[evan_au (OP)]

There is a massive, multi-continent/multi-time-zone press conference planned for April 9/10 this week, to announce the results of the Black Hole telescope, attempting to take an image of the supermassive black hole at the center of our galaxy.

It is a challenging task - if it had been an abject failure, a small press conference would have been adequate...Along with a request for a bigger grant involving more telescopes...

They have taken measurements over a period of months, so any short term variations (on the order of minutes, hours and days) will be turned into a blur.

So, did they:
- Find one black hole, or are there more lurking there?
- Did it (or they) have an active accretion disk?
- Were there polar jets visible?
- What direction were the polar jets (are they pointing in our direction)?
- What is your guess?

See, for example: https://www.abc.net.au/news/2019-04-07/black-hole-first-ever-photograph-could-be-unveiled-this-week/10979244

All will be revealed, this week! Then we can discuss it here...

[Halc]

- What direction were the polar jets (are they pointing in our direction)?

How could they be pointed any other way than generally out of the plane of the galaxy?  The average angular motion of 4 million stars has to have an axis similar to the rest of the galaxy, no?

[mad aetherist]

There is a massive, multi-continent/multi-time-zone press conference planned for April 9/10 this week, to announce the results of the Black Hole telescope, attempting to take an image of the supermassive black hole at the center of our galaxy.

It is a challenging task - if it had been an abject failure, a small press conference would have been adequate...Along with a request for a bigger grant involving more telescopes...

They have taken measurements over a period of months, so any short term variations (on the order of minutes, hours and days) will be turned into a blur.

So, did they:
- Find one black hole, or are there more lurking there?
- Did it (or they) have an active accretion disk?
- Were there polar jets visible?
- What direction were the polar jets (are they pointing in our direction)?
- What is your guess?

See, for example: https://www.abc.net.au/news/2019-04-07/black-hole-first-ever-photograph-could-be-unveiled-this-week/10979244

All will be revealed, this week! Then we can discuss it here...

How might they be able to see that there is an Einsteinian blackhole?
It might be some other kind of blackhole.

[evan_au (OP)]

How could they be pointed any other way than generally out of the plane of the galaxy?

That is true if our galaxy were isolated in space.

But our galaxy has merged with a number of dwarf galaxies, each with their own central black hole, and each with their own angular momentum. More dramatically, our galaxy is expected to merge with the Andromeda galaxy in the future.

When the supermassive black holes merge, the merged black hole will have quite a different angular momentum than the original, and the polar axis will change.

This has been seen in space, where the angle of the polar jets change suddenly (and symmetrically).

See: https://en.wikipedia.org/wiki/X-shaped_radio_galaxy

[evan_au (OP)]

Astronomers are hoping that they will be able to see a silhouette of the boundary of where Einstein's General Relativity meets Quantum theory.

We know that these two theories aren't compatible in the region of space near an event horizon. The shape of the event horizon will assist deciding between several different theories which attempt to resolve this major conflict which has dogged physics for almost a century.

Astronomers are also searching for any pulsars near the event horizon, as these would provide a powerful probe of the shape of space near a supermassive black hole.

For more details (and some short videos), see:
https://eventhorizontelescope.org/

For links to live-streaming sites (in a variety of languages), see:
https://eventhorizontelescope.org/blog/media-advisory-first-results-event-horizon-telescope-be-presented-april-10th

[evan_au (OP)]

Well, it appears that at this stage, the EHT team have only released an image of the supermassive black hole at the center of the M87 galaxy.

The image is rather blurry. M87 is much further away than the supermassive black hole in the center of our galaxy (55 million light-years vs 26 thousand light-years). But it is also much bigger (6 billion times the mass of the Sun vs 4 million times the mass of the Sun).

M87 is known to have an active polar jet produced by the central black hole - which implies that it is actively accreting matter, and this would produce a bright backdrop against which to view the central black hole.
See: https://en.wikipedia.org/wiki/Messier_87#Supermassive_black_hole

On the other hand, our own galactic black hole does not currently have a strong polar jet, which might imply that it is currently on a diet. If there is no active accretion disk emitting lots of radiation, then it  will be hard to image this black hole, despite the fact that it is much closer.

But I am sure the EHT team are still working on the data for our own galactic black hole...

[Kryptid]

I'm almost giddy at this news. It's amazing that we were actually able to get this image. I can't wait for the picture of Sagittarius A*.

[evan_au (OP)]

Because the Schwarzschild radius of a black hole is proportional to the mass of the black hole, the increased distance and the increased mass almost cancel out.

So the resolution required to image the M87 black hole is almost the same as that required to image the Milky way black hole.
See: https://en.wikipedia.org/wiki/Schwarzschild_radius

[evan_au (OP)]

How might they be able to see that there is an Einsteinian blackhole?

With this first crude image, Einstein's theory of General Relativity seems to stand up.

The low resolution does not get us close enough to the event horizon to see any deviations due to quantum effects.
- In particular, with this 6 billion solar mass black hole, any Hawking radiation would be at an extremely low temperature (which provides a good silhouette against the extremely hot accretion disk).

[mad aetherist]

How might they be able to see that there is an Einsteinian blackhole?

With this first crude image, Einstein's theory of General Relativity seems to stand up.

The low resolution does not get us close enough to the event horizon to see any deviations due to quantum effects.
- In particular, with this 6 billion solar mass black hole, any Hawking radiation would be at an extremely low temperature (which provides a good silhouette against the extremely hot accretion disk).

Yes -- i think i have mentioned in New Theories that there might be 8 kinds of blackhole (including dark matter blackholes).

Polar jets at M87 would of course support my centrifuging of aether theory which i have mentioned in New Theories.  Are the M87 jets magnetic or something else?
I think that magnetic jets can form anywhere, & polar jets should be rare (are they?).
How do they know they are polar?
Are the jets emitted from inside the Schwarzchild radius, or from outside?
Or are the jets entering?

Are the M87 jets due to accretion?
In which case i would expect the jets to be going inwards, at the poles. But if so then the jets wouldnt be a disc, a disc would i think be an equatorial thing. But i suppose that if the orbiting dust etc is mostly in the equatorial plane then that is where it is most likely to arrive.

[Bored chemist]

Polar jets at M87 would of course support my centrifuging of aether theory which i have mentioned in New Theories. 

At best, they may be not inconsistent with it.

[evan_au (OP)]

The Wikipedia article mentions that the jet is only seen on one side of the galaxy (our side). A jet on the other side is not excluded, as most of the energy will be directed away from us due to relativistic beaming. It would be hard to see it through the dense population of stars at the center of M87.

At radio wavelengths, symmetrical jets are seen.

It also says that the Jet is at right-angles to the plane of the accretion disk.
- And that the accretion disk is gaining about 80 Earth masses per day (as an average)

If you imagine Saturn as a black hole, the Saturn's rings are the accretion disk (around the equator), and the jet scomes out the North and South poles.

So that should halve the number of models you have put on the table....
See: https://en.wikipedia.org/wiki/Messier_87#Jet

[mad aetherist]

The Wikipedia article mentions that the jet is only seen on one side of the galaxy (our side). A jet on the other side is not excluded, as most of the energy will be directed away from us due to relativistic beaming. It would be hard to see it through the dense population of stars at the center of M87.

At radio wavelengths, symmetrical jets are seen.

It also says that the Jet is at right-angles to the plane of the accretion disk.
- And that the accretion disk is gaining about 80 Earth masses per day (as an average)

If you imagine Saturn as a black hole, the Saturn's rings are the accretion disk (around the equator), and the jet scomes out the North and South poles.

So that should halve the number of models you have put on the table....
See: https://en.wikipedia.org/wiki/Messier_87#Jet

John Michell in 1783 predicted super massive dark stars that trapped light.  He didnt mention GR. He didnt mention a singularity. Stupid i guess.

[Bored chemist]

The Wikipedia article mentions that the jet is only seen on one side of the galaxy (our side). A jet on the other side is not excluded, as most of the energy will be directed away from us due to relativistic beaming. It would be hard to see it through the dense population of stars at the center of M87.

At radio wavelengths, symmetrical jets are seen.

It also says that the Jet is at right-angles to the plane of the accretion disk.
- And that the accretion disk is gaining about 80 Earth masses per day (as an average)

If you imagine Saturn as a black hole, the Saturn's rings are the accretion disk (around the equator), and the jet scomes out the North and South poles.

So that should halve the number of models you have put on the table....
See: https://en.wikipedia.org/wiki/Messier_87#Jet

John Michell in 1783 predicted super massive dark stars that trapped light.  He didnt mention GR. He didnt mention a singularity. Stupid i guess.

It's not an intrinsically complex or relativistic idea (as you have pointed out)
Once you have  the understanding of orbits and escape velocities, and a knowledge of the speed of light, you can work out that a big enough (dense enough) thing won't let light escape.

Newton just missed it; he died 1727 but the speed of light was measured in 1728.
I guess John Michell  didn't want to speculate about what would happen.
That's sensible of him. At the time, practically nothing was known about how stars worked. They didn't know what they were made of, not what kept them hot.
So what?

Why would you call that "stupid"?

[Janus]

The Wikipedia article mentions that the jet is only seen on one side of the galaxy (our side). A jet on the other side is not excluded, as most of the energy will be directed away from us due to relativistic beaming. It would be hard to see it through the dense population of stars at the center of M87.

At radio wavelengths, symmetrical jets are seen.

It also says that the Jet is at right-angles to the plane of the accretion disk.
- And that the accretion disk is gaining about 80 Earth masses per day (as an average)

If you imagine Saturn as a black hole, the Saturn's rings are the accretion disk (around the equator), and the jet scomes out the North and South poles.

So that should halve the number of models you have put on the table....
See: https://en.wikipedia.org/wiki/Messier_87#Jet

John Michell in 1783 predicted super massive dark stars that trapped light.  He didnt mention GR. He didnt mention a singularity. Stupid i guess.

It's not an intrinsically complex or relativistic idea (as you have pointed out)
Once you have  the understanding of orbits and escape velocities, and a knowledge of the speed of light, you can work out that a big enough (dense enough) thing won't let light escape.

Newton just missed it; he died 1727 but the speed of light was measured in 1728.
I guess John Michell  didn't want to speculate about what would happen.
That's sensible of him. At the time, practically nothing was known about how stars worked. They didn't know what they were made of, not what kept them hot.
So what?

Why would you call that "stupid"?

The wave model for light hadn't taken hold yet either, not until the Thomas Young double slit experiment revealed it in 1801.
So Michell was also assuming the corpuscular model for light.

[evan_au (OP)]

John Michell in 1783 predicted super massive dark stars that trapped light

About 12 years after Michell, the French mathematician Laplace independently predicted black holes.
- 3 years later, Laplace provided a mathematical proof of their possibility.
- His proof shows that he was thinking in terms of light as particles with some velocity.
- The concepts of the energy of a photon and the mass of a photon only arrived with quantum theory, otherwise Laplace could have made a similar prediction based on the energy of light particles.

See: http://www.narit.or.th/en/files/2009JAHHvol12/2009JAHH...12...90M.pdf

[mad aetherist]

John Michell in 1783 predicted super massive dark stars that trapped light

About 12 years after Michell, the French mathematician Laplace independently predicted black holes.
- 3 years later, Laplace provided a mathematical proof of their possibility.
- His proof shows that he was thinking in terms of light as particles with some velocity.
- The concepts of the energy of a photon and the mass of a photon only arrived with quantum theory, otherwise Laplace could have made a similar prediction based on the energy of light particles.

See: http://www.narit.or.th/en/files/2009JAHHvol12/2009JAHH...12...90M.pdf

Thanx for that link.
Michell using a ballistic calculation said the Sun would be a dark star if 497 times larger (ie 122,763,473 solar masses). My ballistic calculation based on modern numbers says 485.3.
Here i didnt need GR nor a silly singularity.

I allso using ballistics calculated that we would have a dark star if the same size as Earth & 2156 solar masses.
This reduces to 1079 solar masses if i use GR to calculate the kmps of the slowed light near this dark star. Here i inserted the escape velocity into the equation for gamma.
This reduces to 779 solar masses if i assume that the dark star has an atmosphere with n=1.33 (ie like water), ie slowing the escaping light in that proportion.

Anyhow there is no need for GR or for a singularity. And simple ballistics is good enuff.
So, how will we detect whether a blackhole is a Michellian dark star, or is a Laplacian invisible body, or is an Einsteinian blackhole?

[Petrochemicals]

Has it given an idea of the shape, ie , domed, sphere cone etc ? Or is the resolution and gravity just not good enough ?

[mad aetherist]

The wave model for light hadn't taken hold yet either, not until the Thomas Young double slit experiment revealed it in 1801.
So Michell was also assuming the corpuscular model for light.

I suppose that the wave model would need a smaller mass than the ballistic (corpuscular) model.  Based on the wave model suffering a slowing due to the nearness of mass, ie as per Einstein's GR (ie inserting the escape velocity into the equation for gamma). Or is the wave model more complicated than that?

[mad aetherist]

The Wikipedia article mentions that the jet is only seen on one side of the galaxy (our side). A jet on the other side is not excluded, as most of the energy will be directed away from us due to relativistic beaming. It would be hard to see it through the dense population of stars at the center of M87.

At radio wavelengths, symmetrical jets are seen.

It also says that the Jet is at right-angles to the plane of the accretion disk.
- And that the accretion disk is gaining about 80 Earth masses per day (as an average)

If you imagine Saturn as a black hole, the Saturn's rings are the accretion disk (around the equator), and the jet scomes out the North and South poles.

So that should halve the number of models you have put on the table....
See: https://en.wikipedia.org/wiki/Messier_87#Jet

John Michell in 1783 predicted super massive dark stars that trapped light.  He didnt mention GR. He didnt mention a singularity. Stupid i guess.

It's not an intrinsically complex or relativistic idea (as you have pointed out)
Once you have  the understanding of orbits and escape velocities, and a knowledge of the speed of light, you can work out that a big enough (dense enough) thing won't let light escape.

Newton just missed it; he died 1727 but the speed of light was measured in 1728.
I guess John Michell  didn't want to speculate about what would happen.
That's sensible of him. At the time, practically nothing was known about how stars worked. They didn't know what they were made of, not what kept them hot. So what?  Why would you call that "stupid"?

I agree with Michell, GR is not needed (alltho i think that GR does come into play)(the nearness of mass slows the photons), & a singularity aint needed (& i dont believe in a singularity).