Fifth force. Fishmonger

1989/12/01 Legarreta, J. A. Iturria: Elhuyar aldizkaria

• Fisika

According to Big Bang theory, the moment when the entire mass of the universe and all energy was concentrated at one point (“zero moment”) was then when the four forces (gravitational, electromagnetic, nuclear weak and violent) we know today were unified. The instability of this situation caused the most intense explosion that occurred, breaking four interactions or the convergence of these forces 10 -11 seconds from the expansion of the universe.

The main challenge of physicists today is to obtain a unified theory of these four forces, separated in such a short time. This process of unification is intrinsically hindered, but if the influence of the fifth force is demonstrated, physicists will have to overcome even more the difficulty in finding the only force that directs the universe. According to experts, this only force can be the basis of the universe. Moreover, this only force had the ability to create the universe, that is, it was the cause of the Great Explosion and depended on the same light, matter, energy, structure and space/time of the universe at the time of its birth. Will it just be a dream?. Let's see it.

Today we know four interactions. Let's say that about 300 years and many efforts have been necessary to know them well.

One of the concerns of physicists is to get a common theory of the four interactions that govern the universe. But the desire to achieve a unified theory was very heavy, E. When Fischbach announced in January 1986 the existence of the fifth force. But what is this fifth force?

As is known, for all material bodies two types of masses are defined. The inertial mass is that which opposes the change of movement of the body affected by a force. The gravitational mass represents the gravitational force between two objects.

By convention, inertial and gravitational mass are considered equal. But in the study that Hungarian Baron Lorand Eötvös published before World War I, he exposed some changes in the equivalence between gravitational and inertial mass. In his experiments he used different materials and measured small differences between both types of masses. However, the equivalence between both types of masses was deeply rooted, L. Eötvös thought that the results obtained were not too important and were only the result of a poor experimental measurement.

(Note: To see this image well go to pdf).

Frank D. from the University of Queensland. Stacey was an Australian physicist who took up this issue in the 1980s. He conducted experiments to measure gravitational changes that occur as they move to the center of the Earth and descended to 2,000 m. Gravity decreased faster than expected by Newton's law. Moreover, the universal gravitational constant (considered universal constant) at this depth was 1% lower than on the earth's surface. F. Stacey attributed these differences to the errors he made in his measurements or, perhaps, the gravitational anomalies caused by the metal deposits present in the surroundings falsified the results of his experiments.

But E. Fischbach in 1985 L. Results of Eötvös and F. Stacay claimed that they were correct and accused the fifth force, which creates a gravitational mass somewhat smaller than the inertial. His gravimetric experiments showed that it would be a repulsive force and its intensity 100 times lower than that of gravitational force. The curious thing would be that, instead of relying on the mass of bodies, as in the case of gravity force, it would be a function of its atomic structure, the varionic number of materials. Remember that the barionic number is the sum of the number of neutrons and protons of the atomic nucleus.

In fact, if the existence of this fifth force was demonstrated, in the vacuum there would be more than 1 kg of lead (82 protons, 125 neutrons) than 1 kg of aluminum (13 protons, 13 neutrons). Therefore, we should use very good instrumentation to detect the influence of the fifth force, since the intensity of the gravity force is 100 times higher, so it would be exceeded in all experiments.

There seems to be a great debate between the physicists, some in favor and others against. Some say that instead of being repellent it is attractive. But in short, what confirms or denies a theory is experimentation, and in this case there are two means of proof: gravimetric research, F. What Stacey uses and differential research. Differential research allows to know the relationship between the fifth force and the composition of the matter to which it affects.

As Earth has about 4x10 51 protons and neutrons, it would be a good agent of the bariotropic force (fifth force). Therefore, the Earth will not equally affect the bodies of the same mass if they have different numbers of protons and neutrons. However, in the congress held by physicists from around the world in the French town of Ars, research work has been analyzed for and against the fifth force. The conclusion is that the fifth force does not exist and is very weak.

Most of the experiments carried out since 1985 have been of secondary type and contradictory results have been obtained. In fact, the fifth force affects differently bodies of different atomic composition, and although experiments with different materials have obtained optimistic results, with others no satisfactory results have been obtained. Moreover, the results obtained in experiments that demonstrate the existence of the fifth force do not coincide in intensity and field of action.

Researchers from the United States of New York have conducted studies in Greenland on the fifth force and have rebuilt F on polar ice. Stacey's experiment, by discovering that, like him, gravity decreases a little faster than Newton's theory foresees. Physicists attribute these results to the fifth force. Its intensity is 2% or 3% of the force of gravity and its field of action is up to 500 m. In any case, the geophysical director of the experiment, Mark Ander, is not very comfortable and acts prudently referring to the vicissitudes observed, without speaking for or against.

New experiments are currently being carried out, one of them in the South, since the South ice is twice as compact and uniform as that of Greenland. Researchers plan to descend to 4,000 m deep and expect reliable experiments (twice as reliable as those in Greenland). Another interesting experiment is planned at the CERN (Nuclear Research Centre) in Geneva. The fall of protons and antiprotons is being investigated and if the fifth force existed, the antiproton would fall faster than the proton.

The truth is that we are facing a mysterious force whose existence is uncertain. In any case, it is not exclusive and many expert researchers believe it exists.

Finally, we will say that physicists working in the Massachusetts Geophysics Laboratory in the United States have found another force. This sixth force is estimated to reach 200 m in height and is an attraction. For Frank Stacey, the fifth and sixth forces would be part of the force of gravity and their small intensity and field of action would not affect Newton's law.

But things get complicated for physicists working on the joint theory of the four interactions. In fact, if these four forces are difficult to combine, now with the five will face a much more complicated challenge, if these fifths and sixth forces are not lost chains (which allowed Einstein to unify electromagnetic and gravitational forces).

(Note: To see this image well go to pdf).(Note: To see this image well go to pdf).