Frequently Asked Questions

What happened to the solutions of problems from various textbooks?

Due to a DMCA (copyright violation) complaint from the publisher of some of these books, I have had to remove my posts on these books from the site. I hope to gradually repopulate the site with more general articles that don't include explicit solutions to problems.

Can you send me some of the files that have been removed due to copyright problems?

Sorry, no, I cannot release any of these files. I realize that some people would just store them on their local drive and thus not be subject to copyright violations, but I have no way of verifying this or of controlling how far a file will spread if I send it to you.

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 data for the past few hours or days. The method for clearing browsing data 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?

As I mentioned above, due to copyright restrictions, I cannot post solutions to specific problems from textbooks. If you want help with a particular problem, you can try joining Physics Forums or Physics Stack Exchange 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 or Physics Stack Exchange 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?

Google's database contains links to many of the old pages that have now been removed due to copyright restrictions, as described above. Hopefully, these old dead links will disappear over time.

Can you provide a single PDF file with all the posts?

No, since I periodically update files with corrections or additions, and also pingback links are added to older posts that link them to later posts. If I provided a single PDF with all the existing posts, I'd have to update this file every time any of the files within it were modified, which isn't practical.

Would you be interested in monetizing physicspages by placing ads on it?

The short answer is NO! I, like most other internet users, find ads highly annoying, so I will not clutter up physicspages with them. The site is entirely non-profit and will remain so.

How do you generate the equations, diagrams and plots in the posts?

I write the posts entirely in Latex using the Lyx editor, which is free. It requires an installation of Latex on the same machine, but this is provided as part of the Lyx download.

To handle lengthy or tedious calculations and to draw plots I use Maple. Maple isn't free, but there is a personal edition available for a much reduced price. To get this, you need to convince them that you're not associated with a university or business, and that you aren't making any money out of it. For me, this was just a matter of exchanging emails with them explaining I was using Maple for a non-profit physics blog. The Maple personal edition is identical to the full version. If you plan to do a lot of calculations, I find the investment is well worth it. If you're on a limited (or zero) budget, there is a free mathematics package called Maxima which I've heard is quite powerful, though I've never used it.

Another popular mathematical package is Wolfram's Mathematica which is not free, but I've never used it either.

For Feynman diagrams, I use JaxoDraw, which is also free. JaxoDraw can be linked with Latex to allow mathematical symbols to be included in diagrams, although this requires a separate Latex installation. However, since Latex must be installed for Lyx to work, this isn't a problem.

For other types of diagrams, I use the Draw program which is part of the LibreOffice package, which is also free. For general editing of HTML files, I use Notepad++, which again is free.

Who are you/what's your background?

A bit of info about me is available on my personal web site, although I don't update it very often.