This article is based on answering a similar question from a user, originally titled: What is the principle of gamma rays and when will humans master it?

Gamma rays, or gamma rays, are the section of the electromagnetic spectrum with the shortest wavelength and highest frequency, and humans have long known about them and been able to produce them. But this is a bit of an odd question to ask, poorly phrased, e.g., What is mastery?

Will it be able to be dealt with, or will it be able to be used? That depends on how it is put. Here's some general knowledge about gamma rays to elaborate on the subject, and friends who can read this article carefully will find it a bit strange, as I did, and will have an understanding of gamma rays.

First, let's understand the electromagnetic spectrum

Everything we humans see and feel now, even everything involved in eating and drinking, is dependent on electromagnetic waves. Why is that? Because electromagnetic waves fill every corner of our world, and any object that is above absolute zero will have electromagnetic radiation, and the so-called electromagnetic radiation is dependent on electromagnetic waves for transmission.

Electromagnetic waves are transmitted by photons, so they can also be called light waves. But this light wave is divided into visible and invisible light, and in everyday life, light waves generally refer only to the visible part of the electromagnetic spectrum; visible light is only sandwiched in the middle of the electromagnetic spectrum for such a small period. The longest band of electromagnetic waves is several kilometers or even longer; the shortest is just under 1Å, and this shortest is gamma rays.

Electromagnetic waves have wavelength and frequency, and wavelength is inversely proportional to frequency, i.e., the longer the wavelength, the lower the frequency, and the less the energy; conversely, the more the energy. The relationship between electromagnetic wave wavelength and frequency is: c=λf. Here c is the speed of light, λ is the wavelength, and f is the frequency. The longest wavelength of electromagnetic wave is radio wave (including long wave, medium wave, short wave, microwave), after that from long to short order: infrared, visible light, ultraviolet, X-rays, gamma rays.

Radio waves have wavelengths in the kilometer to millimeter range, with long-wave radio wavelengths of up to several kilometers and the shortest microwave wavelengths of only 0.1 mm; visible light wavelengths are about 760 nm to 380 nm, nm being nanometers, 1 mm = 1000 μm (micron), 1 μm = 1000 nm, and 1 nm = 10^-9 m (meter).

The wavelengths of ultraviolet, X-rays, and gamma rays (gamma rays) behind visible light are shorter than one another. Gamma rays are the shortest wavelengths of high-energy rays in electromagnetic waves, with a wavelength of only 0.1 nm or less.

All matter in this world vibrates and therefore has a frequency. Frequency is the number of times an object vibrates per second, and the frequency of an electromagnetic wave is the number of times an electromagnetic wave vibrates per second, expressed in Hz (Hertz). Radio waves range in frequency from 1000 Hz or less to 10^9 Hz; visible light ranges from 3.9*10^14 to 7.7*10^14 Hz; and gamma rays range from as low as 10^12 Hz to as high as 10^30 Hz or more.

New coronavirus size of about 100nm, the longest gamma ray band is only 0.1nm, we think about it, we know that humans have to deal with the new coronavirus, let alone than the new coronavirus more than 1000 times smaller gamma rays, and its frequency is more than a trillion times per second vibration, how much energy this, once swept by gamma rays, there is no reason not to penetrate?

Thus gamma rays are the most powerful "light" in the universe, but this light is invisible, but it kills.

Principles of biological damage from gamma radiation

Gamma rays can penetrate the body of any living creature because of their very short wavelength and very high energy. For example, the human body is made up of 40-60 trillion cells, the largest being the egg cell, which is 200 μm (microns) in size, and the smallest being the platelet, which is only about 2 μm in diameter.

When the human body is exposed to gamma rays, the gamma rays enter the body's cells and ionize with them, and the ionized ions invade the complex organic molecules in the cells and destroy the cellular tissue. The most important core genetic material in a cell is DNA, a large molecule with a double helix structure, which is coiled in the core of the cell and dominates its life, death and inheritance.

This DNA double helix opens to a length of about two meters, and if all the DNA in 1 person's cell were opened and joined together, it could allegedly make more than 300 round trips from Earth to the Sun. However, the DNA helix is only 2 nm in diameter and gamma rays would break and destroy its structure. Thus, when living beings are exposed to gamma rays, all the DNA molecular bonds are broken, leaving the living organism no longer viable.

When the radiation is high, the creature dies instantly, and even if the radiation is not high, but the molecular bonds of the organism's DNA are severely damaged, it will die slowly. That kind of death is extraordinarily horrific to watch your organism die inch by inch. In the infamous Chernobyl nuclear power plant explosion, many residents and firefighters died from this hellish ordeal.

gamma-ray generation principle

The nuclei of radioactive atoms undergo alpha decay and beta decay to produce a new nucleus, which is at a high energy level and must leap to a lower energy level, and the leap process radiates gamma photons, which are called gamma rays. gamma rays occur in both nuclear fusion and nuclear fission, so the universe is filled with gamma radiation.

Nuclear fusion in the Sun occurs continuously inside a core within a quarter of the volume radius, and the main process is a chain reaction of protium nuclei with protium nuclei, from protium to deuterium to helium-3 and finally to helium-4. The end result is the fusion of four protium nuclei into a single helium-4 nucleus and the release of gamma photons, neutrinos and positrons in the process. While neutrinos quickly escape the surface of the Sun to reach space because of their great penetrating power, gamma rays carrying enormous energy do not escape easily.

This brings us to the theory of photon walking inside the sun. The propagation of photons is characterized by the fastest vacuum, reaching 300,000 kilometers per second, but stumbling through the medium. The interior of the sun is full of protons, and photons encounter protons with every step they take, constantly colliding and exchanging. Therefore, these photons to penetrate 700,000 km radius of the sun, to collide with the proton exchange as many as 10 ^ 26 times, each exchange on the consumption will be decayed, after hundreds of thousands of years or even millions of years to reach the surface of the sun photons, mainly is visible light.

So don't be surprised, folks, that the sunlight that shines on us is actually photons that were born hundreds of thousands, if not millions, of years ago.

According to scientific analysis, sunlight includes the entire electromagnetic wave full wavelength band, but more than 99.9% of the energy is concentrated in the 200~10000nm wavelength range, and the maximum radiation energy is located at 480nm, which is exactly the range of visible blue light. Therefore we see the sky is blue, and the sea is also blue.

And 200nm band belongs to the ultraviolet category, ultraviolet light is harmful to the human body, but the vast majority of ultraviolet light through the atmosphere is absorbed by the ozone layer or reflected away, to the surface of the very little. But still a little, so when the sun is strong when the sun for a long time will be damaged skin.

Stars in the universe are fusing and constantly radiating gamma rays; there are also supernova explosions, collisions of massive dense objects such as neutron stars, which produce more gamma rays and even gamma ray bursts, so there are many gamma rays in space. But these gamma rays are blocked by the atmosphere and very few come to the surface.

If they operate at high altitudes or outside the atmosphere, they are vulnerable to gamma rays and other cosmic rays, so astronauts are protected. But gamma rays are difficult to block, and astronauts operating in space or on an alien planet are exposed to much more radiation than on the surface of the Earth, despite the better protection provided by their spacecraft and spacesuits.

Gamma rays are extremely penetrating and cannot be shielded by normal buildings, only specially made high-density materials such as lead plates are effective, and the thickness of the lead plates needs to be increased depending on the intensity of the gamma rays.

On Earth, people can be harmed by gamma rays mainly from nuclear fission

The heavy nuclear fission process undergoes deformation, e.g., after the absorption of a neutron by a U-235 nucleus, an excited state of U-236 nucleus is formed, which then deforms and eventually breaks off and flies away in the opposite direction, while the classical Coulomb energy is converted into two fragment kinetic energies, but soon the broken fragment shrinks into a sphere and the deformation kinetic energy is converted into internal excitation energy, emitting several neutrons and γ-rays to balance the deconvolution energy.

There are also many radioactive elements that emit gamma rays through the decay process, such as cobalt-60, which releases high-speed electrons with energies up to 315 keV through beta decay, decaying into nickel 60 and emitting two beams of gamma rays at the same time. These gamma rays can harm humans if they are not properly controlled.

As in the case of atomic bomb explosions or leaks from nuclear power plants, the explosion of the Chernobyl nuclear power plant in the former Soviet Union led to severe radioactive contamination that threatened the health of millions of people, with more than 7,000 deaths directly caused by radiation.

Use of gamma rays for the benefit of society

Human civilization is elevated by the continuous understanding of the laws of nature. Gamma ray itself is a natural phenomenon, a kind of energy released by elements in the process of polymerization or splitting, and people can cope with and make use of it when they know the intrinsic nature of gamma ray.

Any science can be used for the benefit of mankind as well as for the detriment of mankind, and so can gamma rays, which can either kill or benefit mankind. Much has been said about the dangers of gamma rays, but now a few words about the benefits to mankind.

Nowadays, the more common gamma rays for human services are industrial flaw detection and health care applications. Industrial flaw detection mainly uses the penetrating power of gamma rays to see whether there are problems with the internal structure of industrial products, such as probing the welds of steel plates, 30 mm thickness of steel plate welds can be inspected using X-rays, but more than this thickness will not be able to do anything, the penetrating power of gamma rays will come into play.

Gamma rays can detect 300 mm thickness of steel plate, the method is to put a light-sensitive film behind the object being inspected, the use of gamma rays to irradiate the object being inspected, gamma rays through the object will be sensitized on the film, thus leaving an image, people through the analysis of these images, will be able to understand whether the object has problems, whether it is qualified.

X-rays also play a large role in medical treatment, but are mainly used for imaging the human body and can see the internal state of the body. Gamma rays are much more energetic than X-rays and can penetrate the surface of the body to kill lesions in the body, thus killing cancerous tumors in the body without leaving trauma and reducing the damage to the body, and also reaching areas that can be reached by trauma surgery.

The radioactive sources used for industrial flaw detection and for medical purposes use the principle that radioactive elements emit gamma rays when they beta decay, generally using cobalt-60. cobalt-60 is one of the radioactive isotopes of cobalt with a half-life of 5.27 years, and it will release high speed electrons of up to 315 keV through beta decay, decaying into nickel 60, in which two beams of gamma rays are released at the same time.

Humans are now also capable of producing high-energy gamma rays

Now, not only can humans use natural gamma rays for the benefit of humanity, scientists have also created high-energy gamma rays.In September 2011, a team led by Professor Tino Janosinski of the University of Strathclyde in the UK, discovered that an ultrashort laser pulse can react with ionized gas and produce an extremely powerful laser beam.

The laser beam, obtained by Prof. Yarosinski's team, is 1 trillion times brighter than the sun and can penetrate a 20-cm-thick lead plate, and it takes a 1.5-meter-thick concrete wall to completely shield it.

The most in the sun's electromagnetic spectrum is visible light in the 480nm band, 1 trillion times shorter than this wavelength, the wavelength is such that is 4.8*10^-21m, such a short wavelength of electromagnetic waves corresponding to a frequency of 6.25*10^28Hz, which is undoubtedly a beam of extremely powerful energy gamma rays.

This creation discovery is significant and has the potential for future use in many areas, such as better enabling medical imaging, radiotherapy, and also enabling wider use in industrial and scientific experiments. Since its duration is only 10 millionths of a second, fast enough to capture the response of the nucleus to excitation, it could further facilitate in-depth studies of the nucleus.

Therefore, mankind has long recognized and mastered the principle of gamma rays and has long been using this natural law for the benefit of mankind. I wonder if my answer has solved this friend's question? Thanks for reading and feel free to discuss.

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