I reduced the heading to fit

A crazy new theory solves an age-old mystery by explaining what happens if you touch a black hole

A crazy new theory solves an age-old mystery by explaining what happens if you touch a black hole

There’s a common notion that at the edge of every black hole lies a back door to the universe — an exit from reality into a new realm where fundamental laws of nature, like time, no longer behave the way that we understand them.

What happens once you cross this threshold is a long-standing mystery that the world’s leading scientists have been pondering for decades with little headway.

Now, a recent paper presented at a conference in Paris this week has proposed a solution by looking at black holes in a completely different way.

Taking a novel approach to this age-old problem, the theory proposes that there is no back door to the universe in the first place. Instead, black holes are impenetrable bodies, called fuzzballs.

More…

>Mathur’s fuzzball black holes are actually giant, balled-up collections of strings. So, theoretically, when an object touches the surface of the fuzzball, its mass gets converted into light, generating a holographic copy of its former self. Other string theorists disagree, though.<

Ok

you’d be torn apart by gravitational forces before you ever get near it

wookiemeister said:

you’d be torn apart by gravitational forces before you ever get near it

true, but the article is hypothetical and bypasses that bit

it would depend on the size of the BH as to weather tidal forces would tear you apart when you got close. the larger they are the closer you can get, and in the case of really massive ones you could actually cross the EH and not be aware of the fact.

ChrispenEvan said:

it would depend on the size of the BH as to weather tidal forces would tear you apart when you got close. the larger they are the closer you can get, and in the case of really massive ones you could actually cross the EH and not be aware of the fact.

True, but again they are bypassing the spaghetti bit, then touching the black hole

no, they aren’t. spaghettification happens when the tidal forces are such that you get stretched. this will happen nwhen the gravity gradient is sufficient to do this. this might happen outside the EH, for a small BH, or inside the EH for a large BH.

oh, and it should be whether not weather.

:-)

> Taking a novel approach to this age-old problem, the theory proposes that there is no back door to the universe in the first place. Instead, black holes are impenetrable bodies, called fuzzballs.

Excellent. I’ve been a fan of the fuzzball theory since it was first proposed (in 2002), but had wondered about it not being mentioned lately. A couple of things to know about fuzzballs that may not be immediately obvious.

1) If fuzzballs exist then wormholes don’t. The two are incompatible.

2) Fuzzballs are perfectly consistent with Susskind’s solution of the black hole information paradox using the holographic principle. Susskind’s solution is more general in that it includes both fuzzball and non-fuzzball possibilities.

3) The famous book “not even wrong” by Peter Woit (in 2007) is wrong. Whether fuzzballs exist is testable relatively easily, and if fuzzballs exist then string theory is right.

ChrispenEvan said:

it would depend on the size of the BH as to weather tidal forces would tear you apart when you got close. the larger they are the closer you can get to the event horizon, and in the case of really massive ones you could actually cross the EH and not be aware of the fact.

The opposite is also true. If a black hole is smaller than a subatomic particle then it would pass right through you without you being aware of the fact. For example, a black hole with a mass of 1 ton has a radius of 1.3*10^-24 metres whereas, for example, the classical radius of the electron is a whopping 2.8*10^-15 metres. So a 1 ton black hole could pass right through you without you knowing it.

mollwollfumble said:

ChrispenEvan said:

it would depend on the size of the BH as to weather tidal forces would tear you apart when you got close. the larger they are the closer you can get to the event horizon, and in the case of really massive ones you could actually cross the EH and not be aware of the fact.

The opposite is also true. If a black hole is smaller than a subatomic particle then it would pass right through you without you being aware of the fact. For example, a black hole with a mass of 1 ton has a radius of 1.3*10^-24 metres whereas, for example, the classical radius of the electron is a whopping 2.8*10^-15 metres. So a 1 ton black hole could pass right through you without you knowing it.

Energy = 1/2 m V squared so I suggest that it would do a shirt load of damage. Yeah So a 1 ton black hole could pass right through you without you knowing it you wouldn’t survive to know it.

mollwollfumble said:

ChrispenEvan said:

it would depend on the size of the BH as to weather tidal forces would tear you apart when you got close. the larger they are the closer you can get to the event horizon, and in the case of really massive ones you could actually cross the EH and not be aware of the fact.

The opposite is also true. If a black hole is smaller than a subatomic particle then it would pass right through you without you being aware of the fact. For example, a black hole with a mass of 1 ton has a radius of 1.3*10^-24 metres whereas, for example, the classical radius of the electron is a whopping 2.8*10^-15 metres. So a 1 ton black hole could pass right through you without you knowing it.

Well provided the toilet paper doesn’t break, you shouldn’t have any problems of shit under your finger nail.

mollwollfumble said:

The opposite is also true. If a black hole is smaller than a subatomic particle then it would pass right through you without you being aware of the fact. For example, a black hole with a mass of 1 ton has a radius of 1.3*10^-24 metres whereas, for example, the classical radius of the electron is a whopping 2.8*10^-15 metres. So a 1 ton black hole could pass right through you without you knowing it.

… but a black hole can’t exist at that size yeah?

Jing Joh said:

mollwollfumble said:

The opposite is also true. If a black hole is smaller than a subatomic particle then it would pass right through you without you being aware of the fact. For example, a black hole with a mass of 1 ton has a radius of 1.3*10^-24 metres whereas, for example, the classical radius of the electron is a whopping 2.8*10^-15 metres. So a 1 ton black hole could pass right through you without you knowing it.

… but a black hole can’t exist at that size yeah?

Nobody knows if it can or not. If it does then it was probably born very early in the universe, before any stars were born, that’s why mini-black holes like these are also known as “primordial” black holes.

ChrispenEvan said:

it would depend on the size of the BH as to weather tidal forces would tear you apart when you got close. the larger they are the closer you can get, and in the case of really massive ones you could actually cross the EH and not be aware of the fact.

Got a ref for that?

it is just a well known aspect of gravity. black holes aren’t anything special in that regard. roche limit, comet shoemaker-levi is a good example.

it is just a well known aspect of gravity. black holes aren’t anything special in that regard. roche limit, comet shoemaker-levi is a good example.

ChrispenEvan said:

it is just a well known aspect of gravity. black holes aren’t anything special in that regard. roche limit, comet shoemaker-levi is a good example.

My Prime Minister repeatedly said, My Prime Minister repeatedly said…

ChrispenEvan said:

it is just a well known aspect of gravity. black holes aren’t anything special in that regard. roche limit, comet shoemaker-levi is a good example.

Well I don’t know it.

What does a comet have to do with it?

And what does the Roche limit have to do with it, which is the limit for bodies of similar composition held together just by gravity?

because tidal affects are the cause of the comets breakup into multiple pieces. if it had been a human of similar size then it, most probably, have been stretched, or spaghettified. and things are held together by more than just gravity.

the roche limit just deals with the gravity aspect of the two bodies rather than one body just being held together by gravity.

the roche limit just deals with the gravity aspect of the two bodies rather than one body just being held together by gravity.

https://en.wikipedia.org/wiki/Spaghettification

ChrispenEvan said:

https://en.wikipedia.org/wiki/Spaghettification

So, not bolognaised?

ChrispenEvan said:

the roche limit just deals with the gravity aspect of the two bodies rather than one body just being held together by gravity.

The Roche limit is for bodies of similar composition held together jut by gravity.

Spaghettification in a black hole context is to do with stretching of space/time, so has nothing to do with what is holding the bodies together.

ChrispenEvan said:

https://en.wikipedia.org/wiki/Spaghettification

OK, so that says:

The point at which tidal forces destroy an object or kill a person will depend on the black hole’s size. For a supermassive black hole, such as those found at a galaxy’s center, this point lies within the event horizon, so an astronaut may cross the event horizon without noticing any squashing and pulling, although it remains only a matter of time, as once inside an event horizon, falling towards the center is inevitable.

I don’t see how that works, since a toe at the event horizon will be accelerated to the speed of light, whereas a head at 2 metres before the event horizon will have much less acceleration.

So a more detailed explanation would be good.

If you don’t have one handy I’ll go and look myself (since it’s almost as likely that I’ve got it wrong as the Wikipedia is wrong).

font color = gold>since a toe at the event horizon will be accelerated to the speed of light,

why?

ChrispenEvan said:

since a toe at the event horizon will be accelerated to the speed of light,

why?

He’ll be back when he finds out.

since a toe at the event horizon will be accelerated to the speed of light,

why?

do you have anything constructive to add roughie or just being a dick?

ChrispenEvan said:

do you have anything constructive to add roughie or just being a dick?

Why do you feel the need to post crap like that?

The Rev Dodgson said:

ChrispenEvan said:

do you have anything constructive to add roughie or just being a dick?

Why do you feel the need to post crap like that?

Not enough coffee?

i see this thread is going to shit so i’ll drop out. carry on getting info from roughie then rev.

you would only cross the EH at the SoL if you had fallen from an infinite distance away. the EH is the point where the escape velocity equals the SoL. so no, your toes wouldn’t cross the horizon at SoL while the rest of you wasn’t also travelling at SoL. it is the gravitational gradient that is important re spaghettification.

hmmmm so no your toes wouldn’t cross the eh unless the rest of you were also travelling at SoL.

fixed.

so no your toes wouldn’t cross the eh at SoL unless the rest of you were also travelling at SoL.

maybe this time.

Spaghettification in a black hole context is to do with stretching of space/time

no. it is a normal tidal effect.

wouldn’t time effectively stop at the bottom of a gravity well such as s black hole ?

wouldn’t time effectively stop at the bottom of a gravity well such as s black hole ?

relative to the ambient time of the surrounding universe

Wouldn’t you be destroyed by collisions in the accretion disc ?

we’re bypassing that problem tauto. though not all BH have accretion discs.

we don’t know what happens at the point inside a BH where quantum effects take over from relativity.

ChrispenEvan said:

we’re bypassing that problem tauto. though not all BH have accretion discs.

—-

Ah yes, stellar black holes would have little in their vicinity unless they were close to another system.

I thought we could make tiny tiny black holes? Surely that is a clue to what is in them? And there is stuff in them otherwise why the different sizes. They are stuffed with something.

though even without an accretion disk there is probably all sorts of bad radiation happening around a BH as space isn’t empty and stuff would still be falling inwards and getting hot.

ChrispenEvan said:

though even without an accretion disk there is probably all sorts of bad radiation happening around a BH as space isn’t empty and stuff would still be falling inwards and getting hot.

I seem to recalls they expected black holes to be invisible and hard to find stealth objects but now it seems they are the brightest things out there as they shred Suns.

except for the “singularity”, and that is just a mathematical aspect of relativity where infinity comes in and mucks everything up, basically there is nothing inside a BH, disregarding anything that has crossed the EH but has yet to reach the singularity. a BH is just a description of the EH, and the EH isn’t anything apart from a point where the escape velocity equals the speed of light. you wouldn’t be able to see the EH only the effects the BH has on spacetime around it and the view of the universe beyond.

http://casa.colorado.edu/~ajsh/

some good images and stuff.

AwesomeO said:

ChrispenEvan said:

though even without an accretion disk there is probably all sorts of bad radiation happening around a BH as space isn’t empty and stuff would still be falling inwards and getting hot.

I seem to recalls they expected black holes to be invisible and hard to find stealth objects but now it seems they are the brightest things out there as they shred Suns.

——
I think you mean super massive black holes at the centre of galaxies, they are so large that the collisions in the accretion disc are so much that they produce quasars.

yep, it is everything outside the EH that emits light. “light” being all emr, visible or not.

AwesomeO said:

I thought we could make tiny tiny black holes? Surely that is a clue to what is in them? And there is stuff in them otherwise why the different sizes. They are stuffed with something.

—-

The Large Hadron Collider hasn’t yet found one yet, but if they do it would be signifiicant, to say the least.
http://phys.org/news/2015-03-mini-black-holes-lhc-parallel.html

wookiemeister said:

wouldn’t time effectively stop at the bottom of a gravity well such as a black hole ?

In a classical (Schwarzschild) black hole, viewed from outside, time slows down to a stop as you approach the event horizon, so it appears to take an infinite amount of time to get to the EV but, on crossing it, the positive infinity becomes a negative infinity and time speeds up back to normal as you approach the singularity. In other mathematical coordinates (such as Penrose coordinates), the slow-down and speed-up of the time-like coordinate doesn’t happen.

>> I thought we could make tiny tiny black holes? Surely that is a clue to what is in them? And there is stuff in them otherwise why the different sizes. They are stuffed with something.
> The Large Hadron Collider hasn’t yet found one yet, but if they do it would be significant, to say the least.

Yes, the LHC would have only found on if both of the following conditions existed:
a) String theory is correct.
b) The compactification scale of at least one of the rolled-up coordinates is very large, as opposed to the more-likely Planck scale.

> except for the “singularity”, and that is just a mathematical aspect of relativity where infinity comes in and mucks everything up, basically there is nothing inside a BH

For a classical black hole yes. But this thread started with an article about fuzzballs, which are a string theory variant of black holes in which the black hole is not empty but is filled with rolled-up strings. The fuzzball is one of several string theory solutions to the black-hole information paradox.