imagine a small black hole wandering around the milky way, it’s got the big force of attraction happening, it’s looking outward with gravity maybe, communicating itself in a limited way, nothing external can really see into it, it appears somewhat anomalous, even strange

anyway the black hole wants to merge everything, exerting its power of super density multiplying

make it up, whatever, keep a safe distance, nobody’s ever come back from a near encounter with a black hole

a simulation of black hole lensing from wiki, for your entertainment, much safer than the real thing

anyway, i’m contemplating the view outward from inside a black hole, a perhaps entirely hypothetical proposition, but if you could see out with gravity, what might it look like. The resolution could be terrible, and likely further away objects would be obscured by near mass accelerating into the black hole

a little history from wiki

https://en.wikipedia.org/wiki/Black_hole
“The idea of a body so massive that even light could not escape was briefly proposed by astronomical pioneer and English clergyman John Michell in a letter published in November 1784. Michell’s simplistic calculations assumed such a body might have the same density as the Sun, and concluded that such a body would form when a star’s diameter exceeds the Sun’s by a factor of 500, and the surface escape velocity exceeds the usual speed of light. Michell correctly noted that such supermassive but non-radiating bodies might be detectable through their gravitational effects on nearby visible bodies….”

transition said:

imagine a small black hole wandering around the milky way, it’s got the big force of attraction happening, it’s looking outward with gravity maybe, communicating itself in a limited way, nothing external can really see into it, it appears somewhat anomalous, even strange

anyway the black hole wants to merge everything, exerting its power of super density multiplying

make it up, whatever, keep a safe distance, nobody’s ever come back from a near encounter with a black hole

a simulation of black hole lensing from wiki, for your entertainment, much safer than the real thing

anyway, i’m contemplating the view outward from inside a black hole, a perhaps entirely hypothetical proposition, but if you could see out with gravity, what might it look like. The resolution could be terrible, and likely further away objects would be obscured by near mass accelerating into the black hole

a little history from wiki

https://en.wikipedia.org/wiki/Black_hole
“The idea of a body so massive that even light could not escape was briefly proposed by astronomical pioneer and English clergyman John Michell in a letter published in November 1784. Michell’s simplistic calculations assumed such a body might have the same density as the Sun, and concluded that such a body would form when a star’s diameter exceeds the Sun’s by a factor of 500, and the surface escape velocity exceeds the usual speed of light. Michell correctly noted that such supermassive but non-radiating bodies might be detectable through their gravitational effects on nearby visible bodies….”

It has no more gravitational attraction than any other object of the same mass. Small BH have pretty strong tidal forces though. Why not use light to see the view outside a BH?

>Why not use light to see the view outside a BH?

good point

transition said:

>Why not use light to see the view outside a BH?

good point

Because allegedly the light takes an infinite time to cross the event horizon.

The Rev Dodgson said:

transition said:

>Why not use light to see the view outside a BH?

good point

Because allegedly the light takes an infinite time to cross the event horizon.

only to an outside observer.

ChrispenEvan said:

The Rev Dodgson said:

transition said:

>Why not use light to see the view outside a BH?

good point

Because allegedly the light takes an infinite time to cross the event horizon.

only to an outside observer.

You sure about that?

I don’t think we have any evidence about what an inside observer would see.

The Rev Dodgson said:

ChrispenEvan said:

The Rev Dodgson said:

Because allegedly the light takes an infinite time to cross the event horizon.

only to an outside observer.

You sure about that?

I don’t think we have any evidence about what an inside observer would see.

well yes, cos outside the light appears to be slowed because it is coming out of a gravity well. if inside it wouldn’t be.

ChrispenEvan said:

The Rev Dodgson said:

ChrispenEvan said:

only to an outside observer.

You sure about that?

I don’t think we have any evidence about what an inside observer would see.

well yes, cos outside the light appears to be slowed because it is coming out of a gravity well. if inside it wouldn’t be.

I presume the incoming light would appear to have the same velocity as the outgoing light, which implies that the incoming light can never get in, since the outgoing light never gets out.

The Rev Dodgson said:

ChrispenEvan said:

The Rev Dodgson said:

You sure about that?

I don’t think we have any evidence about what an inside observer would see.

well yes, cos outside the light appears to be slowed because it is coming out of a gravity well. if inside it wouldn’t be.

I presume the incoming light would appear to have the same velocity as the outgoing light, which implies that the incoming light can never get in, since the outgoing light never gets out.

what?

ChrispenEvan said:

The Rev Dodgson said:

ChrispenEvan said:

well yes, cos outside the light appears to be slowed because it is coming out of a gravity well. if inside it wouldn’t be.

I presume the incoming light would appear to have the same velocity as the outgoing light, which implies that the incoming light can never get in, since the outgoing light never gets out.

what?

Would you like me to repeat it, or translate into another language, or what?

The Rev Dodgson said:

ChrispenEvan said:

The Rev Dodgson said:

You sure about that?

I don’t think we have any evidence about what an inside observer would see.

well yes, cos outside the light appears to be slowed because it is coming out of a gravity well. if inside it wouldn’t be.

I presume the incoming light would appear to have the same velocity as the outgoing light, which implies that the incoming light can never get in, since the outgoing light never gets out.

you realise that from the photons perspective everything appears normal and it crosses the EH going in at c? supermassive BH must have “consumed” matter to get so large and if that is the case then light would ave no probs crossing the EH.

The Rev Dodgson said:

ChrispenEvan said:

The Rev Dodgson said:

I presume the incoming light would appear to have the same velocity as the outgoing light, which implies that the incoming light can never get in, since the outgoing light never gets out.

what?

Would you like me to repeat it, or translate into another language, or what?

nah, just read it and see why it makes no sense.

ChrispenEvan said:

The Rev Dodgson said:

ChrispenEvan said:

well yes, cos outside the light appears to be slowed because it is coming out of a gravity well. if inside it wouldn’t be.

I presume the incoming light would appear to have the same velocity as the outgoing light, which implies that the incoming light can never get in, since the outgoing light never gets out.

you realise that from the photons perspective everything appears normal and it crosses the EH going in at c? supermassive BH must have “consumed” matter to get so large and if that is the case then light would ave no probs crossing the EH.

No-one knows what happens from a “photon’s perspective” when it approaches an event horizon.

No-one knows what happens when a supermassive black hole forms either, but if we work on the basis that time stops at the event horizon, from the perspective of something not at the event horizon, then it follows that something not at the event horizon will never observe anything crossing it in either direction.

The Rev Dodgson said:

ChrispenEvan said:

The Rev Dodgson said:

I presume the incoming light would appear to have the same velocity as the outgoing light, which implies that the incoming light can never get in, since the outgoing light never gets out.

you realise that from the photons perspective everything appears normal and it crosses the EH going in at c? supermassive BH must have “consumed” matter to get so large and if that is the case then light would ave no probs crossing the EH.

No-one knows what happens from a “photon’s perspective” when it approaches an event horizon.

No-one knows what happens when a supermassive black hole forms either, but if we work on the basis that time stops at the event horizon, from the perspective of something not at the event horizon, then it follows that something not at the event horizon will never observe anything crossing it in either direction.

really? can you back these statements?

The Rev Dodgson said:

ChrispenEvan said:

The Rev Dodgson said:

I presume the incoming light would appear to have the same velocity as the outgoing light, which implies that the incoming light can never get in, since the outgoing light never gets out.

you realise that from the photons perspective everything appears normal and it crosses the EH going in at c? supermassive BH must have “consumed” matter to get so large and if that is the case then light would ave no probs crossing the EH.

No-one knows what happens from a “photon’s perspective” when it approaches an event horizon.

No-one knows what happens when a supermassive black hole forms either, but if we work on the basis that time stops at the event horizon, from the perspective of something not at the event horizon, then it follows that something not at the event horizon will never observe anything crossing it in either direction.

time stops? LOL, no. time does not stop.

ChrispenEvan said:

The Rev Dodgson said:

ChrispenEvan said:

you realise that from the photons perspective everything appears normal and it crosses the EH going in at c? supermassive BH must have “consumed” matter to get so large and if that is the case then light would ave no probs crossing the EH.

No-one knows what happens from a “photon’s perspective” when it approaches an event horizon.

No-one knows what happens when a supermassive black hole forms either, but if we work on the basis that time stops at the event horizon, from the perspective of something not at the event horizon, then it follows that something not at the event horizon will never observe anything crossing it in either direction.

really? can you back these statements?

Certainly.

Which bits would you like me to back?

ChrispenEvan said:

The Rev Dodgson said:

ChrispenEvan said:

you realise that from the photons perspective everything appears normal and it crosses the EH going in at c? supermassive BH must have “consumed” matter to get so large and if that is the case then light would ave no probs crossing the EH.

No-one knows what happens from a “photon’s perspective” when it approaches an event horizon.

No-one knows what happens when a supermassive black hole forms either, but if we work on the basis that time stops at the event horizon, from the perspective of something not at the event horizon, then it follows that something not at the event horizon will never observe anything crossing it in either direction.

time stops? LOL, no. time does not stop.

I didn’t say it did stop. I said “if we work on the basis that time stops at the event horizon, from the perspective of something not at the event horizon”.

Insert an “appears to” in there if it makes you happy. The argument remains the same.

> i’m contemplating the view outward from inside a black hole, a perhaps entirely hypothetical proposition, but if you could see out with gravity, what might it look like.

I have seen this on a TV science show many years ago. I’ll see if there’s something similar on the web.

It’s on this video https://www.youtube.com/watch?v=3pAnRKD4raY
If you want to jump straight to it, it’s about 6 minutes it.

mollwollfumble said:

> i’m contemplating the view outward from inside a black hole, a perhaps entirely hypothetical proposition, but if you could see out with gravity, what might it look like.

I have seen this on a TV science show many years ago. I’ll see if there’s something similar on the web.

It’s on this video https://www.youtube.com/watch?v=3pAnRKD4raY
If you want to jump straight to it, it’s about 6 minutes it.

“when we get to the singularity, we don’t really know what would happen”

Now why didn’t I think of that.

While talking black holes, I wonder what would be the result if the Penrose diagram is an accurate depiction of the multiverse.

For starters, each black hole that forms spawns two new universes. Every black hole is a Kerr black hole, or a close approximation to same. One of the two new universes is from matter falling into the ring-shaped singularity, from the Penrose diagram we know that it spews out, totally randomised (eg. no electrons make it through undamaged) a new universe. The second of the the two new universes is from matter falling into the disc shaped opening bounded by the singularity. Here again, we know that because the infalling matter’s gravity changes the shape of the black hole the result is also totally randomised.

Apart from those, the Penrose diagram tells us that there are other universes beyond infinite time and space.

An advantage of that way of generating a multiverse is that no physics beyond GR relativity is necessary. And no physics beyond the standard model of QM. (Although the standard model of QM does also have a different way of creating new universes – metastability).

It’s just that, well, if new black holes each create two new universes then universes breed, and that makes it possible to apply evolution by natural selection to universes.

mollwollfumble said:

While talking black holes, I wonder what would be the result if the Penrose diagram is an accurate depiction of the multiverse.

For starters, each black hole that forms spawns two new universes. Every black hole is a Kerr black hole, or a close approximation to same. One of the two new universes is from matter falling into the ring-shaped singularity, from the Penrose diagram we know that it spews out, totally randomised (eg. no electrons make it through undamaged) a new universe. The second of the the two new universes is from matter falling into the disc shaped opening bounded by the singularity. Here again, we know that because the infalling matter’s gravity changes the shape of the black hole the result is also totally randomised.

Apart from those, the Penrose diagram tells us that there are other universes beyond infinite time and space.

An advantage of that way of generating a multiverse is that no physics beyond GR relativity is necessary. And no physics beyond the standard model of QM. (Although the standard model of QM does also have a different way of creating new universes – metastability).

It’s just that, well, if new black holes each create two new universes then universes breed, and that makes it possible to apply evolution by natural selection to universes.

Are these universes limited in size or almost infinite like ours

The Rev Dodgson said:

mollwollfumble said:

> i’m contemplating the view outward from inside a black hole, a perhaps entirely hypothetical proposition, but if you could see out with gravity, what might it look like.

I have seen this on a TV science show many years ago. I’ll see if there’s something similar on the web.

It’s on this video https://www.youtube.com/watch?v=3pAnRKD4raY
If you want to jump straight to it, it’s about 6 minutes it.

“when we get to the singularity, we don’t really know what would happen”

Now why didn’t I think of that.

because we are talking about BH and the singularity isn’t the BH, maybe.

The Rev Dodgson said:

ChrispenEvan said:

The Rev Dodgson said:

No-one knows what happens from a “photon’s perspective” when it approaches an event horizon.

No-one knows what happens when a supermassive black hole forms either, but if we work on the basis that time stops at the event horizon, from the perspective of something not at the event horizon, then it follows that something not at the event horizon will never observe anything crossing it in either direction.

time stops? LOL, no. time does not stop.

I didn’t say it did stop. I said “if we work on the basis that time stops at the event horizon, from the perspective of something not at the event horizon”.

Insert an “appears to” in there if it makes you happy. The argument remains the same.

Still wrong. Because we are now looking at the scene from the other side. and as i said earlier the light is infalling and so not redshifted due to gravitational time dilation.

ChrispenEvan said:

The Rev Dodgson said:

ChrispenEvan said:

time stops? LOL, no. time does not stop.

I didn’t say it did stop. I said “if we work on the basis that time stops at the event horizon, from the perspective of something not at the event horizon”.

Insert an “appears to” in there if it makes you happy. The argument remains the same.

Still wrong. Because we are now looking at the scene from the other side. and as i said earlier the light is infalling and so not redshifted due to gravitational time dilation.

Would it be blue shifted

ChrispenEvan said:

The Rev Dodgson said:

mollwollfumble said:

> i’m contemplating the view outward from inside a black hole, a perhaps entirely hypothetical proposition, but if you could see out with gravity, what might it look like.

I have seen this on a TV science show many years ago. I’ll see if there’s something similar on the web.

It’s on this video https://www.youtube.com/watch?v=3pAnRKD4raY
If you want to jump straight to it, it’s about 6 minutes it.

“when we get to the singularity, we don’t really know what would happen”

Now why didn’t I think of that.

because we are talking about BH and the singularity isn’t the BH, maybe.

I only listened to about 15 sec worth, but when he says singularity there, he seems to mean the event horizon.

Cymek said:

ChrispenEvan said:

The Rev Dodgson said:

I didn’t say it did stop. I said “if we work on the basis that time stops at the event horizon, from the perspective of something not at the event horizon”.

Insert an “appears to” in there if it makes you happy. The argument remains the same.

Still wrong. Because we are now looking at the scene from the other side. and as i said earlier the light is infalling and so not redshifted due to gravitational time dilation.

Would it be blue shifted

don’t believe so as the EH is at c and as long as you aren’t moving in relation to the EH then no shift would be observed. though remaining stationary within a BH would be problematic, still for arguments sake…

ChrispenEvan said:

The Rev Dodgson said:

ChrispenEvan said:

time stops? LOL, no. time does not stop.

I didn’t say it did stop. I said “if we work on the basis that time stops at the event horizon, from the perspective of something not at the event horizon”.

Insert an “appears to” in there if it makes you happy. The argument remains the same.

Still wrong. Because we are now looking at the scene from the other side. and as i said earlier the light is infalling and so not redshifted due to gravitational time dilation.

So you think that for observers inside the black hole light travelling towards them appears to go faster than light travelling away from them?

The Rev Dodgson said:

ChrispenEvan said:

The Rev Dodgson said:

I didn’t say it did stop. I said “if we work on the basis that time stops at the event horizon, from the perspective of something not at the event horizon”.

Insert an “appears to” in there if it makes you happy. The argument remains the same.

Still wrong. Because we are now looking at the scene from the other side. and as i said earlier the light is infalling and so not redshifted due to gravitational time dilation.

So you think that for observers inside the black hole light travelling towards them appears to go faster than light travelling away from them?

no, it travels at c, always.

ChrispenEvan said:

The Rev Dodgson said:

ChrispenEvan said:

Still wrong. Because we are now looking at the scene from the other side. and as i said earlier the light is infalling and so not redshifted due to gravitational time dilation.

So you think that for observers inside the black hole light travelling towards them appears to go faster than light travelling away from them?

no, it travels at c, always.

c-empre…

ChrispenEvan said:

The Rev Dodgson said:

ChrispenEvan said:

Still wrong. Because we are now looking at the scene from the other side. and as i said earlier the light is infalling and so not redshifted due to gravitational time dilation.

So you think that for observers inside the black hole light travelling towards them appears to go faster than light travelling away from them?

no, it travels at c, always.

Right, so you agree with what I said in the first place.

Excellent.

Not sure whether I should get involved here

dv said:

Not sure whether I should get involved here

Can’t hurt.

The Rev Dodgson said:

dv said:

Not sure whether I should get involved here

Can’t hurt.

Bold words

dv said:

Not sure whether I should get involved here

go for it.