this post was submitted on 11 Apr 2025
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[–] tpyo@lemmy.world 32 points 2 days ago

I feel it is very important to post this here:

[–] LostXOR@fedia.io 47 points 3 days ago (3 children)

Some rough calculations:

5 leagues ≈ 15 mi ≈ 24.1 km. An average human has hair that's maybe 20 cm wide. Using the small angle approximation we get an angular size of 0.2/24100 ≈ 8.3x10^-6 radians.

At 400 nm wavelength, resolving details of that angular size requires an aperture of 1.22(400 nm / 8.3x10^-6) ≈ 5.88 cm.

So either Legolas has some absolutely massive eyes, has the ability to use both his eyes for optical interferometry (I'm voting for this since it's the coolest), or is just plain magic.

[–] Siethron@lemmy.world 7 points 2 days ago

There's magic in this world, it's possible elf sight is slightly magical.

[–] blanketswithsmallpox@lemmy.world 9 points 3 days ago (2 children)
[–] grubberfly@mander.xyz 3 points 2 days ago

didnt know old.lemmy was a thing.

Thanks !

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[–] rljkeimig@lemm.ee 106 points 3 days ago (13 children)

The reason Legolas can see that far is because the curvature of Earth doesn't exist for elves. It is the same reason they can sail off into the Undying Lands without circling back around.

[–] Skua@kbin.earth 53 points 3 days ago (1 children)

If you get 50m above the ground and have nothing in the way, you can see 5 leagues away as well. Good luck counting individual people from that distance though. The anime eyes are a necessity

[–] gravitas_deficiency@sh.itjust.works 12 points 3 days ago (1 children)

That, or he’s got absolutely bonkers retinas that have truly incredible sensory density, and an absurdly developed visual cortex to support it.

Argument basis: DSLRs. Compare the detail you can extract from a 1MP sensor to a 100MP sensor, shooting through the same optical setup at the same target.

[–] notabot@lemm.ee 31 points 3 days ago (1 children)

I think the pupil size calculation is based on defraction, so it doesn't matter how dense your retina is, if your pupils are smaller than that you still wont see enough detail. This is one of the reasons why we keep building bigger telescopes and especially telescope arrays. The bigger the effective apeture, the finer the detail it can resolve.

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[–] hinterlufer@lemmy.world 41 points 3 days ago (6 children)

even if you ignore curvature you have a resolution limit that depends on the aperture. Look up Rayleigh criterion for more info

[–] rimjob_rainer@discuss.tchncs.de 13 points 3 days ago (1 children)

But does it consider magic?

[–] SkyeStarfall@lemmy.blahaj.zone 9 points 3 days ago (4 children)

That would fall under "nonvisual perception"

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[–] frezik@midwest.social 25 points 3 days ago (2 children)

Didn't Middle Earth lore say the Earth was flat, but was made spherical later? Had that happened by then?

[–] Revan343@lemmy.ca 40 points 3 days ago (3 children)

Yes, but it's not spherical for the elves, just the other races, which is why elven boats can sail to the undying lands, but human boats can't.

[–] Isoprenoid@programming.dev 18 points 3 days ago (2 children)

Wait, is it the boat that ignores the spherical attribute or the entity that commands the boat?

Can an elf sail to the undying lands commanding a human built vessel?

[–] RedFrank24@lemmy.world 9 points 3 days ago (1 children)

It's neither, it's the Will of Eru Illuvatar that determines whether you can travel the Straight Road or not. Ælfwine travelled the Straight Road and landed at Tol Eressëa in 869AD after fleeing the Danes, and he was a Man, not an Elf.

[–] Lv_InSaNe_vL@lemmy.world 3 points 2 days ago (1 children)

Gimli and Frodo both also were able to sail to the undying lands

[–] RedFrank24@lemmy.world 4 points 2 days ago

Yeah but Ælfwine got there by accident, and wasn't escorted by elves.

[–] Kellenved@sh.itjust.works 21 points 3 days ago

I think you have to be an elf building a ship and convince each plank individually that the world is flat

[–] MajorMajormajormajor@lemmy.ca 15 points 3 days ago

Eru damn tangential elves flying off into space.

[–] IrritableOcelot@beehaw.org 9 points 3 days ago

This gives strong "Lovecraft describing things he doesn't understand as noneuclidian" vibes.

[–] huf@hexbear.net 16 points 3 days ago (1 children)

the world was flat until numenor made war on the undying lands. at that point, numenor sank and the world was made round and the undying lands were placed somehow outside them, so that elves could still sail west along the straight way and get there, but everyone else just sailed west around the globe.

later, tolkien changed his mind about a lot of this and played with it, trying to turn it into an always roundworld (scientifically accurate myth was his goal at this point) but couldnt really figure out how it'd work and he was old and then he died

[–] Swedneck@discuss.tchncs.de 1 points 1 day ago

so you're saying flat earth killed tolkien?

[–] Foofighter@discuss.tchncs.de 6 points 3 days ago (1 children)

You mean the curvature of middle earth, right? RIGHT?!

[–] Revan343@lemmy.ca 2 points 1 day ago

Middle Earth is canonically our Earth, in the past

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[–] e8d79@discuss.tchncs.de 57 points 3 days ago (1 children)

If anyone was looking for the exact quote its from The Two Towers, Chapter 2 "The Riders of Rohan".

“’Riders!’ cried Aragorn, springing to his feet. ‘Many riders on swift steeds are coming towards us!’
“’Yes,’ said Legolas, ‘there are one hundred and five. Yellow is their hair, and bright are their spears. Their leader is very tall.’
“Aragorn smiled. ‘Keen are the eyes of the Elves,’ he said.
“’Nay! The riders are little more than five leagues distant,’ said Legolas.
“’Five leagues or one,’ said Gimli; ‘we cannot escape them in this bare land. Shall we wait for them here or go on our way?’

[–] vrojak@feddit.org 14 points 3 days ago (1 children)

So 5 leagues wasn't even the limit for him, he could have discerned their hair color at an even greater distance.

[–] Klear@lemmy.world 12 points 3 days ago (1 children)

I like the "lucky guess" theory. He's bullshitting them.

[–] vrojak@feddit.org 15 points 3 days ago

His thought process was probably "we're gonna run away anyways, I'm gonna tell these idiots I can see their hair color lol"

[–] LovableSidekick@lemmy.world 5 points 2 days ago* (last edited 2 days ago)

3.5 cm pupils? I've heard of "wide-eyed" but this is ridiculous!

But I never knew a "league" was 3 miles. That's like, a lotta football fields!

[–] Lumidaub@feddit.org 32 points 3 days ago (11 children)

He has very strange-looking ears as well so I don't see the issue.

Also, take that, people who were whining about artists drawing manga-style LotR fanart after the Peter Jackson movies.

Anyway, does Legolas' ability to see very far necessarily mean his pupils must be humongous? The pupils on eagles aren't exactly very large either but as a cursory internet search tells me their internal structure is very different from human eyes. Anyone able to speculate on elvish eye anatomy?

[–] Skua@kbin.earth 22 points 3 days ago (4 children)

Your pupil is functionally the same as the aperture on a camera. Whenever light passes through an aperture, there is some diffraction that happens to it; the angle of the light changes. This is separate to anything the lens does. If there's too much diffraction, you won't be able to tell two different sources of light apart. The amount of diffraction depends on the wavelength of the light and the size of the aperture. Bigger apertures and shorter wavelengths diffract less. This "diffraction limit" has a formula accordingly.

So for the question, we make some basic assumptions: take the wavelength of red light as it's the longest wavelength for visible light, and assume he needs to be able to tell apart two light sources 2 metres apart at a distance of 15 miles to distinguish individual riders. We figure out the angle between two points 15 miles away and 2 metres apart and now we know the angular resolution necessary. We know that the diffraction limit of Legolas' eyes has to be at least as small as that resolution. We also know our wavelength, so we can stick those into the formula and find out the minimum aperture (ie, the minimum diameter of Legolas' pupils to make out the riders at that distance)

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[–] Hope@lemmy.world 13 points 3 days ago

I don't know enough about eyeballs to be able to answer, but 5 leagues is a bit more than 5x farther than eagles can see, and eagles already have larger pupils than humans do.

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[–] propter_hog@hexbear.net 12 points 3 days ago (5 children)

Ok but 15 miles is over the horizon isn't it?

[–] entwine413@lemm.ee 16 points 3 days ago* (last edited 3 days ago)

Yes, but it doesn't mention that he's 30ft tall. That might make 3.5cm pupils proportional.

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