Cosmic rays generate the most energetic particles in the universe, utterly dwarfing anything we can generate in particle accelerators. Astrophysicists thought these cosmic rays were created in powerful gamma-ray bursts. Turns out they were completely, utterly wrong. So now what?

Plans are afoot to build a gigantic, state-of-the-art neutrino detector beneath the Mediterranean Sea. This particle-hunting behemoth would be taller than the Burj Khalifa and the second biggest structure ever built, second only to the Great Wall of China.