Camera lenses are often described as being 'aspherical', but what does it mean, and is it the only way to design a lens? A lot of lenses are spherical, though. What we mean by “spherical” is usually ...

Through telescopes on Earth and in space, astronomers can glimpse the far-flung reaches of the universe. And no matter how far away or how strange the planet, at least one thing seems to hold true in ...

Every product is carefully selected by our editors. If you buy from a link, we may earn a commission. Learn more Cyclists, get ready to celebrate: Giro has just released its lightest helmet yet, the ...

An ice wall does not surround Earth, which is spherical, not flat, contrary to a conspiracy theory video viewed widely online. A voiceover in the clip says: “If Antarctica's wall is 60,000 miles in ...