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The SMASH Model May Solve The Biggest Mysteries In Physics

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For decades, physicists have been hard at work trying to answer the universe's unanswered questions. In October 2016, they may have solved five of them in one fell swoop.


To understand what they achieved, it's important to have a basic grasp of particle physics. Everything in the universe is made from a few basic building blocks called fundamental particles. Those particles are governed by four fundamental forces. Our best understanding of how those particles and forces interact is known as the standard model of particle physics, which has so far explained and predicted all phenomena in physics.

Well, almost all. There are still open questions. We know that nearly a third of the universe is made up of dark matter, but we still don't know what dark matter is. We know neutrinos have mass because they oscillate, but we don't know what that mass comes from (heard of the Higgs boson? It's one possible explanation.) We're pretty certain that a fraction of a second after the Big Bang, the universe's expansion accelerated—a phenomenon called cosmic inflation—but we don't know what caused it. The Big Bang also should have created equal amounts of matter and antimatter, which would have canceled each other out. Instead, it enabled the universe's existence by making more matter than antimatter (a process called baryogenesis), and we don't know why. Something called the "strong CP problem" helps explain that question of matter, but brings its own questions to the table.

Physicists say that the SMASH model answers every single one of those questions. Previous models that have provided solutions to a handful of them, such as supersymmetry, have done so by adding hundreds of fundamental particles to the cosmic menu, none of which have ever been witnessed in a particle accelerator. SMASH only adds six: three neutrinos, a fermion, and a field that includes two particles. The team behind the new model believes it could be tested in the next 10 years. Until then, we'll just have to wonder. Explore the world of particle physics in the videos below.

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The Standard Model Of Particle Physics

Learn about the fundamental particles that make up everything in the universe—and the fundamental forces that govern them.

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What Is Dark Matter?

We know it exists, but we don't know what it is.

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Key Facts In This Video

  1. The known universe consists of about 70% dark energy, 25% dark matter, and 5% visible matter. 00:08

  2. Dark energy seems to be intrinsic to empty space, which has more energy than everything else in the universe combined. 03:45

  3. One theory of dark energy postulates that it comes from virtual particles in empty space that form and disappear constantly. 04:47

Studying Particles At Fermilab

See what physicists are doing to answer the biggest questions of the universe.