The one cosmic secret that demands a new particle collider | by Ethan Siegel | Starts With A Bang! | Sep, 2024

The observation that everything we know is made out of matter and not antimatter is one of nature’s greatest puzzles. Will we ever solve it?

Here in our Universe, there are some cosmic puzzles that loom very large, casting a grand veil of uncertainty over our attempts to understand all of reality. Some of the biggest ones include:

• Why does the Universe obey the rules that it does, as opposed to any other rules?
• Why do the fundamental constants have the values that they do, rather than any other values that they could have taken on?
• Why do the particles of the Standard Model have the masses that they’re observed to have, and why are neutrinos massive at all?
• Why do we have dark matter and dark energy, and what, exactly, are these mysterious forms of energy that have eluded direct detection so far?

Yet there’s one enormous question, of importance on cosmic scales as well as to those who study nature at an elementary level, that often gets overlooked: why is our Universe, and everything in it, predominantly composed of normal matter, and not of antimatter? We’ve learned a whole slew of lessons about the Universe — what makes it…