Through The Wormhole: What Are We Made Of?Our understanding of the universe and the nature of reality itself has drastically changed over the last 100 years, and it's on the verge of another seismic shift. In a 17-mile-long tunnel buried 570 feet beneath the Franco-Swiss border, the world's largest and most powerful atom smasher, the Large Hadron Collider, is powering up.

Its goal is nothing less than recreating the first instants of creation, when the universe was unimaginably hot and long-extinct forms of matter sizzled and cooled into stars, planets, and ultimately, us. These incredibly small and exotic particles hold the keys to the greatest mysteries of the universe. What we find could validate our long-held theories about how the world works and what we are made of. Or, all of our notions about the essence of what is real will fall apart.

What are we made of? The question has rankled scientists and philosophers for millennia, and even with the amazing progress made in fields like particle physics and astronomy, we are left with only a partial answer. We know, of course, that the visible world is composed of protons, neutrons and electrons that combine to form atoms of different elements, and we know those elements are the building blocks of the planets and stars that give rise to solar systems and galaxies.

What we didn't know until very recently, however, is that those protons, neutrons and electrons appear to form less than 5 percent of the universe, and questions remain about how these building blocks arose. If regular matter represents only a small slice of the universe, what is the rest of the universe made of?

Such questions prompted the construction of the Large Hadron Collider (LHC) beneath the border between France and Switzerland. As the world's largest particle accelerator, experts designed the LHC to recreate conditions that occurred shortly after the very foundation of universe itself. Here are a few of the mysteries scientists hope the LHC and other particle accelerators can shed light on.

This is the seventh episode. See the list of all episodes here: Through The Wormhole.

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