Picture of black hole...

[Paul M]

1 hour ago, xtreemchaos said:

here you go,

 

Well, after all the hype I think they could have made it look a bit less like a doughnut!!

[Knight of Clear Skies]

14 minutes ago, Buzzard75 said:

I don't know about you, but I cringe a little everytime I read a headline stating that it's an image of a black hole. I'm afraid it's just confusing the issue for some people.

I know what you mean but I think it's OK to call it that as you can see the black hole's 'shadow'. From the BBC article:

"The image shows an intensely bright "ring of fire", as Prof Falcke describes it, surrounding a perfectly circular dark hole. The bright halo is caused by superheated gas falling into the hole. The light is brighter than all the billions of other stars in the galaxy combined - which is why it can be seen at such distance from Earth.

The edge of the dark circle at the centre is the point at which the gas enters the black hole, which is an object that has such a large gravitational pull, not even light can escape."

Which is pretty good for a very short summary. I'm not sure it's quite correct though, as the dark circle isn't perfectly round and I'm not sure what that means. Also, I read somewhere that the apparent size of the black hole is 2.5 times its event horizon and I'm not sure why. Hopefully in the next few days there will be some more technical (but readable) articles from people like the Bad Astronomer and Ethan Siegel which will shed some more light on what the image means.

[xtreemchaos]

17 minutes ago, Knight of Clear Skies said:

Has anyone said when the image of Sgr A* is expected?

havnt heard yet, yes it was a bit of a bait and switch job but it was worth watching for M87 image in my view.

[Buzzard75]

5 minutes ago, Knight of Clear Skies said:

"ring of fire"

Now I've got Johnny Cash playing in my head. Thanks for the description and link to that article. As you said, I think it's sufficient for a short summary and much better than just stating that it's a picture of a black hole. Perhaps stating that it's an image of evidence that highly suggests the presence of a black hole would be more accurate?

[Space Oddities]

Amazing picture! I also have Johnny Cash playing in my head now...  

More information on the official website of the EHT: https://eventhorizontelescope.org/

[Knight of Clear Skies]

Here's a cleaner image.

[Space Oddities]

Still looks like a donut on fire as observed by a nearsighted person!

[Buzzard75]

Perhaps the oblongocity (I'm making that a word) has something to do with the jet of material being ejected from the core and causing some sort of distortion.

[Captain Scarlet]

49 minutes ago, Knight of Clear Skies said:

...Has anyone said when the image of Sgr A* is expected?

That was the first question in the Press Conference. the answer was that they pointed everything at M87 first so that's what got processed properly first, and as for Sgr A*, they "hope to have something very soon, without making any promises"...

[Knight of Clear Skies]

1 hour ago, Paul M said:

Well, after all the hype I think they could have made it look a bit less like a doughnut!!

I think it's pretty good for an object which has the angular size of a mustard seed - on the other side of the Atlantic.

[reezeh]

Didn't I hear on the news it was going to be the first optical light image of a black hole?

Looks like a radio interferometer "image" mapped out on a screen to me!

Or a doughnut fresh out of the fryer...

You take your pick, but I'm pretty underwhelmed considering the hype and insane expense involved!

Maybe I'm just getting cynical in my old age. I know it's one heck of a long way away, but that's what very long baseline interferometers are good at; sheer resolution power.

[ollypenrice]

29 minutes ago, reezeh said:

Didn't I hear on the news it was going to be the first optical light image of a black hole?

Looks like a radio interferometer "image" mapped out on a screen to me!

Or a doughnut fresh out of the fryer...

You take your pick, but I'm pretty underwhelmed considering the hype and insane expense involved!

Maybe I'm just getting cynical in my old age. I know it's one heck of a long way away, but that's what very long baseline interferometers are good at; sheer resolution power.

Taking the black hole from its first theoretical conception (John Michel,1783) to it's first direct image today, has to be a great moment in science. Suppose they had been unable to find it...

Spiral galaxies began like this with Lord Rosse in 1848...

... whereas today an amateur relying entirely on the expertise of the technical experts behind his equipment can produce this (or better than this) from a small telescope in his back yard.

I think that today we are witnessing one of the greatest astrophotos of all time.

Olly

 

 

 

 

 

 

[Stu]

57 minutes ago, reezeh said:

Maybe I'm just getting cynical in my old age

I think perhaps you are a tad. Seems like quite an achievement to me. Given that you cant actually see a black hole, this seems a pretty next best thing, and I think we can agree it is 'quite' a long way away....

[DaveS]

I confess that I was a little disappointed that the image was as the astronomers expected, since science often progresses through things that aren't as theory predicts.

[ollypenrice]

32 minutes ago, DaveS said:

I confess that I was a little disappointed that the image was as the astronomers expected, since science often progresses through things that aren't as theory predicts.

Like trying to break general relativity. But each failure is a success...

Olly

[saac]

1 hour ago, ollypenrice said:

I think that today we are witnessing one of the greatest astrophotos of all time.

Olly

 

 

I agree, it's an amazing achievement, on par with with the detection of gravitational waves perhaps.  I can't help but wonder what Stephen Hawking would have made of it.

Jim 

Edited April 10, 2019 by saac

[Ruud]

A video summary by veritasium

 

 

 

Edited April 10, 2019 by Ruud

[ollypenrice]

5 minutes ago, saac said:

I agree, it's an amazing achievement, on par with with the detection of gravitational waves perhaps.  I can't help but wonder what Stephen Hawking would have made of it.

Jim 

I think he'd have smiled but I don't doubt that he had no doubts...

Olly

[andrew s]

See BBC 4 at 9 tonight.

Regards Andrew 

[saac]

17 minutes ago, ollypenrice said:

I think he'd have smiled but I don't doubt that he had no doubts...

Olly

I think so Olly, perhaps even with a wee tear in his eye .

Ruud, thanks for sharing the video, really informative and helped in better understanding the image. 

Jim 

[Knight of Clear Skies]

2 hours ago, reezeh said:

You take your pick, but I'm pretty underwhelmed considering the hype and insane expense involved!

It exceeds my expectations, I find the image both interesting and inspiring. It's encouraged me to learn about the subject and think about the implications of living with such a monster in your galaxy. M87 spits out a jet 5,000 light years long with the energy - If my math is correct - of 200 million, trillion Deaths Stars. Continually. What effect does that have on star formation, or any planets that stray across its path?

Considering the educational value, public interest generated and that it's a test of fundamental physics I'd say the EHT easily passes muster in terms of cost/benefit. (The cost to myself is, at most, a few pence of my taxes.) There may be many applications for a radio telescope the size of the Earth.

A couple of my favorite astronomical images are just dots.

A single point of light in changed brightness in a predictable manner and we discovered the universe. The Cepheid Variable Edwin Hubble found in M31 proved that it was a separate galaxy rather than a feature of our own.

Or the Pale Blue Dot. Not very pleasing aesthetically but as Carl Sagan said " That's us. On it, everyone you ever heard of, every human being who ever lived, lived out their lives."

We been somewhat spoiled by Hubble images cosmic vistas and planetary images by probes parked on their doorsteps but there are other aspects to astronomy. Radio astronomy is often overlooked but, for example, observations of neutral hydrogen were an essential tool to mapping out the structure of our own galaxy.

[Knight of Clear Skies]

1 hour ago, Ruud said:

A video summary by veritasium

Very good summary, well worth watching. Thanks Ruud. Surprised to see the Sgr A* image there too.

[Tykeviewer]

5 hours ago, Knight of Clear Skies said:

I know what you mean but I think it's OK to call it that as you can see the black hole's 'shadow'. From the BBC article:

"The image shows an intensely bright "ring of fire", as Prof Falcke describes it, surrounding a perfectly circular dark hole. The bright halo is caused by superheated gas falling into the hole. The light is brighter than all the billions of other stars in the galaxy combined - which is why it can be seen at such distance from Earth.

The edge of the dark circle at the centre is the point at which the gas enters the black hole, which is an object that has such a large gravitational pull, not even light can escape."

Which is pretty good for a very short summary. I'm not sure it's quite correct though, as the dark circle isn't perfectly round and I'm not sure what that means. Also, I read somewhere that the apparent size of the black hole is 2.5 times its event horizon and I'm not sure why. Hopefully in the next few days there will be some more technical (but readable) articles from people like the Bad Astronomer and Ethan Siegel which will shed some more light on what the image means.

It has been described as “perfectly circular”, but to me it looks elliptical, or possibly even ‘egg-shaped’.  Has anyone seen any discussion on that aspect?

 

Edited April 10, 2019 by Tykeviewer

[Alien 13]

3 minutes ago, Tykeviewer said:

It has been described as “perfectly circular”, but to me it looks elliptical, or possibly even ‘egg-shaped’.  Has anyone seen any discussion on that aspect?

 

I noticed that and its definitely not circular but thinking about it why would it be round anyway, why not even a very thin ellipse.....

Alan

[Tykeviewer]

If it is elliptical because of its spin, then it would imply it has volume. A singularity, however, cannot have volume. ?