What is the relationship between mass and energy?

The textbook is right.

In a nuclear reaction, it is said that there is a loss of mass, but in fact the mass (that is, energy) is released in some way, such as the release of high-energy gamma photons, because these photons have energy, so these photons also have mass, because the rest mass of the photon is equal to zero, according to the energy momentum relationship, the mass of the photon is equal to the energy divided by the square of the speed of light, and the energy of the photon is the product of the frequency of the photon and Planck's constant. It is easier to understand that other particles with a non-zero mass at rest, such as electrons, are released without a loss of mass.

There is also a "mass loss" in carbon combustion, and these "lost mass" are released in the form of photons, but this mass difference is too small relative to the mass of atoms and molecules, so it will be ignored in chemistry. Nuclear reactions are different, the energy released is relatively large, and the corresponding mass of these energies (energy divided by the square of the speed of light) is relatively large and cannot be ignored.

There is also the energy at rest and the "kinetic energy" due to motion, e=m*c 2 m in which m is the rest mass divided by the root number (1 v 2 c 2), that is, the energy is equal to.

m_0*c^2/√（1－v^2/c^2）

m 0 is the rest mass of the object. If the velocity is small relative to the speed of light, Taylor obtains that the kinetic energy of Newtonian mechanics is equal to v 2 2m

For a particle with zero mass at rest, moving at the speed of light, such as a photon, its energy is Planck's constant multiplied by frequency, and the mass is HV c 2.

In short, according to e=m*c 2, there is as much mass as there is energy, and there is only one scale factor c 2 between the two, and in the natural unit system, the speed of light is taken as 1, so even this scale factor is gone, and the mass is the same as energy, so in high-energy physics, mass and energy are often not distinguished in units, and the mass of hadrons is often measured in billions of electron volts (gev).

e=mc 2, mass multiplied by the square of the speed of light, representing the total amount of energy contained in these masses. It cannot be understood as the mutual transformation of mass and energy, and the two are conserved separately.

e = mc2 energy = mass multiplied by the square of the speed of light.

e=mc is the mass-energy equation (mass-energy equation).

The mass-energy equation is an equation that describes the equivalence relationship between mass and energy. In classical physics, mass and energy are two completely different concepts, there is no definite equivalence relationship between them, and objects of a certain mass can have different energies; The concept of energy is also relatively limited, and there are years of collapse kinetic energy and potential energy in mechanics.

In the special theory of relativity, the concept of energy is generalized, mass and energy have a definite equivalence relationship, and the mass of the object is m, then the corresponding energy is e=mc.

The mass-energy equation e=mc, where e is energy, m is mass, and c is the speed of light (constant, c=299792458m s). Presented by Albert Einstein. This equation is mainly used to explain the mass loss in nuclear transformation reactions and to calculate the energy of particles in high-energy physics.

This also led to the birth of de Broglie waves and wave dynamics.

According to Einstein's formula for energy loss, all the mass lost in the nuclear reaction is released as energy, and the energy released is e=mc 2

In general energy, kinetic energy e=(1 2)m*v 2, gravitational potential energy e=mgh, are also related to mass.

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Problem description: If energy has mass, isn't the mass of a star calculated by the law of gravitation instantaneous? But if energy has no mass, is Einstein's mass-energy equation wrong?

Analysis: First of all, what kind of energy are you talking about? Do you understand what energy is?

Energy must be accompanied by matter, and there is no separate so-called "energy" that is separated from matter.

Einstein's equation is an equation of mass-energy relation, which means that mass and energy are always accompanied, and there is as much mass as there is, and how much energy must be accompanied by how much mass, and mass and energy are conserved separately and cannot be converted into each other.

Even light is matter, not "pure energy". Although light does not have a mass at rest, it does have a moving mass, and it is completely in accordance with Einstein's mass-energy equation.

This formula, which is the mass-energy equivalence formula, is one of the most important corollaries of the special theory of relativity, which indicates the relationship between mass and energy.

In the formula, E represents energy, M represents mass, and C represents the speed of light, which is a large constant (about 300,000 kilometers per second).

The meaning of the formula is: the energy of an object is equal to its mass multiplied by the square of the speed of light. In other words, all matter has a huge amount of latent energy, and as long as it can be converted into energy, it can be released.

For example, the atomic bomb uses the process of nuclear fission or nuclear fusion to convert a part of the mass in the atomic nucleus into energy, thus producing a powerful force.

This formula also illustrates that matter and energy are equivalent and are two different manifestations of the same object. Matter can be converted into energy, and energy can also be converted into matter.

For example, when an electron (matter) and a positron (anti-matter) collide with each other, they annihilate and produce massless particles (such as two photons). This is the example of the conversion of matter into energy.

Conversely, when two high-energy photons collide with each other, they may also produce a pair of electrons and positrons. This is the example of the conversion of energy into matter.

This formula was proposed by Albert Einstein in 1905, before he knew about the existence of nuclear reactions, and he simply deduced this astonishing conclusion from the basic principles of special relativity.

This formula is valid not only in nuclear reactions, but also in any phenomenon that involves changes in mass and energy, as it is a universal consequence of the special theory of relativity.

Einstein's mass-energy relation: e=mc

Energy mass x the square of the speed of light Ah.

The relationship between energy and mass is converted into each other.

e=mc 2, Einstein told us through this equation that mass can be converted into energy. However, he did not directly describe the process of energy conversion mass and its laws, so his later work focused on the study of this inverse process.

This process has not made good progress, but it was not until the advent of the HeNe laser in 1964 (it was actually discovered in 1960, but the experiment did not work well), people were free to control some high-energy particles, many previously unsolved academic problems were solved, and the possibility of energy conversion mass became the focus of attention again. This is because many previously unproven theories have been tested by technological advances, and these theories point to the fact that energy may actually become mass.

The way energy is converted into mass, there are 2 opinions in the scientific community:

1: The energy is large enough. We know that nuclear fission can release a lot of energy, but this is far from the energy conversion threshold predicted by current theories.

Now in Shanghai, there is Shanghai Guangyuan, an experimental institution under construction in China. What will be done here is nuclear fusion, which can produce the equivalent of 10 6 times more energy (at the same nuclear mass). If this experiment is made, it is estimated that it will be a big step closer to our final result (energy conversion of matter).

2: With the help of dark energy or antimatter that is not yet known. Antimatter existed in large quantities at the beginning of the formation of the universe, and then annihilated with the current positive matter, as a result, the positive matter was left behind after the annihilation of the catastrophe with the advantage of 1 10000000000000 antimatter, forming the current macroscopic situation of the universe, but now a certain amount of antimatter is being carried out at the edge of the universe, and this matter may be converted from energy under normal circumstances, because it is the opposite of the opposite nature of positive matter, so there is the possibility of "energy-mass".

There is also dark matter, if there is no dark energy in the universe, the gravitational effect of matter should make the universe smaller, or slow down and expand. And now astronomical observations show that the universe is expanding at an accelerated rate. There may be dark energy in the universe, and the relationship between them may be more of a repulsive force, causing the universe to expand at an accelerated pace.

Dark energy also has the opposite properties of existing forms of matter energy, and there is also the possibility of "energy-mass".

In 1905, when the study of relativity was progressing, Albert Einstein proposed the law of the interconnectedness of mass and energy, E-2MCZ. However, many people understand it as "the equivalence of mass and energy", confusing matter and mass, separating energy from matter, and thus thinking that mass will transform energy, which means that matter will become energy: the result is that matter consumes only the energy that is transformed.

Whether this understanding is correct or not, this article will talk about my own opinion. 1 What is mass The concept of mass is one of the most important concepts in the whole of physics. Historically, Newtonian mechanics first constituted the concept of mass in a clear form.

According to Newton, the normally visible matter is made up of unchanging atoms. The more atoms there are in any object, the greater the amount of matter. The tighter the atoms are arranged, the greater the number of atoms, which means that the greater the amount of matter contains.

The quantity (mass) of matter is measured by the product of the density of the object and the volume of the object.

Mass is energy, and both are quantities that describe interactions, so in order to distinguish, the definition of static mass in particle physics is called mass.

Energy is equal to mass multiplied by the speed of light squared.

According to Einstein's mass-energy equation: e=mc 2