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Maximizing Survival Time Inside the Event Horizon of a Black Hole

Article Updated: 26 Dec , 2015

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Here’s a scenario that will face many of us in the far future. You’re hurtling through the cosmos at nearly the speed of light in your spaceship when you take a wrong turn and pass into the event horizon of a black hole. Uh oh, you’re dead – not yet, but it’s inevitable. Since nothing, not even light can escape the pull from a black hole once it passes into the event horizon, what can you do to maximize your existence before you join the singularity as a smear of particles?

Physicists used to think that blackholes were sort of like quicksand in this situation. Once you cross the event horizon, or Schwarzschild radius, your date with the singularity is certain. It will occur at some point in the future, in a finite amount of proper time. The more you try to struggle, the faster your demise will come. It was thought that your best strategy was to do nothing at all and just freefall to your doom.

Fortunately, Geraint F. Lewis and Juliana Kwan from the School of Physics at the University of Sydney, have got some suggestions that fly in the face of this stuggle = quick death hypothesis. Their paper is called No Way Back: Maximizing survival time below the Schwarzschild event horizon, and it was recently accepted for publication in the Proceedings of the Astronomical Society of Australia.

When an unlucky victim falls into the event horizon of a black hole, they will survive for a finite amount of time. If you fall straight down into a stellar black hole, you’ll last a fraction of a second. For a supermassive black hole, you might last a few hours.

Due to the tremendous tidal forces, an unlucky victim will suffer spaghettification, where differences in gravity from your head to your feet stretch you out. But let’s not worry about that for now. You’re trying to maximize survival time.

Since you’ve got a spaceship capable of zipping around from star to star, you’ve got a powerful engine, capable of affecting your rate of descent. Point down towards the singularity and you’ll fall faster, point away and you’ll fall more slowly. Keep in mind that you’re inside a black hole, flying a spaceship capable of traveling near the speed of light, so Einstein’s theories of relativity come into play.

And it’s how you use your acceleration that defines how much personal time you’ll have left.

In a moment of panic, you may point your rocket outwards and fire it at full thrust, keeping the engine running until you arrive at the central singularity. However, Lewis and Kwan have demonstrated that in the convoluted space-time within the event horizon, such a strategy actually hastens your demise, and you’ll actually end up experiencing less time overall. So, what are you to do? Lewis and Kwan have the solution, identifying an acceleration “sweet-spot” that gives you the maximal survival time. All you have to do, once across the event horizon, is fire your rocket for a fixed amount of time, and then turn it off and enjoy the rest of the fall.

But how long should you fire your rocket for? Lewis and Kwan show this is a simple calculation involving the mass of the black hole, how powerful your rocket is, and how fast you crossed the event horizon, easily doable on a desktop computer.

Here’s another analogy from Lewis:

“Consider a race to the centre between a free faller and a rocketeer. Suppose they cross the event horizon together holding hands. As they cross, they start identical stop watches. One falls inwards, while the other accelerates towards the centre for a little, then swings their rocket round and decelerates such that the free faller and the rocketeer meet and clasp hands again just before hitting the singularity. A check on their stop watches would reveal that the free faller would experience the most personal time in the trip. This is related to one of the basic results of relativity – people in freefall experience the maximum proper time.”

So now you know. Even after you’ve fallen into the black hole’s event horizon, there are things you can do to lengthen your harrowing journey so that you get to experience more time.

Time to you can use to deal with your spaghettification problem.

Original Source: Arxiv research paper


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N Stone
Guest
N Stone
January 26, 2008 3:00 PM

wow

robert martin
Guest
February 11, 2008 10:01 AM

thats how i wanna go out!! thats fukin awesome!!! spagetify me!!!

Dave
Guest
Dave
May 5, 2008 10:39 AM

As the gravity field increases the rate of time would slow to a crawl and stop eventually. So as you were falling closer to the singularity, everyone outside would have aged and died long before you would. So, you would have the last laugh.

Anonymous
Guest
Anonymous
June 28, 2008 3:49 PM

Uh, the hell would you want to lengthen the time?
The correct course of action upon realizing you’ve hit an event horizon (assuming you’d ever notice) is to pull out that trusty revolver you’ve been keeping from under your seat, pray that it’s functional, and say goodnight.

Yes all space captains should have revolvers for the marauding alien boarding parties and what not.

Sam D.
Guest
Sam D.
June 29, 2008 8:07 PM

I can imagine situations where falling into a super-massive black hole would make sense. For instance, if the Big Rip hypothesis turns out to be valid, our descendants might want to turn the Local Group of galaxies into a really big rabbit hole. The Big Rip ends with all singularities being flattened; the only place to survive it might be to place yourself within one.

AllanH
Guest
AllanH
July 8, 2008 10:56 AM

What happens if I turn the (near-light-speed-capable) spaceship at rightangles to the singularity and attempt to orbit it using maximum (survivable) acceleration to achieve maximum speed? IF the black hole is big enough, don’t I get time to accelerate to very-near light speed and extend my experienced time (potentially) indefinitely?

As the spaceship gets nearer to the singularity, centrifugal force will rise proportional to 1/R for a given velocity … unfortunately gravitational force will rise proportionately to 1/R2.

I assume that, in reality, the gamma rays would fry anybody in millisecs, so it makes little difference! Or, at near-light speed, would gamma rays appear to be nothing more than infra-red (still too hot)?

Eric Marsh
Member
Eric Marsh
July 11, 2008 11:21 AM

So why not try to orbit the singularity?

yester64
Guest
yester64
July 27, 2008 6:29 PM

wow… thats always my dream to get over the event horizon and see down at the pit. at least now i am prepared in how to get the most fun out of it. thanks smile

ID Skeptic
Guest
ID Skeptic
September 5, 2008 12:06 PM
Sorry Alan H., but there is no such thing as traveling perpendicular to the radial direction inside the event horizon. One of the things Relativity tells us is that inside the event horizon, space becomes time-like, in the sense that there is only one direction one can travel (toward the singularity), just as, outside the event horizon, one can only travel in one direction in time (barring wormholes). Furthermore, trying to use centrifugal force to your advantage becomes futile once inside the photon sphere (1.5 times the radius of the event horizon), because spacetime gets so warped there that the faster you orbit, the stronger the centrifugal force you’d feel pushing you TOWARDS the event horizon, not away… Read more »
RejectCo
Guest
RejectCo
September 10, 2008 7:45 AM

What about the black hole being a vacuum and lack of friction in the black hole? and wouldn’t your rocket require friction to be propelled?

erichansa
Guest
erichansa
September 10, 2008 10:05 AM

Simply calculate the essentially impossible odds of your escape, the infinite improbability drive will do the rest.

tenox
Guest
tenox
September 10, 2008 7:29 AM

if i was capable of flying through space star to star i would imagine i would have an intergalactic UPS (universal positioning system) to guide me in my intergalactic missions.. and it would show me where black holes are..

Zakstudio
Guest
September 10, 2008 7:48 AM

Obvious…

Mark
Guest
Mark
September 10, 2008 7:56 AM

RejectCo: no, rockets work in a vacuum. Don’t forget regular space is also a vacuum. Very simplistically, a rocket is an explosion in a box – the box experiences pressure on all its internal sides. If you remove one of the sides (the nozzle on the rocket) the forces are out of balance and it moves.

There’s a recent episode of astronomycast that covers this.

Reg
Guest
Reg
September 10, 2008 8:30 AM
Erm … “… analogy from Lewis: Consider a race to the centre between a free faller and a rocketeer. Suppose they cross the event horizon together holding hands. As they cross, they start identical stop watches. One falls inwards, while the other accelerates towards the centre for a little, then swings their rocket round and decelerates such that the free faller and the rocketeer meet and clasp hands again just before hitting the singularity. A check on their stop watches would reveal that the free faller would experience the most personal time in the trip. This is related to one of the basic results of relativity – people in freefall experience the maximum proper time.” The latter is… Read more »
endloser
Guest
endloser
September 10, 2008 10:34 AM

This is the ultimate demise of any pastafarian.

RejectCo
Guest
RejectCo
September 10, 2008 11:23 PM

thanks Mark smile

Mike Harris
Guest
Mike Harris
September 10, 2008 8:28 PM

These so-called “scientists” are just trying to hide the truth: that when you go into a black hole, you arrive in a dimension of “pure chaos, pure evil” where all sorts of nasty torture happens to you as well as cannibalism and so on.

Or so Sam Neill and Laurence Fishburne tell me.

Black Hole
Guest
Black Hole
September 11, 2008 7:30 AM

What happen ?
Somebody set up us the hole.
We lose signal.
What !
Main screen turn on.
It’s you !!
How are you gentlemen !!
All your space are belong to us.
You are on the way to destruction.
What you say !!
You have no chance to survive make your time.
Ha ha ha ha ….

Monique P Chouinard
Guest
Monique P Chouinard
September 11, 2008 3:45 PM

oh and by the way… all your bases are belong to us!

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