@RomeoTBravo It is extremely cool and very amazing indeed. I am just a stickler for accuracy is all.

As I understand it interferometry isnt just about how far apart your constituent telescopes are but how many of them you have as well. If you really want to have useful interferometry in space you'd need a cloud of telescopes. Doable, but a bit more expensive. It also would have to orbit since just having one at each lagrange point wouldnt help as much.

@raucao By that logic we have never seen any pictures of extraterrestrial stars either (aside from beetleguese).

But even then its more complex than that. Blackholes themselves can never be seen no matter how many pixels they resolve to. The only thing we can see is the einstein rings they cause. Those have taken up many pixels in the past just as they did in the most recent picture.

So still not the "first" no matter how you slice it.

@freemo That's splitting hairs over the word "seen" imo. By all accounts and measures, this is actually the first time anyone has seen the event horizon in a real image. And we can absolutely see a lot of stars in higher resolution than 1px. You can even do that with your naked eye. That's a rather absurd statement.

If you know so many images of the actual light around the event horizon (not from the mass rotating around the hole), I'd be happy to see one!

@raucao Well I wouldnt say its splitting hairs. Its applying the same definition we use for stars when we use the word "seen" in astronomy. We see light, filtered through light-years of interstellar gas, that resolves to less than a pixel for the actual object (the star). Same is true of the blackhole, we see the light that shows the blackhole, but the blackhole itself resolves to less than a pixel.

And no, when you look at stars none of them are greater than a pixel when you look with your eye. Telescopes can do it but only for a few very rare stars. When Beetlegeuse could be resolved beyond 1 pixel it was a HUGE deal.

I assume you dont read many astronomical/physics scientific journals.

Don/'t take my word when it comes to the "absurd" assertion. Here is a voice recording with a scientist She talks about and confirms all the points I said about stars being unable to be resolved in photos (they act as point sources, sub-pixel sizes).

Here read this section of the transcript it talks about how we cant resolve ANY stars with a single telescope and there are VERY few stars we have resolved and in all those cases it used interferometry and multiple telescopes. You know exactly like the "absurd" assertion I made earlier. Also here is the full link.

http://www.astronomycast.com/2012/04/ep-256-resolution/

Pamela: Well, it would be able to detect it because there’s still light coming off – so this is one of those things in astronomy that can get confusing at times. You have a light source, it’s radiating light, all of that light quite happily hits a pixel, and there’s a difference between whether or not you detect it, and whether or not you resolve it, so you’re able to detect that light, but you’re not able to resolve it into, “well, what does that look like? What’s the shape of that?” So we’re able to detect things like stars. We can’t resolve stars, but we detect them all the time, and so this is the difference between pretty picture, and blob of light — and mostly we just see blobs of light.

Fraser: Right, all of the…so even with the Hubble space telescope, if you’re going to view a distant star, you’re just going to get the light coming off of it, but you’re not going to resolve the disk. But there’s a few cases, right, where the resolution of the detector is good enough that you actually can resolve the disk, right? Hasn’t, like, Betelgeuse been resolved?

Pamela: Betelgeuse has been resolved; we’ve resolved the stars in the Alpha Centauri system, and in all of these cases, it wasn’t one single telescope doing the job — and this is where it gets tricky. The ability of a telescope to resolve an image is based on two different factors (we’re going to keep having things that are based on two different factors today): one of those factors is what color of light are you’re using. If the color of light you’re using has a really long wavelength, well, if your wavelength is longer than the object you’re trying to look at, the wavelength isn’t going to allow you to resolve the object. So you need to use shorter wavelengths of light to be able to resolve finer details. Now, at the same time, you have to be able to take all of those wavelengths and combine them in a meaningful way, and the more wavelengths you can combine, the better you’re going to do, and the more wavelengths you can combine depends on how big is your detector. Now, this starts to work in a kind of screwball way because it’s not actually “I have one, two, three, four, five stacked across and I’m collecting all five.” It actually has to do with the separation between these two is, well, actually usually 1000s of wavelengths, and I can cut a hole out of the center, or I can actually cut a whole lot of holes out, and we call that the very large array in New Mexico. So the resolution that you get depends on how far apart are the two most extreme wavelengths that you detect in your baseline between the two telescopes, and so that baseline, or the diameter of your single mirror, your single dish — that defines your resolution in combination with what wavelength you’re looking at.

@freemo That is an epic exercise in hairsplitting. Agree to disagree, but all that confirms what I see as splitting hairs in that case.

@raucao I also never claimed there were previous photos of "mass around a black hole". The picture released also wasnt mass around a black hole. there were photons that passed near, or emitted from the area around a black hole. Yes that is a new achievement, the WHOLE achievement was novel in many ways indeed. It just wasnt the first picture of a black hole as all, it was something much better than that.

@freemo No, that's my point. This is the first time you actually see the *light* (yes, photons) around the *event horizon*, not from the mass that the hole attracts. That's how I understand it, and that means you can very well argue that this is the first time ever that the event horizon was seen in an image.

@freemo But you can also split your own hairs and disagree with the EHT project's scientists. That's a valid opinion, of course. Thanks for clarifying your point./

@freemo I'd still be interested in which previous images you were talking about by the way.

@raucao Oh sure, here are a few.