Listen&Learn: The mystery of antimatter

One of many questions that scientists still have about the universe – why is there more matter than antimatter?

Pre-listening vocabulary

• theory: an attempt to explain a scientific concept
• matter: anything that has mass and occupies space
• antimatter: material made up of antiparticles
• subatomic particle: a particle that is smaller than an atom
• identical: exactly the same as something else
• electron: a type of subatomic particle with a negative electrical charge
• Big Bang: the explosion that likely created the universe

Listening activity

Podcast: Play in new window | Download (Duration: 1:34 — 1.4MB)

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Gapfill exercise

In 1928, British physicist Paul Dirac the existence of antimatter. His theory was that every type of subatomic particle had an antiparticle. He believed that an antiparticle would be almost identical to a normal particle, only with an electrical charge. This theory was proven two years later, when American physicist Carl David Anderson discovered a positively-charged electron, later named the “positron”. Today, physicists know that our is made up of both matter and antimatter. They have even successfully created antimatter atoms. However, antimatter is still one of the greatest in the universe. Scientific theory states that the Big Bang should have created equal amounts of matter and antimatter. The problem with this idea is the fact that matter and antimatter instantly destroy each other when they come into contact. This means that if the Big Bang had as much antimatter as it did matter, the universe would not exist today.

Comprehension questions

Discussion/essay questions

1. For years, scientists have debated the reason why our universe has more matter than antimatter. Some scientists have even suggested the idea that the Big Bang created another, parallel universe, made up mostly of antimatter. However, there isn’t a lot of evidence for this. Do you think scientists will ever know the answer to this question, or are there just some things about the universe we will never understand?

Transcript

In 1928, British physicist Paul Dirac predicted the existence of antimatter. His theory was that every type of subatomic particle had an antiparticle. He believed that an antiparticle would be almost identical to a normal particle, only with an opposite electrical charge. This theory was proven two years later, when American physicist Carl David Anderson discovered a positively-charged electron, later named the “positron”. Today, physicists know that our universe contains both matter and antimatter. They have even successfully created antimatter atoms. However, antimatter is still one of the greatest mysteries in the universe. Scientific theory states that the Big Bang should have created equal amounts of matter and antimatter. The problem with this idea is the fact that matter and antimatter instantly destroy each other when they come into contact. This means that if the Big Bang had created as much antimatter as it did matter, the universe would not exist today.