暗物质与反物质
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?
在宇宙学和天文学中,暗物质是指无法通过光学或射电望远镜检测到的任何形式的物质。望远镜看到的是发射,反射或散射的光或其他形式的电磁波。如果某些形式的物质不发射,散射或反射光和其他电磁波,则这些物质形式被归类为暗物质。就目前而言,只有通过引力效应才能预测暗物质的存在。有几种引力方法可以检测和估计系统中的暗物质量。一种方法是使用从暗物质的背景辐射的重力镜头来估计存在的暗物质量。对于星系和星系簇,可以使用银河旋转,景点和碰撞来确定存在的暗物质量。根据基于弗里德曼方程和FLRW指标的可观察到宇宙大型结构的观察结果,据估计,暗物质约占可观察到的宇宙的总质量 - 能量密度的23%,而普通物质仅贡献大约贡献可观察到的宇宙的质量 - 能量密度为4.6%。宇宙中的暗物质数量在确定扩展率及其宇宙的未来方面起着重要作用。
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. |
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