I’ve been trying to remember the names of a couple of science fiction short stories. Perhaps you can help, based on the following vague descriptions. Be warned though. These descriptions may contain spoilers.
One story described a manned mission to Mars. At least I think it was Mars. It might have been a different planet. Some of the expedition members disappear. After the protagonist’s dog disappears, he follows it to find that he can understand what the dog is thinking and finds that he enjoys wandering around the surface.
The second is a description of a project to travel back in time. In some respects, the story is like “A Sound of Thunder” by Ray Bradbury in that it described how the present is changed by a small action of one of the time travelers in the past. I remember a pendulum being described as part of the mechanism. There is a person at a podium making a speech and swinging his arms widely. At the end of the story, he has changed.
Damn, I just read this one a couple of weeks ago. It was in a mass-market paperback, one of those compilations like, “The Year’s Best Time-Travel Stories” or something. I’ll be going to the bookstore tomorrow, and I’ll see if I can find it again. Your first one, I have no idea.