Synesthesia is a condition where one involuntary sensory pathway leads to a(n) sensation from another involuntary sensory pathway; the two pathways seem to act in a cross-sensing manner.

this age may represent the age of the earth's accretion, of core formation, or of the material from which the earth formed. this dating is based on evidence from radiometric age-dating of meteorite material and is consistent with the radiometric ages of the oldest-known terrestrial and lunar samples.