You'd better start watching where you're stepping because there are portals opening up everywhere thanks to Apple's ARKit.
We've previously seen portal doors appearing leading to many different places, including a recent one leading to inside the Doctor's TARDIS. However, new portals are starting to appear and they're now on your floor.
The demo was posted by Gina Adamova, an AR/VR developer who has been toying around with ARKit for a while now. In the demo, Gina taps on any part of the floor and a portal yawns into existence, seeming to burn away the floor to reveal another universe. She approaches the portal and is able to look inside of it to see some part of space. There are different portals, planets, and meteors. The portal is so realistic that it would actually make me nervous to go near.
If you'd like to make a space portal of your own, Gina Adamova has created a blog post detailing exactly how you can do that.