The ingredients required to make a rainbow are sunlight and raindrops. Currently, there is no other planet known to have liquid water on its surface or in sufficient quantities in the atmosphere to make rain.
A battery that runs on sunshine and fresh air sounds like something from a utopian novel, along with fusion-powered hover cars and cancer-curing breakfast cereals. But that is exactly what scientists at The Ohio State University have just invented: a solar cell that stores its own power.
When light hits wet hair, some of the light reflecting off the surface of the hair strikes the inside surface of the water film at the right angle to be reflected or refracted back onto the hair again.
It is one of the greatest mysteries in science: why does the Universe consist almost entirely of matter? Answering this question is the ultimate goal of scientists who are attempting to make antimatter in the lab.
Substances generate a smell when their molecules land on so-called olfactory neurones in our noses (which, for some things, is a pretty unpleasant thought). But the exact nature of the interaction is somewhat controversial.
Strictly speaking, the Earth’s gravity will always pull on an object, no matter how distant. Gravity is a force that obeys an ‘inverse square law’. So, for example, put an object twice as far away and it will feel a quarter of the force.
The Earth takes about 365.25 days to complete an orbit around the Sun (one year). If you just round the calendar year down to the nearest whole number, the date recorded by the calendar will drift out of sync with the seasons.
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