What Exactly IS Einstein’s Theory of Relativity?

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Is time travel possible? Why can’t we travel faster than the speed of light? Do clocks really run at different speeds depending on how fast you’re moving? Does gravity really warp space and time as well as bend light?

These possibilities have been used in science fiction for decades. H.G. Wells’ classic, “The Time Machine,” was published in 1895, before Einstein’s Special Theory of Relativity was even published in 1905. This goes to show that man’s imagination was exploring the possibility of such things long before it was proven scientifically. In fact, Einstein stated himself that “Imagination is more important than knowledge” and it was his own propensity for what he called “thought experiments” that brought him to the concept of relativity in the first place. Supposedly, he was staring at a gas light one foggy night wondering what it would be like to travel on a light beam and shortly after that the Special Theory of Relativity (STR) was born.

The main point of the STR is that the only thing that’s constant is the speed of light; time is not, space is not. The speed of light, 186,000 miles per hour, is often referred to simply as c. In fact, the term “miles per hour” which you hear every day contains the basis of a physics equation related to time and distance. In other words, if you only know simple algebra you can understand how the distance you travel (length or L) depends on how fast you’re going (velocity or v) and for how much time (t), or L = vt. Simple.

But there’s a catch. That only applies to what is known as an inertial reference frame, or one that is not moving. Now I’m sure you know that the Earth is moving, through space as well as around the Sun, but as far as you’re concerned when you’re riding in a car the Earth is standing still. However, when you get into what are known as relativistic speeds or those closer to the speed of light, that equation changes.

For L = vt, any of those values is considered a variable, meaning it can change. However, the speed of light is constant. Therefore, the only things that can change are the distance (L) or time (t). And that’s where things start to get weird. The scientific terms are length contraction and time dilation. Length contraction means that distances get shorter when traveling near the speed of light and time stretches, meaning that time passes more slowly for someone traveling at the speed of light even though to them clocks would appear to move at the same rate as they do to you.   This is why they say that someone who traveled to a distant planet may only think they’ve been gone for a few years while a century or more will have passed on Earth. Time and distance are both relative and thus the term “relativity.”

As far as a time machine is concerned, going forward in time seems more feasible than going back but that’s not to say it’s impossible. However, the STR really doesn’t postulate going back in time, only that clocks run at different rates. This has been proven at the atomic level by observing atoms that have a known rate of decay (or lifetime) traveling at relativistic speeds where they last longer as measured by Earth clocks.

So why can’t we travel faster than the speed of light? This comes back to the speed of light being a constant. Energy of movement, or what is required to move something, is defined by the mass of the object times its velocity squared, or E = mv2. Starting to sound familiar, like the infamous E=mc2? Here we go again, velocity can’t change so the others must and what this boils down to is that the energy required far exceeds what can be achieved as the mass increases, which also occurs at the speed of light. So, according to Einstein, the reason we can’t travel at the speed of light is because at those speeds the mass of the vehicle will exceed its ability to carry the fuel necessary.

Of course if you’re a UFO fan like myself, you may wonder how they could possibly get here and move erratically like they do. And that brings us to Einstein’s Theory of General Relativity which relates to gravity. Gravity is a force that creates acceleration, or a change in velocity. Drop something and it accelerates to the floor or ground. According to Einstein, the gravity of large objects like the Earth or Sun will also warp space and time. When you see those pictures depicting a blackhole they usually show a funnel-shaped grid, indicating how the force field around it warps space.

Gravity can even change the path of light, which was proven by Sir Arthur Eddington during a solar eclipse on May 29, 1919. When you look up at the sky the stars are in predictable locations, which is why they have been used for navigation, even by the “star tracker” on the Space Shuttle until the advent of the Global Positioning System, a.k.a. GPS. However, during a solar eclipse, there is a massive gravitational object available in the sky (the Sun) that when darkened by the passage of the Moon, allows the stars to be visible during the day. Knowing where the stars should be versus where they appeared showed a difference that proved Einstein’s Theory of General Relativity. This has been proven repeatedly since then by observing distant stars, an effect known as gravitational lensing, which will sometimes even cause an object to appear to exist in two places.

As far as UFOs are concerned, it appears that they utilize extremely high magnetic fields combined with certain radioactive elements to create a gravity field around the craft itself. This, in turn, provides the vehicle with its own gravitational field, essentially creating its own reference frame so that it no longer is subjected to Earth’s gravity and can thus move in ways that defy what our known technologies can currently achieve as far as hovering and drastic changes in direction.

Einstein wanted to discover a Grand Unified Theory that explained how all the forces in the Universe related to one another. He was never able to do that and scientists today continue his quest. The evidence today, however, suggests that they are getting close! Various new theories continue to evolve such as String Theory, which relates to subatomic particles (or those smaller than an atom) and M-Theory which suggests there are multiple universes. Quantum Theory is another fascinating subject that’s been around for a while with significant potential for science fiction such as telepathy. More on that next time.

Marcha Fox is the author of the Star Trails Tetralogy which includes the novels “Beyond the Hidden Sky,” “A Dark of Endless Days,” and “A Psilent Place Below.” The final volume, “Refractions of Frozen Time” was released in March 2015. With a physics degree from Utah State University and over 20 years working at NASA’s Johnson Space Center in Houston, she is never at a loss for something new to incorporate into her stories. Her Facebook Page is https://www.facebook.com/marchafoxauthor and her book website is http://www.startrailssaga.com. Follow her on Twitter @startrailsIV.

A Roughneck and a Rocket Scientist Went to a Movie…

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Back in 1998 when the movie “Armageddon” first came out I went to see it with a friend who was in the oil business. I was working at NASA at the time, so we’re talking about a roughneck and a rocket scientist going to a movie, which somehow sounds like the prologue to a bad joke. While it may have been a fairly decent Bruce Willis flick, at least at the time, my friend and I did so much eye-rolling at the inaccuracies in the movie’s script that we hardly saw what was going on. Later when we were home and still ranting about how technically incorrect it was, my teenage daughter just shook her head at us.

“Mom! It’s only a movie!” she said, not understanding what all the fuss was about.

To me as well as my friend the fuss was about doing something correctly. Since we were both in technological fields we knew that was important. Do something wrong in either of our career fields and someone could die. Furthermore, with all the money spent producing movies it was nothing short of lazy to not hire a science and/or engineering consultant to get it right. Around that same time the movie “Deep Impact” came out, a Steven Spielberg movie, and to his credit, the science in that movie was accurate but apparently Robert Duvall didn’t have the drawing power of good ol’ Bruce.

My point, however, remains the same. If you’re going to do something, do it right. Seriously. Or as Yoda so eloquently put it, “Try not, do. Or do not. There is no try.”

I have wanted to be a writer since I was in elementary school. And I wanted to do it right. I wanted to write science fiction and knew that would require not only research but the background necessary to understand the principles and apply them properly. So I went back to school and got a physics degree. I thought I would know a lot more than I did by the time I graduated but I still knew a whole lot more than when I started. So many people say they stupider after going to college than before because they then realize how much there is to know about our amazing world.

After graduation I went to work in the aerospace industry, ultimately winding up at NASA’s Johnson Space Center in Houston, Texas where I worked for over 20 years. And even after that, what I know is relatively little compared to everything that is out there.

Science is loaded with theories that make fantastic plot material. The subject of physics and how it applies to the Universe is often so weird that it actually makes the story more interesting when you tell it like it is. Like they say, truth is stranger than fiction and that certainly applies to science as much as anything. Science fiction is all about taking science to its limits and showing the effects it could have on mankind. There is nothing more exciting than that.

What’s Behind the “Science” in Science Fiction? (Part 1)

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You don’t have to be a scientist to enjoy science fiction. If you’re lucky, you may learn a few scientific facts painlessly while enjoying a good read, or at least that’s my goal as a science fiction author. But what exactly lies behind stories categorized as science fiction?

Science, of course, but it goes beyond that because it often addresses the impact of technology on society. Science alone is a real snoozer if you don’t combine it with how it affects your life. Unless you happen to be a rocket scientist, however, much of the actual science in science fiction stories often gets lost in the plot. But guess what? Then you’re missing a lot of the fun, too. If you’re someone who thinks that science is really cool stuff, you may want to know more about the actual science behind such things as time travel, teleportation, other dimensions and telepathy. But here’s the bad news. You needed to learn to crawl before you could walk or run and know the alphabet before you could read, so before you can get to the good stuff you need to know the basics.

In the Beginning there was Classical Physics

Originally physics only dealt with, big surprise, physical phenomena. It related to mass, motion and time, things which were apparent in the world around us. Math was used to create formulae to calculate their relationship to one another. Using algebra, if you knew two of the quantities you could figure out the third. A common example is D=vt (Distance equals velocity times elapsed time) which when rearranged become v = D/t. If that sounds vaguely familiar maybe it’s because in a more familiar form, velocity = miles/hour or miles per hour.

Classical physics derived from D=vt. To do so gets into higher math called calculus which is an interesting subject in and of itself. It was invented simultaneously way back in the 17th century by Isaac Newton and Gottfried Liebniz in order to solve more complicated problems such as orbital dynamics. More on that some other time. For now just file away the notion that the world of classical physics mostly involves the movement of objects in your everyday world such as how long it takes to get to work or school, how much momentum a baseball has when hit by a star player or how much energy there is in a garbage truck moving at 65 mph.

For a long time scientists thought that these basic formulae could explain everything in the universe. After all, they do a pretty good job of dealing with everyday life. They also thought that if you took everything down to the most fundamental level you could predict anything that might happen in the future. This was called determinism and in many ways reinforced the concept of fate and denied the idea of free will. This was the philosophy of the day, as noted in the movie “A Knight’s Tale,” where it was pointed out that it was extremely difficult if not impossible to “change your stars.”  You were dealt a certain hand in life that you had to play.  Period.

As is often the case, however, when an individual or group of like-minded people think they know everything there is to know, they eventually find out otherwise. Indeed, life isn’t that simple and toward the end of the 1800s and early 1900s new discoveries showed that indeed they were flat-out wrong. Not just a little wrong, but really wrong. For starters, the elements definitely did not consist of air, water, earth and fire.

More on that next time when we get into atomic theory. Stay tuned.

© Copyright 2014 by Marcha Fox  All Rights Reserved