Just as the spaceship was traveling faster than light, you are traveling faster than snail-mail, so you beat some (or all) of your mailed selfies home. The day after your homecoming, the mail carrier delivers two of your pictures: one from the trip out, and a second from your trip back.
Ongoing research has shown that oral melatonin supplements can promote the dipping process. They can reduce nocturnal systolic blood pressure by about 6 mm/Hg, and diastolic pressure by 4 mm/Hg. Not surprisingly, the studies also indicate that melatonin improves sleep quality, which allows the body to relax more.
Regulation of Blood Pressure. Several functions of the cardiovascular system can control blood pressure. Certain hormones along with autonomic nerve signals from the brain affect the rate and strength of heart contractions. Greater contractile force and heart rate lead to an increase in blood pressure. Blood vessels can also affect blood pressure.