The fourth installation of Hourglass, our monthly blog carnival devoted to the biology of aging, is up at Existence is Wonderful.

In honor of the upcoming Halloween holiday, Anne chose as her theme the fascination (and sometimes fear) with which we regard the frontiers of the unknown, and also the way that the definition of the unknown changes over time:

While not all countries celebrate Halloween, it’s clear from looking at numerous cultures that humans have a longstanding fascination with such fantastic creatures as ghosts, ghouls, zombies, and vampires. I decided to draw upon this theme for this October edition of the Hourglass Longevity Blog Carnival because of how many modern medical advances and investigations seem to tread upon the same psychological and emotional territory that our notions of monsters and the macabre do. …

Similarly, speculations about impressive longevity gains or other boundary-pushing advances seem to intrigue some while frightening others — which is understandable considering that nobody knows what is ultimately going to be possible when it comes to altering, maintaining, and fine-tuning bodies over time, nor what the implications of any of this will be.

There’s plenty of great material at the carnival, so be sure to click on over and check it out.