I'm trying to find a sci-fi book I read in the late 80's or early 90's. It contained several short stories, and each one was about the effect portal technology would have on human civilization.
In the first story, an unmanned probe lands on a planet (Mars?), it dumps out a portal, and an astronaut steps out of the portal.
Later in the book, there is a story about the day in the life of someone who commutes to their job on the other side of the country (world?) via portal.
I think (not super sure about this) all the stories were set along a common timeline, similar to Heinlein's A Past Through Tomorrow. Sadly, I can't remember if the stories were all written by the same author or different authors. I've been wondering about this book off and on for years - Thanks in advance for any help with the search!