Which of the technologies that you have seen on TV or imagine yourself could be possible or impossible to make

I have seen some science fiction movies and sometimes I think this machine or thing could be possible in a near or a far future but some of the improvements I think are impossible to make for humans beings. 

For example I think that maybe exist another intelligent form of life in other planets, 

I think that flying cars will exist very soon and they will be very common, 

However I think that is impossible to make a time machine or a machine that can teletransport humans immediately like the one in stark trek or in other movies.

What do you think?

Share your opinion about it