What is the effect on the tides when gravitational force of the sun is added to that of the moon?

Although the effect of the sun on earth's tides is less than the effect of the moon, if the two are aligned (i.e. during either a new or full moon) you get higher tides than when they are not. These are called "spring tides." When the sun and moon are not aligned (that is, during 1st and 3rd quarter moon) the sun's effect on the tides partially cancels out the moon's, and you get smaller tides (called "neap" tides).

There is no evidence that eclipses have any physical effect on humans. However, eclipses have always been capable of producing profound psychological effects. For millennia, solar eclipses have been interpreted as portents of doom by virtually every known civilization. These have stimulated responses that run the gamut from human sacrifices to feelings of awe and bewilderment. Although there are no direct physical effects involving known forces, the consequences of the induced human psychological states have led to physical effects.
Although not proven scientifically, some religions believe that pregnant women should stay indoors during a solar eclipse to prevent the baby from developing birth defects. Hindus also believe that water becomes undrinkable and food becomes inedible.The only proven scientific fact about from a solar eclispse is if you watch it without adequate protection for you eyes you can go blind

EFFEcts of tides in your health..