Scientifically it has always been the belief that objects with mass can never reach the speed of light. Einstein taught that it was only possible for an object without mass, like a photon can only travel at the speed of light and no slower. So no one has observed yet what happens at faster than light speeds depicted in science fiction movies.
Elizabeth Howell, recently writing for space.com, explaining the scientific findings of a 2021 study by researchers at the Massachusetts Institute of Technology, says that the way science fiction movies often depict the space travelers’ view of high-speed faster than light maneuvers in space is likely to be wrong.
Barbara Šoda, Vivishek Sudhir, and Achim Kempf studied the Unruh effect and wrote about it in their 2021 paper Acceleration-Induced Effects in Stimulated Light-Matter Interactions.
The Unruh effect is one of the most exciting theories in astrophysics. The YouTube channel PBS space-time describes event horizons (a concept in astrophysics of boundary events) generated every time you or something moves, e.g., get out of a chair, put one foot in front of another, go for a sprint, drive fast. An event horizon is a boundary beyond which events cannot affect an observer. The more you accelerate away, the closer an event horizon is to you. How you moved 1 minute ago created an event horizon, how you moved 10 seconds ago is an event horizon, and how you moved 0.01 milliseconds ago is an event horizon.
The simple act of acceleration/movement cuts off your causal access to a region of the universe. You can’t be back in the moment you were 1 minute ago, 10 seconds ago, or even 0.01 milliseconds ago, even though 0.01 milliseconds ago is very close to the moment you are now. In one sense, what happened 0.01 milliseconds ago does not affect you right now. In the scientific sense, your past moving events do not catch up with you, but something scientists call Unruh radiation does catch up with you.
When we create event horizons, we distort what scientists call the quantum vacuum, making particles. Scientists have named this process the Fulling-Davies-Unruh effect, or sometimes just the Unruh effect.
You will likely never experience the Unruh effect of faster than light speeds
At faster than light speed in science fiction, spacecraft may be moving so fast that Unruh radiation (the particles created from distorting the quantum vacuum) from their previous movement doesn’t catch up with them unless they slow down or stop. What would you see if you achieved this kind of speed, you would never know unless you get sucked into a black hole or ejected from a white hole. Where black holes and speeds are concerned, the scientific terminology changes name and references Hawking radiation rather than Unruh radiation; the two theories have some similarities.
In science fiction movies where spaceships suddenly go into faster than light speed, the audience is used to seeing fast-moving streaks of light appearing in the spaceship window. If you have seen Star Wars films, you may remember that this was the case when Han Solo and Chewbacca flew the Millenium Falcon, and they would see fast-moving streaks moving towards the spaceship’s window as it zoomed away into space.
This would not be the case if and when science does create a machine that can travel that fast through space. The new study proposes that when hyper speed is reached, either due to quantum fluctuations or shifting the wavelengths of stars into the X-ray range, space travelers will instead see a glow rather than the star streaks often depicted in science fiction.
It may be possible to demonstrate the Unruh effect with lasers and electrons
It has been difficult for scientists to prove the ‘glow’ theory even though the quantum fluctuation idea dates back to the 1970s. Star War was released in 1977. Hollywood has run amuck with the visualization that faster than light speed looks like streaks of light.
To see this effect happen, atoms have to accelerate to the speed of light in less than a millionth of a second. This latest study proposes that there will hopefully be a way to simulate that and finally see the Unruh effect.
At these speeds, a body moving swiftly through the vacuum of space should feel warm radiation. Quantum interactions and fluctuations in space would cause the warm radiation.
The researchers have planned to build a particle accelerator, roughly the size of a laboratory. It was their ambition to accelerate an electron close to the speed of light. They would achieve this with a laser beam operating at microwave wavelengths.
The researchers will try and make an atom accelerate with a particular trajectory through a field of photons. If all goes to plan, the atom will interact with the photon field so that other photons on a specific frequency would essentially appear invisible to the atom. It is likely to create some glow.