Thanks to Einstein’s laws of general relativity, researchers have known for well over a century that nothing can possibly travel faster than the speed of light. If a mass-carrying object approaches this speed limit, increasing its speed any further would cause it to gain more mass – increasing the amount of energy required to accelerate it further still. Ultimately, this relationship means that the object would technically need an infinite amount of energy to reach the speed of light itself.

But despite this seemingly unbreakable constraint, some researchers are still hopeful that loopholes could exist in Einstein’s laws. This possibility has inspired countless works of science fiction – including one of Glenn’s biggest sources of inspiration:

In Star Trek, ships including the USS Enterprise explore the galaxy with the help of a device named a ‘warp drive’. Instead of moving the ship directly through space – which would take years to reach even the closest stars – the warp drive works by bending the fabric of spacetime itself, so that the ship “surfs” along on curved spacetime. In both theory and observation, the velocity of the disturbances in spacetime itself can actually exceed the speed of light.

To date, physicists still haven’t ruled out this exciting concept as impossible. But all the same, the idea has so far remained purely theoretical – and the warp drive has stayed firmly within the realms of science fiction.

Through his experimental research, Dr. Chance Glenn believes he may have discovered that the fabric of spacetime could be distorted, much like the warp drive, by extremely strong electric fields. His concept still has some uncertainties to iron out – but if his ideas are correct, they would hint at the existence of a remarkable effect which theoretical physicists continue to wrestle with. What’s more, they would show for the first time how spacetime can be warped using simple and affordable apparatus.

In order to build a functioning warp drive, many physicists believe we will first need to overcome the problem of ‘negative energy density’. This as-yet theoretical concept describes a case where the energy contained in a portion of space is less than it would be in a completely empty vacuum.

If this condition could be achieved, some researchers argue that it could lead to some extremely exotic effects, including the distortion of spacetime. But in the decades since this concept was first proposed, researchers have come no closer to discovering how negative energy density could be achieved in a practical experiment.

Through his work at Morningbird, Glenn has explored this seemingly insurmountable challenge from a variety of angles. One of his experiments involves two ordinary components which are small and simple enough to fit on a table in his lab.

The first of these is a ‘spark gap’: where a pair of electrodes are separated by a gap of just a few millimetres. When a high voltage is applied across such a tiny gap, it generates an extremely strong electric field: ionizing the air inside the gap. This allows the electrons which have accumulated in one of the electrodes to jump across the gap, producing a dramatic blue spark.

The second part of Glenn’s setup is an interferometer: essentially a far smaller version of the instruments operated by the LIGO-Virgo collaboration, which led to the groundbreaking discovery of gravitational waves in 2015. These waves are created when the fabric of spacetime is stretched and squeezed as massive objects, such as black holes and neutron stars, spiral around each other before merging together

In an interferometer, a beam of light is first split into two equal parts, which each travel along straight, separate, and identical arms at right angles to each other. At the end of each arm, the light is reflected back to the point where the original beam was split, and both parts are recombined into a single beam. Finally, the recombined beam is projected onto a screen at the other end of the table.

If a distortion in spacetime, such as a gravitational wave, happens to pass through an interferometer, one arm would temporarily become shorter, or longer, than the other, meaning the light travelling through it would need to travel a shorter or longer distance before recombining. Due to the effects of wave interference, this shift would alter the pattern of light projected onto the screen. This is called a change in the optical path length.  In Glenn’s setup, one arm of an interferometer passes through a millimetre-wide spark gap, while the other doesn’t. The interferometer can detect distortions on the order of nanometres, or 10^-9 metres. Extremely small distortions.

In Glenn’s lab, the effect of the extreme electric field is immediately obvious: when the spark gap is fired in a series of rapid pulses, the projected light pattern undergoes a clearly visible distortion. This can only imply that the light travelling through one of the arms experienced slightly different conditions on its journey before recombination.

When he first observed this effect, Glenn didn’t jump to conclusions. Through a series of experiments, he considered whether this shift in the interference pattern could have been caused by other effects, such as vibrations in the setup produced by the rapidly pulsing spark, or even shockwaves created by the formation of the plasma.

Following these tests, Glenn is now confident that he has ruled out all but two possibilities. The first of these is that the projected interference pattern could have been distorted by a change in refractive index to the air in and around the spark, due to the formation of plasma. That leaves only one other theory: that the extreme electric field within the spark gap really is bending the structure of spacetime, for reasons which physicists have yet to understand.

For now, much more experimental work will be needed for Glenn to confirm whether or not this interpretation is correct. But if he is right, this result could have profound implications for our understanding of physics: implying that negative energy density may not be strictly necessary to distort the fabric of spacetime.

If the bending of spacetime could be understood and controlled by extreme electric fields, Glenn’s discovery may ultimately take us a step closer to bringing the warp drive out of the realms of science fiction; and making the interstellar voyages of the USS Enterprise a reality.