According to the dictionary, man can refer to both men and women. Take this example:
Understanding the laws of physics allows a man to understand the world around him in profound ways.
Is this considered wrong English these days? Or just old-fashioned? Would it be frowned upon? Would the following be better?
Understanding the laws of physics allows one to understand the world around him in profound ways.
Again, according to the dictionary, him can refer to both sexes.
Any more alternatives I should consider?
The reason I'm asking: I really dislike the use of the overly lengthy him or her. (Not to mention using just her—that's just plain wrong according to any dictionary, if one is referring to both sexes.) I'm trying to simplify my writing as much as possible.