Why is pair production not possible in empty space?

Why is pair production not possible in empty space?

Reason: The pair production can not take place in a vacuum or space. The pair production can happen only in the presence of an external object like an atomic nucleus which can experience some recoil during the collision process to conserve the energy and the momentum at the same time.

How can you prove that pair production is not possible in vacuum?

If you have only one photon than the QED vertex that would describe the pair production is forbidden because it violates momentum conservation. If you have zero photons, but just vacuum fluctuations, you have not enough energy to create real particles, but only virtual pairs.

Can pair annihilation occur in free space?

Explanation: Space constantly produces particle-anti particle pairs. They are called virtual particles because they are very short lived and quickly annihilate each other. Although this appears to violate conservation laws it actually doesn’t.

Where does pair production occur?

pair production, in physics, formation or materialization of two electrons, one negative and the other positive (positron), from a pulse of electromagnetic energy traveling through matter, usually in the vicinity of an atomic nucleus. Pair production is a direct conversion of radiant energy to matter.

What can occur in empty space?

Perfectly “empty” space will always have vacuum energy, the Higgs field, and spacetime curvature. More typical vacuums, such as in outer space, also have gas, dust, wind, light, electric fields, magnetic fields, cosmic rays, neutrinos, dark matter, and dark energy.

Can pair production occurs in vacuum?

There is, however, a further condition which must be satisfied during the pair-production process: conservation of momentum. Taking this requirement into account, we can anticipate that pair production cannot take place in empty space; something must absorb the momentum (p=h/l =hf/c) of the initial photon.

Why can the momentum not be conserved at pair production in vacuum?

The photon must be near a nucleus in order to satisfy conservation of momentum, as an electron–positron pair produced in free space cannot satisfy conservation of both energy and momentum. Because of this, when pair production occurs, the atomic nucleus receives some recoil.

What is pair production and how it differs from pair annihilation?

Hint: Pair production is the process in which the photons fall on a nucleus and there is the formation of electron and positron pair, where positron is the charge having a mass equal to that of the electron but possess positive charge, on the other hand, annihilation is the process in which the electron and positron …

Is pair production random?

When a particle and its corresponding antiparticle meet they annihilate one another. These annihilations do not occur in a purely random way however; they must obey 3 rules: the conservation of energy, the conservation of momentum and the conservation of charge.

Does empty space exist?

Empty space does indeed exist, as part of the four-dimensional spacetime fabric. Empty space can be stretched and bent, and because space itself is expanding, objects which are very far apart in the universe can be receding from each other faster than the speed of light.

What elements make up empty space in the universe?

Which correctly list the two elements that make up the empty space in the universe? Dark matter and dark energy. Which is one piece of information that astronomers use to calculate the age of the universe?

Can you split a photon?

The photon cannot be split as one can split a nucleus. As it has zero mass it cannot decay. But it can interact with another particle lose part of its energy and thus change wavelength. It can be transmuted.