Say you have learned how to subscribe to RSS feeds using a feed reader, or an email account. You are ready to create your own RSS feeds.

A post is like an atom, and a feed a molecule. You can be a chemist to create your own molecules by discovering ways to form feeds. Here are the basic chemistry.

Atoms

• User number. Each user has a user number. You can find the number of a user by clicking his name or photo anywhere on iMechanica. You can also search for a user. For example, when you click a photo of John Hutchinson, you will be on this page, http://imechanica.org/user/452. The number in the URL, 452, is the user number of Hutchinson.
• Node number. Each post has a node number. You can find the node number of a post by clicking the title of the post, and looking at the URL of the post. For example, the post, http://imechanica.org/node/474, has the node number 474.
• Tag number. Each tag has a tag number. You can find the number for a particular tag by clicking the tag. For example, the tag "Research" is a channel featured in the header of iMechanica. Clicking "Research", you will see the URL, http://imechanica.org/taxonomy/term/76. The tag number is 76.

Rules of chemistry

• Blog entries of a user. e.g., the feed for the blog entries of Hutchinson (user number 452) is http://imechanica.org/blog/452/feed.
• Comments on a post. e.g., for comments on node 474, the feed is http://imechanica.org/crss/node/474
• Posts with the same tag. e.g., for all posts in the Research Channel (tag 76), the feed is http://imechanica.org/taxonomy/term/76/0/feed
• Comments on all posts with the same tag. e.g., for all comments on posts in the research Channel (tag 76), the feed is http://imechanica.org/taxonomy/term/76/0/feed.
• Posts in a forum. A forum works like a tag. For example, the Computational Mechanics Forum has the tag number 357, and its feed is http://imechanica.org/taxonomy/term/357/0/feed
• All comments in a Forum. e.g., for all comments in Computational Mechanics Forum (tag 357), the feed is http://imechanica.org/crss/term/357
• Posts with at least one tag in a set of tags. For example, the feed http://imechanica.org/taxonomy/term/357+445/0/feed gives you feeds of posts of both the Computational Mechanics Forum (357), and Technology Corner (445).
• Posts in Channels in the header of iMechanica. http://imechanica.org/taxonomy/term/76+128+346+75+77+118+74+73+135+437/0...
• Posts in Forums. http://imechanica.org/taxonomy/term/109+362+357+596+361+666+440+363+390+...
• Posts with a set of common tags. For example, the feed http://imechanica.org/taxonomy/term/527,528,529/0/feed gives you all posts of a course I taught, with tags ES 241 (Tag number 527), Advanced Elasticity (Tag number 528), and Spring 2007 (Tag number 529).

Tag numbers for channels featured in the header of iMechanica

• Research 76,
• education 128,
• classic 346,
• mechanician 75,
• opinion 77,
• industry 118,
• conference 74,
• job 73,
• tip 135,
• video 437.

Tag numbers for forums

• Ask iMechanica 109,
• Biomechanics Forum 362,
• Computational Mechanics Forum 357,
• Contact Mechanics Forum 596,
• Experimental Mechanics Forum 361,
• Fracture Mechanics Forum 666
• Fluid Mechanics Forum 440,
• Integrated Structures Forum 363,
• Materials Forum 390,
• Mechanics Course Forum 374.

Acknowledgments

I thank Michael H. Suo for showing me how comment RSS feeds work.