5 sci-fi concepts that are possible (in theory)
Science fiction novels and movies are packed with far-out ideas, most often as the springboard for an action-packed adventure rather than a serious attempt to predict future trends in science or technology. Some of the most common tropes, such as accelerating a spacecraft to fantastic speeds in a matter of seconds without crushing the occupants , are just plain impossible according to the laws of physics as we understand them. Yet those very same laws appear to permit other seemingly far-fetched sci-fi concepts, from wormholes to parallel universes. Here's a rundown of some of the sci-fi ideas that could really be done — in theory, at least.
Wormholes
The idea of a wormhole —a shortcut through space that allows almost instantaneous travel between distant parts of the universe — sounds like it was created as a fictional story-driver. But under its more formal name of an Einstein-Rosen bridge, the concept has existed as a serious theoretical concept long before sci-fi writers got hold of it. It comes out of Albert Einstein's theory of general relativity, which views gravity as a distortion of space-time caused by massive objects. In collaboration with physicist Nathan Rosen, Einstein theorized in 1935 that points of extremely strong gravity, such as black holes, could be directly connected with each other. And so the idea of wormholes was born.
Warp Drive
An essential prerequisite for most space-based adventure stories is the ability to get from A to B much faster than we can today. Wormholes aside, there are multiple stumbling blocks to achieving this with a conventional spaceship. There's the enormous amount of fuel required, the crushing effects of acceleration, and the fact that the universe has a strictly imposed speed limit. This is the speed at which light travels — precisely one light-year per year, which in a cosmic context isn't very fast at all. Proxima Centauri, the second-closest star to Earth, is 4.2 light-years from the sun, while the center of the galaxy is a whopping 27,000 light-years away.
Time travel
The concept of a time machine is one of the great sci-fi plot devices, allowing characters to go back and change the course of history — for better or worse. But this inevitably raises logical paradoxes. In "Back to the Future," for example, would Doc have built his time machine if he hadn't been visited by the future Marty using that very same machine? It's because of paradoxes like these that many people assume time travel must be impossible in the real world — and yet, according to the laws of physics, it really can occur.
Teleportation
The archetypal sci-fi example of teleportation is the "Star Trek" transporter, which, as the name suggests, is portrayed simply as a convenient way to transport personnel from one location to another. But teleportation is quite unlike any other form of transport: Instead of the traveler moving through space from the starting point to the destination, teleportation results in an exact duplicate being created at the destination while the original is destroyed. Viewed in these terms — and at the level of subatomic particles rather than human beings — teleportation is indeed possible, according to IBM.
Parallel universes
The universe is everything our telescopes reveal to us — all the billions of galaxies expanding outward from the Big Bang. But is that all there is? Theory says maybe not: There might be a whole multiverse of universes out there. The idea of "parallel universes" is another familiar sci-fi theme, but when they're depicted on screen they typically differ from our own universe only in minor details. But the reality may be much weirder than that, with the basic parameters of physics in a parallel universe — such as the strength of gravity or nuclear forces — differing from our own. A classic portrayal of a genuinely different universe of this kind, and the creatures living in it, is Isaac Asimov's novel "The Gods Themselves" (Doubleday: 1972).
Complete story here: https://www.livescience.com/sci-fi-concepts-real-life
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