Dark Matter vs Antimatter
Dark matter and antimatter are two forms of matter, which are least, understood. Dark matter is a form of matter, which is not observable through the electromagnetic spectrum but only observable through the gravitational interactions. Antimatter is a form of matter, which is the “negative”, or the “opposite” of matter. Both of these concepts play very important roles in fields such as astronomy, astrophysics, particle physics, cosmology and even energy generation. It is vital to have a very good understanding in these concepts in order to excel in such fields. In this article, we are going to discuss what dark matter and antimatter are, their similarities, the definitions of dark matter and antimatter, and finally the difference between dark matter and antimatter.
What is Dark Matter?
In cosmology and astronomy, dark matter means any form of matter that is not detectable through optical or radio telescopes. What telescopes see is the emitted, reflected or scattered light or other forms of electromagnetic waves. If some forms of matter do not emit, scatter, or reflect light and other electromagnetic wave, those forms of matter are classified as dark matter. For now, it is only through the gravitational effects the presence of dark matter can be predicted. There are several gravitational methods to detect and estimate the amount of dark matter in a system. One method is to use the gravitational lensing of the background radiation from the dark matter to estimate the amount of dark matter present. For galaxies and galaxy clusters, galactic rotations, attractions, and collisions can be used to determine the amount of dark matter present. According to the observations based on large structures of the observable universe based on Friedmann equations and the FLRW metric, it has been estimated that dark matter accounts for about 23 percent of the total mass – energy density of the observable universe whereas ordinary matter only contributes approximately 4.6 percent for the mass – energy density of the observable universe. The amount of dark matter in the universe plays a major role in deciding the expansion rate and thereby the future of the universe.
What is Antimatter?
To understand antimatter one must first understand what antiparticles are. Most of the particles we know have antiparticles. Antiparticle is a particle having exactly same mass but the opposite charge. However, charge is not the only difference between particles and antiparticles. If a particle and an antiparticle contacts, they will annihilate to produce energy. For the annihilation to occur, both the particle and the antiparticle must be in the appropriate quantum states. Antimatter is the matter made up of antiparticles. For an example, an antihydrogen atom can be formed by the combination of an antiproton and an antielectron (also known as the positron).
What is the difference between Dark Matter and Antimatter?
• Dark matter does not interact with the electromagnetic spectrum; therefore, it is not detectable with any electromagnetic wave detecting method (ex: telescopes, radio receivers, etc.). Antimatter can be detected via the electromagnetic spectrum.
• Antimatter annihilates when collided with normal matter but dark matter does not display such behavior.
• The nature of antimatter is somewhat better understood than the nature of dark matter.