8 min read

LuxeSci Show Notes: S3E8 - Stripes and Science

Hello Fancy Folks, welcome back to LuxeSci, where we make science a little less intimidating and a little more luxurious by exploring the intersection of science and luxury. I’m your host, Dr. Lex, global health consultant, survivor of too much flow cytometery in grad school and lover of all things fashion.

This week we’re taking a classic pattern, stripes! Stripes these days invoke anything from a New England seaside vacation, complete with boat shoes and a large dose of coastal grandma chic, to sitting at a cafe in Paris sipping coffee. Stripes are considered the ultimate classic pattern. For Spring/Summer 2024, Gucci, Bottega Veneta and Dries Van Noten all included stripes in their runway shoes and Elle magazine declared stripes as the print for accessories for the season.

While we’ve all heard that horizontal stripes can make you look wider, what else is there to know about stripes? Join me as I learn about why stripes are helpful in the natural world, what in the world charge stripes are and a little more solar panel fun.

Enjoy!

Background

Stripe - textile design consisting of lines or bands against a plain background
In our last episode, I made reference to laws during the Middle Ages (and beyond) that dictated who could wear what type of clothing. This applied to stripes as well. There’s a legend that I found in almost every article about the history of stripes
Apparently in 1310 a French cobbler was condemned to death because he was wearing striped clothes
This was because striped clothing was, at the time, reserved for social outcasts, prostitutes, clowns, and hangmen, etc were all ordered to wear striped clothing so that they could be easily identified.
The stripes at the type were mostly horizontal and likely influenced the horizontal striped uniforms of prisoners in more modern times (again, to be easily spotted in the vent of an escape)
Stripes got a more popular spin in the Napoleonic era when Napolean himself had a striped, tented room added to the Chateau de Malmaison and American and French Revolutionary stripes appeared everywhere (vertical stripes being for the aristocrats)
By the mid-1800s, striped shirts were the uniform of the French navy (horizontal stripes to be easily spotted if you fell overboard)
It was in 1846 when Queen Victoria dressed her son in a sailor suit that stripes became wildly popular in fashion
Modern stripes in fashion is a product of Ms Coco Chanel. The story is that she was on holiday on the coast in France and fell in love with the sailor’s uniforms and created her 1917 nautical-themed collection. It included the Breton top (2” of white stripes and 1” navy stripe)
She was photographed in the top and this was a sensation because the tops were associated with men
Acknowledge that Coco Chanel has a sordid history of collaboration with Nazis
Striped beach clothing became the vogue in the mid 19th century.
In the 1980s Jean-Paul Gaultier - started using a stripe pattern on his male fragrance collection and has integrated into his collection since
Stripes are seen as rebellious and bold and at the same time timeless and classic

Science

Ok so you know I love an animal print and stripes are no exception. We’re going to start our journey into stripe science with zebras. For me, when I think stripes in nature, I definitely think of this animal. But how do zebras get their stripes?
Like with many coat patterns in animals (think leopards), zebra stripes are inherent at birth. The pattern develops during embryonic development and they are born with brown stripes that darken as the animal ages
The color is from the transfer of melanin from skin cells
Melanin - dark brown to black pigment occuring in hair, skin and iris of animals
Polymer that originates with amino acid tyrosine (remember polymers and amino acids)
Produced by melanocytes
While zebra stripes are inherent from birth, there is regional adaptation of the stripes depending on where the zebras live
A 2014 paper published in Royal Society Open Science and authored by scientists from The University of California, The University of Tubingen and Princeton University looked at modeling zebra stripe patterns along with temperature, fly biting and predation by lions to see if there were adaptations in the patterns due to any of those pressures
They quantified stripe patterns at 16 sites across the plains zebra range (included stripe number, thickness, length and color of saturation)
They used a random forest model and a set of 19 predictive variables to see which environmental variables would be explain the variance of the stripes.
Random forest model - a form of machine learning uses decision trees. Each treed gives a suggestion to the question provided and the algorithm then looks at the suggestions from the trees and picks the most popular choice
They found that environmental variables could explain between 30-63% of the variance (difference) in patterns
The most consistently important variables were isothermality and mean temperature of the coldest quarter
Bottom line - temperature was a significant predictor of zebra stripe patterns across their entire range in Africa.
Now, despite this finding in 2014, the prevailing thought on why zebras have stripes now is for fly deterrence.
There are multiple fly species that are known to attack zebras including tabanid (these include horse flies), glossinid (tsetse flies) and Stomxys species (biting house fly, dog fly)
Aside from the painful bits and blood loss, these flies can also carry parasites
It would be advantageous to avoid getting bitten
Because i cant resist talking about parasites, here are some that can be transmitted by flies. First is sleeping sickness, or Trypanosoma brucei. In humans, this presents as a sickness that includes behavior changes, confusion, sensory disturbances and poor coordination. This is due to the parasite’s presence in the central nervous system. This is usually fatal without treatment
Another one is Loa loa. This is a filarial parasite (the kind that i studied). In humans, the worms can live in your eye, though they don’t cause a lot of pathology, though it can be painful and cause inflammation
But how exactly does this work? A group from Princeton, City University of New York, USC, UCal Los Angeles published a paper in Nature Scientific Reports in 2022 with their research on the mechanism of flies not liking stripes
They tested the landing choices of flies (within the range that flies should be able to see the stripes) using real animal pelts (striped zebra and plain impala) and they used the pelts over live animals so that animal behavior could be factored out as part of the landing choice of the flies
They salt cured the pelts to remove the odor
Used wide-striped and narrow-striped zebra pelts
So what did they find:
They found that the impact of stripes is liking in close range for the flies (right before they are going to land)
There was no difference in fly landing between the wide stripes and the narrow stripes
When they do land, flies prefer the black stripes over the white striped areas
Did not come to a conclusive hypothesis about why stripes are disliked so much by flies
However, not all stripes in the animal kingdom are used for bug repellent. Lizards have evolved longitudinal body stripes and colorful tails that are thought to confuse predator’s attacks by a mechanism called “motion dazzle”
Motion dazzle - type of defensive coloration that operates when in motion, causing predators to misjudge the speed and direction of object movement
I’m now going to try to pick out my outfit for maximal motion dazzle. I feel like that’s a solid fashion method
So stripes on animals seem almost self-explanatory, though I did learn a ton about zebras. What other types of stripes can we find in science?
OK - I’m going to be super honest about this. I found an article about charge stripes in graphene and I thought in my hubris that I could read it and make a reasonable understanding of it. I was astoundingly wrong. It might as well have been Greek to me and I’m learning Greek and it still didn’t make any sense.
So I back-pedaled a bit and found a really help article from the Brookhaven National Laboratory and a huge shout-out to them for making a complex concept easier to understand
Brookhaven is run by the US Department of Energy. Research there includes energy science and technology, nuclear physics, nanoscience and more.
So stripes are interesting to researchers at Brookhaven because they are thought to be involved in superconductivity
Superconductivity (per Brookhaven) - is the ability of some materials to carry electric current with no energy loss
So it seems that particular arrangements of electrical charges that scientists call stripes may contribute to superconductivity
Previous research from Brookhaven showed that magnetic spin stripes - how adjacent atoms’ spin directions are arranged - are compatible with superconductivity.
In a paper published in 2013 in Physical Review Letters, scientists looked to see if alternating stripes of more densely or more loosely packed atomic charges are associated with superconductivity.
A great way to visualize this was explained in the article. If you’re looking at a parking lot, the lines of the parking spots are the positions of the atoms making up a crystal and the cars are the electrons. If you took a picture then you could see if there was a pattern (such as alternating car color). That would be the magnetic spin. To visualize the charge density, you’d have to take a very long exposure shot and it would all look like a blur.
The scientists got around this challenge by looking for a signature that suggests the presence of stripes but is much easier to measure.
They ground up crystals and and placed them in a neutron beam. At first they saw atoms displaced in a regular way - think parking spots that alternate wide, than narrow.
These displacements force the electrons to follow a striped arrangement
With increasing temperature, though the crystal structure changed, the striped pattern of charge density also remained.
This was a to look for superconductor materials using a method that was less expensive and took less time than previous methods
So stripes are heavily involved with superconductors but why is that important? They are currently used in mag lev trains and Magnetic Resonance Imaging. They could be the key for faster computing power and much more efficient electricity conduction for national grids. I’d say that’s pretty impressive.

Glossary

Melanin - dark brown/black pigment in hair, skin, and iris
Random forest model - statistics that compare different decision trees and decides on what is the most likely association
Motion dazzle - defensive markings that throw off a predators strike when in motion
Superconductivity - the ability to carry electrical current with no energy loss

Fun facts:

Zebras have stripes as bug repellent
Stripes are responsible for superconductivity, which allows you to get a MRI

Thank you for going on this journey into stripes with me. I have to admit that I wasn’t expecting to find what we did. THe history was fascinating and the science was of course cool and it included parasites!!!

If you learned something new, please pass it on to a friend by sharing the podcast. And don’t forget to click that subscribe button, nothing is more satisfying than a good click.

LuxeSci podcast is an Erevna Media production. Produced by me, Dr. Lex. Audio engineer is Dr. Dimos and our theme music is Harlequin Mood by Burdy.

You can find us all over social media at LuxeSci pod. Feel free to jump us a line. We always love to hear from you.

Until next time!

References:

LuxeSci Show Notes: S3E8 - Stripes and Science

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