The hot dark matter was assumed to consist of neutrinos, ghostly particles that have the advantage of being known, although no one has yet proved whether they have any mass.

Neutrinos are ghostly particles, one of the fundamental building blocks of the universe, like quarks, electrons and photons.

Now some researchers believe that they have discovered a key to the universe in the ghostly particles.

But Zorach knew there was a wind of ghostly microscopic particles blowing fitfully from the Sun, a solar wind that sometimes reached hurricane velocities and more.

Neutrinos have been called "ghostly" particles because, like ghosts, they are unhindered by walls.

The ghostly particles are still understood to carry no charge, but experimental results announced at the conference seem to have clinched the case, building for years, that they are not entirely without heft.

It recorded flashes caused by ghostly particles called neutrinos, which were produced by the radioactive decay of uranium and thorium deep in the heart of the Earth as they shot up through the ground and the detector.

But so far efforts to create one of these ghostly particles in accelerators, which mimic the high levels of energy in the first fraction of a second after the birth of the universe, have come up empty.

Neutrinos, those ghostly elementary particles produced in radioactive decays, have a reputation for being elusive: they interact so weakly with matter they can pass right through the Earth unimpeded.

A huge underground chamber that made historic observations of ghostly particles called neutrinos that stream through the cosmos was crippled over the weekend when thousands of light detectors imploded in a chain reaction.