- #1

Jimster41

- 783

- 82

I've seen this a few times now, but it's not quite sinking in? How are the left and right sides of that 2-side BH Penrose diagram disconnected but share the BH? I keep thinking you could go around the black hole.

Trying to think of a metaphor that correctly captures my confusion.

Picturing a literal big BH, with observer A on one side, and observer B say on the opposite side, like two people standing on opposite sides around a fire-pit. Both have flashlights. Both shine their flash lights at the fire, but the light never gets across the fire pit. It just goes into the fire-light, never comes out the other side. They each have no idea the other is there - their locations are disconnected.

But if observer B was standing at 90 degrees from observer B around the firepit, he could shine his light right on A, and vice versus. Those spaces are not disconnected.

So the space that is disconnected from observer A's space is only the space that a light ray would have to "go through the BH" to get to. It is space at a specific angle w/respect to observer A and the BH, aligned more or less opposite observer A from the black hole.

Is that understanding it?The circle in the right-hand diagram being the fire-pit, and the entanglement measure of flashlight shiners A and B being related to their fire-pit circle boundary interval, and the angle of those intervals w/respect to the black hole, or how much of their respective flash-light meets in the BH.

got that from this cool vid by the way from @atyy

which I am trying to follow.

Trying to think of a metaphor that correctly captures my confusion.

Picturing a literal big BH, with observer A on one side, and observer B say on the opposite side, like two people standing on opposite sides around a fire-pit. Both have flashlights. Both shine their flash lights at the fire, but the light never gets across the fire pit. It just goes into the fire-light, never comes out the other side. They each have no idea the other is there - their locations are disconnected.

But if observer B was standing at 90 degrees from observer B around the firepit, he could shine his light right on A, and vice versus. Those spaces are not disconnected.

So the space that is disconnected from observer A's space is only the space that a light ray would have to "go through the BH" to get to. It is space at a specific angle w/respect to observer A and the BH, aligned more or less opposite observer A from the black hole.

Is that understanding it?The circle in the right-hand diagram being the fire-pit, and the entanglement measure of flashlight shiners A and B being related to their fire-pit circle boundary interval, and the angle of those intervals w/respect to the black hole, or how much of their respective flash-light meets in the BH.

which I am trying to follow.

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