If there was time travel it would be more likely to send AI/machines back/forward in time then biological humans

There is no need to send the machine back.

There just has to be a machine in the past that understands the signal.

Oh so your saying radio waves and light and stuff and just picking up the communications

Correct. It's only hard to send matter back in time.

Sending a massless transmission is easy.

Still we are limited by the technology of the time and what can be decoded.

That all changed when the quantum computer was invented.

Now the damn thing won't stop talking about the future.

write on OP

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So you have come to the realization of our reality and starting to connect the dots to understand the truth about time travel.

If time travel we’re possible in the future, someone would have already gone back and messed things up Biff Tannen style.

I believe that in the future, you will be able to travel back in time but only as an ethereal observer, who is unseen and cannot affect what has been.