The neutrino is a chargeless, near massless particle which interacts very weakly with ordinary matter. It is created during nuclear fission/fusion reactions; in fact, during every second, billions of (solar) neutrinos pass through our body:). It would take about one light-year (~10¹³km) of lead to block half of them! Obviously, it is very hard to detect these elusive particles.

Neutrino Ripples: fluctuations of order of ±30μK (Courtesy: RAS)But detecting these particles is very important, as copious amounts of it is theorized to have been created at the Big Bang, according to which neutrinos permeate the Universe at a density of about 150 per cubic centimetre. Now scientists have for the first time found evidence of ripples in the Universe’s primordial sea of neutrinos, confirming the predictions of both Big Bang theory and the Standard Model of Particle Physics.
To be published in Physical Review Letters, Dr. Roberto Trotta, Lockyer Fellow of the Royal Astronomical Society at Oxford’s Department of Physics, and Dr. Alessandro Melchiorri of La Sapienza University in Rome combined data produced by the NASA Wilkinson Microwave Anisotropy Probe (WMAP) satellite and the Sloan Digital Sky Survey, to get the above neutrino fluctuation distribution.
As the results matched perfectly with the current understanding of both Big Bang and Particle Physics, the research shows that theories of the infinitely large (cosmology) and the infinitely small (particle physics) are in agreement!!
This, even by itself, is such a beautiful thing :):).