UPDATE:  SOLVED by Sean at 12:02 CDT

Tom and I are getting ready to run a bonus riddle later this month.  I’ll have an announcement for you in a couple of days.

In the meanwhile, I think it’s about time to ring your chimes with another Sci Fi subject.  I wouldn’t want you to get bored and complacent over there.  Besides, I like playing around with Sci Fi subjects, and it’s all about me, right?  Me, me, me, me, me… oh!  Sorry about that.  I had a moment.

Today’s answer is a Sci Fi concept.

NASA image - you know who this is, right?

Like all good Sci Fi concepts, you’ll find this rooted in reality.

This concept has been kicked around since about 700 BCE.

It became more familiar to us in the late 19th century.

Image by Ferdinand Schmutzer 1921

This concept shows up in a lot of strange places; like through a looking glass.

This might be a one-way street.

Sometimes this happens spontaneously in fiction; just don’t take a nap at a mountain.

This iconic image has been around for a while

You’ll find this concept in places where you wouldn’t expect it to be lurking; like in a Dickens novel.

It’s even made an appearance in pop music.

Lots of people today - but you should know this one

There you go – one fun, fast riddle.  I’m hanging out in the comments, so don’t abandon me!