نظريات معلقة في الفيزياء والكونيات .. الفيزياء

Pending Theories in Physics and Cosmology .. Physics

Pending Theories in Physics and Cosmology

This book gives a good idea of ​​what physics is, and sheds some light on some of its modern theories: But physics, like any known science, is not static, but is constantly expanding. Every new observation in it needs a new explanation periodically, which may require the rejection of theories that were not tainted in the past at all. One of the duties of the physicist is to maintain an open mind, which qualifies him to reject all old theories if they are no longer suitable for explaining new things in a satisfactory and good way.

One of the tasks that falls on the physicist, in addition to his acceptance of changing existing theories, is the task of searching for new theories that help in solving pending issues. Perhaps the issue of the relationship between the nature of the four forces in the universe is one of the most puzzling issues that still confronts man to this day.

The mutual actions of attraction are expressed in the same formula in which the mutual actions of electromagnetism are expressed. The electrostatic Coulomb force between charged particles is proportional to K1 K2 / F2 . The magnetic force between two magnetic poles with magnetic strengths G1 and G2 is proportional to G1 G2 / F2 . The force of attraction between two masses is proportional to K1 K2 / F2 . Although the force of attraction is different from its counterparts because it is always an attractive force, the form of these equations requires finding a way to express all of these forces in a single set of equations. However, no one has yet come up with a unified field theory. Even Einstein himself did not come up with it after years of toil and investigation.

This is because the unified theory requires abandoning the concept of field, and therefore calls for interpreting all existing forces as exchange forces between the particles of the bodies subject to its influence. We have already mentioned the existence of exchange forces between the nuclei of fast mesons. Likewise, the electrostatic forces between charged bodies are interpreted as an exchange of photons between them. However, these photons are called imaginary because they only last for a short time, not enough to be detected. Similarly, the attractive forces between heavy bodies can be interpreted as an exchange of a hypothetical particle called the graviton. It is known that the nuclear force is about a hundred times stronger than the electromagnetic force, that it is about 1210 times stronger than the weak force, and that it is about 3610 times stronger than the attractive force.
Perhaps the day will come when we will be able to combine a single set of equations. Such a theory would be able to reconcile two aspects of force, the ripple effect and the corpuscular effect.

The prevailing view today of protons, neutrons and electrons is similar to the view that chemists viewed the atom in the late last century, in that some of these particles have their own structure. One of the popular theories that lacks physical proof is the theory that all baryons and mesons are composed of a group of fundamental particles called quarks.

Perhaps the great success of modern physics is due to understanding the relationship between mass and energy. It is now known that mass and energy are two different aspects of the same thing: mass is transformed into energy and vice versa. The most prominent example of the creation of matter is the production of pairs, which is explained by the existence of imaginary photons and electrons that help transfer energy and momentum in the proton-photon reaction, and their generation of a real electron-positron pair.

The theory of particles, both real and imaginary, has not yet reached a state of complete clarity, and it needs a unified central concept that brings together all the threads that must be dealt with today independently.

Another aspect of our ignorance concerns the origin of both matter and energy in the universe. There are two theories in this regard.

According to the first theory, called the steady state theory, the universe has existed since eternity. Although it is very natural to believe that everything has a beginning and an end, it is not always necessary to acknowledge this. Perhaps the universe has existed since eternity and will continue to exist forever.

As for the second theory, it assumes that the beginning of the universe occurred when the mass and energy that made it up were concentrated in an infinitely dense pile.
Then, at a certain moment (for unknown reasons, and in an unknown way), this pile exploded and threw into space masses of matter similar to fragments of an exploding bomb. This theory has been called the infinite density theory or the big bang theory.
What is the evidence that proves and supports one of these two theories?

The redshift phenomenon found in some galaxies provides some of this evidence. The redshift increases as the galaxy moves away from us, and its interpretation by the Doppler effect allows us to conclude that galaxies are moving away (pair production - by the rapid interaction of a photon with a proton. This results in the formation of an electron and a positron) from each other and that the rate of recession increases as the galaxy moves away from the Earth. This evidence can be used to support the Big Bang theory - in this case, it becomes possible to estimate the time that has passed since this explosion occurred, and this period is known as the Hubble constant and ranges between 10 billion and 40 billion years.

As for the supporters of the steady state theory, they explain the expansion of the universe by assuming that matter, in the form of hydrogen, is still being formed, and that the universe is expanding in order to maintain a uniform density in it. The rate of hydrogen production required to maintain this density is estimated at one atom per m3 every 300,000 years. It is difficult to pay attention to such a small amount, and therefore we must look for other evidence for this theory.

The density of the present matter in the universe is one of the main vital pieces of information in it, and is considered evidence for the theory of the steady state if it is somewhat regular within the universe. However, if the universe is dense in its remote parts, this makes the Big Bang more likely than others. In addition, light needs an enormous time to travel within the universe because of the latter's enormity. The unit used to measure space distances is the light year: that is, the distance that light travels in one year (about 1610 m). The light coming to us from stars that are a million light years away from us gives us a clear idea of ​​the state of

(the supposed union of quarks to form neutrons and protons)

the universe - its density, for example - a million years ago. The light coming to us from more distant stars gives us information about events close in time to the Big Bang itself.

The evidence seems to indicate that the universe was denser than it is now. But this does not constitute proof of the Big Bang theory - and it is not convincing enough - in addition, a proposal has recently appeared to consider the universe as oscillating between the two states of expansion and contraction, and the current phase that we are in is the expansion phase, and perhaps science will be able to find an answer to these exciting questions in the near future.