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The black hole picture is both an astonishing achievement and a deceptive image

prospectmagazine.co.uk

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Re: The black hole picture is both an astonishing achievement and a deceptive image

#11

Post by gibybo »

nvahalik wrote: post #7

FTA: "An object in the centre of our galaxy (the Milky Way) called Sagittarius A* is thought to be such a “supermassive” black hole." If this black hole is 55M LY away and the center of our galaxy should have one. So, why is it that we can see this one, but not the one at the center of our galaxy? Is it because there are things in our line of site with it?

The black hole that they revealed is about 1,000 times larger than the one at the center of our milky way. So even though it's also 1,000 times further away, it's about the same angular diameter in the sky. Same size but less stuff in the way/more active makes it an easier target.

Re: The black hole picture is both an astonishing achievement and a deceptive image

#12

Post by wiredfool »

nvahalik wrote: post #7

FTA: "An object in the centre of our galaxy (the Milky Way) called Sagittarius A* is thought to be such a “supermassive” black hole." If this black hole is 55M LY away and the center of our galaxy should have one. So, why is it that we can see this one, but not the one at the center of our galaxy? Is it because there are things in our line of site with it?

1) This one is actively ingesting material (active galaxy) so there are emissions from the accretion disk. Our galaxy is quiet, so there isn't the same emission from the black hole.

2) The one in our galaxy is 1600x closer and roughly that much smaller, so they're approximately the same angular size.

3) They have tracked the orbit of a star that orbits our galaxy's central black hole through an orbit, and it goes ~2% (iirc) of the speed of light at closest approach, but it's nowhere near the event horizon. There are other things that have been tracked near A*, but nothing at the event horizon like this one.

Re: The black hole picture is both an astonishing achievement and a deceptive image

#13

Post by markkanof »

sk5t wrote: post #6
jameshart wrote: post #4

The use of the word 'deceptive' in this headline is astonishingly disingenuous. I don't think the article intends to accuse the publishers of the image of deception, but the headline sure reads that way. The article is just trying to explain that imaging a black hole is inherently counterintuitive.

Well, from the other side of the peanut gallery, I think your outrage is misplaced. "Deception" needn't be malicious, and the title already calls this out as an "astonishing achievement."

That is the actual definition of deception.

Re: The black hole picture is both an astonishing achievement and a deceptive image

#14

Post by lttlrck »

jameshart wrote: post #4

The use of the word 'deceptive' in this headline is astonishingly disingenuous. I don't think the article intends to accuse the publishers of the image of deception, but the headline sure reads that way. The article is just trying to explain that imaging a black hole is inherently counterintuitive.

‘deceiving’ may have been more appropriate.

Re: The black hole picture is both an astonishing achievement and a deceptive image

#15

Post by kurthr »

sk5t wrote: post #6
jameshart wrote: post #4

The use of the word 'deceptive' in this headline is astonishingly disingenuous. I don't think the article intends to accuse the publishers of the image of deception, but the headline sure reads that way. The article is just trying to explain that imaging a black hole is inherently counterintuitive.

Well, from the other side of the peanut gallery, I think your outrage is misplaced. "Deception" needn't be malicious, and the title already calls this out as an "astonishing achievement."

I think you're trying to say that telling white lies is deception, but not malicious... however, in this case it is not the scientist nor the picture, but they claim nature that is malicious in showing us what we expect to see (or what the writers think we expect to see).

"The temptation is to interpret the EHT image as a straightforward telescopic view of the hot accretion disk, seen from above, with the black hole carving out a hole in the middle. But it isn’t quite that."

So that's not what I expected to see, nor what I think I saw, but then I'm probably not part of the typical public. I do realize that it's a radio image not in the visible spectrum... so maybe that's deceptive too, like thermal imaging. But it's still click bait.

Re: The black hole picture is both an astonishing achievement and a deceptive image

#16

Post by wongarsu »

sk5t wrote: post #6
jameshart wrote: post #4

The use of the word 'deceptive' in this headline is astonishingly disingenuous. I don't think the article intends to accuse the publishers of the image of deception, but the headline sure reads that way. The article is just trying to explain that imaging a black hole is inherently counterintuitive.

Well, from the other side of the peanut gallery, I think your outrage is misplaced. "Deception" needn't be malicious, and the title already calls this out as an "astonishing achievement."

The image is deceiving, in the way that it is causing you to think something is true that isn't. Of course any 2d image is a black hole is deceptive by nature, no matter what you do.

The problem is that when the deception is caused by a person instead of an object it is malicious. "The picture is deceptive" is neutral, but "scientists created a deceptive image" sounds very malicious. And while the headline states the former, it's not a big leap to assume the latter.

Re: The black hole picture is both an astonishing achievement and a deceptive image

#17

Post by vertline3 »

nvahalik wrote: post #7

FTA: "An object in the centre of our galaxy (the Milky Way) called Sagittarius A* is thought to be such a “supermassive” black hole." If this black hole is 55M LY away and the center of our galaxy should have one. So, why is it that we can see this one, but not the one at the center of our galaxy? Is it because there are things in our line of site with it?

I heard it can be hard to see our center black hole because we are on the Galaxy disk so we have to look through a lot of light pollution and dust things to see it?

Re: The black hole picture is both an astonishing achievement and a deceptive image

#18

Post by huhwatnow »

It's not deceptive as much as it is dumbed-down and devalued as a tool for increasing scientific literacy and curiosity - at the very least the image should have included a distance and radiation energy scales - preferably several at different distances from the event horizon to account for GR. As it was released the xkcd comic of it provides more value than the image itself.

Re: The black hole picture is both an astonishing achievement and a deceptive image

#19

Post by pushpop »

markkanof wrote: post #13
sk5t wrote: post #6

Earlier quoted context omitted.

Well, from the other side of the peanut gallery, I think your outrage is misplaced. "Deception" needn't be malicious, and the title already calls this out as an "astonishing achievement."

That is the actual definition of deception.

One of the definitions but not the only one.

https://www.dictionary.com/browse/deceptive

It’s quite common - in the UK at least - to say things like “It’s deceptively cold outside.” When the weather is cooler than it looks. Clearly we are not saying “The weather is not intentionally deceiving us.” Because that would imply sentience in something that isn’t. The same logic applies with this title as well.

Re: The black hole picture is both an astonishing achievement and a deceptive image

#20

Post by nvahalik »

vertline3 wrote: post #17
nvahalik wrote: post #7

FTA: "An object in the centre of our galaxy (the Milky Way) called Sagittarius A* is thought to be such a “supermassive” black hole." If this black hole is 55M LY away and the center of our galaxy should have one. So, why is it that we can see this one, but not the one at the center of our galaxy? Is it because there are things in our line of site with it?

I heard it can be hard to see our center black hole because we are on the Galaxy disk so we have to look through a lot of light pollution and dust things to see it?

Yeah, I was researching further and found this[0] SE question. Seems to also say the same thing that there is a lot of "space dust" between here and there.

[0]: https://astronomy.stackexchange.com/questions/30339/why-not-...

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