Neuroscience

Three types of cells help the brain tell day from night

Bright light at night interrupts the body's normal day-night cycles, called circadian rhythms, and can trigger insomnia. In fact, circadian rhythms play a major role in health. Disrupted day-night cycles have even been linked ...

Health

Innovative approach to lighting set to improve sleep quality

New Australian research by the Cooperative Research Centre for Alertness, Safety and Productivity (Alertness CRC) reveals blue light may be even more important than previously thought. The work points to the amount of blue ...

Diseases, Conditions, Syndromes

Q&A: Treating melasma

Dear Mayo Clinic: Years ago, I had some patches of melasma on my face removed with IPL treatment. When I went to make an appointment with my dermatologist recently for the same condition, I was told IPL should not be used ...

Health

Photoinitiators detected in human breast milk

Photoinitators (PIs) are compounds used in the ink of many types of food packaging. The substances have been shown to migrate into food and, when consumed, show up in human blood serum. Now, for the first time, researchers ...

Diseases, Conditions, Syndromes

WHO prequalifies first Ebola vaccine

The World Health Organization (WHO) on Tuesday said it had prequalified an Ebola vaccine for the first time, hailing a "critical step" towards its licensing, access and roll-out in countries most at risk of outbreaks.

Radiology & Imaging

Low-cost, portable system takes OCT beyond ophthalmology

Researchers have developed a way to perform optical coherence tomography (OCT) in hard-to-reach areas of the body such as joints. The advance could help bring this high-resolution biomedical imaging technique to new surgical ...

Health

French MPs okay budget for medical marijuana experiments

Lawmakers in France, one of few European countries to still ban medical cannabis use, approved the budget Friday for two years of patient experiments that advocates hope will pave the way for a change in the law.

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Light

Light is electromagnetic radiation, particularly radiation of a wavelength that is visible to the human eye (about 400–700 nm, or perhaps 380–750 nm.) In physics, the term light sometimes refers to electromagnetic radiation of any wavelength, whether visible or not.

Three primary properties of light are:

Light, which exists in tiny "packets" called photons, exhibits properties of both waves and particles. This property is referred to as the wave–particle duality. The study of light, known as optics, is an important research area in modern physics.

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