No one has observed any evidence for proton decay. That might be disappointing professionally for physicists, but it's good news for the universe. If it turns out to be possible, proton decay could be the beginning of the end of everything. Here's why.
Just 30,000 years after the Big Bang, the universe started singing. Vast soundwaves rang out and expanded through the primordial cosmos, their ripples determining the universe's large-scale structure. And this all fits perfectly with one particularly theory of dark energy.