What happens to you if you get pulled into a black hole?

[DrPhy]

I know that because of the great gravity pulling at your feet much not as much at the upper half of your body you become like spaghetti but I want to know why this happens and what else could possibly happen.

 

[anj16]

First of all I would like to point out that it is not just your leg getting pulled. It could possibly be your head too. This happens because whichever side of the body is facing the source of the gravity comes in contact with the source before the other side. Therefore getting pulled. For example, if a body is moving towards the black hole with its legs facing towards the black hole, the legs will come in contact with the gravity field of the black hole before the rest of the body and the spaghetti effect will take place. And as for other possibilities: I believe it is if you either go through the event horizon or dive right into the center of the black hole you won't face the spaghetti effect.

 

[phinds]

I believe it is if you either go through the event horizon or dive right into the center of the black hole you won't face the spaghetti effect.

The event horizon has absolutely zero to do with spaghettification. For small black holes you get spaghettified WAY outside the EH and for really really big ones you don't get it until WAY inside the EH.

 

[anj16]

The event horizon has absolutely zero to do with spaghettification. For small black holes you get spaghettified WAY outside the EH and for really really big ones you don't get it until WAY inside the EH.

Yes I do realize that. What I meant was that there is a way of going inside a black hole without getting spagettified. I read it somewhere just don't remember where.

 

[phinds]

Yes I do realize that. What I meant was that there is a way of going inside a black hole without getting spagettified. I read it somewhere just don't remember where.

What does "inside a black hole" mean to you? The only meaningful thing I can think of is "inside the event horizon" and I have already stated that you don't have to "do" anything to get inside the EH of a really large BH without getting sphagettified, it just happens that way and there is absolutely nothing you can do to avoid sphagetification outside the EH of a small BH.

 

[PaulS1950]

Because space time is pulled and distorted the person or object being "spaghettified" would have no sensation of it. The rest of the universe would look funny but you would be "just fine so far". (typical optimistic view)
The heat and pressure on the "interior" of a black hole would disassemble the atoms that you are made up of and you would become a collection of sub-atomic particles in a sea of subatomic particles. The heat and pressure of a black hole is the closest thing to the universe at the very beginning of its existence. Too hot to form elemental particles in a dence soup that fused and decomposed sub-atomic particles continuously.

The foregoing is not scientific fact - no one knows what happens inside a black hole but it is reasonable to assume that with the heat and pressure matter cannot exist. That leaves just energy - a lot of it to generate the mass of the black hole.

 

[Danger]

If the theoretical "split event horizon" exists, leading to a naked singularity, you can pass through it unimpeded as long as the distance from the singularity doesn't impart lethal tidal forces. Elsewise, you'll get stretched out like Reed Richards in an orgy.

 

[phinds]

Because space time is pulled and distorted the person or object being "spaghettified" would have no sensation of it. .

I cannot imagine how you can justify that statement. The sphagettification is real. How could you not experience it (for the little time you remain alive).

 

[PaulS1950]

We exist in the fabric of space time. If space time is distorted how would you know?
We could be living in a six dimension universe that has been distorted by a black hole in three of the dimensions and so we only see the three we experience. There would be nothing within your frame of reference to tell you that something was wrong.
An outside observer would see the "spaghettification" and may notice the time dilation but you wouldn't from your frame of reference.
Light is pulled into the black hole in the same manner - it looks spaghettified too but it doesn't even have mass. It is, like you being pulled in along with the fabric of space/time. both of you are in "free fall" - there is no gravitational effect on the falling object.

 

[phinds]

there is no gravitational effect on the falling object.

You are missing the point. Sphagetification is not caused by the gravity, it is caused by the DIFFERENCE in gravity between your head and your feet. Do you understand the concept of tidal forces?

For a small black hole, you'll be ripped to shreds before you even get to the event horizon, so what happens in the "interior" of the black hole is irrelevant.

 

[Jimmy]

both of you are in "free fall" - there is no gravitational effect on the falling object

There is a gravitational effect- tidal force.

I think falling toward a neutron star would do some damage as well.

http://hyperphysics.phy-astr.gsu.edu/hbase/tide.html#mtid

 

[PaulS1950]

You are missing the point: You are riding the space/time curvature in free fall. There is a difference in the space/time curvature from one point on your body to another but you are still locked into a space time reference.

You are treating gravity as a force. It is not. It is simply the effect of bent time/space and objects following it.
There is no gravitational effect in free fall. - think about it...

 

[Jimmy]

If that were the case, we wouldn't experience tides on Earth caused by the moon, and to a lesser extent, the sun.

 

[phinds]

There is no gravitational effect in free fall. - think about it...

I HAVE thought about it. You don't seem to get the concept of tidal forces.

 

[PaulS1950]

You have to accept that light has no mass - right?
If light has no mass and it is curved around a massive object then it cannot be a force acting upon a massless object - it has to be bent space/time like Einstein set forth in GR. It can't be both. Gravity either exists as a force or it exists as a curvature in space/time. If it exists as the effect of space/time curving then what an outside observer would see is the spaghettification process but the one in the local reference frame would be totally unaware that anything was happening to him. He would see the rest of the universe deforming. Add to this process the time dilation that takes over as you get closer to a massive object. For the person falling it would take very little time for the whole event to complete but the distant observer would see him "languishing" at the event horizon for a long time.
There are two different frames of reference here and they are relative - or one is relativistic.

 

[Drakkith]

You are missing the point: You are riding the space/time curvature in free fall. There is a difference in the space/time curvature from one point on your body to another but you are still locked into a space time reference.

This is incorrect. Tidal forces DO happen in many other cases, and the results range from benign to catastrophic. For example, the Earth's tides are caused by tidal forces arising from gravitation. Tidal forces can also rip stars apart in binary systems if a star gets too close to a neutron star or other small massive object. You are never "locked in" to a spacetime reference, whatever that is supposed to mean.

You are treating gravity as a force. It is not. It is simply the effect of bent time/space and objects following it.
There is no gravitational effect in free fall. - think about it...

The way spacetime curvature manifests itself is easily able to be described as a force in almost all cases. And I don't really know what you mean when you say "there is no gravitational effect in free fall". Free fall is a direct result of gravity, so it is itself a gravitational effect. Did you mean something else?

 

[Mark M]

I HAVE thought about it. You don't seem to get the concept of tidal forces.

Phinds is correct. Einstein's equivalence principle only holds in local coordinates. That is, over sufficiently small intervals of time and space. Otherwise, gravity has certain effects that acceleration does not (such as the tidal effect).

 

[Drakkith]

If it exists as the effect of space/time curving then what an outside observer would see is the spaghettification process but the one in the local reference frame would be totally unaware that anything was happening to him. He would see the rest of the universe deforming.

I suggest you read this article on the effect: http://en.wikipedia.org/wiki/Spaghettification

 

[PaulS1950]

Jimmy,
The tides are also generated by the curvature of space/time. Just as a ball that is thrown into the air is following the curvature of space/time back to the Earth.
Gravity is not a force, it is an effect that we perceive from the curvature and velocity of the time/space around us.
Paul

 

[Drakkith]

Jimmy,
The tides are also generated by the curvature of space/time. Just as a ball that is thrown into the air is following the curvature of space/time back to the Earth.
Gravity is not a force, it is an effect that we perceive from the curvature and velocity of the time/space around us.
Paul

Yes, tides are the result of gravity. They are also an example of weak tidal forces. Strong tidal forces can, and will, rip objects apart. See the article I linked in post #18 about it.

 

[PaulS1950]

If you feel the need to hold on to the Newtonian concept of gravity as a force then fine. There are still people who believe that the world is flat. Maybe you could have a party with them. Mass bends space/time. Gravity as a force does not exist. There is no instance where space/time curvature will not explain the effects you are calling gravitational force but there are situations where gravitational theory does not properly explain the effects of bent time/space.
This is my last post on the subject.
Paul

 

[Drakkith]

If you feel the need to hold on to the Newtonian concept of gravity as a force then fine. There are still people who believe that the world is flat. Maybe you could have a party with them. Mass bends space/time. Gravity as a force does not exist. There is no instance where space/time curvature will not explain the effects you are calling gravitational force but there are situations where gravitational theory does not properly explain the effects of bent time/space.

The issue whether gravity IS a force or not is only a minor one. From wikipedia on force:

In physics, a force is any influence that causes an object to undergo a certain change, either concerning its movement, direction, or geometrical construction

I believe that gravity, in general, meets this definition. But it also requires a vastly more complex description to completely describe it's effects. Hence the reason General Relativity works.

The REAL issue is that you believe that tidal forces are not capable of disrupting objects. This has been shown to be false just with the tides of the Earth example.

This is my last post on the subject.
Paul

Goodbye then. Feel free to return when you are ready to put your arrogance aside and listen and learn.

 

[Jimmy]

The tides are also generated by the curvature of space/time.

Yes, and this contradicts your statement that a freely falling object experiences no "gravitational effects".

Different points on a [strike]rigid[/strike] body will follow- or try to follow- their own geodesic. Near extremely massive bodies the curvature is severe. Your feet are going to follow one geodesic while your head follows another. Indeed, every point in your body will be following its own geodesic as it is ripped apart. It's akin to being tied between two cars traveling at high speed whose paths suddenly diverge.

 

[PaulS1950]

Jimmy, the oceans are not in freefall, but I am here for another reason:
I am going to attempt this one last time. I will not be sticking around for comments but you can say or do whatever you want.

Since, at the black hole, we are talking about a stretching of time/space I thought I would compare it to the opposite effect. If you are traveling through space in a ship at .9C and standing up. Because of your relativistic velocity your ship and everything in it, including you, you are "squished" in the direction of travel. When standing you are still 5'10" tall but when you face foreward you are only 10" thick instead of the 11" normally. So you walk back to your bunk and lie down (in the direction of travel) instead of 5' 10" you are now only 5 feet tall in your prone position. (I didn't do the math, the numbers are for illustration purposes only). Do you feel the changes? Do you notice the changes? No! because you are living in a compressed time/space field due to your relativistic velocity. Are there tidal effects on your body when you stand or turn or lie down? NO! why? Because the time/space you are living in seems perfectly normal to that frame of reference. The differences are only apparent to someone in a distant fixed point of reference.

Now, back to the black hole:
When sliding into the black hole you are traveling in a changing space/time frame and would be unaware of the changes that a distant fixed position observer would see.
Tidal forces were brought up but there is only one gravitational field, the one you are sliding into. Tidal effect only occur when two massive objects are close enough that their time/space deflections interact. As we slide into the black hole we are only effected by the one massive object which negates tidal forces. We remain in the same space time framework the whole way.

I leave you with that and the example of the spaceship and the compressed crew to consider both as the same concept.
Have fun with it and try to find any differences between the two examples.

Paul

 

[Danger]

Just for the hell of it, Paul, are you familiar with the differences between the photosphere, the ergosphere, the static limit, the event horizon, and the singularity? While your references to relativity are valid in some instances, they don't apply to every contingency.

 

[Drakkith]

Are there tidal effects on your body when you stand or turn or lie down? NO! why? Because the time/space you are living in seems perfectly normal to that frame of reference. The differences are only apparent to someone in a distant fixed point of reference.

There isn't an external gravitational field, so there would be no tidal effects.

Now, back to the black hole:
When sliding into the black hole you are traveling in a changing space/time frame and would be unaware of the changes that a distant fixed position observer would see.
Tidal forces were brought up but there is only one gravitational field, the one you are sliding into. Tidal effect only occur when two massive objects are close enough that their time/space deflections interact. As we slide into the black hole we are only effected by the one massive object which negates tidal forces. We remain in the same space time framework the whole way.

This is entirely wrong. First, you do have 2 gravitational fields, yourself and the black hole. (Not that it really even matters) Second, tidal effects occur because of the gradient in the field, aka the difference in strength between one area and another. As has been explained already, falling feet first into a black hole would result in your feet getting pulled much harder than your head is, due to the gravitational gradient. This MUST happen, as the gravitational strength falls off with distance, so parts of you that are further away are being pulled less strongly. It is only the electromagnetic force holding your molecules together that keeps you whole. Until gravity overcomes it at least.

I leave you with that and the example of the spaceship and the compressed crew to consider both as the same concept.
Have fun with it and try to find any differences between the two examples.

Paul

Sorry, you are incorrect. They are two different effects with very little in common. One is a result of viewing an object traveling at very high speeds relative to your frame, the other is the result of a gradient in the gravitational field.

 

[yang22]

I think, when pulled into the black hole, because of the gravitational intensity , you may be torn into strips like spaghetti and be torn, then converted into energy of black hole.Finally, return to the universe as a form of radiation, this may be regarded as a kind of rebirth, but it is undeniable that your time is completely over and you cease to exist.