Sentenced to Prism by Alan Dean Foster. It's set in his wider universe, but is a stand alone. The main character is a jack of all trades that fixes unique situations. When a far off base on an unregistered planet stops responding, the corporation sends him in to figure out what went wrong. The planet is very, very different. It's an interesting take, don't think too hard about the physics, and it's a neat writing style. The characters are very interesting.

The Practice Effect by David Brin. Essentially, the more you use a thing, the better it gets at that thing, even if that's not what it was made for, but that effect decays if it's left unused. A modern day physicist is transported there and gets caught up in political and physics shenanigans.