- EXPLORE FURTHER: Ways for humans to journey millions of light years towards far-off worlds
Anyone who was deeply fascinated during their upbringing due to Star Wars will know the thrill of seeing Han Solo and Chewbacca launch the Millennium Falcon into hyperspace for the first time.
In the films, hyperdrive engines allow ships like the Falcon to leap around the Universe faster than the speed of light to reach distant planets in just minutes.
But as fans celebrate 'Star Wars Day' this May 4, experts have said that this futuristic tech isn't entirely science fiction.
Scientists suggest that a genuine 'warp drive' in reality might enable spacecraft to leap between galaxies similar to what is seen in Star Wars.
Instead of consuming fuel as rockets do to propel the spacecraft through space, warp drives have the potential to alter and extend spacetime, effectively bringing the final destination nearer.
Professor Tim Dietrich, a specialist in gravitational physics at Potsdam University, explained to MailOnline, "The allure of employing a warp drive lies in its ability to enable nearly instantaneous travel between two locations."
'In this sense, it could in principle enable galactic travel, similar to what we see in science fiction.'
Nevertheless, specialists caution that an actual warp drive would be much less feasible and considerably riskier compared to the hyperdrives depicted in movies.
What is a warp drive?
As per Einstein, masses cause spacetime to curve and warp, similar to how weights placed on a rubber sheet create distortions.
Subsequently, the other masses on the sheet slide into these 'spacetime curves,' resulting in gravitational effects.
In 1994, physicist Miguel Alcubierre discovered that Einstein's theory of spacetime permits the development of an entirely novel kind of engine.
Dr Katy Clough, a cosmologist at Queen Mary University of London and Professor Dietrich's collaborator, told MailOnline: 'A warp drive is a hypothetical system that would allow a spacecraft to travel from A to B by bending spacetime.
'Normal rockets accelerate by burning and ejecting fuel, which allows them to speed up to cover distances faster.
'A warp drive simply contracts the distance in front of the ship, and expands it behind, so that the ship moves from A to B without needing to accelerate.'
Like the hyperdrive on the Millennium Falcon, a warp drive creates a 'warp bubble' of distorted spacetime around the ship.
The ship remains within a flat region of spacetime at the centre of the bubble and is simply carried along with the bubble as it moves.
Dr Clough says: 'This sounds like science fiction, and it probably is, but the idea that space and time are flexible and can be warped is a fact, and the basis of Einstein’s theory of general relativity.'
Can a warp drive allow you to travel between the stars?
The challenge of traveling between star systems akin to the spacecraft in Star Wars lies in the fact that the universe has a speed limit.
In addition to suggesting that warp drives could be feasible according to his theories, Einstein also posited that nothing can travel quicker than the speed of light — roughly 300,000 kilometers every second.
That means it would take over four years to reach Proxima Centauri, the nearest star to Earth at a distance of 4.3 light-years, even travelling close to the speed of light.
Journeying to the center of the Milky Way would require approximately 26,000 years, which is far from the instantaneous voyages depicted in movies.
The advantage of employing a warp drive is that a spacecraft could potentially circumvent this velocity limitation by taking advantage of an anomaly within general relativity theory.
The growth of spacetime isn’t bound by any speed limits, allowing the warp bubble to travel at virtually any velocity it desires.
At the same time, the spacecraft stays stationary within the flat region of spacetime enclosed by the warp bubble, which means it does not move relative to the surrounding space.
It sounds wild, but this physics loophole allows a ship to 'move' faster than lightspeed without ever accelerating.
Moving faster than the speed of light, a ship can cover any distance in an 'arbitrarily' short period of time.
NASA engineer Dr Harold 'Sonny' White posits in an essay that spacecraft could depart from Earth utilizing traditional rockets prior to positioning themselves towards their target and engaging the warp drive technology.
Once close enough, the warp drive would then deactivate at a safe distance and the trip would be finished using conventional forms of propulsion.
Dr White writes: 'This approach would allow a journey to say Alpha Centauri as measured by an earthbound observer (and spacecraft clocks) measured in weeks or months, rather than decades or centuries.'
What would it be like to ride a warp drive?
In Star Wars, a jump into hyperspace comes complete with a stunning visual display of streaking lights and stars.
But what would it really be like to look out of the window of a ship riding at warp speed?
Dr Clough says: 'Depending on whether you look in the forward or backward direction, the wavelength of incoming light from stars would get squashed or stretched, and so ahead things would look more blue and behind more red.
'In addition, the shape of objects would be distorted, like when looking through a curved lens.'
Unfortunately for Star Wars fans, Dr Clough says that Star Trek actually comes a lot closer to visualising this correctly.
Dr. Clough mentions that the 'bullet shot' scene in Star Trek Beyond was loosely inspired by how light might bend within the distorted space-time surrounding a warp bubble.
For fans of the series, this is yet another disappointment: research indicates that those traveling through warp speed wouldn’t actually observe starlight streaking past their windows.
A team of physics students from the University of Leicester found through their modeling that individuals onboard the Millennium Falcon would actually observe a flat, luminous disk.
This occurs due to the fact that the cosmic microwave background radiation, which is residual energy from the Big Bang, would shift from microwaves into visible light wavelengths as a result of the Doppler effect.
Could a warp drive actually be feasible?
But before you start packing your bags for a trip to Alpha Centauri, the experts warn that a real warp drive might still be a long way off.
This is because a warp drive requires something called 'exotic matter', which is matter with negative energy.
Dr Clough says: 'If the curvature of spacetime is represented by a sheet stretching when massive objects are placed on it, positive energy objects create a dip in the sheet, which other massive objects tend to fall into – this explains gravitational attraction.
'However, in this picture negative mass would instead pull the sheet upwards, creating a hill that other objects fall away from.'
Through harnessing negative energy, future space travelers could mold spacetime into the exact configuration required to generate a warp bubble.
Even though this might sound as fantastical as the Force, negative energy is indeed a genuine outcome of quantum physics, and researchers have succeeded in generating minute quantities of it in laboratory settings.
"Scaling this up to create a protective bubble around a sizable vessel, requiring an energy output many times greater than that of the sun, remains firmly within the realms of science fiction," explains Dr Clough.
Travelling quicker than the speed of light also brings about a series of challenges that might create significant difficulties for those exploring space.
Professor Dietrich warns that using a warp drive might cause 'causality paradoxes once it crosses light speed' - which the Universe might not allow to occur.
However, simply because we can't comprehend this technology, it doesn't imply that it's unachievable.
Hunting for warp drives
And if there is anyone in a galaxy far far away already jumping through hyperspace, Dr Clough and Professor Dietrich think we should be able to find them.
Much like the plasma in a fusion reactor, the exotic matter powering a warp drive would be so unstable that it would need to be contained by some kind of field.
Should that containment field fail, the exotic matter would rapidly dissipate.
Doctor Clough and Professor Dietrich examined the scenario that unfolds right after the failure of such a containment field.
Professor Dietrich says: 'When this happens, the bubble becomes unstable and collapses, and the distortion of space fragments and creates ripples that propagate outwards – these are gravitational waves that we could in principle detect arriving on Earth.
'These waves within our galaxy might be quite powerful, making them theoretically detectable over the noise produced on Earth.'
Even though he cautions that waves generated by vessels shorter than a kilometer wouldn't register with our present detection equipment due to their frequency, this implies that we could identify any nearby usage of warp drives.
Dr Clough states: "Tim [Professor Dietrich] is doubtful and believes we won’t observe anything at all. Although I agree with him, I still find it intriguing enough to warrant giving it a try."
'It’s thrilling to consider that, even if we cannot create a warp drive ourselves, another civilization somewhere in our galaxy might have mastered it, allowing us to potentially observe its usage.'
Dr. Clough mentions, "Should anybody have an extra billion pounds available for a high-frequency gravitational wave detector, kindly get in touch with us!"
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