Frequently Asked Questions

How do I leave a comment or report an error?

Go to the auxiliary blog and post your comment there. If you're commenting on a particular article, PLEASE include the title or URL of the article so I can find it. Also, if you're asking about a particular equation in a post, PLEASE include the equation number. Many of these posts were written several years ago so they will not be fresh in my memory.

Why can't I see my approved comment in the original post?

If a comment asked for an explanation of something, I will add my response to the comments at the end of the relevant post. If you can't see the response, it may be because your browser is using an old cached version of the page. Try clearing your browsing history for the past few hours or days. The method for clearing browsing history varies with the browser, but for Google Chrome, click on the icon with three vertical dots in the upper right corner, select "More tools", then "Clear browsing data". Then click "Cached images and files" (and make sure no other checkboxes are selected unless you want other stuff to be cleared as well), and select the time interval from the drop down menu at the top.

Can you post solutions to problem X or book Y?

I'm working through some textbooks at my own pace and according to my own interests, so sadly, no, I can't accept requests to post articles on specific problems or textbooks. (Also, my own knowledge is quite limited, so I don't know the answers to everything!) If you want help with a particular problem, you can try joining Physics Forums, where a large audience is available to help you with physics-related problems. Note that to get help there, you will need to show that you have made a serious attempt at solving the problem yourself before asking for help.

Can you check my work on problem X and see where I went wrong?
Again, I don't have the time (or in many cases, the knowledge) to check work sent in by readers. If you've done a fair bit of work on a problem but can't get the right answer, again, I suggest visiting Physics Forums for help.
Can I get notifications of new posts?

I will post a link to each new article on the auxiliary blog and you can sign up for email notifications for that blog.

Why does the search facility on the home page give dead links?

The current version of was created in October 2017, and is a completely rebuilt version of the original site which dates from 2011. As such, the URLs of all the pages have been changed since the earlier version, so Google may still have some of the older URLs in its search database. Hopefully, these old dead links will disappear over time.