A picture of Antimatter. 23 April 2021

I’m sure you’ve heard of antimatter—perhaps it’s a resource in a show you watch, a fantasy novel you’ve read, or maybe a videogame you’ve played. In many stories, antimatter is portrayed as an incredibly powerful substance capable of producing immense energy or destroying entire worlds. While these portrayals are exaggerated, antimatter is actually a real and fascinating part of modern physics. Scientists have discovered that for every type of particle that makes up ordinary matter, there exists an opposite version called an antiparticle. These antiparticles have the same mass as normal particles but carry opposite charges. For example, the antiparticle of an electron is called a positron, which has a positive charge instead of a negative one. When matter and antimatter meet, they annihilate each other and release energy, often in the form of light.

This raises an important question: if antimatter is real and should have been created alongside matter at the beginning of the universe, why does almost everything around us—including stars, planets, and people—consist only of matter? Understanding what antimatter is and why it is so rare in our universe helps scientists explore one of the biggest mysteries in physics: why matter came to dominate the universe after the Big Bang. 

To answer this, scientists look back to the very beginning of the universe, just moments after the Big Bang, when matter and antimatter should have been created in nearly equal amounts. In theory, these particles would have quickly collided and annihilated each other, leaving behind only energy. However, something unusual happened. A tiny imbalance allowed a small amount of matter to survive. This phenomenon, known as baryon asymmetry, is still not fully understood. Researchers in fields like particle physics continue to investigate why this imbalance exists, using powerful experiments and theories to uncover what tipped the scales in favor of matter. Without this slight difference, the universe as we know it, galaxies, stars, and life itself would not exist.

Even today, antimatter hasn’t completely disappeared. Scientists can create small amounts of it in laboratories using particle accelerators, but it is extremely difficult and expensive to produce and store. This is because antimatter cannot come into contact with regular matter, or it will instantly annihilate. In nature, tiny amounts of antimatter are also produced in high-energy events, such as cosmic rays interacting with Earth’s atmosphere. However, these amounts are so small that they don’t play a significant role in our everyday lives. By studying antimatter, scientists hope to better understand the origins of the universe and uncover why something exists rather than nothing at all.