May be seventy or eighty years ago if some one would have suggested flat panel TV’s, digital cameras, hand held communications devices now known as cell phones, copy machines, sending space probes to the far reaches of our universe or heaven forbid a computers in many homes and those ideas would have been exposed to a forum of readers as we see here, we probably would have been treated to similar rather brilliant comments, putting it mildly, as we find them here.
Most discoveries or concepts start with an idea and many of such ideas eventually become reality. If the human mind can conceive it we should not be surprised if some day we will see it transformed in to reality.
I am still in possession of a book dealing with scientific discoveries at the time and remember distinctly that about two pages were entirely devoted to the subject, why a fictitious thing such as a death ray never could be possible. And on top of it was written by some one who had more than one PhD. to his name. Never say never as chances are better than good that in time you may be proven wrong.
I firmly believe that devices have been built which can transmit data using quantum entaglement (changing spins in digital sequences?) and that the very moment those devices came into existence, certain labs have been privy to communication from the future.
Depending on one's view of time/multiple timelines one has to assume that those in the future would purposely hold back on certain details in order to ensure that nothing communicated would endanger the future communicant's own eventual births.