Light

Light is a fundamental part of the Universe. The speed of light in a vacuum is the cosmic speed limit: no matter how advanced our technology, we'll never travel faster than that. Since the speed of light is a natural measurement, we often measure distances in space in lightyears. The Sun's light is the ultimate source of all energy for life on Earth: without the warmth and energy from sunlight, not even plant life could exist.

In pictures: The electric-blue lava pouring from Earth’s strangest volcano

The luminous blue lava found on Java is caused by the sulphuric gasses burning in the oxygen-rich air once they reach the surface.
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What is the doppler effect?

This fundamental concept in physics is why the Moon sometimes looks red, and can help doctors analyse blood flow in tissues.
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Are there any benefits to using a daylight SAD lamp? A GP explains

They're a non-invasive and drug-free treatment for seasonal depression - here's what a GP thinks of them.
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How to see the total lunar eclipse this May

Cameras at the ready, May's full Moon brings with it a lunar eclipse that will turn the Moon red.
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The best smart bulbs to make your home glow in 2024

Shining a light on the best smart bulbs with voice activation and a full range of colour to help brighten any modern home.
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How the brightest minds in science – from Einstein to Da Vinci – revealed the nature of light

The nature of light puzzled some of humanity’s greatest thinkers for 2,000 years, behaving like a wave in certain conditions and as a particle in others.
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What is polarised light?

What is polarisation and why is it in my sunglasses?
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Researchers verify ‘extremely odd’ black hole physics

A team at the University of Glasgow set out to validate British physicist Roger Penrose’s 1969 work.
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Far-UVC light could be used against coronavirus without harming people

Scientists found that a specific type of ultraviolet light could be used for air disinfection.
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Flashing blue lights switch on cancer-fighting cells

Researchers were able to reduce tumour size in mice by between eight and nine times without harming healthy tissue using the new technique.
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Why the sky is dark at night

The dark sky paradox, also known as Olbers’ Paradox, explains why, despite the infinite number of stars in the Universe, the sky at night appears black.
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Blue light from smartphones may lead to brain damage... in flies

However, results cannot be applied to humans as the human brain “would receive much less light than fly brains”.
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Light shed on secrets of glow-in-the-dark sharks

While we know how corals and jellyfish can fluoresce, researchers haven’t figured out exactly how sharks can do it – until now.
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Can taking digital photos damage art?

Galleries would have you believe that a camera flash damages paintings.
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Why does light leave the position from which it is created?

An accelerated electric charge causes ever moving waves of energy travelling at the speed of light, according to the laws of physics.
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Do two mirrors facing each other produce infinite reflections?

While they seem to extend into the infinite, the truth is a little darker.
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Can weather forecasters predict rainbows?

"Somewhere, there might be a rainbow..."
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Is the dark really making me sad?

How do Scandinavians deal with long, dark winters? And what might this teach us about the relationship between our moods and sunlight? By Linda Geddes.
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Why is red light used on submarines?

Red light, night light.
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How does ‘glow in the dark’ work?

Important knowledge for your next rave.
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What is the darkest human-made substance?

Step one in becoming the ultimate goth.
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