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Old August 23rd 17, 10:46 PM posted to sci.physics,sci.astro,sci.physics.relativity
Odd Bodkin
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Default We can't see Sgr A* PROPER, directly.

On 8/23/17 4:26 PM, Michael Moroney wrote:
Jeff-Relf.Me @. writes:

We can't see Sgr A* PROPER, directly, and you need
INFINITE precision to measure a TRUE singularity.


Doesn't matter, it's the size of the event horizon that counts, not
the singularity. As long as there is enough mass inside an event horizon
there is a black hole, even if there is weird physics unknown to us
inside that prevents formation of a singularity. We can never know what
happens inside an event horizon.

We see that Sgr A* is there, not by seeing it, but by tracking stars
that are orbiting it.

https://en.wikipedia.org/wiki/S0%E2%80%93102
https://en.wikipedia.org/wiki/S2_(star)
amongst others


And to emphasize this, the "true" black hole is NOT the singularity. The
defining feature is the event horizon.

There's no point in demanding proof in terms of something unobservable.

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Odd Bodkin -- maker of fine toys, tools, tables