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Astronomers reveal first image of the black hole at the heart of our galaxy

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Re: Astronomers reveal first image of the black hole at the heart of our galaxy

#181

Post by VikingCoder »

Dave_Rosenthal wrote: post #149
VikingCoder wrote: post #133

Earlier quoted context omitted.

Can someone do the math for me? Let's say I'm 6 feet tall... what object would I have to hold out at arm's length, to have the same angular width as the entirety of this image? A bacteria? A virus?

https://www.wolframalpha.com/input?i=50+microarcseconds+*+%2... The answer is ~200 picometers. Wolfram lists some helpful comparisons: 1/2 the distance between base pairs in DNA 3x the atomic diameter of helium (the smallest atom) Suffice to say you'd have a hard time seeing it as it would be 3,000x smaller than the wavelength of visible light.

Thank you! That's freaking bonkers.

Re: Astronomers reveal first image of the black hole at the heart of our galaxy

#182

Post by malfist »

fasteddie31003 wrote: post #141
malfist wrote: post #137

Earlier quoted context omitted.

You realize peer review isn't just something you do and they automatically publish you, right? Peer review makes sure your science is sound. But I'm sure you're more of an expert than anybody serving in a peer review board.

Peer review has let plenty of bad science through. Don't burn me at the stake because I speak heresy against the holy theologians of astronomy.

All you're saying is: They're wrong, not gonna say how, but trust me.

Why should I trust you that you know more about astronomy than a team of astronomers and a peer review board?

I've asked you this three times so far and you've not given an answer.

Re: Astronomers reveal first image of the black hole at the heart of our galaxy

#183

Post by JacobThreeThree »

dotnet00 wrote: post #75
fasteddie31003 wrote: post #29

I am very skeptical of the Event Horizon Telescope (EHT) images because they are not following a scientific method that results in a true representative image of their target. In my opinion astronomy is jumping the shark with these images by making this a big PR stunt. I've looked at their methods for their earlier images and they seem to be hunting for a circle that looks like a black hole in their data. The EHT's f…

Checking against callibration measurements isn't the only way to do things. With M87's SMBH for instance, they had a simulated image of what they ought to see given general relativity and what they knew about M87. The extracted data matches that fairly closely, thus lending credibility to the result for obtaining parity with physics without actually applying those physics to the data.

>With M87's SMBH for instance, they had a simulated image of what they ought to see given general relativity and what they knew about M87.

How confident are we that our current simulations accurately reproduce the universe?

Given how many unpredicted and supposedly impossible exoplanet and star configurations that keep being found, I'd say the current model is not doing so well on the prediction front.

https://www.science.org/content/article/forbidden-planets-un...

Re: Astronomers reveal first image of the black hole at the heart of our galaxy

#184

Post by adgjlsfhk1 »

amelius wrote: post #180
fsh wrote: post #125

Earlier quoted context omitted.

The resolution of these telescopes is limited by diffraction, not by the number of pixels on the sensors. The achievable angular resolution is roughly the wavelength divided by the aperture diameter [1]. JWST works in the few µm wavelength range and has a 6.5 m aperture, such that the angular resolution is ~0.1 arcsec. The EHT works with 1.3 mm wavelength and has an effective aperture of roughly the earth diameter (~…

Can we invert the diffraction process numerically?

no

Re: Astronomers reveal first image of the black hole at the heart of our galaxy

#186

Post by gnulinux »

jankovicsandras wrote: post #136
fasteddie31003 wrote: post #29

I am very skeptical of the Event Horizon Telescope (EHT) images because they are not following a scientific method that results in a true representative image of their target. In my opinion astronomy is jumping the shark with these images by making this a big PR stunt. I've looked at their methods for their earlier images and they seem to be hunting for a circle that looks like a black hole in their data. The EHT's f…

I share your skepticism. To others: Before voting me down, please consider these arguments. As I understand, this image is not from visible light, not a photo, more like plotting radio measurements. "black holes" are the brightest objects in the universe. It's a bit like an alien scientist showing an X-ray picture of a skeleton:"This is a human!" Some quotes from https://en.m.wikipedia.org/wiki/Black_hole : "Moreover…

> It's a bit like an alien scientist showing an X-ray picture of a skeleton:"This is a human!"

What is the problem here? Surely skeleton (or other things detectable via X-rays) is an integral part of a human. If you have no way of seeing an alien, but have an x-ray of them, wouldn't you say we have a significantly better understanding of this alien species, than having nothing at all?

Re: Astronomers reveal first image of the black hole at the heart of our galaxy

#187

Post by JacobThreeThree »

malfist wrote: post #137
fasteddie31003 wrote: post #40

Earlier quoted context omitted.

Peer reviewed has nothing to do with the scientific method. It is just a layer of scientific bureaucracy. Just give me a calibration image of another celestial body and I'll be happy.

You realize peer review isn't just something you do and they automatically publish you, right? Peer review makes sure your science is sound. But I'm sure you're more of an expert than anybody serving in a peer review board.

>Peer review makes sure your science is sound

No it doesn't. Most peer review doesn't even attempt to reproduce results, which is the real way to make sure the science is sound.

Re: Astronomers reveal first image of the black hole at the heart of our galaxy

#188

Post by ISL »

hammock wrote: post #155
fsh wrote: post #125

Earlier quoted context omitted.

The resolution of these telescopes is limited by diffraction, not by the number of pixels on the sensors. The achievable angular resolution is roughly the wavelength divided by the aperture diameter [1]. JWST works in the few µm wavelength range and has a 6.5 m aperture, such that the angular resolution is ~0.1 arcsec. The EHT works with 1.3 mm wavelength and has an effective aperture of roughly the earth diameter (~…

Should have clarified. Does a black hole have fuzzy edges or sharp edges?

The edge should be quite sharp. Any deformation or movement in the edge will be smoothed extremely quickly, on timescales comparable to the light-crossing time of the object -- in this case ten seconds or so.

If you're a photon and you're in, you stay in. If you're out and heading out, you get out. (if you skim the surface, you might make an orbit and then leave :) ). It is that fact that makes the edge quite sharp.

Re: Astronomers reveal first image of the black hole at the heart of our galaxy

#189

Post by wumpus »

belter wrote: post #159
wumpus wrote: post #34

Earlier quoted context omitted.

Didn’t I already reply to you weeks ago about a similar comment? Now you can read the actual papers which explain in detail why your comment is incorrect.

I think you are talking about the conversation we had here. So in this case you replied to a different person. https://news.ycombinator.com/item?id=31281773

No, this one, same user, same skepticism, 19 days ago: https://news.ycombinator.com/item?id=31134691

Btw we released the 2017 calibrated data today, too.

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