Water is life. Yet when the LANDSAT-9 satellite looks down on the water of the Pacific Ocean, it sees dark matter. Here is what the satellite sees when it looks over the rainbow at the sunlight bouncing back from the sea in the infrared.
The play of light from the Sun off the crests of the waves near the sea shore tells a story that began in the Big Bang when dark matter first formed. Forged from matter and antimatter, each particle of dark matter has a flavor that matches one of the twelve flavors of matter in the Standard Model of particle physics: Up, down, charm, strange, top, bottom, electron, muon, tau, and the three neutrinos. By contrast, light comes in just two kinds: Left and right.
In the Big Bang, each flavor of dark matter and each kind of light were made in equal amounts. That means the ratio of the number of dark matter particles to the number of particles of light left over from the Big Bang must be twelve to two. Combining this ratio with measurements of the number density of particles of light left over from the Big Bang and the energy density of dark matter in the Universe, scientists at Science Synergy have determined the rest mass of dark matter within a percent: The resulting rest mass of dark matter gives it a Compton wavelength of 2.44 microns that lands on top of the sharp dip in the infrared reflectance spectrum of liquid water from the open ocean.