Nearly 11 kilometers deep, the ocean is still a noisy place, according to scientists that have eavesdropped on the deepest part of the world's ocean, and instead of finding a sea of silence, discovered a cacophony of sounds both natural and caused by humans.

For three weeks, a titanium-encased hydrophone recorded constant ambient noise from the ocean floor at a depth of more than 36,000 feet, or 7 miles, in the Challenger Deep trough in the Mariana Trench near Micronesia. The ambient sound field is dominated by the sound of earthquakes, both near and far, as well as distinct moans of baleen whales, and the clamor of a category 4 typhoon that just happened to pass overhead.

The hydrophone also picked up sound from ship propellers. Challenge ...

As soon as we're born, we're destined to age. Some of us age gracefully - we enjoy years of youthfulness - while others experience hair loss, wrinkles, and greying earlier than expected.

Found in the core of each hair, a pigment known as melanin gives rise to a person's hair color. This universal pigment is also found in our skin and eyes, giving use our unique physical traits. Dark and light versions of melanin - eumelanin and phaeomelanin, respectively - combine in various combinations to create all natural hair colors.

Melanin itself is the product of a specialized cell, the melanocyte, which is found in each hair follicle, from which the hair grows. As hair grows, the melanocyte injects melanin into the hair cells, which contain the s ...