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Her frustration with the priorities of theoretical physics probably is justified, but in this case I disagree with @skdh. Her claim is that any solution for the

Her frustration with the priorities of theoretical physics probably is justified, but in this case I disagree with @skdh. Her claim is that any solution for the BHIP cannot be falsified, and that strikes me as too pessimistic for two reasons. First, look at the results of pushing the theory harder with respect to spinning black holes. Many predictions of Kerr's theory have been observed, even if the ring singularity at the center hasn't. Second, we're observing new black hole phenomena every day, and if black holes really do explode at the end of evaporation, then maybe that is also observable. Sure, Hawking radiation is normally too small to be directly observed, but the theory can be driven into a place where it can make a testable prediction.

ddxxdd 6y ago
I completely agree with this. Ancient philosophers debated the existence of atoms for centuries; then Boltzmann took the theory up to second gear by discovering the implications on temperature and entropy, and then Einstein proved their existence beyond a shadow of a doubt through his work on Brownian motion. It might take centuries of mathematical work to discover an artifact of quantum gravity that's observable within our macroscopic world, but the work must be done.
avz 6y ago
> and if black holes really do explode at the end of evaporation, then maybe that is also observable I suppose her reason to assume we can't observe this is that evaporation takes extremely long time. For example, a solar mass black hole will take about 10^64 years to evaporate [1] (this is approximately 7 * 10^54 times the age of the universe). Note that astronomical black holes are heavier than the Sun, so take even longer to evaporate. I suppose the micro black holes [2] might offer a glimmer of hope, but these objects are entirely hypothetical. [1] https://en.wikipedia.org/wiki/Hawking_radiation#Black_hole_evaporation https://en.wikipedia.org/wiki/Hawking_radiation#Black_hole_e... [2] https://en.wikipedia.org/wiki/Micro_black_hole https://en.wikipedia.org/wiki/Micro_black_hole
- adrianN 6y ago
  Creating a microscopic black hole is not completely out of our reach. https://arxiv.org/abs/0908.1803 https://arxiv.org/abs/0908.1803 discusses this topic a bit. If the assumptions there are not wrong, and climate change doesn't get us first, creating small black holes might be become possible an a couple of generations.
phkahler 6y ago
>> Her claim is that any solution for the BHIP cannot be falsified, and that strikes me as too pessimistic for two reasons. No. She said there isn't any data. I know the word falsify has become prominent in the last 15 years or so, but a "theory" that doesn't agree with some real world data is just a hypothesis. In other words a theory needs confirmation in addition to not being falsified. This is where the divide should exist between physics and mathematics. You can have a bunch of cool math, but that's not physics. It's not scientific theory by itself. You can hypothesize that it describes the real world, but until there is confirming evidence that assertion is just mental self-gratification.
- mikeappell 6y ago
  > until there is confirming evidence that assertion is just mental self-gratification. I'd say this is a bit overly negative. There's value in developing theories and frameworks which aren't yet provable but should be as soon as technology or other theoretical frameworks catch up.
  - edgyquant 6y ago
    But those, by definition, are not theories they are hypothesis.
    - mikeappell 6y ago
      I'm pushing back on describing them as 'mental self-gratification', as that seems like it implies a lack of value in them, potential if not immediate.
      - phkahler 6y ago
        >> I'm pushing back on describing them as 'mental self-gratification' I said "You can have a bunch of cool math, but that's not physics. It's not scientific theory by itself. You can hypothesize that it describes the real world, but until there is confirming evidence that assertion is just mental self-gratification." The math can be cool - and often is. It's the unsubstantiated claim that it underpins reality that is whackin' ones brain.

ddxxdd 6y ago

I completely agree with this. Ancient philosophers debated the existence of atoms for centuries; then Boltzmann took the theory up to second gear by discovering the implications on temperature and entropy, and then Einstein proved their existence beyond a shadow of a doubt through his work on Brownian motion. It might take centuries of mathematical work to discover an artifact of quantum gravity that's observable within our macroscopic world, but the work must be done.

avz 6y ago

> and if black holes really do explode at the end of evaporation, then maybe that is also observable I suppose her reason to assume we can't observe this is that evaporation takes extremely long time. For example, a solar mass black hole will take about 10^64 years to evaporate [1] (this is approximately 7 * 10^54 times the age of the universe). Note that astronomical black holes are heavier than the Sun, so take even longer to evaporate. I suppose the micro black holes [2] might offer a glimmer of hope, but these objects are entirely hypothetical. [1] https://en.wikipedia.org/wiki/Hawking_radiation#Black_hole_evaporation https://en.wikipedia.org/wiki/Hawking_radiation#Black_hole_e... [2] https://en.wikipedia.org/wiki/Micro_black_hole https://en.wikipedia.org/wiki/Micro_black_hole

adrianN 6y ago
Creating a microscopic black hole is not completely out of our reach. https://arxiv.org/abs/0908.1803 https://arxiv.org/abs/0908.1803 discusses this topic a bit. If the assumptions there are not wrong, and climate change doesn't get us first, creating small black holes might be become possible an a couple of generations.

phkahler 6y ago

>> Her claim is that any solution for the BHIP cannot be falsified, and that strikes me as too pessimistic for two reasons. No. She said there isn't any data. I know the word falsify has become prominent in the last 15 years or so, but a "theory" that doesn't agree with some real world data is just a hypothesis. In other words a theory needs confirmation in addition to not being falsified. This is where the divide should exist between physics and mathematics. You can have a bunch of cool math, but that's not physics. It's not scientific theory by itself. You can hypothesize that it describes the real world, but until there is confirming evidence that assertion is just mental self-gratification.

mikeappell 6y ago
> until there is confirming evidence that assertion is just mental self-gratification. I'd say this is a bit overly negative. There's value in developing theories and frameworks which aren't yet provable but should be as soon as technology or other theoretical frameworks catch up.
- edgyquant 6y ago
  But those, by definition, are not theories they are hypothesis.
  - mikeappell 6y ago
    I'm pushing back on describing them as 'mental self-gratification', as that seems like it implies a lack of value in them, potential if not immediate.
    - phkahler 6y ago
      >> I'm pushing back on describing them as 'mental self-gratification' I said "You can have a bunch of cool math, but that's not physics. It's not scientific theory by itself. You can hypothesize that it describes the real world, but until there is confirming evidence that assertion is just mental self-gratification." The math can be cool - and often is. It's the unsubstantiated claim that it underpins reality that is whackin' ones brain.