Today is our first "Engineering Tuesday". In general, anything that I feel relates to my engineering degree can be posted on this day. That can be actual science type things or more work/human factors related stuff. Today's post, however, has a little more to do with actual science, and it also connects to writing, so don't just skip over this post because you're a writer and not a science geek.
So if you're a science fiction reader or writer, you've probably thought about faster than light travel. You've probably imagined hyperspace, warp drive, or some other futuristic thingamabob that allows man to go faster than the speed of light. You may have read a little about Einstein's theories and got confused. (If you didn't get confused, you're either a theoretical physicist or in denial.) Relativity is confusing. I don't pretend to understand it, so if you were hoping that I was going to dive into an easy to grasp explanation of it, well...I'm sorry to disappoint.
So the speed of light is 300,000,000 m/s (or in scientific notation, which is commonly used 3x10^8). You're probably looking at that number and thinking two things: 1) that's a big number and 2) how fast exactly is a m/s? So to give you an idea let's look at the speed of sound. At sea level its on the order of 300 m/s.
Yeah - that's a big difference between the two numbers.
So you've heard the phrase "sound barrier"? When the shuttle comes in and you hear a sonic boom, people say "it's broken the sound barrier." Did you ever wonder where this phrase came from? Undoubtedly you're wondering what this has to do with the speed of light - but hang in there.
It's called the sound barrier because at one time, scientist and engineers thought it was seriously a barrier - as in, you could not break it. We would be able to approach the speed of sound, but never actually hit it. No matter how hard we tried, our airplanes were going to only go so fast.
Now this thought wasn't around too long - as airplanes were invented at the turn of the twentieth century and Chuck Yeager went over Mach 1 in 1947. So you're probably wondering why they thought this. Well, if you looked at the equations for subsonic aerodynamics*, you would see that hitting Mach 1 would make you divide by zero. And you know what happens if you divide by zero.... (just google image "divide by zero". You'll learn.) Going over Mach 1 according to these equations would require taking the square root of a negative number.
What does this have to do with the speed of light and FTL (faster than light) drives? Well, my friend, if you look up special** relativity, you will see there are some similar equations where if your velocity hits the speed of light - you divide by zero. If it goes over, hello imaginary numbers!
If you don't write science fiction, this is just fun facts. If you do write science fiction, you need to realize something. Inventing a new engine that allows you to go faster than the speed of light isn't good enough. You have to invent new science.
It's like when aerodynamicists created new theories for sonic and supersonic flight. Someone in your world - some physicist or propulsion engineering needs to create a new theory for luminal and superluminal flight.
So when you're creating the story Bible for your world, make sure you take into account that your advanced society needs to have a new Newton, a new Einstein, or at least a new Bernoulli - someone who can see beyond what current science is telling them and discover what no one has thought of before.
On the other hand, maybe you don't need FTL travel in your future world. Not every science fiction society needs to have discovered FTL or even have a need for it. But how do you know if this applies to you? Sounds like a post for Thursday...
*I would post one or two if I knew how to make blogger and Equation Editor play nicely together, but unfortunately I don't.
** Don't look up general. Seriously. It's not worth trying to figure out. Your brain might explode.