Origin of the Universe - Fiat Lux


The above picture is the Hubble eXtreme Deep Field, taken by the Hubble Telescope. Every single spot represents a galaxy. The Universe we live in consists of ~100 billion galaxies, where each galaxy consists of ~100 billion stars (the sun at the center of our solar system is just one of them, nothing appears special). By observing the Doppler effect of these galaxies in 1929, Edwin Hubble came to the conclusion that the universe is expanding rapidly. By now, we have overwhelming evidence that the universe keeps expanding and at 14 billion light years away from us, it is recessing at the speed of light. The important consequence of this observation is that some 14 billion years ago, our universe was a hot, dense, tiny object, called the Big Bang.


How can we investigate such an extraordinary condition? Remarkably, we scientists, came up with a clever idea of smashing particles and particles at extremely high energy. It is called an accelerator. And now we have begun the biggest scientific project ever called LHC (Large Hadron Collider) at CERN in Switzerland shown above.

Symmetry Breaking - Higgs Mechanism, Structure Formation

By smashing protons and protons at the LHC, we are basically recreating the condition of the beginning of the Universe, the Big Bang. To be exact, after 0.1 nano second after the Big Bang. One of the crucial studies is to understand how the Universe created something from nothing. To be exact, how matter could acquire its own mass. To explain it an intriguing concept, called Spontaneous Symmetry Breaking by the Higgs Mechanism, was proposed by particle theorists back in 1960's. It took over 50 years for the experimentalists and we have finally observed the clear evidence at LHC in 2012. Below is one of the Higgs particles decaying into two energetic gamma rays in the CMS detector, recorded on May 13, 2012.


This is a remarkable triumph of particle physics. But this is not the end of the story. Once the particles such as electrons and quarks were created and acquired their mass, they must be bound together to form atoms first (called Neucleosynthesis), then eventually to form stars and galaxy It turned out that the formation of stars and galaxies requires a complete new type of yet-to-be-discovered particles called Dark Matter. In other words, the dark matter would act as a seed to create the initial structure in the universe. Without dark matter, there was no structure, no life, and thus we were not here today.

Researches at Arisaka Lab

At Arisaka Lab, we are currently focusing on the direct detection of dark matter, while participating the CMS at LHC. We have also been active on detecting the messenger from the Big Bang, looking for the ultra high energy cosmic rays.

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