APOD: NGC 1365: Majestic Island Universe (2017 Oct 12)

Comments and questions about the APOD on the main view screen.
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neufer
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Re: APOD: NGC 1365: Majestic Island Universe (2017 Oct 12)

Post by neufer » Sat Oct 14, 2017 9:00 pm

Chris Peterson wrote:
neufer wrote:
Chris Peterson wrote:
But it's important to recognize that these are the conclusions of mathematical analyses, taken to limits where our theories may not work. These abstractions are very useful, but we have no clue what a physical singularity (point or ring) really means outside of the math.
The point here is that point singularities probably don't exist in the real world.
I wouldn't go as far as "probably". We just don't know.
Point singularities:
  • 1) produce strong infinities that must be treated with ad hoc renormalizations
    2) and contain angular momentum, mass & other info that must be assigned ad hoc.
Chris Peterson wrote:
neufer wrote:
The cores of black holes and elementary particles consist of strings or sheets or other higher dimensional objects.
A conclusion that stems from highly speculative and only marginally scientific ideas. We don't know what the cores of black holes or elementary particles consist of. Maybe the idea of "core" doesn't even apply.
It is a reasonable assumption that doesn't require that current scientific ideas are anywhere near close to any final solution.
Art Neuendorffer

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Chris Peterson
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Re: APOD: NGC 1365: Majestic Island Universe (2017 Oct 12)

Post by Chris Peterson » Sat Oct 14, 2017 9:15 pm

neufer wrote:
Chris Peterson wrote:
neufer wrote: The point here is that point singularities probably don't exist in the real world.
I wouldn't go as far as "probably". We just don't know.
Point singularities:
  • 1) produce strong infinities that must be treated with ad hoc renormalizations
    2) and contain angular momentum, mass & other info that must be assigned ad hoc.
Yes? Doesn't seem to help resolve anything.
neufer wrote:
Chris Peterson wrote:
neufer wrote:
The cores of black holes and elementary particles consist of strings or sheets or other higher dimensional objects.
A conclusion that stems from highly speculative and only marginally scientific ideas. We don't know what the cores of black holes or elementary particles consist of. Maybe the idea of "core" doesn't even apply.
It is a reasonable assumption that doesn't require that current scientific ideas are anywhere near close to any final solution.
It's still just a mathematical result that appears elegant, but largely fails as a scientific theory on the grounds that virtually nothing about it seems testable or falsifiable. An interesting channel of investigation, but too premature, I think, to treat as even provisionally likely.
Chris

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neufer
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Re: APOD: NGC 1365: Majestic Island Universe (2017 Oct 12)

Post by neufer » Sun Oct 15, 2017 12:45 am

Chris Peterson wrote:
neufer wrote:
The cores of black holes and elementary particles consist of strings or sheets or other higher dimensional objects...It is a reasonable assumption that doesn't require that current scientific ideas are anywhere near close to any final solution.
It's still just a mathematical result that appears elegant, but largely fails as a scientific theory on the grounds that virtually nothing about it seems testable or falsifiable. An interesting channel of investigation, but too premature, I think, to treat as even provisionally likely.
BDanielMayfield just provided us an unsophisticated "proof" that a rotating black hole can't have a simple point singularity (in spite of it being an excellent approximation). There's no reason not to think that string singularities wont be with us for a long time.
https://en.wikipedia.org/wiki/Regge_theory wrote:
<<In 1960 Geoffrey Chew and Steven Frautschi conjectured from limited data that the strongly interacting particles had a very simple dependence of the squared-mass on the angular momentum: the particles fall into families where the Regge trajectory functions were straight lines for all the trajectories. The straight-line Regge trajectories were later understood as arisin From massless endpoints on rotating relativistic strings.>>
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Re: APOD: NGC 1365: Majestic Island Universe (2017 Oct 12)

Post by Chuck6060@hotmail.com » Sun Oct 15, 2017 11:38 pm

Does 1365 have the remnant of two black holes that merged? This looks kind of like a late stage of two galaxy's that merged...