6 ms·

I understand that a singularity by definition can never be reached. It's like the speed of light or absolute zero; infinity just out of reach no matter how much

by jp555 12y ago

I understand that a singularity by definition can never be reached. It's like the speed of light or absolute zero; infinity just out of reach no matter how much energy you spend trying to get there.

Voloskaya 12y ago
A black hole is a singularity. You can reach it, you just can't come back from it.
- aligajani 12y ago
  Didn't Hawking a while ago say Black Holes don't exist?
  - Voloskaya 12y ago
    Black holes most certainly exist. What he said is that their is a problem with the way we comprehend them now and that our current model for an event horizon may be false.
- jp555 12y ago
  Does that not depend on your relative point of view?
  - Voloskaya 12y ago
    Yes, if you looked at something going into a black hole, it would appear to you that it is slowing down exponentially the closer it gets to the event horizon, until a point where it appears to completely stop (before reaching it). But in the aforementioned scenario, you are not an external observer but a part of the system going into the singularity (but analogies have their limits).
    - jp555 12y ago
      slowing down or speeding up? I could be mixing things up but I understand that if I was falling into a BH (lets imagine I'm infinity tough and not torn to shreds due to tidal forces) the universe would appear to be slowing-down/getting-smaller until it had dimensions of zero (or to put it another way, time would "stop") at C. An outside observer would see me moving faster and faster and "stretching" longer and longer. SR makes my brian hurt. :P
      - Voloskaya 12y ago
        First you have to understand that a black hole in fact, doesn't have anything really special (until you enter the event horizon), except that their escape velocity is greater than the speed of light. But gravity applies to it like for any other thing. So let's say you are the object going into the blackhole, and I'm looking at you. From your point of view, the closer you get to it, the faster you will travel, just like when you get closer to earth, because it's gravity is stronger and stronger. So you will end up colliding with it (entering the event horizon) in a finite time (where time, is the time YOU feel, your proper time). But a black hole is so massive, that space and time get stretched to extreme extents. So from my point of view, you'll be speeding up into the blackhole until a certain point, where you'll appear to be slowing down and stretching (the point where your increase in speed get smaller than the stretching of space-time), and the dimmer you'll get (because of redshifting). So i would see you going slower and slower and appear dimmer and dimmer until almost not moving at all, up to a point where I would simply not see you anymore (before you reached the event horizon). All this also apply to other object like earth, It would appear to an astronaut that time on earth is flowing more slowly than it's own time (in reality it is of course unnoticeable , but it is true).
      - Voloskaya 12y ago
        Also, to clear things up, you are mixing two point of view here, so here is the separation (you are the object going into the black hole): "the universe would appear to be slowing-down/getting-smaller until it had dimensions of zero" From your point of view it would appear to be getting smaller, although I don't think it would go as far as dimension 0. "(or to put it another way, time would "stop")" It would appear to the external observer, that YOUR time had stopped. But from your point of view it did not stop, nor did their time from their point of view. "An outside observer would see me moving faster and faster and "stretching" longer and longer." You would feel you are falling faster and faster. The external observer would see you stretching longer and longer. (Although you would also feel like you are stretching, because of the difference of gravity between your head and your feet, but much less than for the external observer)
rtkwe 12y ago
When talking about AI or technology in general the singularity isn't a mathematical one. John von Neumann who used it in this context first said: > "ever accelerating progress of technology and changes in the mode of human life, which gives the appearance of approaching some essential singularity in the history of the race beyond which human affairs, as we know them, could not continue" It's a different use of the word singularity outside the mathematical sense. Also absolute zero isn't so absolute it seems: http://www.nature.com/news/quantum-gas-goes-below-absolute-zero-1.12146 http://www.nature.com/news/quantum-gas-goes-below-absolute-z...
- jp555 12y ago
  Ah that makes more sense. He seemed to mean it as we use Stone Age, Bronze Age, etc. After we got bronze, we could not continue with stone alone. That below-absolute-zero is in the quantum sense, not the classical sense. Entropy cannot be stopped (absolute zero) in the classical sense.
gus_massa 12y ago
You are confusing a "mathematical singularity" with "the AI singularity". In math, a singularity is an unusual point, not sure if it can't be reached. I think it's used in different areas to describe different things. For example, if you model water in a channel, after some time the waves accumulate and you get a vertical water profile, the depth is not more a function, the mathematical model collapse, but in real life the water just make some nice crashing effect.

by jp555 12y ago

I understand that a singularity by definition can never be reached. It's like the speed of light or absolute zero; infinity just out of reach no matter how much energy you spend trying to get there.

Voloskaya 12y ago

A black hole is a singularity. You can reach it, you just can't come back from it.

aligajani 12y ago
Didn't Hawking a while ago say Black Holes don't exist?
- Voloskaya 12y ago
  Black holes most certainly exist. What he said is that their is a problem with the way we comprehend them now and that our current model for an event horizon may be false.
jp555 12y ago
Does that not depend on your relative point of view?
- Voloskaya 12y ago
  Yes, if you looked at something going into a black hole, it would appear to you that it is slowing down exponentially the closer it gets to the event horizon, until a point where it appears to completely stop (before reaching it). But in the aforementioned scenario, you are not an external observer but a part of the system going into the singularity (but analogies have their limits).
  - jp555 12y ago
    slowing down or speeding up? I could be mixing things up but I understand that if I was falling into a BH (lets imagine I'm infinity tough and not torn to shreds due to tidal forces) the universe would appear to be slowing-down/getting-smaller until it had dimensions of zero (or to put it another way, time would "stop") at C. An outside observer would see me moving faster and faster and "stretching" longer and longer. SR makes my brian hurt. :P
    - Voloskaya 12y ago
      First you have to understand that a black hole in fact, doesn't have anything really special (until you enter the event horizon), except that their escape velocity is greater than the speed of light. But gravity applies to it like for any other thing. So let's say you are the object going into the blackhole, and I'm looking at you. From your point of view, the closer you get to it, the faster you will travel, just like when you get closer to earth, because it's gravity is stronger and stronger. So you will end up colliding with it (entering the event horizon) in a finite time (where time, is the time YOU feel, your proper time). But a black hole is so massive, that space and time get stretched to extreme extents. So from my point of view, you'll be speeding up into the blackhole until a certain point, where you'll appear to be slowing down and stretching (the point where your increase in speed get smaller than the stretching of space-time), and the dimmer you'll get (because of redshifting). So i would see you going slower and slower and appear dimmer and dimmer until almost not moving at all, up to a point where I would simply not see you anymore (before you reached the event horizon). All this also apply to other object like earth, It would appear to an astronaut that time on earth is flowing more slowly than it's own time (in reality it is of course unnoticeable , but it is true).
    - Voloskaya 12y ago
      Also, to clear things up, you are mixing two point of view here, so here is the separation (you are the object going into the black hole): "the universe would appear to be slowing-down/getting-smaller until it had dimensions of zero" From your point of view it would appear to be getting smaller, although I don't think it would go as far as dimension 0. "(or to put it another way, time would "stop")" It would appear to the external observer, that YOUR time had stopped. But from your point of view it did not stop, nor did their time from their point of view. "An outside observer would see me moving faster and faster and "stretching" longer and longer." You would feel you are falling faster and faster. The external observer would see you stretching longer and longer. (Although you would also feel like you are stretching, because of the difference of gravity between your head and your feet, but much less than for the external observer)

rtkwe 12y ago

When talking about AI or technology in general the singularity isn't a mathematical one. John von Neumann who used it in this context first said: > "ever accelerating progress of technology and changes in the mode of human life, which gives the appearance of approaching some essential singularity in the history of the race beyond which human affairs, as we know them, could not continue" It's a different use of the word singularity outside the mathematical sense. Also absolute zero isn't so absolute it seems: http://www.nature.com/news/quantum-gas-goes-below-absolute-zero-1.12146 http://www.nature.com/news/quantum-gas-goes-below-absolute-z...

jp555 12y ago
Ah that makes more sense. He seemed to mean it as we use Stone Age, Bronze Age, etc. After we got bronze, we could not continue with stone alone. That below-absolute-zero is in the quantum sense, not the classical sense. Entropy cannot be stopped (absolute zero) in the classical sense.

gus_massa 12y ago

You are confusing a "mathematical singularity" with "the AI singularity". In math, a singularity is an unusual point, not sure if it can't be reached. I think it's used in different areas to describe different things. For example, if you model water in a channel, after some time the waves accumulate and you get a vertical water profile, the depth is not more a function, the mathematical model collapse, but in real life the water just make some nice crashing effect.