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Unveiling the first-ever image of a black hole [video]

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Re: Unveiling the first-ever image of a black hole [video]

#321

Post by phonypc »

ttul wrote: post #279
chirau wrote: post #269

MASSSIVELY UNDERWHELMING As a person who has no interest in these intergalactic shenanigans, it looks just like another ball on fire. I wanted to be excited, I really was, but this is just another picture. A giant leap for mankind, and i fully recognize that, but the awe... nada. It's just another picture really. There is nothing fascinating about it. Hats off to the people who brought this to us though. I know gravi…

Perhaps consider this: "VLBI allows the EHT to achieve an angular resolution of 20 micro-arcseconds — enough to read a newspaper in New York from a sidewalk café in Paris [6]." What's surprising about this image is how utterly microscopic the thing is that was observed - from our location. The width of the event horizon is 40 billion kilometers. That's only 267x the diameter of our orbit around the Sun. But the M87 b…

53 million light years. 26 thousand would still be in our own galaxy.

Re: Unveiling the first-ever image of a black hole [video]

#323

Post by sandworm101 »

jjeaff wrote: post #277
noir_lord wrote: post #167

Earlier quoted context omitted.

It's good science. Been able to make testable predictions and then confirming them or disproving them is the entire (awesome) point.

After having said that, I did a bit more research into how the image was made. I am of course reserving judgement as I don't fully understand the underlying technology. But it sounds like they used an interpolation algorithm to come up with the image based on renderings of what we "think" a black hole should look like. This high level overview from a ted talk goes into how they 'unbias' the data. But it is obviously…

Indeed. Whenever you go looking for something you think is already exists, as opposed to stumbling across an object, there is a danger that the parameters of your search will favor your preconceived notions. One will also tend to describe observed objects in terms that tends to fit your theory. I'm not saying that happened here just that it is a danger.

Astronomy/cosmology is one of those strange disciplines where rather than discover new objects in situ, one discovers their possibility in the mathematics and then goes out to find them. So I and many others were hoping that this image was radically different than the math, potentially opening the door to some new theories. Confirmation just isn't as much fun as raw discovery of the unknown. Example: the recent "cannonball star" observations. We are going to need some new science to explain how that is a thing.

Re: Unveiling the first-ever image of a black hole [video]

#324

Post by awb »

JumpCrisscross wrote: post #27

Good video that correctly predicted the image and describes why it looks the way it does [1]. TL; DR The dark area is the entire surface of the event horizon, including the side facing away from us, plus some more due to photons missing the event horizon "directly" being drawn in. One side is brighter due to its being Doppler boosted. [1] https://www.youtube.com/watch?v=zUyH3XhpLTo

Here's the follow up video after the image was released: https://www.youtube.com/watch?v=S_GVbuddri8

Re: Unveiling the first-ever image of a black hole [video]

#327

Post by chirau »

ttul wrote: post #279
chirau wrote: post #269

MASSSIVELY UNDERWHELMING As a person who has no interest in these intergalactic shenanigans, it looks just like another ball on fire. I wanted to be excited, I really was, but this is just another picture. A giant leap for mankind, and i fully recognize that, but the awe... nada. It's just another picture really. There is nothing fascinating about it. Hats off to the people who brought this to us though. I know gravi…

Perhaps consider this: "VLBI allows the EHT to achieve an angular resolution of 20 micro-arcseconds — enough to read a newspaper in New York from a sidewalk café in Paris [6]." What's surprising about this image is how utterly microscopic the thing is that was observed - from our location. The width of the event horizon is 40 billion kilometers. That's only 267x the diameter of our orbit around the Sun. But the M87 b…

I am fully aware of the theory and excitement over all this. I just expected something... different. I thought i'd be wowed by something new. It literally looks just like a regular photo.

Is there a lot of context behind it? Sure. Is it a HUGE leap in our advancement? Definitely. Is it an eye-turning picture? NO. That is all.

Black holes are fascinating, their picture simply isn't, for me at least.

Re: Unveiling the first-ever image of a black hole [video]

#328

Post by t3hz0r »

dugluak wrote: post #325

Why did they choose this very distant galaxy? why not something that's close to us like the andromeda galaxy or even the center of our own galaxy?

As I understand it, by being more massive this black hole has roughly the same angular size in the sky as Sag A* at the center of our galaxy, but none of the dusty foreground in the way so we get a clearer vantage point.

Re: Unveiling the first-ever image of a black hole [video]

#330

Post by LolWolf »

nonbel wrote: post #298
LolWolf wrote: post #291

Earlier quoted context omitted.

If you observe a very wide band of light (e.g., EM radiation) and there is nothing received from those spots, then, for all intents and purposes, the region of that image is black. Now, if you're asking if, perhaps, the region isn't really black, but rather it's emitting some sort of small radiation relative to the bright region, it would be essentially impossible to know without much higher resolving powers (since i…

Makes sense. So I guess they could probably tell us an upper bound on how bright it is.

Indeed! That’s for sure: it’s probably not hard to extract a bound on the magnitude of a part of the spectrum from this analysis.
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