Free Republic

“A prior indigenous technological species might have arisen on ancient Earth or another body, such as a pre-greenhouse Venus or a wet Mars,” he wrote. ... Earth’s plate tectonics would effectively have “erased” the traces of a civilization that lived billions of years ago. Venus is in the grip of a severe greenhouse effect and also undergoes similar “resurfacing” that would scour it clean of artifacts. This leaves just a handful of places where archaeologists might find traces of a lost extraterrestrial civilization. “Remaining indigenous technosignatures might be expected to be extremely old, limiting the places they might still be...

One of the leading lights of the science fiction world, editor and author Frederik Pohl, passed away this weekend after a career that defined the genre for decades... Pohl was known for his mind-bending, often satirical novels (many co-authored with longtime collaborator C.M. Kornbluth), his editing acumen, his science fiction criticism, and his witty, fascinating blog, which he was updating right up until his death...