Define Periodic Services

Which season occurs in the northern hemisphere when the sun is at its lowest point in the sky

Some gamma ray bursts are hypothesized to come from mergers of neutron stars or black holes. if this hypothesis is correct, what else should we in principle be able to detect from such mergers? a. gravitiational waves b. x-ray bursts c. significant disruption of gas thousands of light-years away in the surrounding galaxy d. an "afterglow" of bright visible light, lasting for weeks

The chemical or mechanical process by which rock is gradually broken down eventually becoming soil