What is something that's crazier than the wildest dreams of any ~1970s nerd, but exists today? I'll start with an easy one:

The Patch was hypothesized in 1988 and first documented in 1997, by a passing yacht racer. Research on the patch began in earnest in 2009.

Estimates on the size are still nebulous, as it continues to expand and shift. But I doubt anyone in the 1970s was predicting a patch of trash twice the size of Texas would appear in the Pacific Ocean over the next 50 years.

This was actually renamed to the Great American Garbage Patch

Also wish more effort and attention went into countries coming together to clean this up, and simultaneously stop any new trash from entering into our waters.