Prolonged sexual intercourse: Coalesce to a cosmically deep climax.
After a half hour or so, as with most other repetition-based phenomena, your consciousness will begin to change. Sensations begin to take on new ecstatic aspects as the one-hour mark is approached. Now only the sexual-body energy-environment exists. Now sensations blend and coalesce. Letting go to orgasmic climax is pyrotechnic, possibly divine, cosmically deep.