The introduction of new technologies has a huge effect on the world, with mechanisation, computerisation, and the Internet changing every aspect of global culture. As forward-thinking humans, we like to make predictions about possible new technologies and how they will shape the world around us. While science fiction books and futurologists have made some very accurate predictions, there are lots of other examples that were way off the mark. From hoverboards and jetpacks through to teleportation and free energy devices, let's take a look at some tech predictions that are unlikely to ever happen.

When Marty McFly hopped on-board his hoverboard in Back to the Future Part II, kids around the world looked up at their parents and asked when they would hit the shops. Unfortunately, that day never arrived, with replica non-working versions now selling as Halloween costumes as nerds around the world admit defeat. While self-balancing scooters were recently introduced into the market with the "hoverboard " name, they have wheels, obey the laws of gravity, and some models have even been known to catch fire. Unfortunately, a similar situation exists for lightsabers, with photonic molecules that affect matter very hard to understand and even more difficult to control. 

A similar fate seems to have befallen the jetpack, which captured the world's attention when George Jetson and his family flew around on them over 50 years ago. While the Jetsons were able to accurately predict videophones, drones, smartwatches, and robotic assistance technology, the only functional jetpacks that exist today and huge, dangerous, and very costly. Even if you have a spare $500,000 to spend on one, the massive fuel costs, obnoxious noise, and very real dangers involved mean they're unlikely to enter the commercial market.

Flying cars are another highly problematic piece of technology that are unlikely to show up any time soon. While there were two very brave men named Henry Smolinski and Hal Blake who attempted to make a flying car back in the 1970s, what they really did was conjoin a Cessna to a Ford Pinto and hope for the best. Unsurprisingly, the plane detached from the car during the first flight and the two men were killed on impact. While we should celebrate their vision, the reality of flying cars is another thing entirely. Even if we could work out the mechanics involved, introducing flying cars into modern cities would present more than a few logistical challenges.

If you've ever watched a single episode of Star Trek, then you'll understand just how useful teleportation devices can be. Whether it's transporting yourself to a new planet or visiting a nearby starship, having the ability to move to a new place without worrying about the middle ground is obviously very enticing. Unfortunately, teleportation devices are highly unlikely unless we manage to change the laws of physics. Even if we can find a way to map every atom in the human body, at current data transmission speeds, it would take centuries to teleport all of our atoms from place to place. The same thing could be said for digitised minds, with the amount of connections and likely quantum nature of the human brain proving impossible to map. 

Another pipe dream that still eludes us is free energy. While sustainable energy technology has improved by leaps and bounds, and the world is moving towards a solar, wind and water powered future, there is always some kind of price you need to pay in order to access energy. No matter how hard we try, it seems we're tied to the first law of thermodynamics that defines the conservation of energy. While solar and wind devices are getting more efficient all the time, and are definitely the smartest option, even they are not actually sustainable. The sun will eventually power down and the wind will stop blowing, although hopefully that won't happen for billions of years.   

Image source: Pavel Chagochkin/Shutterstock