences option under the Tools menu. Tutorials and full documentation are available on Hydrogen’s Web site.
What You Can Do With Hydrogen
Arguably, users are limited only by their imaginations when using Hydrogen. Compositions can be played back as desired and easily modified. There are some pre-designed drum kits available for Hydrogen on SourceForge with which to experiment. In short, users can create the musical composition of their dreams. More advanced student programmers may interested in knowing that Hydrogen is written in the C++ programming language. As it is open source, this opens up wonderful opportunities for collaboration between music and tech departments. If properly implemented, students from the realms of computer programming and music could meet, share ideas and create that indispensable Hydrogen component. How cool would it be if students from your school could make this claim? Best of all, Hydrogen is available for Linux, Microsoft Windows and Apple MacOS, so it probably will run on the platform of your choice.
Hydrogen [computer software]. (n.d.). GNU General Public License.
Piraino, A. et al. (n.d.). Hydrogen manual. GNU General Public License.
One of the two people who reviewed my book on Amazon stated that he was disappointed as he expected a collection of lesson plans with open source technology integrated into them. My line of thought was that I’d put enough effort into researching, organizing and presenting the book’s contents that I really didn’t want to construct lesson plans to go with the software. Here, I attempt to amend this. This activity incorporates science (ecology), mathematics and physical fitness. As this involves going outside, choose a week when the weather looks most cooperative.
This would work best with students in primary grades, but could be modified for intermediate-level students with ease. The best time for this is at the height of the fall season, when plenty of leaves litter the ground. Each student will need a plastic grocery bag or food storage bag. Each student will also need a Leaf Sorting Sheet (see below) and access to an electronic spreadsheet. In keeping with the open source theme of this blog, I chose LibreOffice Calc, but any such application will do. At the end of this article there are links to download the Leaf Sorting Sheet, in ODT format, and the Leaf Tally Sheet spreadsheet, which is in ODS format and can be used as a template to design your own. Note that the species of trees listed on these two items are indigenous to the northeastern United States, so please feel free to adapt them to match species found in your vicinity.
Introduce the activity by asking if anyone knows what a safari is. Tell your students that we’ll be going out to the playground on a leaf safari and, in so doing, will learn a little about local ecology. They are to collect as many leaves as they can, but they should try to select a variety of leaves. When we’re finished, we’ll take a look at what we’ve got and make spreadsheets and graphs showing our findings.
Head out to the playground, preferably between recesses, so your students will have fewer distractions. Give them 20 minutes to complete this task. They can work with a partner, if desired. At the prearranged time, call them back and head back to the classroom. Each student/group will need a Leaf Sorting Sheet. Give the students 10 minutes to sort their leaves and be prepared to answer any questions that may arise regarding leaf types and sorting practices.
When the sorting is finished, you can have your students open the spreadsheet that you have previously created. I’d suggest using mine as a template and make any changes needed to it. Anyway, each student, or group of two students, should have his or her own spreadsheet into which they will enter the quantity of each collected leaf type. When done, guide the students, if necessary, preferably using a projector connected to your computer, through the chart creation process. This will provide them with a graphical representation of their leaf collections. These graphs can be printed and put on display in the classroom. For closure, ask students what they may have learned while doing this activity. Were some species of leaves more prevalent? What does this tell you about the kinds of trees that grow in this area? Now that you now how to put data into a spreadsheet and to create graphs, in what other tasks could you use these tools?
I hope you’ll find this activity useful and that you and your students both enjoy and learn from it. I welcome any comments or ideas.
Do you know a writer who would benefit from a distraction-free writing environment? This writer could be yourself, a student or a colleague. Distraction-free refers to any application that allows you to work without inundating you with menus, pop-ups and other distractions. Thus you can just focus on the task at hand. FocusWriter is a distraction-free word processor that exemplifies this concept.
Once launched, FocusWriter fills the screen with an image of a blank piece of paper resting on a desktop or table top, as shown in the screenshot. The user just has to start typing. By default, FocusWriter runs in full-screen mode. This blocks out the operating system’s graphics, including the desktop/wallpaper, icons, window widgets, taskbars and docks/panels (if your OS has them). With said distractions removed, the user need only concentrate on his or her literary creation.
Don’t let the apparent lack of tool and menu bars fool you. FocusWriter is a full-featured word processor with support for .TXT, .RTF and .ODT file formats. Integrated features include, but are hardly limited to, text formatting, spell-check, a search-and-replace feature, smart quotes and autosave. Once a user has saved his or her work, this piece will be opened by default the next time FocusWriter is launched. Add to all of this the high level of customization available and you have a powerful writing tool.
Should you need to access the menu or toolbar, have no fear. Though said items are not visible on the screen, they can be readily accessed. Hovering the mouse pointer at the top of the screen causes the menu and toolbar to drop down. From here, users can save or load files, format text and adjust settings, among other things. Moving the mouse pointer to the bottom of the screen reveals a bar that lists open files in tabs, tracks the word count, tracks daily progress and provides a digital clock. Moving the mouse pointer to the left-hand side of the screen presents a panel that can be expanded to allow for easy page navigation. Opposite this, on the right-hand side of the screen, hovering your mouse pointer opens a scroll bar.
For educators, FocusWriter has much to offer. A timer and alarm can be set up so that students, and their teachers, can verify the amount of time invested in writing. Daily goals can also be established and monitored. It’s possible to enhance the distraction-free environment by adjusting the Focus Text option under the Settings menu. Here, lines or paragraphs not being currently worked on can be set to appear as faded. Students will love the fun ways in which FocusWriter can be customized. There are four themes from which to choose (I chose Space Dreams for the screenshot), as well as an optional typewriter sound effect. Finally, FocusWriter is available in over 20 languages. Get FocusWriter now and enter the world of distraction-free writing.
FocusWriter is available for Linux, Microsoft Windows and MacOS.
Gott, G. (2017). FocusWriter [computer software]. GNU General Public License.
Gott, G. (2017). FocusWriter. Retrieved from https://gottcode.org/focuswriter/.
Getting back to educational technology, I’d like to focus on a tool that music teachers and their students will love. Rosegarden is an open source application for composing, mixing and editing music and sounds. It was developed around a MIDI sequencer with an understanding of musical notation and featuring support for digital audio.
Rosegarden is feature-rich, although this depends on the available hardware resources. The more recent or “cutting edge” the hardware, the more features available to the user. Rosegarden supports the importing and exporting of MIDI files. One caveat regarding this is that the Rosegarden Manual states that information about the file in question will be lost if the file is not saved in Rosegarden’s native .rg format. Such files are referred to as Rosegarden Project Files and contain all of the musical note information of the file in question as well as MIDI controller settings, plugin details and the names of any audio files included in the composition. Other supported sound formats include, but are not limited to, Csound, Hydrogen and MusicXML.
The default track-based overview allows users create sound “segments” by clicking-and-dragging or by double-clicking on the desired sound file. Additionally, Rosegarden offers some powerful editing tools. These allow users to get their ideas down and to tweak them as desired. There are three editing windows -the matrix editor, the notation editor and the event editor. These windows share a common interface for ease of use. Musical notes can be entered using either a MIDI keyboard or a computer keyboard. Furthermore, all editors offer unlimited undo and redo. The pan and zoom interface near the bottom of the matrix and notation editors provides axis-independent zoom and fast navigation.
Rosegarden offers many other features. The notation editor allows users to view the musical notation of their work, which can provide an alternative view of a composition. This editor can be used simultaneously with other Rosegarden components. Rosegarden will automatically update the work, saving recent changes simultaneously in all instances of it running in other components. Sheet music can be printed using LilyPond, an open source music engraving program. In terms of audio, file creation is easy. As mentioned previously, external sound files can be dragged from a file manager window and dropped into Rosegarden. From there they can be moved, resized, repeated and more. The synth plugin allows for accurate synthesis of MIDI tracks. The full-audio-effects plugin allows for the addition of audio effects to the composition. Add to all this the capacity to integrate Rosegarden with other Linux sound applications via the JACK audio connection framework and you have a very powerful and flexible sound mixing tool.
If you’re serious about sound mixing, you should definitely give Rosegarden a test drive. Rosegarden is available in English and, thanks to volunteers, in Russian, Spanish, Finnish, Japanese and Indonesian to name a few other languages.
Rosegarden is currently available for Linux and Microsoft Windows.
All images property of the Rosegarden Team.
Cannam, C., Bown, R. & Laurent, G. (2008). The Rosegarden handbook. GNU Genreal Public License.
Laurent, G., Cannam, C. & Bown, R. (2008). Rosegarden [computer software]. GNU General Public License.
Arguably, storyboards provide the ideal way to introduce young academicians to writing. Story Maps is an open source application that provides young authors with a graphical interface with which they can plot their stories and a text editor to provide the details that will bring their stories to life. In short, Story Maps is a virtual storyboard. The developer who created this application did so as part of his post-graduate studies in conjunction with teachers, students, creative writing experts and an illustrator. It utilizes story elements commonly found in fairy tales.
Upon launch, the user is presented with Planning View, which offers a simple interface. The screen is divided into upper and lower halves. The upper half has a green background and offers tiles, called story cards, from which users can choose story events. The story cards are labeled and have a corresponding image to further convey their purpose. Hovering the mouse pointer over each story card enlarges it and provides the user with additional information about that particular story card.
These story cards can then, individually, be dragged and dropped onto the gray field in the lower half of the screen. Here, they can be arranged into a story map. Near the top of the Story Maps window is a menu bar offering one option, File. From here, users can save the current story, open an existing story, preview the current story, save the current story as HTML or print the story. At the bottom of the screen is a panel offering options to Write your story!, enter your story’s title and a button that allows users to sort story cards. The result is an interface that allows ready access to features and that is also aesthetically appealing and delightfully engaging.
Using Story Maps is easy. As mentioned above, simply click on and drag story cards to the canvas below. Once the story cards are selected, users click on the Write your story! button. This brings up the story editor that takes up the lower half of the screen, while the selected tiles move to the upper half of the screen. The current story card is displayed to the left of the editor.
The story card is described (e.g. Home: “How the story starts”) to the right and ideas for what to write are presented below this description (e.g. for the Home tile: “You could: Introduce the main characters and…”). Scrolling down in this pane brings the user to the editor where the stories are typed. Below this is a toolbar offering Cut, Copy and Paste options on the left and Save Story, Preview Story, Save Story as HTML and Print Story on the right. Prev and Next buttons with appropriate arrows are, respectively, on the far left and far right of this pane and allow users to scroll through tiles without having to leave the editor. Clicking on the Go back to planning button moves the editor pane down so that the writer can access the story cards.
In terms of exportability, Story Maps can save only to its native format and HTML. The HTML format is more like of snapshot of the sessions in question, as can be seen in the screenshot above. Printed pages look just like the HTML pages. The beauty of this is that the hard copy can serve as a graphic organizer when moving the story text to a word processor where the story can be viewed without graphic organizer components.
So, if you’re looking for an engaging application that serves as a graphic organizer and as a motivator to get young academicians writing, give Story Maps a try.
Story Maps is available for Linux, but there are similar Web-based programs available online.
The Story Maps Web site
Fernandez-Sanguino, J. (2012). Story maps: general commands manual. GNU General Public License.
Hammond, S. (2012). Story maps [computer software]. GNU General Public License.
Arguably a difficult transition that Windows users undergo when switching to Linux is the lack of video editing software, like Microsoft Movie Maker. Have no fear! Pitivi comes to the rescue. Pitivi (pronounced pee-tee-vee) is an open source video editor for the Linux operating system and built upon the GStreamer multimedia framework.
Upon launch, Pitivi opens a greeting window providing the user with the opportunity to open an existing project or to create a new one. Behind this is the main screen where the film editing/creation takes place. The interface is pleasantly straightforward and intuitive. A menu and toolbar at the top of the screen are referred to as the header bar. Below this are two tabs, or primary tabs, to the left, above a pane. These tabs allow users to toggle between the media library and effects library. To the right are the contextual tabs, which allow users to view clip properties, add transitions and to add titles. To the right of this, is the viewer, through which users can observe their developing creations. The interface for the viewer is the same as for any media player. Below these three panes is the ruler and below that the timeline. This is where videos are placed to be modified.
Media can be added to the media library by either clicking on and dragging the desired file from the file manager window to this pane or by clicking on the Import button above this pane and to the left. When imported, media can then be dragged to and dropped on the timeline. Once a film clip is added, the clip as it will be seen by viewers appears in the viewer. When a user clicks anywhere along the timeline, the viewer jumps to that position. Using the timeline toolbar to the right of the timeline, users can delete selected clips, group clips, ungroup clips, copy, paste and toggle gaps in media. All edits affect the selected clip.
A click of a mouse button (right or left) places the playhead at the desired point on the timeline. This is where splits are inserted. Other tweaks involve being able to control the zoom on the timeline, adding a title, adding special effects and adding transitions. As effects are added to a clip, they are listed in the contextual tab with a checkbox next to each. The checkboxes are checked by default, so, as expected, unchecking one disables it. Effects include, but are by no means limited to, such items as facedetect (detects faces in videos), kaleidoscope and Tunnel (creates a light tunnel effect).
Pitivi is very versatile in terms of file support. Projects may be saved (or rendered which is the term used in Pitivi) in the following formats: AVI, Apple QuickTime, Ogg Vorbis, MP4 and MPEG to name a few. Furthermore, Pitivi offers excellent project management. The term project in Pitivi refers to any film being edited. But users can save their projects at different levels of completion or in different file formats. Many different settings can be adjusted, such as pixel and display aspect ratios, and there is an excellent Undo/Redo utility.
Now that you’ve read about what Pitivi can do, give it a try. Better still, let your students give it a try if you really want to see Pitivi put through its paces. If you’re so inclined, you can also contribute to their fund drive. Such support is always appreciated.
Note: Pitivi is designed to run on the GNOME Desktop Environment. However, all of the author’s screenshots were taken while running Pitivi on the Xfce Desktop Environment upon which it ran without issue.
Pitivi [computer software]. (n.d.). GNU General Public License.
JPitivi quick Start manual. (n.d.) GNU General Public License. Retrieved from http://www.pitivi.org/manual/.
Taking a break from my more traditional topics of STEM and programming, I’d like to put the Arts into the spotlight for a change and talk about Ardour, an open source application that allows users to create audio compositions. Undoubtedly, music teachers out there are familiar with the proprietary, but WYSIWYG software, Accoustica Mixcraft. Ardour is just as WYSIWYG, but, as mentioned above, open source. Let’s take a look at Ardour right now.
Ardour is designed to be suitable for audio engineers, musicians, soundtrack editors and composers, but it should be just as ideal an environment for young composers to create their masterpieces. The interface is very similar to the aforementioned Mixcraft. The Editor Window presents a menu at the top of the screen allowing for ready access to features. Below this, the Transport Menu allows users to navigate (Play, Fast Forward, Loop, Record, etc.) through clips added to the Main Canvas below.
. To the right of the Transport Menu are the Clocks, offering four time formats. Right of the Clocks are the Edit Modes and Cursor Modes controls, which allow users to edit clips. Below this is the aforementioned Main Canvas in which sound and video tracks appear, each with its own track. Each track can then be edited individually. To the left of the Main Canvas is the Editor Mixer, which allows users to control volume and other features using slider controls.
So, what can you do with Ardour? I’d venture to say that you could do just about anything that you could do with Mixcraft. Rather than to compare the two, I’ll focus on Ardour’s features and what can be done with them. First of all, Ardour supports importing of the following audio types: AAIF, BWF, CAF ,FLAC and WAV. In terms of audio exporting, the following formats are supported: AAIF, BWF, CAF, FLAC, Ogg and WAV. Ardour is not just limited to handling sound. Videos can be imported and soundtracks extracted from them. Videos can be displayed frame-by-frame on the Video Timeline for easy editing. Users can add start/stop points to the video as well as blank frames and mix the video with the soundtrack of the current session. An Ardour session can even be run simultaneously on multiple computers.
This all sounds great, but it gets better. There are many plugins available for Ardour that enhance its functionality. These are conveniently handled through the Plugin Manager. Plugins allow users to create various audio or MIDI effects and to generate audio by functioning as “software instruments.” Additionally, although Ardour does not include music/sounds of its own, these can be downloaded from sites like Freesound (see below) and then imported into Ardour.
After reading this, I don’t know why you’re not downloading Ardour right now. Your students may not thank you with words, but their compositions will speak volumes.
Ardour is available for Linux and Apple MacOS.
Thanks to Paul Davis of the Ardour Development Team for permission to use all images included in this article.
Ardour [computer software]. (n.d.). GNU General Public License.
Ardour Manual. (n.d.). GNU General Public License.
Mixcraft 7 vs Ardour -audio editing comparison. (2016). Software Insider: Graphiq, Inc. Retrieved from http://sound-editing.softwareinsider.com/compare/39-169/Acoustica-Mixcraft-7-vs-Ardour.
It’s been almost three years since a wrote a little blurb on an exciting application that allows learners to explore geometry. That application was Dr. Geo and its developers recently, and with much-deserved pride, announced the release of its latest version. With that in mind, I thought that maybe it was time to take an in-depth look at Dr. Geo.
Dr. Geo is an open source application that provides an engaging environment through which school-age learners may explore, and learn about, geometry. So, what can users do with Dr. Geo? Users have the opportunity to work with the building blocks of geometry, including points, line segments and rays. Users can create arcs, circles and polygons. Vectors can be used to accurately assign points. Virtually anything geometric in nature can be created.
What’s even more amazing is that Dr. Geo allows users to bring their creations to life through computer programming. The programming language used in Dr. Geo is the same one used to create Dr. Geo –Smalltalk. Some of my regular readers may remember a blog that I wrote a while back on Pharo, a computer programming environment. Pharo also uses Smalltalk. Smalltalk is an open source object-oriented programming language. This simply means that it focuses on objects and data rather than commands and logic. Portland State University computer science professor Harry H. Porter III (March 24, 2003) describes Smalltalk as “highly efficient, extremely portable, easy to use, and very reliable. But more importantly, Smalltalk is still the most enjoyable language in which to program.” What better tool to employ to introduce learners to computer programming?
As can be seen in the screenshots, Dr. Geo’s interface is very straightforward. All actions can be performed readily via a menu, a toolbar or tabs, all located at the top of the Dr. Geo window. This traditional interface certainly minimizes the learning curve. Even without having used the software, users can jump right in and begin creating. Functionality is also enhanced by tooltips, which provide a quick way to identify tools.
So, what are you waiting for? Your students’ potential as geometricians and computer programmers is waiting to be unleashed.
Dr. Geo is available for Linux, Microsoft Windows and Apple MacOS.
Fernandes. H. (2016). GNU Dr. Geo [computer software]. GNU and MIT General Public Licenses.
Porter III, H.P. (2003). Smalltalk: a white paper overview. Portland OR: Portland State University. Retrieved from http://web.cecs.pdx.edu/~harry/musings/SmalltalkOverview.html#Basic%20OOP%20Concepts%20and%20Terminology.
ExpEYES is a low-cost open source framework of computer hardware and software that provides a means to perform low-cost science experiments using computers. ExpEYES offers formats designed for students from high school on. Let’s take a look at what can be done with ExpEYES.
According to its Web site, ExpEYES is a tool for learning science through exploration and experimentation, It includes integrated an oscilloscope and a signal generator and is powered via USB. ExpEYES offers 12-bit analog resolution, accurate measurements and is physically compact, for easy relocation. The software for ExpEYES is written in Python, an open source programming language. The online manual presents 50 (yes, fifty!) experiments that users can duplicate and, perhaps tha coolest feature of all, others can be easily created and added to the list.
So, from where does this marvel of scientific exploration come? ExpEYES was developed by the PHOENIX project of Inter-University Accelerator Centre (IUAC) of New Delhi. The long-term goal of this project is to make the equipment and methods used in research available to the student community. In science, experiments are performed, data is collected and analyzed. Conclusions drawn. The difference offered by ExpEYEs is the fact that the equipment is affordable.
So, what kind of experiments can a burgeoning scientist perform with ExpEYES? According to the ExpEYES User’s Manual, users can conduct experiments involving electricity, magnetism, electronics, sound, mechanics, optics, heat and computer programming. In terms of electricity, young scientists can perform experiments involving, among many other topics, voltage measurement, water conductivity and AC circuit study. Regarding electricity and magnetism, possible experiments include creating a simple AC generator and making an electromagnet. Some of the other experiments include amplitude and frequency modulation (electronics), sound velocity, using a stroboscope and hardware communication.
As potentially enriching as ExpEYES sounds, it is just one of several open source technology products created as part of the PHOENIX Project. If you’re interested in learning more about this and other opportunities to cultivate the scientists and engineers in your school, you should check out the ExpEYES Web site. Your students will thank you through their creations, if not through their words.
Thanks to Ajith Kumar for his support, the contributions that he provided and for suggested modifications.
ExpEYES is available for Linux and Microsoft Windows. It is available in Canada and the UK.
ExpEYES junior user’s manual: experiments for young engineers and scientists. n.d.). New Delhi: Inter-University Accelerator Centre. GNU General Public License. Retrieved from http://www.iuac.res.in/~elab/expeyes/Documents/eyesj-a4.pdf.
I came across this little gem while perusing the Ubuntu Software Center and decided to give it a shot. Stellarium is an open source, free planetarium that runs right on your computer. To be honest, I was really taken aback by Stellarium’s stunning appearance and visual quality. For one thing, it doesn’t run in a window. It launches into full-screen mode, which beautifully presents the eye-catching graphics. I can discuss this further at another point.
As previously mentioned, Stellarium opens in full screen mode by default. The user finds him or herself looking up at the night sky in the northern hemisphere. Only the major heavenly bodies and cardinal compass points are labeled. The interface is very straightforward. At the bottom of the screen, a panel provides information such as location (Paris, France by default), elevation, Field of View (FOV), Frames Per Second (FPS), date and time. Clicking on a heavenly body brings up information about that body, such as its name, position and distance from Earth. Configuration is handled through two docks/panels called toolbars in the lower left corner. The bottom toolbar, or main toolbar, allows the user to turn visual effects on and off. The side toolbar opens dialog boxes used to configure Stellarium.
So, what does Stellarium have to offer in terms of features? According to the Stellarium Web site, Stellarium includes a default catalog of over 600,000 stars (though additional catalogs containing up to 210 million are available) There are optional connecting lines and/or illustrations (referred to as Constellation Art) that can be toggled to better visualize constellations. Stellarium offers constellations for over 20 cultures and the stories behind those constellations. Views of every planet, and their satellites, are provided. Other features include powerful zoom, multilingual support, time controls, excellent graphics and integrated help.
Arguably, one of Stellarium’s greatest strengths is the level of customization that it offers. First of all, as I mentioned, Paris, France is the default location. Paris is, however, one of hundreds of locations around the world from which users may choose for their session. Additionally, if you’re bored with Earth, you can view the stars from such heavenly bodies as Mars, Saturn or the Moon. One feature that the author thought was pretty cool was being able to toggle the visibility of the ground. Remove the ground and you can view the whole night sky, northern and southern hemispheres, just as if you were in outer space. Other features that can be controlled include equatorial and azumuthal lines, the flow and direction of time and visibility of nebulae. Combine these with the many other features available and you have an incredible platform upon which your students can explore the universe.
Stellarium is available for Linux, Apple MacOS and Microsoft Windows.
Category: User’s guide. (2014). Retrieved from the Stellarium Wiki: http://www.stellarium.org/wiki/index.php/Category:User’s_Guide