Energy from the sun's rays can cause skin damage and cancers. Sunscreens can absorb or reflect the dangerous UV light. Here's how it works.
Coating paper with an inexpensive thin film can allow users to print and erase a physical page as many as 80 times. That reduces both the cost and the environmental effects of paper use.
Melanoma, the deadliest form of skin cancer, can usually be cured when caught early. When it has spread, however, it becomes a challenge. Recent findings are bringing hope. Here are a few examples.
Orkney's ultra-high incidence has been linked to the weak northern sun. So how come the more northern Shetlands are less afflicted?