Allegedly, Nils Bohr began his lectures with the question “Gentlemen, what does an atom look like?”.
How do you imagine atoms today? Is the first image in your mind a kind of brick or a famous model of an atom in the center of which is a sphere, and around it are several rings – paths through which electrons move? These are certainly some particles that cannot be further divided – at least that is how we were taught in school.
“An atom can be more visually imagined as a small sphere (nucleus) around which is a round cloud (the so-called electron cloud). The electrons do not have defined positions and trajectories in that cloud, “explains Dr. Marko Vojinović, a researcher in the Group for Gravity, Particles and Fields at the Institute of Physics in Belgrade. “Moreover, the entire cloud can only correspond to a single electron, in the case of a hydrogen atom.”
In popular lectures given by pupils and students, Dr. Vojinović often talks about how different physics and the world around us are from what we learn in school, and that is exactly the case with atoms.
But let’s go in order.
The American writer Bill Bryson, in his pictorial way, in his “Short History of Almost Everything”, describing the size of an atom, starts from a millimeter, which is such a long line -.
“Now, let’s imagine that the line is divided into 1000 parts of equal width. Any such width is a micron. That is the size of microorganisms. One typical paramecium, for example – a tiny single-celled creature that lives in fresh water – is about 2 microns wide, 0.002 millimeters, which is really very small. If you would like to see the paramecium swimming in a drop of water with the naked eye, you would have to enlarge the drop so that it is twelve meters wide. However, if you wanted to see atoms in the same drop, you would have to enlarge it so that it is 24 kilometers wide, “explains Bryson.
That all beings and all things in the world are made up of some extremely tiny constituents is seemingly far beyond the reach of human intuition and even imagination. However, the idea that the entire universe is composed of atoms was not remembered by modern physicists or chemists, but was known as early as the 4th century BC in ancient Greece, while in India a similar idea appeared three centuries earlier.
“An atom consists of a nucleus and an electron shell, but neither the particles in the nucleus nor the electron can be imagined as some kind of spinning balls, by analogy with the movement of the planets around the sun. The real picture of atoms is completely different, and it is based on fields, not particles “, explains Dr. Vojinović.
“It turns out that the notion of a particle cannot be a fundamental, basic building block of nature, but matter is built from the so-called fields, while particles are just a certain manifestation of the field “, says Dr. Vojinović.
Physicists today, when they look inside an atom, do not say that there is an “electron particle” somewhere, but actually think that the “electron field” is equal to zero at all points except one, where it is greater than zero, and they say that finds an electron.
Essentially, as Dr. Vojinović explains, the field of electrons (and other particles) does not differ qualitatively much from the electric, magnetic and gravitational fields, with which we have direct sensory experience.