| Type | Form of matter |
| Regulation | Tight regulation and secrecy around production and applications |
| Applications | Medical imaging • Materials science • Energy research |
| Potential uses | Advanced propulsion • Weaponry |
| First theorized | Late 19th century |
| Ongoing research | Continuing to shed light on the fundamental nature and origins of antimatter in the universe |
| First detected and produced | Early-to-mid 20th century |
Antimatter is a form of matter that has the opposite charge and certain other properties of normal, or "baryonic", matter. The concept of antimatter was first proposed in the late 19th century and experimentally confirmed shortly thereafter, leading to a rapid expansion of research and applications in the 20th century.
The idea of antimatter was first put forth in 1883 by the Scottish physicist William Thomson, who theorized the possible existence of a "mirror image" form of matter with opposite electrical charge. This was further developed in 1928 by the British physicist Paul Dirac, whose relativistic quantum mechanics equations predicted the existence of a particle with the same mass as an electron but opposite charge - what we now call the "positron".
The positron was experimentally detected in 1932 by the American physicist Carl Anderson, providing the first clear evidence of antimatter. Over the next decade, antimatter particles like the antiproton and antineutron were also discovered, and the mass production and containment of antimatter began in labs around the world.
By the 1950s, antimatter had become a valuable scientific tool, with applications in fields like particle physics, materials science, and medical imaging using PET scans. However, the potential dangers of antimatter, particularly in terms of advanced propulsion and weapons, were also recognized early on. This led to increasing secrecy and regulation around antimatter research and development.
Antimatter has the same mass as normal matter but the opposite electrical charge. When antimatter and matter particles collide, they annihilate each other in a burst of pure energy. This makes antimatter incredibly energy-dense but also challenging to produce and contain.
The most common practical applications of antimatter include:
More speculative applications, which are tightly controlled, include:
While antimatter has been extensively studied for over a century, many fundamental questions remain about its origins and behavior in the universe. Why does the observable universe appear to be dominated by normal matter rather than a balance of matter and antimatter? Are there regions or pockets of antimatter matter in the cosmos? What are the most promising avenues for producing and containing larger quantities of antimatter?
These questions drive ongoing research, which is often highly classified due to antimatter's potential military applications. There is also ongoing public and scientific debate about the ethics and regulation of antimatter development, especially as it relates to advanced propulsion and weapons. As antimatter technology continues to advance, these discussions will only become more critical.
