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.
A bowl of a typical iron-fortified cereal has 18 milligrams. How much iron do you need? The recommended dietary allowance for adult males and for women over 50 is 8 milligrams per day. For women aged 19-50, the RDA is 18 milligrams per day (itâs higher to compensate for menstrual losses).