QandA

Q&A Tabs

Phlegm is the mucous secretion of the respiratory passages. The cilia cells that line these passages are continually driving the phlegm upward to the throat, where it triggers the swallow reflex...

No. At least, not in the popular sense that creative people are more ‘right-brained’ than logical or analytical people are: a study that scanned the brains of over 1,000 people found...

Not really - all movement is relative. To have absolute stillness you would need an absolute frame of reference. The (supposedly) fixed stars were once thought of as such a unique reference point...

Beard hair is quite different to head hair; it is coarser, curlier and doesn't fall out as we get older. Comparatively little work has been done on the genetics of human hair colour, but it is...

Most people can’t focus on anything as close as a face at kissing distance so closing your eyes saves them from looking at a distracting blur or the strain of trying to focus. Kissing can...

All female mammals have a clitoris, the sole purpose of which is to react to sexual stimulation, and presumably this stimulation has evolved to be pleasurable for most species. But establishing...

To create a sound, we have to set matter - whether it's a gas like air, a liquid or even a solid material - in regular motion, creating a wave of specific frequencies, which we hear as a sound of...

Mirrors don’t reverse left and right either – that’s just our interpretation of what happens. Your reflection in the mirror is actually reversed front to back – if you have...

Discovered by an American student named Gary Flandro in the mid-1960s, the slingshot manoeuvre usually involves spacecraft briefly 'coat-tailing' a planet orbiting the Sun, extracting some of the...

The ice disappears because the wind blows away water molecules that have evaporated or 'sublimed' from the ice, so the ice slowly shrinks in size. The molecules that escape are those with the...

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No. At least, not in the popular sense that creative people are more ‘right-brained’ than logical or analytical people are: a study that scanned the brains of over 1,000 people found...

Butterflies and moths use their wings for many purposes: for flight, as mobile billboards to advertise how poisonous they are, and to create camouflage patterns. So you would expect them to be...

Deciduous trees shed their leaves as an active process that evolved to conserve resources and protect the tree from being blown over in the windier winter months. The process is controlled by the...

Most reports of the discovery of the Higgs boson at the Large Hadron Collider in Geneva in 2012 focused on its role in explaining the origin of mass. But for physicists, the real excitement lay in...

Yes, if a recent experiment is to be believed. In an attempt to locate the source of an epileptic patient’s seizures, doctors at George Washington University, USA, inserted electrodes into...

Yes it does, especially if you put the phone and the rice into a sealed plastic bag. But while the rice will draw out the moisture, that doesn’t necessarily mean your phone will work...

Stars emit light over a whole range of wavelengths (or colours). The wavelength where the amount of light peaks determines the colour we see, although they will also emit plenty of light at other...

There are 7 billion humans and around 200 billion birds in the world. That seems like a lot of two-legged animals, but non-human mammals number around 500 billion and almost all of them are four-...

A combination of the words ‘smoke’ and ‘fog’, the term emerged around a century ago to describe the dense, choking mix of gases and soot that was becoming common in big...

It would be very difficult. Insects pollinate at least a third of the total volume of crops cultivated worldwide, and many are useful predators of non-insect pests such as mites. Even if we...

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