Skip to Content
Uncategorized

How To Spot a Rotating Black Hole

A newly discovered effect of general relativity means that rotating black holes should be visible to the current generation of telescopes, say astronomers

Black holes do strange things to the fabric of space time, particularly if they are rotating. One well known effect is that a rotating black hole drags this fabric with it, intermixing space and time in nearby regions.

Today, Fabrizio Tamburini at the University of Padova in Italy and a few pals say this ought to have a significant effect on light that gets caught up in this process and is then emitted from the disc of accreting matter around a rotating black hole. They say the rotation ought to distort the wave front and phase of this light, while imparting orbital angular momentum to the beam.

That’s an effect of general relativity that appears to be entirely new. What’s more, it should make rotating black holes visible. “It should be possible to detect and measure this twisted light,” say Tamburini and co.

So where might we find such a black hole? One candidate is the supermassive black hole at the centre of the Milky Way. Tamburini and pals have simulated the way this object ought to twist the light it emits as it rotates and say it could be detected today by the world’s best telescopes.

In principle, this kind of observation should be possible tonight, provided the scopes are kitted out with right kind of gear. And since the first observation of a rotating black hole would be a useful thing to have on an astronomical CV, it may not be long before we see the results of just this kind of observation.
Ref: arxiv.org/abs/1104.3099: Twisting Of Light Around Rotating Black Holes

You can now follow The Physics arXiv Blog on Twitter

Deep Dive

Uncategorized

Our best illustrations of 2022

Our artists’ thought-provoking, playful creations bring our stories to life, often saying more with an image than words ever could.

How CRISPR is making farmed animals bigger, stronger, and healthier

These gene-edited fish, pigs, and other animals could soon be on the menu.

The Download: the Saudi sci-fi megacity, and sleeping babies’ brains

This is today’s edition of The Download, our weekday newsletter that provides a daily dose of what’s going on in the world of technology. These exclusive satellite images show Saudi Arabia’s sci-fi megacity is well underway In early 2021, Crown Prince Mohammed bin Salman of Saudi Arabia announced The Line: a “civilizational revolution” that would house up…

10 Breakthrough Technologies 2023

Every year, we pick the 10 technologies that matter the most right now. We look for advances that will have a big impact on our lives and break down why they matter.

Stay connected

Illustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at customer-service@technologyreview.com with a list of newsletters you’d like to receive.