A strange phenomenon: Have scientists found a way to bypass the speed of light?
Researchers from the USA have presented a model that allows a wave to appear as if it is moving faster than expected, and under certain conditions, even beyond the speed of light. The phenomenon is related to the way waves reaching a destination via different paths connect to each other. According to the scientists, this finding may be relevant not only to sound in water but also to light in a vacuum, without undermining fundamental principles of physics.
Researchers from the USA have presented a model that allows a wave to appear as if it is moving faster than expected, and under certain conditions, even beyond the speed of light. The phenomenon is related to the way waves reaching a destination via different paths connect to each other. According to the scientists, this finding may be relevant not only to sound in water but also to light in a vacuum, without undermining fundamental principles of physics.
It all started with an attempt to solve a practical problem. Researchers tracking whales in the ocean use underwater recording devices. When an animal emits a sound, each device picks it up at a slightly different time. By comparing these times, it is possible to estimate the location of the sound source.
However, the result is sometimes inaccurate. The reason is that the sound does not necessarily reach the device via a single path. Part of the signal may arrive directly, while another part reflects off the water surface. When the two paths meet, they influence each other, changing the shape of the signal that the device records.
A previous study by the same authors, published in 2025, showed that this process can make sound appear as if it is moving slower. The new study took this idea in a different direction. Researchers John Spiesberger from the University of Pennsylvania and Eugene Tray from the Woods Hole Oceanographic Institution examined situations where two paths synchronize. The result: the peak of the combined signal can appear earlier than the corresponding point on the direct path.
In their simulation, sound moved in water at a speed of about 1,500 meters per second. However, in some cases, the signal peak appeared as if it were moving at about 1,695 meters per second, and in another scenario, it reached about 2,783 meters per second. From the outside, it looks as if the wave did something impossible, but there is an important distinction. Nothing actually exceeded the speed of light. The researchers do not claim to have found a way to transmit information faster than light.
To test this, they created a model where a source transmits one of two options—0 or 1. The result was clear: although the signal peak can appear earlier, the new information still does not reach the destination faster than the direct path allows.
"We prove that the speed of information is less than or equal to the speed of light in a vacuum, and therefore the phenomenon does not violate special relativity," the researchers explain.
This can be compared to two people arriving at a meeting point from different directions. Each arrives at a different time, but their meeting creates a new image that cannot be attributed to either one alone. Similarly, in this case, the signal arriving directly and the signal traveling via another path connect to create a new shape. As a result, the most prominent point in the signal can appear where we did not expect to find it. Therefore, if one measures only the position of the peak, it feels as if the wave moved at an abnormal speed, but this does not mean that matter, energy, or information traveled at that speed.
