So astronomers for generations have been
looking at the sky and of course we’ve done multi-wavelength, multi energy
astronomy so we look in the optical or we look in the infrared or the radio or
we can go to higher energies and look in the x-rays and gamma-rays.
It turns out that when you look at the distant universe much above the TeV scale,
a gamma-ray scale, the universe actually becomes opaque and so multimessenger
astronomy, in particular neutrinos using neutrinos instead of light or photons
has the promise of being able to look at energies well beyond what we can do optically so you go from multi-wavelength to multimessenger and it brings in
higher energy processes that you might be able to observe and it’s also a
different messenger particle which gives you complementary information so when we
talk about multimessenger astronomy we’re using light of multi wavelengths
we’re using neutrinos and of course now with the great success of LIGO we’re
also using gravity waves.