Plasma (physics)

Some things are not solid or liquid.

They are not even gas. This is called plasma. It is the fourth state of matter.

Most of the universe is made of plasma.

Stars are almost all plasma. It is also in lightning.

Plasma is made of tiny charged parts. These parts move around. This makes plasma good at carrying electricity.

We can make plasma in a lab. We can do this by heating gas. This makes the gas turn into plasma.

People use plasma in many things. Some TVs use it. It can also be used to clean parts.

Plasma is a very busy state of matter.

Most things we touch are solids, liquids, or gases. But there is a fourth state of matter called plasma.

It is very common in space. In fact, 99.9% of all ordinary matter in the universe is plasma. Stars are almost entirely made of it.

Plasma happens when a gas undergoes ionization. This means the gas gets charged particles. These particles are called ions and electrons. Because these parts have a charge, plasma can carry electricity well. This is called being electrically conductive.

In a plasma, these charged parts move together in a group. This is called collective motion.

We can see plasma in nature. Lightning is one example.

We can also make it in a lab. We can make plasma by heating a gas. We can also use strong magnetic fields to make it. People use plasma in many tools. Some TVs use it. It is also used for plasma etching. This is a way to clean or shape parts.

Most things in our world are solids, liquids, or gases. However, there is a fourth state of matter called plasma.

While we do not see it often on Earth, it is everywhere in space. Scientists estimate that 99.9% of all ordinary matter in the universe is plasma. Stars are almost entirely made of huge balls of plasma. It also fills the vast spaces between galaxies.

Plasma forms through a process called ionization. This happens when a gas is heated or put in a strong electromagnetic field.

During ionization, the gas gains charged particles called ions and electrons. Because these particles have a charge, plasma is electrically conductive. This means electricity can flow through it very easily. Unlike a normal gas, the particles in a plasma move together in a group. This is known as collective motion.

People have studied this strange matter for a long time. In 1816, Michael Faraday spoke about a type of "radiant matter." He believed it was something different from a gas. Later, in 1879, Sir William Crookes first identified it in a laboratory. He also used the term "radiant matter" to honor Faraday. In the 1920s, Irving Langmuir began studying plasma more closely. He chose the name "plasma" because it reminded him of blood plasma.

There are many different kinds of plasma to learn about. Some are "partially ionized," which means they still have some neutral particles. Lightning and neon signs are common examples of this.

Other plasmas are "non-neutral" because they have too many of one type of charge. You might also find "dusty plasma" in space. This contains tiny charged bits of dust. In a lab, scientists might see a "Jacob's ladder" effect.

We use the special powers of plasma in many modern tools. For example, some televisions use plasma to make images. It is also used in a process called plasma etching. This helps to shape or clean very small parts. The way plasma reacts to magnetic fields is very important too. This helps scientists understand how stars work. It also helps us understand the electricity in the sky.

Plasma is often called the fourth state of matter. It exists alongside solids, liquids, and gases.

A plasma forms when a gas undergoes ionization. This means the gas gains a significant amount of charged particles. These particles include positive ions and negative electrons. Because these particles carry a charge, plasma is highly electrically conductive. In fact, for many purposes, its conductivity is treated as infinite. This makes plasma very different from a standard gas. While a gas is mostly an insulator, plasma responds strongly to electromagnetic fields.

To understand how plasma works, we must look at the movement of its particles. In a normal gas, particles mostly interact through short-range, two-particle collisions. In a plasma, however, the charged particles experience long-range interactions. This leads to collective motion, where the particles move together in complex ways. This motion is governed by electromagnetic fields. Any movement of a charged particle creates an electric current. This movement then affects the fields, which in turn affects the other particles. This cycle creates waves and other collective phenomena.

Scientists categorize plasmas into different types based on their properties. A plasma is called "partially ionized" if it still contains some neutral particles. Common examples of this include neon signs and lightning.

An "ideal plasma" is defined by specific scientific criteria. First, it must follow the plasma approximation, where the number of charge carriers is high. Second, it must be quasineutral. This means the density of positive and negative charges is roughly equal over large volumes. Third, it can be "collisionless" if electrostatic interactions dominate over ordinary gas kinetics.

There are also more specialized forms of plasma. A "non-neutral plasma" has a significant excess of one type of charge. This can happen in charged particle beams or electron clouds. Another type is "dusty plasma," which is often found in space. These plasmas contain tiny, highly charged particles of dust. In a laboratory setting, scientists sometimes refer to these as complex plasmas.

Our understanding of plasma grew through the work of several important scientists. In 1816, Michael Faraday hypothesized the existence of "radiant matter." He believed it was a state far beyond simple vaporization. In 1879, Sir William Crookes first identified this matter in a laboratory. He used Faraday's term, "radiant matter," to describe his findings. Later, in the 1920s, Irving Langmuir began systematic studies of the substance. Langmuir introduced the term "plasma" in 1928. He chose this name by analogy to blood plasma. He noted how blood plasma carries cells, much like how plasma carries charged particles.

Plasma is incredibly important in the universe. While it is rare to encounter on Earth, it is everywhere else. It is estimated that 99.9% of all ordinary matter in the universe is plasma. Stars are almost entirely composed of massive balls of plasma. Plasma also dominates the vast spaces between galaxies, known as the intergalactic medium. On Earth, we use plasma in modern technology. Plasma televisions use it to create images. It is also used in plasma etching to shape tiny components.

Finally, the behavior of plasma is closely tied to temperature and magnetism. High temperatures are usually required to sustain the ionization process. In many technological plasmas, electrons reach thousands of Kelvin while ions stay cooler. Plasma can also be "magnetized." This happens when a magnetic field is strong enough to influence particle motion. When a plasma is magnetized, its properties change depending on the direction of the field. This makes plasma an essential subject for studying both Earth's atmosphere and the deepest parts of space.