Tag Archive: science fiction

Time Dilation

Many of us are familiar with the concept of time dilation, though we may not know it by that name.  Through the worlds of science fiction, we often read about the relativistic effects of traveling at or near the “cosmic speed limit” known as speed of light.  Many of you may not know, however, that time dilation actually occurs with respect to gravitational pull as well.  You may also not know that the effects of time dilation have been observed in experimental settings using atomic clocks.  In fact, the astronauts living and working onboard the International Space Station (ISS) get to experience both types of time dilation.

So what is time dilation?  Essentially, it is an effect predicted by the theory of relativity in which two objects moving relative to each other, or situated differently with respect to the pull of gravitational masses, experience an observable difference of time between them.  An atomic clock can actually be measured to tick at a different rate when compared to a second observer’s own atomic clock.  You may think that perhaps this is related to a mechanical difference between the clocks, or from the fact that signals take time to transfer back and forth, or even the fact that light itself takes time to reflect back and show the observers what they see.  This is not the case.  It is a natural phenomenon in our universe, explained by mathematics and tested through experimentation.

In relative velocity time dilation, a person approaching the speed of light would experience time at a slower rate than those observing the traveler.   In other words, the faster the relative velocity, the greater the magnitude of time dilation.  One could hop onboard a starship, travel for a few weeks, and arrive back at Earth to find that thirty years had passed by.  In a way it is like time travel, except you are limited to a one way trip.

In gravitational time dilation, observable time actually speeds up the further you get from the source of gravity.  A person at sea level would experience slower time than someone at the peak of Mount Everest.  Gravitational time dilation is also the direct cause of gravitational redshift.  Redshift is the process by which electromagnetic radiation (light, radio waves, microwaves, gamma waves, etc) originating from, or passing through, a high gravitational field is reduced in frequency when observed in a region of a weaker gravitational field.  There also exists a corresponding blueshift when moving in the other direction.

Since time slows down with increased gravity and increased velocity, this means that astronauts on the ISS experience two opposing effects of time dilation.  They are further away from the Earth, so their time speeds up.  They are also traveling at high velocity (17,000 mph (~27 500 km/h)), so their relative time is slowing down.  The effects of the relative velocity time dilation is actually stronger than the effects of the gravitational time dilation, so when the astronauts return to Earth after their 6 month stay, they have aged less than the folks in mission control that stayed on Earth.  The difference is about 0.007 seconds.

As you can see, this phenomenon can present a bit of a challenge for the science fiction author.  One must either choose to accept this as fact and apply them to the story, or come up with a way around them.  For sufficiently high speeds the effect is dramatic, and space travellers could leave on a light-speed mission, and return to Earth billions of years in the future.  In the Planet of the Apes and the Ender’s Game series, the authors chose to accept this limit as fact and apply it.  In other works of science fiction, such as Dune, Star Trek and Star Wars, they found ways around it.

In Star Trek, warp drive is a concept that uses a bubble of “normal time” to surround the spacecraft and allow them to get around the relativistic impacts of their faster than light travel, and continue to be able to interact with objects in “normal space”.  Star Wars uses “hyperspace,”  which is an alternative region of space coexisting with our own.  Entering hyperspace requires some sort of shield to protect the craft, and traveling through it allows the people to move from point to point faster than the speed of light, but they cannot interact with objects in “normal space.”.  Dune uses a concept that folds space at the quantum level and enables travelers to move from point to point instantaneously.

In my own writing I plan to take an approach closer to that of Star Wars, since multiple dimensional layers will be somewhat important to the plot. The idea of 11 dimensional space in M-Theory caught my attention, and so I began to wonder if travel through one of these different dimensions might make it possible to travel through time or space without the impacts of relativistic time dilation.  Travelers in my universe will shift into one of these dimensions assuming an effect similar to that of Hyperspace, where one slips put of Normal space into this alternate dimension in which they cannot communicate with, or interact with, normal space.  The exception of course would be gravity, since this seems to be one of the only constants throughout the multi-dimensional universe.  Gravity can also permeate the multi-verse, and has an effect on time travel, the idea being that the graviton particle is the most fundamental piece of life, the universe, and everything.  (And you thought it was 42 😉 )

Of course there are many holes and mathematical improbabilities associated with faster than light travel, but I find a universe where I can travel from place to place without having to worry about when I leave and arrive relative to my speed to be a lot more fun to write about.  I don’t want to believe that it is impossible for me to explore faster than the speed of light.  Of course there are also holes and issues with existing theories of relativistic time dilation, and the interactions of the microverse with the macroverse, and no matter how many times I hear people say something is impossible, I would rather think of it as improbable.  To say that we as humans have learned all that there is to know, and that we truly understand the universe we live in is a farce.  There is always something more to do and something more to learn.  If it can be imagined, it can in all probability be achieved.


The Technology Problem

Anyone who’s ever written or read scifi knows about this problem.  Predicting the future is not a simple skill set, simply because humanity is often difficult to predict.  For example, at the birth of the automobile, the electric car was actually the superior model to the steam and gasoline cars.  Electric vehicles had many advantages over their competitors: they were quiet, you didn’t have the scent of gasoline blowing back on you as you drove, you didn’t have to crank them to get them started, and you didn’t have to change gears.  Steam cars didn’t need to change gears either but if you had that car in a cold climate you often had a long time to wait to get it started.  Anyone looking at the vehicle market in the early 1900’s could have easily envisioned a logical progression of electric cars into the future, but they would have been wrong.

As the roaring 20’s approached, roadways improved, gasoline became cheaper, and our good friend Henry Ford invented the assembly line.  This meant that the gasoline vehicles not only became the affordable choice, but since the electric vehicles did not have the superior range needed to travel those fancy new roads between cities, the demand for shorter range electric vehicles declined.  Plus, if you ran out of gas on the way to your neighboring city, no problem: pull out that spare gas can, fill ‘er up and go on your merry way.  But what happens when you run out of charge on your battery?  You can bring a spare battery, sure, but it’s not as easy as the gas can method.  Plus, gas was CHEAP, and to top it all off, the electric starter had come along eliminating that annoying need to crank.

The moral of the story?  If you ever want to persuade someone, you can often do so just by hitting their wallets and appealing to their laziness. 😉 Little cynical I suppose, but people are people and thinking along these lines can help you make reasonable, believable choices as well as inaccurate ones.

So what does this mean to a science fiction writer?  Consider science fact before you write your science fiction and put your world through a logical, fun progression. Would a telepathic race need to learn how to use speech? How would a blind race learn about the stars? Consider your fiction society’s values and goals, and project them on the world you’ve created. Do your end items make sense?  Are you prepared to be right or wrong?  Are you prepared to have a really cool idea and have it get published or manufactured before YOU get published, or have that idea manifest AFTER and be the one who inspired its creation?

In my own writing, I’ve also put together technologies based on other science fiction novels. Many authors do. The Odin panel, which looks remarkably like an iPad, I actually dreamed up about 14 years before the iPad came out because I loved the idea of the computer “desks” from Ender’s Game.  I wonder if the folks from Apple did, too.  And why not?  After all, the cell phone’s birth was inspired by science fiction – star trek to be precise. Star Trek also inspired NASA and social morality in its own way. What will my novel be the precursor for? Who knows. Probably nothing so fantastic. I am no Jules Verne, but I like to think sometimes that if I had actually gotten my novel out there a little sooner when the idea was still young, perhaps I could have inspired something like the iPad myself.

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