I'm looking for two books that I think are by the same author.
I read them both 10/15 years ago, and they're adult scifi/horror type books.
One was about a group of people - I think a mixture of tourists and a couple of archaeologists visiting some sort of ruins (possibly Roman). Somehow they find themselves in a different time ... After a while there, they keep jumping to different times. The main thing I remember is that because things in the ruins changed over time, a person jumping into the past could end up in the same space and time as an object, like a rock. One person jumped into the same place as a bee and had a bee in their face. As they went further back in time, more people become affected, and these people lived in a community together.
The second book has a man as the main character. There are news reports of aliens, and weird things start happening. I don't remember the bulk of the story, but I do remember the end:
It turned out that there were no aliens, but it was some kind of mass hallucination caused by the earth's magnetic field getting stronger.