Launch yourself from a height big enough and it won’t take you long to see which one would win in a battle between gravity and the forces that bind solid ground.
The relative weakness of gravity, at least compared to the force of electromagnetism and the nuclear forces, seems to limit its force to phenomena on the enormous scale of planets and galaxies.
For this reason, along with the challenge of combining general relativity with quantum physics, physicists tend to handcraft the role of gravity in particle formation by attenuating it with a rather arbitrary correction factor.
Two physicists from the Institute of Gravitation and Cosmology at Peoples’ Friendship University of Russia (RUDN University) are now rethinking the place of gravity between the building blocks of nature, looking for solutions to equations that would give this tiny force a greater role in explaining how fundamental particles could arise.
At first glance it seems like an unnecessary search. For a typical elementary particle, such as an electron, its electromagnetic attraction is 10 ^ 40 times stronger than its gravity.
Including the effects of gravity in describing the movements of an electron around the atomic nucleus would be like taking into account the impact of a mosquito when discussing a car accident.
Researchers Ahmed Alharthy and Vladimir V. Kassandrov think the mosquito might be more important than we think, at least at the astonishingly small level of the Planck scale.
“Gravity could potentially play an important role in the micro-world, and this assumption is confirmed by certain data,” says Kassandrov.
Established solutions to fundamental field theory equations in curving spacetime seem to allow for a small but non-zero influence of gravity when we zoom in close. As distances diminish, gravity’s tug eventually becomes comparable to that of attracted loads.
There are also models describing solitary waves that form in quantum fields where the tiny effect of gravity could amplify the wave.
The duo went back to semi-classical models of electromagnetic field equations, switching the commonly used hand-waved correction and applying rules that allowed them to adjust some quantities while keeping others stuck.
By inserting quantities that determine the charge and mass of known elementary particles, the team went in search of solutions that made sense.
For the most part, there were no clear-cut situations where gravity seemed necessary, at least for known particles.
But there were scenarios where distances decreased to about 10 ^ -33 meters for charged objects with a mass of 10 ^ -5 grams where solutions appeared.
The theorists are not sure whether their answers describe anything we can find in the universe, although they do set some limits on a spectrum corresponding to hypothetical semi-quantum particles called maximons.
Pushing the math further, as electric charge disappears into nothingness at the smallest scale and masses grow to stellar magnitude, it is clear that gravity is becoming a key factor in the emergence of some objects from the quantum landscape.
That may sound like a flight from fantasy, but such neutral matter waves are exactly the things that make up hypothetical objects known as forest monsters.
For now, in particle physics, gravity will be further reduced to a grudge, its small force a mathematical complexity that does not bring any appreciable benefit in solving it.
One day we may have to give the weakest of the four fundamental forces due to it on the smallest scale of the universe.
“In the future, we want to shed light on this problem which is intriguing to physicists, but extremely complex from a mathematics point of view,” says Kassandrov.
This research is published in Universe