When Dodell-Feder tested this vacuum, it was a pricey $179 — now, at 45% off, it's down to what appears to be its best price ...

A compound lens forged by two galaxies is helping astronomers get a bead on the Hubble Constant and dark energy.

A team of astronomers has identified a double gravitational lens system with an extraordinary “zig-zag” light path, rewriting ...

In what is the first discovery of an Einstein zig-zag lens in the universe, a team of international astronomers have sighted ...