Is Warp Drive From 'Star Trek' Possible?

Enterprise replica from Star Trek
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One of the key plot devices in nearly every "Star Trek" episode and movie is the ability of starships to travel at lightspeed and beyond. This happens thanks to a propulsion system known as warp drive. It sounds "science-fictiony," and it is—warp drive doesn't actually exist. However, in theory, some version of this propulsion system could be created from the idea—given enough time, money, and materials.

Perhaps the main reason warp drive seems to be possible is that it hasn't been disproven yet. So, there may be hope for a future with FTL (faster-than-light) travel, but not any time soon.

What Is Warp Drive?

In science fiction, warp drive is what allows ships to get across space by moving faster than the speed of light. This is an important detail, as lightspeed is the cosmic speed limit—the universe's ultimate traffic law and barrier.

As far as we know, nothing can move faster than light. According to Einstein's theories on relativity, it takes an infinite amount of energy to accelerate an object with mass up to the speed of light. (The reason why light itself isn't affected by this fact is that photons—the particles of light—don't have any mass.) As a result, it would appear that having a spacecraft traveling at (or exceeding) the speed of light is simply impossible.

Yet, there are two loopholes. One is that there doesn't seem to be a prohibition on traveling as close as possible to lightspeed. The second is that when we talk about the impossibility of reaching the speed of light, we are typically talking about the propulsion of objects. However, the concept of warp drive is not necessarily based exclusively on the ships or objects themselves flying at the speed of light, as further explained below.

Warp Drive Versus Wormholes

Wormholes are often part of the conversation surrounding space travel across the universe. However, travel via wormholes would be distinctively different from using warp drive. While warp drive involves moving at a certain speed, wormholes are theoretical structures that allow spaceships to travel from one point to another by tunneling through hyperspace. Effectively, they would let ships take a shortcut since they technically remain bound to normal space-time.

A positive byproduct of this is that the starship can avoid undesirable effects such as time dilation and reactions to massive acceleration on the human body.

Is Warp Drive Possible?

Our current understanding of physics and how light travels excludes objects from reaching a velocity greater than lightspeed, but it does not exclude the possibility of space itself traveling at or beyond that speed. In fact, some people who have examined the problem claim that in the early universe, space-time expanded at superluminal speed, if only for a very short interval.

If these hypotheses are proven true, a warp drive could take advantage of this loophole, leaving behind the issue of the propulsion of objects and instead tasking scientists with the question of how to generate the enormous energy needed to move space-time.

If scientists take this approach, warp drive can be thought of in this way: A warp drive is what creates the immense amount of energy that contracts the time-space in front of the starship while equally expanding space-time at the rear, ultimately creating a warp bubble. This would cause space-time to cascade by the bubble—the ship stays stationary to its local area as the warp proceeds to a new destination at superluminal progression.

In the late-20th century, Mexican scientist Miguel Alcubierre proved that warp drive was, in fact, consistent with laws governing the universe. Motivated by his fascination with Gene Roddenberry's revolutionary plot driver, Alcubierre's starship design—known as the Alcubierre drive—rides a "wave" of space-time, much like a surfer rides a wave on the ocean.

Challenges of Warp Drive

Despite Alcubierre's proof and the fact that there is nothing in our current understanding of theoretical physics that prohibits a warp drive from being developed, the idea as a whole is still in the realm of speculation. Our current technology isn't quite there yet, and though people are working on ways to achieve this massive feat of space travel, there are many issues yet to be solved. 

Negative Mass

The creation and movement of a warp bubble necessitate the space in front of it to annihilate, while the space at the back needs to rapidly grow. This annihilated space is what is referred to as negative mass or negative energy, a highly theoretical type of matter that hasn't been "found" yet.

With that said, three theories have moved us closer to the reality of negative mass. For example, the Casimir effect lays out a setup where two parallel mirrors are positioned in a vacuum. When they are moved extremely close to one another, it appears that the energy between them is lower than the energy around them, thus creating negative energy, even if only in minuscule amounts.

In 2016, scientists at LIGO (the Laser Interferometer Gravitational-Wave Observatory) proved that space-time can "warp" and bend in the presence of enormous gravitational fields. 

And as of 2018, scientists from the University of Rochester used lasers to demonstrate another possibility for the creation of negative mass.

Even though these discoveries are inching humanity closer to a functioning warp drive, these minute amounts of negative mass are a far reach from the magnitude of negative energy density that would be needed to travel 200 times FTL (the velocity needed to get to the nearest star in a reasonable amount of time).

Amount of Energy

With Alcubierre’s design in 1994 as well as others, it seemed that the sheer amount of energy required to create the necessary expansion and contraction of space-time would exceed the output of the sun during its 10 billion-year lifespan. However, further research was able to lower the amount of negative energy needed to that of a gas giant planet, which, while an improvement, is still a challenge to come up with.

One theory to solve this obstacle is to extract the massive amount of energy created from matter-antimatter annihilations—explosions of same particles with opposing charges—and use it in the "warp core" of the ship.

Traveling With Warp Drive

Even if scientists succeed in bending the space-time around a given spaceship, it would only lead to more questions regarding space travel.

Scientists theorize that along with interstellar travel, a warp bubble would potentially collect a large number of particles, which could cause massive explosions upon arrival. Other possible issues connected to this is the matter of how to navigate the whole warp bubble and the question of how travelers would communicate with Earth.

Conclusion

Technically, we are still a long way away from warp drive and interstellar travel, but with the advancement of technology and push toward innovation, the answers are closer than ever before. People like Elon Musk and Jeff Bezos who aspire to make us a space-faring civilization are the stimuli needed to crack the code of warp drive. For the first time in decades, there is a rock-and-roll-like excitement about space flight, and this kind of enthusiasm is another essential piece in the quest to explore the universe.