How would it be plausible for in a world without magic that all the people older than 15 disappear for a length of time of 6 years. I have never been a science freak or a mathematician so I’m not sure what would happen to make everyone disappear. What I want to happen that in the middle of a day all the adults disappeared only leaving their clothes behind. But I don’t want the parents to age and also when they return after the 6 years they're NOT naked. And I also don’t want aliens or a crazy daisies or maybe a horrible disease.
- We have no reliable way to tell 15-year-olds from 14-year-olds or 16-year-olds.
- There is no way as we understand it to "put people on ice" for six years without change. Science fiction talks about cryogenic suspension, but we are not up to reviving corpsicles yet.
- Accelerating them to close to lightspeed would theoretically do the job as far as aging is concerned, but the required energy is totally off the scale.
- They are supposed to leave their clothes behind and then come back fully clothed? Where would the spare set of clothing come from?
This sounds like high-end space opera technology, perhaps Star Trek or Iain Banks' Culture setting. Powerful computers, replicator technologies, matter transmission. Even so they'd need some preparation time to pull it off, and for a present-day world they'd be aliens.