1
$\begingroup$

On my understanding what kills you near a black hole is the proccess of spaghettification due to the extreme gravity.

To avoid this my suggestion is to create a spacecraft that can get to 99.999% the speed of light and entering the black hole at a perpendicular angle. The relativity won't let you accelerate to a speed faster that lightspeed. So the acceleration or change in velocity you would experience would be neglible. And therefore you would survive entering the black hole.

Is this idea possible assuming we also have a spacecraft possible of protecting us from the radiation close to the black hole?

$\endgroup$
2
  • $\begingroup$ I think there is a misconception here regarding how speeds in special relativity are added. For instance, suppose I move at 99.999% the speed of light relative to you and fire a photon out in front of me. Let me ask you this: how fast do you see the photon moving, and how fast do I see the photon moving? $\endgroup$
    – gj255
    Feb 13, 2017 at 15:59
  • $\begingroup$ Well according to the special relativity everyone will se the photon moving at the same speed. Your time from my point of view will be passing very slowly, but you would see me and the rest of the universe going very fast. I read some answers here and I see that the problem is the tidal forces not the relativity itself. $\endgroup$
    – user14930
    Feb 13, 2017 at 23:44

3 Answers 3

2
$\begingroup$

In his book "Black Holes and Time Warps" (Very much worth the read), Kip Thorne actually addresses this problems. If you use a much larger black hole, the tidal forces aren't as large, so you don't need to worry about the spaghettification whilst outside of the hole. It's not possible to predict what will happen once you pass the event horizon, but it's likely that you'll feel no difference - people from the outside will just never see you cross the horizon.

$\endgroup$
0
$\begingroup$

It does help a lot to move at speed 0.999 c, mainly because lengths contract to about 1/22 of the rest lengths, which reduces tidal forces to about 1/484.

The above is what happens in the black hole's frame.

In the spacecraft's frame a person on the spacecraft would say that tidal forces caused by the black hole, which is moving at speed 0.999 c, are very small, so the gravity field must be very uniform, so apparently it is so that fast motion of a black hole makes its gravity field more uniform.

$\endgroup$
1
  • $\begingroup$ This seems plausible, although it would be nice to see a more rigorous calculation using GR. $\endgroup$
    – user4552
    Mar 2, 2019 at 15:46
0
$\begingroup$

There is an alternative way of getting real close to a black hole without getting spaghettified:

Find an extremely massive black hole

Because of its huge mass, its size must be huge too, which means that its tidal gravity between two places will be relatively small, compared to the size of the black hole.

That way you can get super near to the event horizon without getting torn apart.

$\endgroup$
1
  • 1
    $\begingroup$ This seems to duplicate Noah P's answer. $\endgroup$
    – user4552
    Mar 2, 2019 at 15:42

Not the answer you're looking for? Browse other questions tagged or ask your own question.