Can we travel faster than the speed of light?
“Earth is the cradle of humanity, but one cannot remain in the cradle forever.”
Konstantin Tsiolkovsky (Russian rocket scientist, 1911)
Yuri Gagarin was the first human being to journey into outer space in 1961. A few years later, we set foot on the Moon – and that’s as far as humans have got. If we’re wanting to visit our neighbouring star systems and beyond, we’re going to need a significant increase in the speed of how we travel. But how fast can we go? Will we ever be able to achieve Faster Than Light (FTL) velocities, perhaps using warp drive and exploiting wormholes? Or is this just another dream of science fiction?
Is warp drive just a dream of science fiction? Or could it become a reality?
We know space is big - really, really big - but the numbers that describe it can be mind-boggling and difficult to realistically comprehend. Our Milky Way galaxy is at least 100,000 light-years from side to side. One light-year is approximately 6 trillion miles (or 9 trillion km). That’s a 6 (or 9) with 12 zeros behind it. Space is beyond vast. We don’t have any benchmarks with which to meaningfully measure it against in our daily lives.
Our nearest neighbouring star is Proxima Centauri, which is 4.2 light-years away. At the speed that Voyager 1 is currently going at, it would take about 75,000 years to get there. This illustrates a major problem. How do you cross that sort of distance in a more reasonable time? Travelling at the speed of light, a round trip would take nearly a decade - and that’s more bearable.
Unfortunately, the laws of physics state that FTL travel isn’t possible. Unlike the sound barrier, the speed of light is an absolute limit. Accelerating anything with mass to that speed would require an infinite amount of energy. That’s the bad news.
But there’s also good news. It turns out there are theoretical loopholes which indicate we might potentially be able to manipulate space-time itself. The key thing here is that these loopholes don’t break the foundations of our current understanding of physics.
While FTL travel is considered both outlandish and exciting, a couple of proposals using textbook physics have nevertheless been put forward. And most of us are already familiar with them: warp drives and wormholes.
An airport’s travelator does the moving for you
Miguel Alcubierre was a PhD student at the University of Wales, Cardiff, in 1994. Inspired by Star Trek, he wanted to see if the fictional idea of a warp drive could be theoretically possible using Einstein’s general relativity equations. He worked out there might be a way to travel faster than light by somehow bending space. The idea is to move with space, not to move through it. If you contract space in front of the spaceship, and expand it behind, you can achieve FTL speed. A simple way of understanding this is to think about a travelator at an airport - you just stand there immobile and the conveyor belt does the moving for you. As Miguel Alcubierre says: “The warp bubble is a distortion in the geometry of space and time…It’s just geometry. That’s all it is.”
Theory is one thing, but the reality of practical engineering is a completely different matter. Based on what we currently know, you’d need a ridiculously massive amount of negative energy to make the necessary space-time distortion happen.
Another theoretical possibility - which also involves bending space-time - is the creation of wormholes. It’s like folding a sheet of paper in half and punching a hole through both sides at once to open a temporary tunnel. You could either travel across the surface of the sheet of paper, or go through the hole, to get to the same place - but going through the hole or tunnel is significantly shorter. However, wormholes are highly unstable and incredibly tiny.
Are wormholes a possible future means of interstellar travel?
There are still too many unknowns for making either theory a workable reality. Both methods rely on the idea of exotic matter, huge amounts of energy, and technology far beyond our current capabilities. That said, recent research on the International Space Station has actually managed to produce a type of exotic matter - the properties of which may be required for stabilising a wormhole. It’s been shown that we can prop open wormholes at the microscopic level using quantum entanglement. Whereas this might be a step in the right direction, it’s just that - one step - and there’s a hell of a way to go.
There could be another way, or a back door, as yet completely unknown to us. Scientists have a poor track record of predicting future or breakthrough technology. Most don’t think outside of the box, held back by psychological constraints such as peer pressure. The majority of technological advancements are incremental steps forward, building on what’s already been established - but knowledge can occasionally take an unexpected turn in a different direction, going where few dared to venture. An unknown avenue is a definite possibility - and maverick scientists should be encouraged, not discouraged.
But do we really have to travel faster than the speed of light? Even if we discovered how to travel at 10% of the speed of light, astrophysicists tell us that it would be mathematically possible to colonise every single star system in the Milky Way galaxy in about 3 million years. If we could design a spaceship and an alternative method of propulsion that could average just 10% of light speed, this would be enough to reach Proxima Centauri in forty years - a huge improvement over the journey time of 75,000 years mentioned above, which is where we’re currently at.
Our propulsion technology is based on Newton’s third law of motion - which states that every action has an equal and opposite reaction - often simply expressed as “chucking things out at the back to go forward”. We’ll undoubtedly get better and better at doing this, as we have to date, until the limit of what’s possible is one day reached.
It’s bizarre that the scientific community giggle, sneer at, or ignore any rational suggestion there might be extraterrestrial spacecraft occasionally flying around in our skies. We’ve reported, for example, what Commander David Fravor and others encountered in 2004. The FLIR video, which supports their expert testimony, clearly points towards a totally different and unknown type of propulsion system being used. Shouldn’t scientists be studying whatever detail can be gleaned from these reliable cases, looking for clues as to what might be happening? Isn’t this the scientific method which has allowed us to replace ignorance and myth with exact knowledge? Their avoidance of these unidentified aerial phenomena is irrational and unprofessional. Stigma or taboo should have no place in true scientific endeavour, yet it dominates in these instances - thwarting enquiry and progress. There will almost certainly be advanced civilisations out there in the galaxies, and it’s looking at least possible that some intelligently-controlled technology is here. Our best scientific minds should be intrigued, eager to find out what might be happening.
Bill Nelson, the new NASA administrator, is open-minded about UAP Credit: NASA/Bill Ingalls
Bill Nelson has only had the job of NASA administrator for one month. During a press conference on 2nd June, he said: “I just want you to know that what you have seen on the TV recently, on the Navy films, I had known about this in my former capacity in Intel in the Armed Services Committee. And I’ve talked to those pilots. And they think it’s real.” He announced that he’s asked the NASA scientists to look at the UAP matter. In an interview with CNN a couple of days later, Nelson added: “We don’t know if it’s extraterrestrial. We don’t know if it’s an enemy. We don’t know if it’s an optical phenomenon. We don’t think so because of the characteristics that those Navy jet pilots described as they saw it move around. The bottom line is, we want to know, and that’s what we’re trying to do.” Whether the NASA scientists will go beyond decades of closed-minded denial of the UFO/UAP subject remains to be seen - which they should, because space travel is supposed to be their specialist area. Regardless of what happens, Bill Nelson’s fair-minded approach to these encounters with unidentified craft should be applauded.
Written by Victoria de las Heras & Cal Stewart, 10th June 2021