TL;DR

Are we each cosmically alone ?

I posted this on the physics sub of reddit but I'd ask here. I saw it on some video and when I googled it apparently there is truth to it in that the delay is nanoseconds, but to me that makes it sound like we are each in some space bubble away from everyone else and cannot contact them. How true is it or rather how much of a concern would it be?

However, your thread title also mentioned time dilation. I'm not sure what "delay" has to do with time dilation.

Do you talk to people and get answers back? That's contact.

For that matter, you're posting here expecting to get a response. That's contact.

The fact that light has a finite speed certainly does not mean that you are disconnected. It just means the light signals that you exchange with the rest of the universe all the time, that bring information about the rest of the universe to you and carry information from you to the rest of the universe, travel at a finite speed. In your day to day life that's not even noticeable; the time scale of your perceptions is many orders of magnitude larger than nanoseconds. But people who deal with things happening on fast enough time scales or at large enough distances (such as the people who designed the GPS system that allows your smartphone to tell you where you are) have to take them into account.

If we want to look at cases of people communicating with each other, the farthest any humans have been from Earth was on the recent Artemis mission that went around the far side of the Moon. It took light signals almost two seconds to travel from Earth to the spacecraft, or vice versa, when it was at its furthest point (or close to four seconds for a round trip). That kind of delay is noticeable, yes--but it didn't stop them from communicating.

TL;DR: Are we each cosmically alone ?

[Moderator's note: Unacceptable reference deleted.]

I posted this on the physics sub of reddit but I'd ask here. I saw it on some video and when I googled it apparently there is truth to it in that the delay is nanoseconds, but to me that makes it sound like we are each in some space bubble away from everyone else and cannot contact them. How true is it or rather how much of a concern would it be?

"Every point in spacetime is affected by only what is happening at that point, yes. You are perpetually cut off from being in actual contact with anything except at your exact location in spacetime.

This doesn’t mean you live in your own private universe, just that nothing can affect you instantaneously. The effects of causes must travel to you first. And those effects cannot ever travel to faster than the speed of light."

"You are separated from everything around you by about 3ns per meter. When you look at something 100m away, you're seeing it as it was 300ns ago."

This reminds me also of the processing delay of the brain. But none of this means we are alone right?

Since we are just going around in circles we will close this thread here. A Reddit thread is not a valid reference, and engaging in debate-by-proxy is entirely pointless.