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Comment by leereeves | Hacker News Reader

> For starters, in real life, there is visible light pollution in several directions around the forest and none of this is visible here on the horizon.

It seems like in many of the pictures, including the one above this quote, the horizon is much lighter than the sky above. Isn't that light pollution?

> You can perhaps recognize...the bright star Vega and Polaris, which would be located above the frame.

How do we recognize those? The arrow to "Polaris" is pointing out of the picture. And how was the bright dot in the picture identified as "Vega"?

View on HN

Vega is pointed out because in relation to the galaxy in the picture it allows the author to locate where Polaris should be (above the frame). Polaris being above the frame is a problem because it is never above the horizon where the photograph is supposed to have been taken.

I get that, but if that bright dot isn't Vega, then the argument falls apart. How do we know it's Vega?

From the article "The night sky offers an unlimited source of markers (e.g. stars, constellations, Milky Way, etc.) that never lie about the time of year and location in the world you shot a night sky picture from."

The key word is unlimited. Vega is correctly identified by the many stars around it that are in turn correctly identified by the many professional astronomers and astro-photographers discussing these very pictures. The photo mentions polaris to point out the absurdity of the north star being in the sky of a picture taken in the southern hemisphere.

That's an argument from authority without even establishing the authority in question.

Evidence, please.

Edit: Well, that's a lot of downvotes. So you all see the pattern? Why not point it out?

Or are you merely accepting this blog post without question?

Are you actually in doubt that the star in question is Vega, or do you believe that the author knows what they're talking about but just think it would be an amusing thing to start an argument over? I'm hoping it's the former.

Here is a photo of the so-called "summer triangle" consisting of the bright stars Vega, Altair and Deneb: https://astrobackyard.com/wp-content/uploads/2019/01/the-sum...

And here is an animation showing that same photo, roughly superimposed on the photo in question: https://i.imgur.com/MM37zt3.gif (EDIT: Imgur seems to be redirecting to a badly converted version of this animation, try copy-and-pasting the link into the address bar.)

Even without being able to identify individual matching stars, you can clearly see that the shape of the stars and dust lanes in the Milky Way are the same.

Thanks for that, that's helpful. That's pretty damning evidence, and I can't find anything that might look similar from Namibia in Stellarium.

Since you mentioned my motives, I'll address that: I'm just tired of the Internet falsely accusing people and want to see more evidence before the pitchforks come out.

But in this case, I'm convinced.

Fair enough. For my part, I'm tired of the internet (and HN in particular) being quick to dismiss the opinions of actual experts in any given field for superficial reasons. Your original comment that started this thread strikes me as a good example of the so-called "middlebrow dismissal": https://news.ycombinator.com/item?id=5072224

Yes, one shouldn't blindly accept the words of an authority. That doesn't mean it's a good idea to constantly demand that those authorities constantly back up every little thing they say, even on topics about which they are more knowledgeable than you are. That gets irritating really fast (which I suspect is why you got downvoted), and more importantly, it tends to derail more interesting and productive discussions.

Usually I wouldn't even comment on an article about astronomy, but this was a public accusation of fraud. I see questioning such posts as a moral obligation.

What's the bigger risk: annoying a few people with persistent calls for evidence, or letting a false accusation spread for fear of annoying people?

The "false accusation" is trivial to verify. The stars never change, not on the scale of human lifetimes anyway. All you had to do is look up a chart and you could prove it for yourself.

It's not trivial if you don't know what to look for, and I obviously didn't.

You obviously did, since your original comment on the matter contains the only three elements: Vega, Polaris, and the Milky Way

The sky at night. Is quite big and appears fairly regularly, you can't miss it.

>Or are you merely accepting this blog post without question?

We are accepting this blog post with knowledge of stars -- and knowing that it aligns with what the article says and not with what the photograph shows.

Not everything has to be proven from first principles in all posts when many readers people already know the proof (and those that don't can look it up).

To understand the downvotes, imagine an article on some class of algorithms, and someone writing X algorithm is "O(N^2)" and so is worse than Y which is "O(logN)" -- them somebody asking similar to your comment "This is an argument from authority, where's the proof that X is O(N^2)".

If X is well known and established in all kinds of textbooks about algorithms, it's trivial to look up on the internet, or open a reference book, then there's absolutely no reason a random post should prove it's O-complexity again -- nor is "argument by authority" merely taking it for granted/as known.

From the article:

>About the author: Adrien Mauduit is a professional astrophotographer and cinematographer and the CEO and owner of Night Lights Films. The opinions expressed in this article are solely those of the author. Mauduit also does science education, communication, and public outreach for Project PoSSUM. You can find more of Mauduit’s work Facebook, Twitter, and YouTube.

From the comment I replied to:

> the many professional astronomers and astro-photographers discussing these very pictures

That's what I was talking about.

Even if we're just talking about the author, and you accept those qualifications, it's still an argument from authority without evidence.

With light pollution, northern hemisphere;

https://s22380.pcdn.co/wp-content/uploads/Vega_SummerTriangl...

from here - https://www.skyandtelescope.com/astronomy-resources/stargazi...

Notice the four tiny stars below Vega and the clear pattern of stars above and to the left of it.

Now look at the photo that is being questioned;

https://petapixel.com/assets/uploads/2019/05/image2-800x541....

Same four dots below, same pattern of stars above and to the left, so not just same pattern but same orientation of pattern. And a lot more other visible stars as there is less light pollution and probably a much longer exposure.

That took me a lot less time than you have spent crafting comments complaining about lack of actual evidence.

Someone else pointed it out already, but thank you as well.

But I'm not going to apologize for expecting more evidence in a blog post accusing someone of fraud.

You could go check yourself before going and doing essentially the same.

I accused no one of anything. Can you not tell the difference between "add more evidence" and "that's a lie"?

So you don't believe Vega can be identified by the pattern of star visible around it?

I believe that if it's correct, the pattern can easily be pointed out and verified.

But a mere claim without evidence, I question.

The pattern was clearly pointed out in the article:

> You can perhaps recognize NGC 7000 (North American, Pelican nebulae, Sadr region)...

Keyword: perhaps...everything else was redundant prose.

Well you can look at the picture and look at any star chart and compare them. It doesn’t take specialized knowledge to do this.

I did. I found Vega in Stellarium. I see Polaris, the Milky Way, and the dippers in Stellarium.

I don't see any pattern that matches the claim made by this blog post. But I'm no expert, so I'm asking for a clear demonstration of the evidence the author sees.

Services like http://nova.astrometry.net/ provide celestial location data of any image of the night sky. Plug the image into it and check that it is indeed Vega.

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