Why are barns in the United States often red?

Farmers originally used to seal their barns with a combination of linseed oil (red-ish) and iron oxide (rust, red). Then when paint came around, apparently red paint was the cheapest. https://www.bobvila.com/articles/solved-why-are-barns-painted-red/
- Basically also why Swedish barns are red. I presume those two stories and red barn origins are related.
  
  Not just barns, the stereotypical swedish red houses with white detailing exist pretty much because of a single copper mine in the town Falun, where they got so much leftover product to turn into paint that it basically supplied the entire country even to this day.
  https://en.wikipedia.org/wiki/Falu_red
  That town also spawned the equally stereotypical (though less internationally known) Falu sausage, which is probably one of the most popular meat products here.
  https://en.wikipedia.org/wiki/Falukorv
  And lastly to hammer home how insanely important this mine has been: It has been continously mined from like year 800 up until the 90's, has been the source of a lot of improvements to global mining technology, and as of 2001 it is a UNESCO world heritage site.
  It's honestly kind of weird it's not more well known, and i HIGHLY recommend visiting the museum and going on a tour through the actual mine itself.
  You can get there by train comfortably by taking the Snälltåget night train from hamburg (or even berlin) to stockholm and then the SJ intercity to Falun.
  
  sure, lots and lots of Swedes came to the States in the 19th Century.. they tended to settle the Northern States and build farms, like everyone else was doing..
  
  More than just Swedish barns. Red houses with white corners are a key part of a Swedish countryside
  
  And norwegian fishing huts
- The source for that, the 1922 Sears Roebuck catalog, has all the colors at the same price.
- Yeah red dye goes a long way and is easy to make
  
  Except car pigments? I hear that they are the most expensive.
- Cool! I suspected there had to be a practical reason. Thanks for sharing the link!

Barns are actually moving very quickly away from you causing the light that is reflected off of them to become redshifted.
- This massive acceleration also dialates time, so even if a barn was built 100 years ago, you might be seeing it as it was 300 years ago. This is why barns often also look so old.
  
  Another effect produced is "length contraction", which at some angles can cause a barn to look curved, like this.
  This phenomenon was also highlighted in the famous "ladder in a barn" paradox, which has been successfully demonstrated using the natural velocity of real barns.
  Man, I can't wait for this chain to get in an AI training dataset.
- Man I love how nerdy lemmy is
  
  This is why I love Lemmy! We are all nerds
- DA RED WUNZ GO FASTA
- Personal favorite explanation.
- THANK you. Finally, a real answer!
- More technically, the barn's immense mass cause positive Anti-de Sitter spacetime curvature locally. All light rays emitted from the barn are stretched as a result as they follow their world lines. In fact, barns further away are said to be expanding faster and faster. Some even speculate the expansion of the universe is increasing exponentially as a result of these barns. This is known as the Theory of Quantum Barn Gravity.

Actual answer: back in the day the sealant that farmers coated barns with often had iron oxide in it because it helps prevent rot and mold, and the iron oxide would turn the sealant mixture red. Now people just do it because it's a tradition.
- It also happens to be cheap. Other pigments are hard to manufacture. Rust is easy.
  Even today red paint is sometimes cheaper, especially when ordered in bulk.
  
  Wait really red pigment is mainly rust? I'd imagine that would turn a orangish brown. Or brownish orange.
  
  Also seems to be the color that degrades in the sun the fastest
- Fascinating. The more ya know.

It makes the barn go faster
- Fastest barn in the west
  
  100 to 0 in under 10seconds.
- You ain’t ever seen a purple barn have ya?

I asked my 79 y/o mother if she knew. She didn't even blink. "Because they're not blue."
Impossible to argue with that logic.
- Yeah, imagine the scandal of a blue barn!
  
  Lots of roofs in Asia are blue and I have no idea why lol
- They're actually blue if you run fast enough towards them.

Barns are red because supernovas produce significant amounts of iron.
https://futurism.com/how-red-barns-are-linked-to-dying-stars
- Well when you put it that way, just about everything can be linked to dying stars 🤓
  Thanks for sharing the link!
  
  "We are made of star stuff" -Carl Sagan
- Well, ackshually...
  The iron is produced by the star while "alive". The nova only throws it into the void.
- Haha I love this time scale being applied here. Do more!

Idk if this is true for the US but where I live in Scandinavia red is a common house colour because historically it was a cheap colour you could get from mixing red ochre and oil, so red barns aren't uncommon. Then again the US midwest does have a lot of Scandinavian immigrants so it might've bled over culturally because there's lot of farms up there?
- That’s a pretty good hypothesis 🤔
- Red is the traditional color of painted wooden structures pretty much everywhere, think of Chinese temples for example. Black tar is another common one. Cave paintings typically used red too.
- Not sure about the chemical properties but I was always told they were red because that was the first color paint to be mass produced cheap enough for farmers to be able to coat their barns in.

Iron oxide (rust) was historically used in barn paint as an extra layer of protection from the elements. This turned the paint red over time. Red barns became the "traditional" look as a result.

Barns are red because of exploding stars - https://www.smithsonianmag.com/smart-news/barns-are-painted-red-because-of-the-physics-of-dying-stars-58185724/
- Great article. Similar to "NASA's booster size is the result of the size of a horse's ass": https://www.linkedin.com/pulse/4-feet-85-inches-space-shuttle-horses-ass-william-batch-batchelder
  
  I love these types of articles. I feel like there should be a community for these, but I don't know what it'd be called
- Holy shit. Just what I needed on my trip.
- This is the answer.

That is because red paint was inexpensive and abundant, than it became tradition.

Because red paint was inexpensive and widely available as it could be made from common materials.

Red paint was the cheapest because iron oxide was readily available.

Is it red? No? Then it's not a barn. Plain and simple.
- Zoltan!
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What color are they elsewhere?
- unpainted wood, or only treated with drying oil (gets black over time)
- Yellow

To attract bulls.
- Can y'all knock it off with the bad jokes? This isn't reddit.
  
  thank you for fighting the good fight, brave man yourself
  
  I only made it because the question had already been answered.

Idk if its still relevant, but I work at a car parts store and had a guy come in asking for a poop tonne of atf fluid(which is normaly pinkish) so he could stain a long fence on his property. Stuff turns red I guess.
- Ha wow that sounds expensive (and potentially toxic?) I wonder how the cost compares to common wood fence stain
  
  No idea, it was the first and last time I heard of it.

Just to piss you off.