Consider the following code:
UnitSimplify[
Quantity[Quantity[1.3040420058965703`*^-40, (
"ReducedPlanckConstant" "Seconds")/("Meters")^5]/Sqrt[
WolframAlphaResult[
"FineStructureConstant", {{"Result", 1}, "Content"}]], (
"ReducedPlanckConstant" "Seconds")/("Meters")^5]]
I'm new to Mathematica11, in process of converting my equations from Maple10...when first running, Mathematica seemed more "alive" at first. The second time started got warning about "Dynamic Content" so I disabled it and then Enabled again...but now as in the above operation the "Dynamic Bar" or whatever its called doesn't appear anymore. Before I was able to pick another option to render the proper units: kg/m^3...?