Explaining why the universe can be transparent

Two papers published by an assistant professor at the University of California, Riverside and several collaborators explain why the universe has enough energy to become transparent.

Extreme turbulence roiling 'most luminous galaxy' in the universe

The most luminous galaxy in the Universe - a so-called obscured quasar 12.4 billion light-years away - is so violently turbulent that it may eventually jettison its entire supply of star-forming gas, according to new observations ...

Drilling Down into Mars

(PhysOrg.com) -- NASA's Phoenix lander revealed water ice mere inches beneath the martian surface, and chemical evidence from the landing site strongly hints that the region is habitable. But learning whether there is life ...

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Ionization is the process of converting an atom or molecule into an ion by adding or removing charged particles such as electrons or other ions. This is often confused with dissociation. A substance may dissociate without necessarily producing ions. As an example, the molecules of table sugar dissociate in water (sugar is dissolved) but exist as intact neutral entities. Another subtle event is the dissociation of sodium chloride (table salt) into sodium and chlorine ions. Although it may seem as a case of ionization, in reality the ions already exist within the crystal lattice. When salt is dissociated, its constituent ions are simply surrounded by water molecules and their effects are visible (e.g. the solution becomes electrolytic). However, no transfer or displacement of electrons occurs whatsoever. Actually, the chemical synthesis of salt involves ionization.

The process of ionization works slightly differently depending on whether an ion with a positive or a negative electric charge is being produced. A positively charged ion is produced when an electron bonded to an atom (or molecule) absorbs the proper amount of energy to escape from the electric potential barrier that originally confined it, thus breaking the bond and freeing it to move. The amount of energy required is called the ionization energy. A negatively charged ion is produced when a free electron collides with an atom and is subsequently caught inside the electric potential barrier, releasing any excess energy.

In general, ionization can be broken down into two types: sequential ionization and non-sequential ionization. In classical physics, only sequential ionization can take place; refer to the Classical ionization section for more information. Non-sequential ionization violates several laws of classical physics; refer to the Quantum ionization section.

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