What will the first image of a Black Hole and its event horizon look like? What will scientists imagine we find in galaxy M87 and what will their imaging algorithms suggest is observed.
If no photographs of Black Holes have been taken before how can astronomers now create images of them?
How do we make a picture from the sparse data collected by the EHT?
The Event Horizon Telescope (EHT) collects light from the black hole using a small number of telescopes distributed around the Earth. Once the EHT has measured data from the black hole, we still need to make a picture from it - a process referred to as imaging. The light we collect gives us some indication of the structure of the black hole. However, since we are only collecting light at a few telescope locations, we are still missing some information about the black hole’s image. The imaging algorithms we develop fill in the gaps of data we are missing in order to reconstruct a picture of the black hole.
Since there is a lot of missing data, you may ask how making a picture is even possible.
Imaging a Black Hole | Event Horizon Telescope
What is actually in reality and in nature there? It will be relatively bright, a plasmoid? Not black, not holes.
But there is one point I want to draw your attention to: there is always some ambiguity in what the true image is. Similarly, for the EHT, the data we take only tells us only a piece of the story, as there are an infinite number of possible images that are perfectly consistent with the data we measure. But not all images are created equal— some look more like what we think of as images than others. To chose the best image, we essentially take all of the infinite images that explain our telescope measurements, and rank them by how reasonable they look. We then choose the image (or set of images) that looks most reasonable.
Using these algorithms we are able to reconstruct pictures from the very sparse measurements measured with the EHT.
What you are looking at, what astronomy think they are observing, really does depend on your point of view. Scientists will say it is the event horizon and the environment of the Black Holes. That you can never directly photograph a BH itself.
Plasma Cosmology and Electric Universe theory suggests that it is not a Black Hole as they do not exist. BH's are just theories and mathematical models.
PC and EU may interpret these Black Hole figures as plasma z-pinches of monstrous Birkeland filaments, or at least very energetic plasmoids in galactic electromagnetic plasma circuits.
BBC documentary on How to See a Black Hole
The project combines radio observatories and telescope facilities from around the world to make up a virtual telescope with a diameter spanning the entire planet. This mega-telescope’s ultimate mission is to capture the first image ever of a black hole.
Although the concept of black holes has been long assumed to be fact, the Event Horizon Telescope’s success would definitively prove the existence of this scientific phenomena for the first time – and provide clear visual evidence.
How to See a Black Hole: The Universe's Greatest Mystery
Update 10 April 2019: Black Hole image released
The image matches what theoretical physicists and indeed, Hollywood directors, imagined black holes would look like, according to Dr Ziri Younsi, of University College London - who is part of the collaboration.
"It is remarkable that the image we observe is so similar to that which we obtain from our theoretical calculations. So far, it looks like Einstein is correct once again."
First ever black hole image released
This is similar to the Black Hole mergers where algorithms were used to filter out data and then select the results that resembled what they expected to find. Although those gravity waves were actually far beyond what they had predicted or theory said could happen.
"Once we were sure we had imaged the shadow, we could compare our observations to extensive computer models that include the physics of warped space, superheated matter and strong magnetic fields. Many of the features of the observed image match our theoretical understanding surprisingly well," remarks Paul T.P. Ho, EHT Board member and Director of the East Asian Observatory. "This makes us confident about the interpretation of our observations, including our estimation of the black hole’s mass."
Astronomers Capture First Image of a Black Hole | Event Horizon Telescope
Electromagnetic plasma, plasma torus, plasmoid?
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.
First ever black hole image released
She started making the algorithm three years ago while she was a graduate student at the Massachusetts Institute of Technology (MIT).
She spearheaded a testing process whereby multiple algorithms with "different assumptions built into them" attempted to recover a photo from the data. Put simply, Dr Bouman and others developed a series of algorithms that converted telescopic data into the historic photo shared by the world's media.
In mathematics and computer science, an algorithm is a process or set of rules used to solve problems. The results of the algorithms were then analysed by four separate teams to build confidence in the veracity of their findings.
Katie Bouman: How did her algorithm create the image? | BBC