Where are the Radio Signals?

I wrote about aliens visiting us earlier. 

But maybe they don't have to visit, they just have to call. The problem is, no one is calling. If there are millions of civilizations out there, why aren't we getting inundated with radio signals?

This is called the Fermi Paradox. We've only been listening for alien radio signals for about 60 years so we can only have heard signals from 60 light years away. And in a galaxy roughly 100,000 light-years across and about 1,000 light-years thick, that's a minuscule bit of space. If there are aliens sending radio signals, they might just be too far away.

I have another theory. They might be so advanced that they no longer use radio. Radio is slow comparatively. It takes is 100,000 years to cross the Milky Way. Aliens might have something better, such as quantum entanglement. Maybe something we can't imagine. Some have suggested artificial gravity waves but they, too, only move at the speed of light. 

We'll probably not know the answer anytime soon. 

What do you think? What explains the Fermi Paradox? Let me know in the comments below.

Also, this is my 1,400th post on this blog.