Our universe is massive. The closest star to Earth other than our sun is 4.22 light years, the distance light travels in one year, or 39.9 x 1012 km, away (“The Nearest Star”).
With current rocket technology, the time it takes to get from Earth to Mars (a distance of only 55,000,000 km) is 150-300 days (Cain). If the average speed of a space shuttle is 28,000 km/hour (“Frequently Asked Questions”), then to travel one light year, it would take about 39,000 years!
So how could aliens and future humans cruise throughout the universe? The way science fiction gets around this issue is by introducing faster-than-light travel technology. This concept is commonly known as “warp drive” in science fiction, most notably in the Star Trek universe. Star Trek takes this further by introducing Starfleet ships that can actually reach speeds of up to 4 billion mi/second, giving future humans almost unlimited potential for exploration.
If interstellar space exploration will ever be possible and if we ever hope to see anything beyond our immediate planetary neighbors, warp drive or something similar must be achieved . We broke the sound barrier (traveling faster than the speed of sound) several decades ago – so what will it take to break the light barrier?
NASA scientists are starting preliminary experimentation on this concept. Star Trek takes place in the 23rd century, giving us 200 years to achieve warp drive. Let’s see how we’re doing.
Breaking the light barrier is much more of a challenge than breaking the sound barrier, not just because of the increased speed (sound travels at 340 m/s, whereas light travels at 300 million m/s), but because of the composition of these barriers.
The sound barrier was broken by an object made of matter. Matter is comprised of atoms and molecules that are connected by electromagnetic fields, the same stuff that composes light. Trying to break the light barrier would be trying to break a barrier composed of the same stuff the barrier itself is made of. It would be as if I was trying to break a banana in half by lying another banana on top of it.
Another problem lies in Einstein’s Special Theory of Relativity. There are two parts to this theory:
1) The distance (d) traveled depends on how fast you move (velocity) and for how long you’re in motion (time). An easy example of this is if you drive 55 mi/hour for one hour, then you traveled 55 miles.
2) The speed of light is the same for all observers, whether or not they’re in motion. This means that people will experience light the same way whether they’re in a rocket traveling 28,000 km/hour, driving a car at 55 mi/hour, or standing still.
When these two ideas are taken together, we come to Einstein’s conclusion that space and time are relative. Objects in motion experience time at a slower rate than objects at rest.
We can’t experience this concept firsthand in our everyday lives because driving at 55 mi/hour and standing still are essentially the same thing when compared to the incredibly fast speed of light. If we start getting toward the incredibly fast speed of light, though, then that’s when Special Relativity starts becoming a problem.
Everything we sense in the world around us is the result of light bouncing off matter, or more generally, electromagnetism. Everything we see, everything we feel (the result of air molecules bouncing off our skin), everything we hear (the result of air molecules bouncing off each other in waves of pressure), the way that we sense time – these are all the result of electromagnetic forces. If we move at the same speed by which we get this information from electromagnetic forces, though, then our information input gets incredibly distorted. According to Special Relativity, we end up moving too fast for information to come in at the right speed for us to process.
Another issue that Special Relativity poses is the energy required to move at the speed of light. To move an object faster, we add energy to the object. If you want to start moving at the speed of light, though, imagine the sheer amount of energy required for this! Moving a mass at the speed of light would require infinite energy (“Status of ‘Warp Drive’”).
There are five stages to scientific development:
Star Trek took care of the first stage when it proposed faster-than-light interstellar space travel. For the past 50 years, though, scientists have been stuck at “speculation,” all of which has merely resulted in the problems you just read. As scientists (and science fiction authors) continue speculating on the subject, it just seems more and more unlikely that warp drive is possible.
Speculation, though, has also led to the conjecture of other possible alternatives to faster-than-light travel, one of the most popular of which is wormholes. But that’s something we’ll save for another snippet.
In the meanwhile, though, we can keep ourselves occupied with our closest planetary neighbor, Mars, and focus on interstellar travel at a later, more fitting time.
Written by Constance Kaita
images courtesy of commons.wikimedia.org, memory-alpha.org, and scientificamerican.com
Cain, Fraser. “How Long Does it Take to Get to Mars?” 9 May 2013. Web. 12 July 2013.
“Frequently Asked Questions.” NASA.gov. 21 May 2013. Web. 12 July 2013.
“The Nearest Star.” NASA.gov. n.d. Web. 12 July 2013.
“Status of ‘Warp Drive.’” NASA.gov. 2 May 2008. Web. 12 July 2013.