Interterrestrials: The "aliens" are inner earthlings...

[Mister Obvious]

All systems are self-contained, in a "bubble"... there is no getting in, and no getting out.

And on a macro scale, the universe is also in its own such bubble...

This is the observable universe:

https://www.jpl.nasa.gov/spaceimages/ima..._hires.jpg

It's enclosed in its own "bubble"...

https://i.imgur.com/zlzjYHn.jpg

https://www.nasa.gov/centers/goddard/new...sults.html

The "radioactive noise" at the farthest reaches of the observable universe is an enclosure.

https://en.wikipedia.org/wiki/Cosmic_mic...background

The universe is INSIDE something bigger...

https://i.imgur.com/Yb3pdez.jpg

Just like we're a self-contained system (earth, atmosphere, electromagnetic field) within something larger (our solar system), so is the universe, and so is everything beyond the universe... from micro to macro.

And it's been my long held hypothesis that we are INSIDE a sun...

Likewise, the universe is INSIDE a sun.

This is what it looks like inside a sun...

https://i.imgur.com/SZnTsnS.jpg