What would happen if you fell into a black hole?

If you fell into a black hole, could you survive? What would happen, and what would you see?

Illustration of a woman falling to a black hole, holding onto an outstretched hand
Published: January 25, 2022 at 10:31 am
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Black holes are one of the most mind-blowing cosmological concepts we know of, and they've certainly been thrust into our consciousness in recent years through detections of gravitational waves and the incredible first image of a black hole, captured in galaxy M87.

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But what would happen if you fell into a black hole? What would you see? Could you survive?

More from Marcus Chown:

The supermassive black hole in galaxy M87 was observed by the Event Horizon Telescope and announced to the world in April 2019. Credit: EHT Collaboration
The image of the supermassive black hole in galaxy M87 was captured by the Event Horizon Telescope and revealed to the world in April 2019. Credit: EHT Collaboration

A matter of space and time

If you could indeed survive the passage through a black hole’s ‘event horizon’ – the point of no return for in-falling matter and light – what you would see and what would happen to you would depend on precisely when you fell into the hole.

This is because the interiors of black holes evolve with time.

Past the event horizon, space-time is so distorted that space becomes time and time becomes space.

Thus, the way to the centre of the hole is not a direction in space, but a direction in time.

This explains why the point of infinite density, or ‘singularity’, at the centre is unavoidable.

You can’t avoid it just as you can’t avoid tomorrow.

If you fell into a supermassive black hole soon after it formed, you would reach the singularity within a few hours.

The tidal forces as you approached the singularity would be so powerful and unpredictable that not only would you be torn apart, but so would space and time.

They would fragment into droplets, destroying any concept of past and future.

Things are better, however, if you fall into the hole long after it has formed.

If it’s rotating, a buckle in space-time, like a ruck in a carpet, will form roughly halfway between the horizon and the singularity.

Here, material falling into the hole piles up and eventually creates a new singularity.

And, crucially, this late singularity will not be as violent.

Cone-shaped shadows emanating from the bright centre of galaxy IC 5063 could be cast by the dusty ring surrounding the supermassive black hole at its centre. Credit: NASA, ESA, STScI and W.P. Maksym (CfA)
Cone-shaped shadows emanating from the bright centre of galaxy IC 5063 could be cast by the dusty ring surrounding the supermassive black hole at its centre. Credit: NASA, ESA, STScI and W.P. Maksym (CfA)

Some theorists believe it might be possible to reach the late singularity without being ripped apart.

It might even be possible to pass through it, some think into the outside Universe in the far-future, while others believe you might reappear in another universe entirely.

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This article originally appeared in the September 2006 issue of BBC Sky at Night Magazine.

Authors

Marcus Chown is an award-winning writer and broadcaster and a former radio astronomer at the California Institute of Technology in Pasadena. He is the author of Breakthrough: Spectacular stories of scientific discovery from the Higgs particle to black holes (Faber & Faber, 2021).

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