Most male fin and blue whales sing at around 17 to 18 hertz, which is too deep for humans to hear, but the 'lonely' whale communicates at 52 hertz. When more recordings were released in the nineties, Dr Watkins studied the 52 hertz whale more closely.
The average person needs to absorb just a small amount of iron each day to stay healthy (around 1 mg for adult males and 1.5 mg for menstruating females). To achieve this, however, we need to consume several times that amount. This is because our bodies absorb only a fraction of the iron contained in the foods we eat.
Daily Iron Requirements. The amount of liver you should eat daily to meet your iron requirement depends on your gender and age. Men and women have different iron requirements throughout the adult years; women's needs also vary according to age. Women of reproductive age need 18 milligrams per day because of blood loss during menstrual periods.