Detection of day or night? I was wondering, are there "particles" that can be detected, when one's side of earth is shined on by the sun?
I understand that there are cosmic radiations present, which probably will drown the little effect the sun has, but is there any way to detect something specific to the sun?
I am also assuming the following:
These "particles" (if in existence) are strong enough to penetrate the earth's outer layers (thus picked up by a sensor of sort no matter if it's under direct sun light or not), but not strong enough to be picked up on the other side of earth.
Please also note that I have very little knowledge in this area!
 A: The sun blasts us continuously with charged particles. When these strike the upper reaches of our atmosphere, they scatter off of and ionize some of the air molecules there. This renders those particular layers of the atmosphere somewhat electrically conductive- and in that state, radio waves beamed from the ground will get refracted off those layers and go back down towards the earth instead of shooting straight out into space.
Amateur radio hobbyists use the shifting daily/nightly balance of ionization in the different layers of the atmosphere to bounce their signals all the way around the world, and to do so they monitor the daily relative activity level of the sun's photosphere (from which the charged particles get ejected).
So this furnishes a simple and direct measure of the particle output of the sun; note that those ionized layers undergo recombination after the sun goes down which shuts off these "skip channels" shortly after dark.
A: I am speculating that the OP thinks about a detector placed at some depth underground. (Because on the surface, we have the time-honored method of using photon sensors.)
One can detect solar neutrinos. The problem is, modern neutrino detectors are large, stunningly expensive and have bad (but not zero) sensitivity about direction. And the direction is all we can have with neutrinos, because the Earth has no measurable absorbtion of neutrinos of solar energies (hey, even our Sun doesn't have measurable absorbtion of neutrinos).
At some moderate (by human measures) dept of few hundreds of meters, one can detect muons generated from the high-energy cosmic rays. At TEV-range energies, both the Moon and the Sun should have detectable shadows when above the what-would-be-the-horizon. The detector is large and expensive as well. You will need a calendar as well.
