This book is a hard-sell. Non-fiction, sciency stuff. If you are still reading...then maybe you should give this book a try! If "Non-fiction, sciency stuff" doesn't totally scare you away, you would get a lot out of this. If you like reading Popular Science, or even National Geographic, read on...
'X' Stands for Unknowns is broken up into 5 sections (this is not to mention the introduction section which completely blew my mind! Issac Asimov is not just one of the world's greatest science fiction writers, but honestly, one of the world's greatest philosophers.):
-Physics
-Chemistry
-Astronomy
-Mathematics
-The Fringe
Each section has a few chapters, and every single chapter starts with a personal anecdote from Isaac's life, as a segway into the science. Now, which sections are enlightening and totally interesting, and which sections are unbearable and almost unreadable-is most definitely a matter of personal opinion. I was utterly in love with his sections of Physics, Astronomy, and The Fringe. Unfortunately I couldn't give the book 5 stars because of those pesky sections on Chemistry and Mathematics. Okay, even the math was mildly interesting. Chemistry can just go die, as far as I'm concerned.
So there is my opinion. Come learn some new stuff. You can learn about how many "octaves" are in different types of non-visible light (one "octave" being red, orange, yellow, green, blue, indigo (blah), purple). You can learn about the first, and the second, and the twenty-seventh sighting of Halley's comet. It's just science, written to inspire.
I leave you with a quote from the book:
"There may never be a time when all mysteries are resolved, when nothing remains to be done within the field that the scientific process is competent to deal with. Consequently, at any fixed moment- say, now- there are unsolved problems, and this proves nothing with respect to G-d, one way or the other. Nor should this eternal perpetuation of mystery be a source of disappointment, it seems to me. It should, rather, be a source of overwhelming relief. If all questions were answered, all riddles solved, every fold unfolded, every wrinkle in the fabric of the Universe smoothed-the greatest and noblest game in the Universe would be ended, and there would be nothing left for the mind to do but console itself with trivia.
Unbearable."