Maximizing Survival Time Inside the Event Horizon of a Black Hole

by Fraser Cain on May 10, 2007

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DonHere’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

About 

Fraser Cain is the publisher of Universe Today. He's also the co-host of Astronomy Cast with Dr. Pamela Gay.

Monique P Chouinard September 11, 2008 at 3:44 PM

ummm…I think people seem to be forgetting a very IMPORTANT aspect of any black hole–they are extremely hot! many of them are at one million kelvin (thats like 3million degrees!). You would not get closer than I would have to say a few million miles before you veritably disintegrate!

Omar Sheira September 12, 2008 at 11:56 PM

“As the gravity field increases the rate of time would slow to a crawl and stop eventually.”

Roxes Kihunata September 28, 2008 at 12:14 PM

wow i hope im dead when this happens .

(hey i think that the black hole is a portal to another dimension u know people think but i belive, if you survive a black hole and live to tell the story then u will know the truth ,remember that a black hole can destory an entire planet EVEN THE SUN DUDE !! ) for what i know black holes are extra demesion portals.if it has energy and its faster than ligh and its hotter than the sun ,dude ur going to hell

Scientists are hiding this everyone knows if ur going to die straight from a black hole that means ur bad luck has reachen max level and ur goi9ng straight to hell

Portals dimensions universes everyone knows

(for what i think ,in pluto there is a big black hole near tha destroys everything )

if a black hole apears in the solar scystem there are some options that may happen .

1.Alien monster s creatures will apear and kill you

2.The black holes tremendous strength will rip even your blood

3.the sun may loose all its light but you will still die dude the sun is gravity that holds the entire galaxy so i suggest die before this even happens (the earth and all the planets in the gaalxy will fall down riping apart all its life)

4.Demons from hell attack you and the black holes turns into a portal throwing monster sat u blablabla

5.survivors may become ateam and destory all the aliens save the galaxy and thn u will become the biggest hero in all the universe

Roxes Kihunata September 28, 2008 at 12:16 PM

well i forgot something

6.scientist will unleash the most destructive and powerfull techonolgy ever discovered for man kind and use it against the black holes desteoying the black hole powers and saving the galaxy

Roxes Kihunata September 28, 2008 at 12:19 PM

black holes wont rip you off they only suck you in the energy is so powerfull there that it will turn you into dust only a monster from hell can go into that thing (dude a black hole is made of the most dangerous explosive and laser like rock to ever excists to even aliens >o< )

zibit September 30, 2008 at 2:31 PM

Thanks for the chuckle Roxes!

robert November 3, 2008 at 8:49 AM

i think it would be interesting to go through a black hole and see the other side that might be where the ufos are coming from when they visit us.i would like to be by the black hole where the time is frozen where i can go back to earth in 4084 and see the real future. i think at that year era we should have a spaceship to venture different stars.

Ross November 8, 2008 at 12:15 PM

Just tell me one thing, why the hell would you want to lengthen your death time? I mean you’re going to die anyways, so why not make it quick and snappy, not slow and spaghettifiedily (is that a word?) :L

Mike Green November 10, 2008 at 10:46 PM

Actually, you won’t die from spagettification. A recent science report showed that you’d actually roast to death inside a black hole first.

And I’d be a bit worried about all the other stuff floating around in the black hole between the event horizon and the singularity.

Oh, and lots of photons will be zipping around the inside edge of the event horizon, never quite able to escape, but ready to blind you. Bring some strong sunglasses.

jordon November 13, 2008 at 12:24 PM

YOU DO HAVE GUNS ON SPACESHIPS BECAUSE IF YOU FALL OFFCORSE INTO THE JUNGLE THEY HAVE PISTLES IN THERE SURVILE KIT TO FIND FOOD

Curtis November 13, 2008 at 12:46 PM

You would roast in seconds if not faster before you can think of anything

Sly November 26, 2008 at 12:11 PM

Maximizing survival time in black holes…classic and imaginative.

I agree that it seems kinda pointless to lengthen the time it takes you to die. I mean, you’re already stuck inside the black hole in your pimped out ship, you are guaranteed to have a one-sided meeting with the singularity, so why spend more time floating in blackness, recording messages you can never send?

heating December 23, 2008 at 12:33 PM

omks inwad zokq

heating December 24, 2008 at 5:45 AM

nsjrm

Luis December 24, 2008 at 5:34 PM

What do you say?

Jun December 31, 2008 at 1:42 PM

Hey, the quote you cite seems to argue the EXACT OPPOSITE (per Reg) of what you’ve written. Can you explain this?:

“A check on their stop watches would reveal that the free faller would experience the most personal time in the trip.”

“Physicists used to think that black holes were sort of like quicksand in this situation…. 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.”

????? EXPLAIN!!!

Bill F January 31, 2009 at 4:50 PM

If you really wanted to lengthen time, ensure that a politician is aboard, then ask him/her to make a speech. I guarantee it will feel like eternity.

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