Today Doc Brown and Marty McFly come to their future. Sadly they've found not only have they time traveled but now they are in an alternate universe. These are the problems with time travel and moving matter through the space time continuum. Here's some things I think would really upset Marty on his arrival.
Let's face it. The first moments in the 21st century for Marty and his future bride shows us what could be the least likely future technology. Highways in the sky are totally possible - but not the way it was envisioned in the movie. In the movie we are treated to Doc Brown actually having to drive the DeLorean. Imagine highways that congested with vehicles at those speeds and somebodies decides to look down at their stereo? Worse, the producers had no idea that cell technology would bring us to a future where we are all so interconnected, and thus, distracted. For personal flight the only safe way to do this would be with autopilot technology. Worse, look at the congestion we live in on the ground. Imagine that in the air with vehicles constantly joining and others descending. Its a three dimensional nightmare that the average person can't handle. That said, personal flight has been around for years. Whole neighborhoods are built around runways with garages for aircraft on the homes. Its doable today if your pocketbook is thick enough and you get a pilot's license.
Imagine Marty's disappointment that the best we can do is the Segway. Yes, Lexus and other companies have figured out forms of hoverboard tech but those rely on metal tracks inbedded in the ground for the magnetic technology to perform over. In the movie this is a child's toy. Today you need to build your own special track and then have the engineers standing just out of camera range to experience this. Imagine the scene reshot with Marty on a Segway. May be corny but it would bring an element of Paul Blart to the show.
This one the producers did well on. Perhaps the fact that they are entertainers they had an idea what audiences would want. 3D is almost mandatory for a film these days (although most 3D is done poorly) and a trip to an IMAX theatre can approximate the shark scaring Marty moment.
Further, remember that large entertainment center at elder Marty's home? This is totally possible today. Now if we could just re-hydrate pizza in the microwave for dinner I'd never have to leave home.
So what did they miss?
Looking 30 years into the future and making predictions is actually pretty hard. Cellular phones existed in 1985. They were bulky and with the abundance of pay phones folks didn't see a future where our lives revolved around a device like a cell phone. We communicate with them. We entertain ourselves. We do just about everything short of live on them. I don't think the producers could see populations living like this. What's even stranger is that, depending on your generation, you may speak in a mono-syllabic language that throws abbreviations around like they were your first words. DLC to a gamer is a second nature word. TTYL. LOL. BRB. If it wasn't for spell correcting software how would someone like Marty even communicate with these people. Language is changing rapidly at a pace no one could have anticipated.
30 years is bad but what if you want to guess 300 years in the future? Naturally we assume space travel will be second nature. But to travel you have to have a destination. Columbus was looking for India. Several explores have searched for a Northwest channel, etc. Very few groups would travel like the Polynesians on a simple catamaran into areas of unknown possibility bringing their livestock and families. But that's a lot easier than unplanned space travel. How do you have enough resources for the trip? If you don't know whats on the other side its very likely you are on a one way trip. Further, we can identify planets with atmospheres and water. What we really need is a planet that also has a magnetic field. Then we know the travelers won't be bombarded with radiation. Mars had free flowing water and a thick atmosphere but without a magnetic field the solar wind just blew all that out into to space. What if the people who travel to those new worlds develop such unique languages that communication is lost not due to technology but human nature?
Doc flying off on his space train in the last movie gives me hope that someday we can solve our differences and do big things. That said a prediction another 30 years in the future from today would probably seem silly to the people of that time.