The key difference between energy and matter is that energy has no measurable mass whereas matter has a measurable mass.
Energy and matter are two very important quantities in physics. These concepts hold a very important place in the fields of physics, theory of relativity, astronomy, cosmology, astrophysics and stellar evolution. It is extremely crucial to have a solid understanding of these concepts in order to excel in any of those fields.
CONTENTS
1. Overview and Key Difference
2. What is Energy
3. What is Matter
4. Side by Side Comparison – Energy vs Matter in Tabular Form
5. Summary
What is Energy?
Energy is a non-intuitive concept. The term “energy” comes from the Greek word “energeia”, which means operation or activity. In this sense, energy is the mechanism behind an activity. Moreover, energy is not a directly observable quantity. However, we can calculate it by measuring external properties.
We can find energy in many forms. Kinetic energy, thermal energy and potential energy are to name a few. In the past, people thought energy was a conserved property in the universe, but the development of the special theory of relativity changed this idea. The theory of relativity, along with quantum mechanics, showed that energy and mass are interchangeable. Thus, giving rise to the energy – mass conservation of the universe.
Figure 01: Electricity is a Form of Energy
However, when nuclear fusion or nuclear fission is not present, the energy of a system is conserved. Kinetic energy is the energy that causes the movements of an object while potential energy arises from the energy stored within an object, due to the object’s position, arrangement or state. Moreover, thermal energy arises due to temperature.
Scientists still believe that there are other types of energy in this universe, which are yet to be discovered. They have categorized this energy as dark energy, and they believe it as a large proportion of the total energy of the universe.
What is Matter?
In the past, matter was another name for “material”. In this context, matter was everything that was tangible. However, with Einstein postulating the theory of relativity in 1905, almost everything classical broke down. He went on to show that waves sometimes behaved as particles and particles behaved as waves. Thus, this was known as the wave-particle duality. It led to the union between mass and energy; both of these quantities are two forms of matter.
Moreover, we can categorize matter according to many criteria. By the physical form, we can categorize it as gas, liquid, solid, and plasma. By detection methods, we can separate it as normal matter and dark matter. Moreover, by the type of the quantity measured, it is in two types, as mass and waves.
Figure 02: Different States of Matter and Possible Transitions Between Them
The famous equation E = mc2 gives us the amount of energy we can get from “m” amount of mass. In the universe, the amount of matter is conserved. Furthermore, the reactions in the sun lead to a nuclear fusion where mass transforms into energy. High energy photon collisions produce matter-antimatter pairs where energy transforms into matter. In the theory of relativity, mass is not an absolute quantity. A mass moving with a high velocity with respect to the observer will display more mass than a mass at rest.
What is the Difference Between Energy and Matter?
Energy is the ability to do work while matter is any substance that has mass and takes up space by having volume. So, the key difference between energy and matter is that energy has no measurable mass, whereas matter has a measurable mass. Similarly, energy has no volume while matter occupies a measurable volume. Therefore, stemming from the above is another significant difference between energy and matter. That is; energy is a property of an object, whereas matter is any object that has a mass and volume.
The below info-graphic shows more comparisons related to the difference between energy and matter.
Summary – Energy vs Matter
Energy and matter are closely related terms. More importantly, matter comes in two forms as energy and mass. Matter is any substance that has a mass and a volume, but energy is a property of a substance. Hence, the key difference between energy and matter is that energy has no measurable mass whereas matter has a measurable mass.
Reference:
1. Helmenstine, Anne Marie, Ph.D. “Why Are Light and Heat Not Matter?” ThoughtCo, Nov. 20, 2018, Available here.
Image Courtesy:
1. “3489395” (CC0) via Pixabay
2. “Physics matter state transition 1 en” By ElfQrin – Own work (CC BY-SA 4.0) via Commons Wikimedia