Singularities play an interesting role in physics, and come in many different varieties, from the mathematically and philosophically challenging to the more mundane. As the place where ‘physics breaks down’ in a black hole, scientists have the sense that anything might happen at a singularity. This begs the question: are there things they might drop into a singularity that have fundamental properties that could be erased absolutely? In a new paper, a team of theoretical physicists from the United Kingdom considers the conservation of electric charge.
“‘Physics breaks down at a singularity’ is one of the most famous statements in pop-physics,” said Professor Martin McCall, a researcher in the Department of Physics at Imperial College London.
“But by showing how this might actually happen, we take aim at one of the most cherished laws of physics: the conservation of charge.”
The conservation of charge says that the total electric charge of any isolated system — including the Universe as a whole — never changes.
This means that if negatively or positively charged particles move into one area, the same amount of respectively charged particles must move out.
This has been shown at the very smallest scales: when different particles are created or eliminated in experiments such as CERN’s Large Hadron Collider, the same amount of negatively and positively charged particles are always produced or destroyed, respectively.
By modifying classic physics equations to include axions, a candidate for dark matter particles, Professor McCall and colleagues were able to show that temporary singularities — such as black holes that appear and then later evaporate — could destroy charge when they come to the end of their life.
The predicted properties of axions could form a field that would interact with the kind of fields physicists have known about for centuries — electromagnetic fields, which are described by a set of equations called Maxwell’s equations.
Using a branch of mathematics called differential geometry, the researchers found out how to create or destroy charge, violating the charge conservation of the Universe.
“You can imagine creating an ‘axion bomb’ that holds charge by combining coupled axion and magnetic fields; and then dropping it into an evaporating black hole,” said Dr. Jonathan Gratus, a researcher in the Department of Physics at Lancaster University and the Cockcroft Institute.
“As the construction shrinks and disappears into the singularity, it takes electrical charge with it. It is the combination of a temporary singularity and a newly proposed type of axion field that is crucial to its success.”
“There are also philosophical implications,” added Dr. Paul Kinsler, a researcher in the Department of Physics at Lancaster University, the Department of Physics at Imperial College London, and the Cockcroft Institute.
“Although people often like to say that ‘physics breaks down,’ here we show that although exotic phenomena might occur, what actually happens is nevertheless constrained by the still-working laws of physics around the singularity.”
The team’s paper was published in the journal Annalen der Physik.
Jonathan Gratus et al. Temporary Singularities and Axions: An Analytic Solution that Challenges Charge Conservation. Annalen der Physik, published online May 5, 2021; doi: 10.1002/andp.202000565
Source link: https://www.sci.news/physics/axions-charge-conservation-black-hole-09800.html