Black Hole Event horizon snapshot due in 2017

_Tombstone_

A network of nine radio telescopes, dotted around the globe, is set to take the first ever picture of a black hole's event horizon in 2017.

The project, called the Event Horizon Telescope, has completed most of its technical preparations as well as extensive theoretical calculations.

It will focus on Sagittarius A*, the black hole at the Milky Way's centre.



http://www.bbc.com/news/science-environment-35258378

_Tombstone_

The snapshot will help prove Einstein's theory of relativity by the black holes shadow either matching what the theory predicts....or not.


Now here's another cracker in the making from his theory (maybe) - ripples in spacetime!

The Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) which uses detectors in Hanford, Washington, and Livingston, Louisiana to look for ripples in the fabric of spacetime.....is in the process of verifying their Data that they've detected it.

http://m.slashdot.org/story/305183


Real star trek stuff!!

_Tombstone_

_Tombstone_ wrote: »

The Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) which uses detectors in Hanford, Washington, and Livingston, Louisiana to look for ripples in the fabric of spacetime.....is in the process of verifying their Data that they've detected it.

http://m.slashdot.org/story/305183

Gravitational-wave rumours in overdrive - WHAT IS THE GOSSIP?

_Tombstone_

The combined powers of 15 Scopes has produced this image of stuff streaming out of a Black Hole 900Million Light years away.

The black hole is located at the center of the BL Lacertae galaxy, and the jet it produces has been observed to have a spiraling magnetic field shooting particles outwards much faster than they would without the coiled acceleration. Researchers hope that future observations of the jets might help revise their theories on how the jets produce microwave radiation.

THE HIGHEST RESOLUTION ASTRONOMICAL IMAGE EVER TAKEN^^^^

http://www.popsci.com/this-is-highest-resolution-astronomical-photo-ever-taken

_Tombstone_

_Tombstone_ wrote: »

Gravitational-wave rumours in overdrive - WHAT IS THE GOSSIP?

Looks like this is all but confirmed and leaked email on twitter has them claiming this years Nobel Physics - Two black holes, of 29 and 36 solar masses, swirling together and merging causing ripples in space time.

‘Woohoo!’ email stokes rumor that gravitational waves have been spotted

After 100 years, scientists are finally closing in on Einstein’s ripples

Wheres PS to explain why this is a big thing cuz Star Trek is the only place I've heard about this stuff before?

_Tombstone_

Announcement due tomorrow - Thursday


What Will It Mean If LIGO Detects Gravitational Waves?

When Einstein’s General Relativity was first proposed, it was incredibly different from the concept of space and time that came before. Rather than being fixed, unchanging quantities that matter and energy traveled through, they are dependent quantities: dependent on one another, dependent on the matter and energy within them, and changeable over time. If all you have is a single mass, stationary in spacetime (or moving without any acceleration), your spacetime doesn’t change. But if you add a second mass, those two masses will move relative to one another, will accelerate one another, and will change the structure of your spacetime. In particular, because you have a massive particle moving through a gravitational field, the properties of General Relativity mean that your mass will get accelerated, and will emit a new type of radiation: gravitational radiation.

But if they find a gravitational wave, this is what it’ll teach us: that Einstein’s relativity is right, that gravitational radiation is real, and that merging black holes not only produce them, but that these waves can be detected. It’s a whole new type of astronomy — one that doesn’t use telescopes — and a whole new way to view black holes, neutron stars, and other objects that are otherwise mostly invisible. For the first time, we may be developing eyes for examining the Universe in a way that no living creature has ever examined it before.

Best Article I've found to explain it all so far...

_Tombstone_

Professor Stephen Hawking delivers the first of his two BBC Reith Lectures on black holes.

_Tombstone_

As mentioned in other Thread. Confirmed.

http://touch.boards.ie/thread/2057531299/1/#post98549728



Next stage is the Pathfinder,

http://touch.boards.ie/thread/2057531299/1/#post98549728

_Tombstone_

The Japs are after losing....control of anyway of a brand spanking new SAT they sent up last month designed to study energetic space objects such as supermassive black holes, neutron stars, and galaxy clusters, by observing energy wavelengths from X-rays to gamma-rays.

Its in an unknown number of pieces and spinning due to...a heap of suggestions given --> battery/propellant explosion, debris hit it or the chinese blew it:eek:.

http://www.bbc.com/news/world-asia-35914652

ps200306

_Tombstone_ wrote: »

A network of nine radio telescopes, dotted around the globe, is set to take the first ever picture of a black hole's event horizon in 2017.

The project, called the Event Horizon Telescope, has completed most of its technical preparations as well as extensive theoretical calculations.

It will focus on Sagittarius A*, the black hole at the Milky Way's centre.

First data collection run commenced on Wednesday!

ps200306

Better late than never. First results from Event Horizon Telescope will be presented at press conferences around the world at 1pm next Wednesday.

https://eventhorizontelescope.org/blog/media-advisory-first-results-event-horizon-telescope-be-presented-april-10th

pleas advice

video explaining what you're seeing when looking at a black hole

Wanderer78

live press conference

Hector Savage

So what I understand, it's still just the outer rim of the Event Horizon photographed ? it's still impossible to see inside the black hole ?
by the very definition of same ?

RebelButtMunch

Hector Savage wrote: »

So what I understand, it's still just the outer rim of the Event Horizon photographed ? it's still impossible to see inside the black hole ?
by the very definition of same ?

Correct. Not even light can escape a black hole, hence nothing to photograph.

Ipso

How does this affect my horoscope?
So everything gets sucked in, and given that matter has empty space does everything just get crushed inside the black hole?

Fourier

Ipso wrote: »

How does this affect my horoscope?
So everything gets sucked in, and given that matter has empty space does everything just get crushed inside the black hole?

Matter doesn't have loads of empty space inside it, but you do get quite crushed when you enter. Black holes are also bigger on the inside than they are on the outside.

What ultimately happens to matter taken into the hole is unknown.

Capt'n Midnight

Ipso wrote: »

How does this affect my horoscope?

Ipso

Let’s say there is another planet @behind”; what we’re seeing from here, would they see the same thing?

Balf

RebelButtMunch wrote: »

Correct. Not even light can escape a black hole, hence nothing to photograph.

Is it even a photograph?

I find the press coverage talks around what it seems to be:

https://www.bbc.com/news/science-environment-47873592

It seems to be an image created by an algorithm, based on data combined from a group of radio telescopes.

Its not a photograph, in the sense of a picture of an image seen through an optical device.

Its a cartoon, not a snapshot.

b318isp

A "photograph", as we traditionally consider it, is only a representation of a tiny part of the electromagnetic field. A film based photograph is based on a chemical reaction, a digital photograph is an algorithm applied to a voltage (and a voltage converted to light in a screen). There are many other ways of representing an electromagnetic field as an image (think x-ray, infrared, radio waves).

It's most certainly not a cartoon.

Balf

b318isp wrote: »

There are many other ways of representing an electromagnetic field as an image (think x-ray, infrared, radio waves).

And, in fairness, a digital image on a phone (for the sake of argument) is reproduced from stored data.

With respect to this image, is it something I would see if I was standing close enough with an optical telescope? Or is it something an algorithm renders into a form, that might not actually look like that to the human eye?

ps200306

Balf wrote: »

With respect to this image, is it something I would see if I was standing close enough with an optical telescope? Or is it something an algorithm renders into a form, that might not actually look like that to the human eye?

Broadly speaking it's the same sort of image, as in, it has the same sort of geometry. Obviously it's different in substantial ways -- it's not an optical image since it was measured at 1.3 mm wavelength. I think your main hangup is the "algorithm". Your DSLR camera image is based on various algorithms too. But I think the main one that might introduce suspicion about the EHT image is the way in which it is reconstructed from pairs of coherent wavefront measurements at the telescope array elements. Because the image is sampled much more sparsely than at the focus of your DSLR camera, there are many possible source images that could have produced the same measurements and the algorithm has to guess which one.

That's not as dodgy as you might think. The only difference between a picture of your friends face and a fuzzy pink blob is that the autofocuser algorithm in your camera decided that "real" images contain sharply contrasting edges. It might fail miserably on an actually fuzzy image.

The EHT imaging algorithm is likewise based on a notion of what a real image looks like. Don't ask me what sort of notion -- it's way above my pay grade :pac: . I gather it's along the lines of regression analysis, in which you have to know something about the distribution of an independent variable (a "predictor") before you can calculate the correlation of a dependent variable. The specific algorithm used is based on Lasso. Interestingly, that algorithm was developed in the 1980s in connection with the interpretation of seismograms. Those "images" are of variations in rock density -- not something you could ever see with an optical telescope or any electromagnetic imager.

You may be able to glean more from papers on the latest variations of the algorithm used on the EHT (see below). I can only get the vaguest sense of what they're talking about.

1. Interferometric Imaging Directly with Closure Phases and Closure Amplitudes, https://arxiv.org/abs/1803.07088
2. Imaging the Schwarzschild-radius-scale Structure of M87 with the Event Horizon Telescope using Sparse Modeling, https://arxiv.org/abs/1702.07361
3. Superresolution Interferometric Imaging with Sparse Modeling Using Total Squared Variation --- Application to Imaging the Black Hole Shadow, https://arxiv.org/abs/1802.05783

ps200306

Some more good info in an astrobite today ...

https://astrobites.org/2019/04/11/the-first-image-of-a-black-hole/

It shows the output from three different algorithms, using data taken on four different days from the EHT. All dozen images are reassuringly similar (although they also think they're seeing some real-world time evolution in the structure across the four days). For further reading, the link at the top of the astrobite takes you to another summary article, and at the bottom of that you can find links to the six discovery papers published yesterday in conjunction with the announcement. Sections 7 and 8 of Paper III talk specifically about the data reduction.

b318isp

Interesting info here on how the picture was taken:

https://www.boards.ie/vbulletin/showpost.php?p=109905962&postcount=667