An American scientist claims to have found evidence suggesting that the speed of light, as described by Einstein’s theory of general relativity, is slower than previously assumed.
According to general relativity, light travels at a speed of 299,792,458 meters per second in a vacuum.
Meanwhile, physicist James Franson from the University of Maryland has presented evidence that he believes indicates that the speed of light must be lower than this figure.
Supernova SN 1987A – (Photo: NASA)
Franson based his findings on information obtained from the observation of supernova SN 1987A, which exploded in 1987, as observed from Earth, according to Space.com.
Researchers on Earth detected photons and neutrinos from the explosion, but the photons arrived 4.7 hours later than expected. At that time, scientists believed this delay could be due to photons originating from a different source.
However, recently, Franson suggested that the reason could be light slowing down because photons have a vacuum polarization characteristic, where a photon briefly separates into a positron and an electron before recombining into a photon again.
This separation would create a gravitational differential between the charged particle pairs, resulting in a slight energy impact when they recombine, sufficient to delay their travel time.
The separation and recombination could occur multiple times with many other photons throughout the journey of 168,000 light-years—the distance between Earth and SN 1987A—leading to the observed delay of 4.7 hours.
