What is Polarization? | Event Horizon Telescope

Light is an oscillating electromagnetic wave. If the waves have a preferred direction of oscillation, they are polarized. In space, moving hot gas, or ‘plasma’, threaded by a magnetic field emits polarized light. The polarized light rays that manage to escape the pull of the black hole travel to a distant camera. The intensity of those light rays and their direction are what we observe with the Event Horizon Telescope. Today, we reveal a breakthrough discovery: the Event Horizon Telescope has imaged polarized light close to the shadow of M87* for the very first time. Using this knowledge, we can map out the magnetic fields that surround the black hole, and connect them to the powerful jet of plasma it ejects. The Event Horizon Telescope (EHT) is an international collaboration that captured the first image of a black hole by creating a virtual Earth-sized telescope. To learn more, you can check out our website at Follow us on Twitter: Fo