[colanderman]

There is in fact no photograph of treetops glowing.

There is a digital UV-wavelength video of the corona, and a visible-wavelength video of the trees.

The paper [1] contains a sole picture with tiny circles indicating where the UV-video detected corona events, overlaid over a frame of the visible-wavelength video.

The paper does also contain a video [2] which overlays a somewhat processed version of the UV video over the visible wavelength video, where UV photon events are indicated by decaying red dots.

[1] https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2025GL11...

[2] https://agupubs.onlinelibrary.wiley.com/action/downloadSuppl...

[raincole]

That's some weird semantic nitpicking.

Wikimedia has a category of "photographs of the Sun":

https://commons.wikimedia.org/wiki/Category:Photographs_of_t...

Do you think they are not photographs of the Sun because these are not what I see if I look at the sun with my eyes? (In which case I'll see pure white then perma black, I assume.)

[pavon]

Sure, a photo taken in non-visible spectrum is still a photo. And stacking photos taken with different wavelength filters or sensor can also be considered a photo. For example the headline image of the spruce tips taken in a lab is photo. And based on the description of the UV camera in the paper, they did generate UV video of the tree tops.

However, the linked article and associated paper don't have any such photos (or video) of the corona in the treetops. Instead the UV video was processed with a detection algorithm, and then the visible-light photos and video were annotated with graphed dots of where detections were seen. Those dots aren't a photo of the corona by any reasonable definition.

[latexr]

> then perma black, I assume.

Probably not.

https://www.bbc.com/news/blogs-ouch-31487662

[YeahThisIsMe]

What he explains sounds exactly like what you (or at least I) see when you close your eyes and then put pressure on them.

[doubletwoyou]

The way I had it explained was trying to look out one eye while the other’s closed

[steve1977]

While reading I thought this is basically visual tinnitus and then the author used exactly that term. As someone with tinnitus, I can definitely understand the longing for "absolute darkness".

[dugidugout]

This was a very depressing read.

[t-3]

They're the same as looking at the sun with your eyes. You won't go blind looking directly for a short time. It's just best not to stare for a long time.

[colanderman]

Can you point me to the images of corona in the paper which I missed?

[moralestapia]

Lol.

At work, some guy has been pushing a 2-day feature into its 5th week now, with questions like "what do you mean by (database) table?" "Is <not_a_database_table> a database table?"

Etc...

We have to fill-in RFDs to answer those kind of questions, so the process is massively slow and st...(expunged due to HN guidelines).

So yeah, some people really love their semantics and are willing to do whatever it takes to keep it that way.

[You can take a guess at where this startup will be in 2-3 years ...]

[em-bee]

wrong thread?

[addaon]

Sorry, in what way is this not a photograph? Are you saying that a video is not a sequence of photographs, that UV photons captured by a sensor don’t count because human retina sensitivity is low in that range, or some hopefully-less-semantic argument?

[clickety_clack]

The headline suggests that people have seen treetops glowing and it just hasn’t been captured on video before. The actual pictures and video is of something that nobody could have seen with their eyes.

[eel]

This reminds me of a chat room interaction I had maybe 25 years ago. The other person was adamant that humans can't see the infrared from TV remotes, and I was adamant that I could. It was pretty a widespread belief (even in school science books) at that time that humans couldn't see infrared. Since then more science was done to prove that, in fact, some humans can see some infrared under some conditions.

I share that mainly to state that humans are amazing and have a wide and inconsistent range of capabilities (and sometimes even mutating into new capabilities!) Personally, I will always hesitate to say "nobody" and I lean towards "no typical human" instead. :)

[lukan]

I suppose this also depends on the types of remote controls? There are some where I can see red and some where I cannot.

[MisterTea]

The faint red glow is actual red light as many IR LED's (esp the ones used in cameras for night illumination) are close to the visible spectrum and have some visible light emission.

[formerly_proven]

850nm is easily visible, but most remotes are 940nm, which is also visible as a faint purple glow but the source needs to be really bright.

[dtgriscom]

Isn't infrared, by definition, wavelengths beyond what people can see?

[jibal]

Which people? And no, it's not defined that way: "radiation having a wavelength between about 700 nanometers and 1 millimeter"

[WarmWash]

You can absolutely see corona discharge like that with your eyes.

If you come to my day job, and we shut off all the lights in the test room, after your eyes adjust in the dark for a minute, you'll see the soft purple glow coming from the edge our 160kV test rig.

Definitely emits UV, but there is enough visible to see it for sure. It comes from the electrons exciting nitrogen in the air.[1]

1. https://commons.wikimedia.org/wiki/File:Nitrogen_discharge_t...

[yetihehe]

> (1:If you come to my day job), and (2: we shut off all the lights) (3:in the test room), (4:after your eyes adjust in the dark for a minute), you'll see the soft purple glow coming (5:from the edge our 160kV test rig).

So, 5 different things that make it glow "not coming from treetops". Parent poster wanted to see glowing treetops in a forest, where we might not be adjusted to dark for a minute.

You can also see such corona discharge with benchtop tesla coils even in lighted room, but those are not trees in forest glowing from a storm.

[MisterTea]

Even a smallish Tesla coil easily produces voltages north of 160kV. I built one using 4" PVC for the secondary with a wound length of maybe ~2 feet of secondary? From memory of the calculations I did at the time I think it was around 350 kV peak? Might have been higher. Threw 24 inch sparks quite easily.

[clickety_clack]

I’m not saying it can’t be seen, I’m saying that you can’t prove something can be seen by showing me a photo that captures light that I can’t see.

[ajkjk]

what's the job?

[chrisfosterelli]

I don't really blame the researchers here but this is yet another article that is happy to have a clickbait headline which any reasonable reader is going to assume will include a picture of "treetops glowing".

At least personally I scanned the article for it and only found the picture at the top, which I was then frustrated to learn that's just a lab photo, and I came here wondering where the actual image is of it in the field so I found OPs comment helpful to indicate that the suggestion there would be a beautiful picture of glowing canopy somewhere is basically a result of editorializing.

[adammarples]

Maybe they take issue with the word "glowing", which doesn't usually refer to invisible electromagnetic radiation

[Brian_K_White]

I was going to say the same.

It's true that the image isn't fiction or a purely fabricated "artists rendering" from data. But it's also true that "filmed" and "glowing" are unusual ways to refer to what happened.

You don't usually say filmed when talking about recording uv or microwaves etc. You technically could, and probably back when film was actually how uv was recorded a few people working in the field probably did, but almost no one else does, or no one at all since decades, which means the author of the title is the one out of step, not the people reading it.

They actually recorded something, and this title is misleading. Both things are true.

[amluto]

When I worked in a lab that took videos with a UV camera, I still called them videos, and I would absolutely have said that I took a video of the subject (a methanol flame in this case).

Essentially every color photograph you have ever seen is a composite of a red photographic, a green photograph, and a blue photograph.

[colanderman]

Which photograph? The one in the article is not from the paper. The paper contains no photographs of corona.

[dang]

I've taken the "captured on film" out of the title above and used representative language from the article. If someone can suggest a better (more accurate and neutral) title, we can change it again. (But the subject is interesting whether on film or not, let alone "for the first time".)

[Bjartr]

While we're being unreasonably pedantic, it also wasn't caught on film because it was a digital camera.

[_Microft]

Half of the comments are in this subthread which derailed the discussion on this submission before it even started. Here the damage is done but maybe, please, refrain from doing so elsewhere.