Hard to read maths equations on Kindle

In response to a recent one-star Amazon review complaining that the equations are too small to read on the Kindle, I’ve now added this note to the end of the Kindle ebook’s Preface:

“In the meantime, if you intend reading the book solely on a small screen reader, I advise that you check you are happy with the legibility of the equations before committing yourself to buying the book.”

Right now I have the book open in front of me on the Kindle Paperwhite (six-inch screen). And, yes, some of the maths images are on the petite side, particularly (as the reviewer points out) the subscripts and superscripts of which, this being the mathematics of general relativity, there are an abundance. Personally, a six-inch screen is the smallest I’d feel comfortable with reading my book, and ideally I’d go for something at least an inch bigger. The root causes of this problem are (1) the necessity of formatting most of the mathematical equations as images, and (2) the inability of (some/all?) Kindle readers to allow zooming of smaller images. I look forward to the day when technology allows the straightforward publishing of ebooks with flowing, scaleable mathematical text. Until that day comes, don’t forget that Amazon offer a range of free Kindle apps to let you read Kindle books on your PC, laptop, Android tablet, iPad, Mac etc.