What even are cats?

Cats are strange. They constantly seem to be plotting to kill you or to take over the world. They lend their name to quantum physics thought experiments or grinning characters from children’s tales. They come up with creative yet actually very annoying ways to brighten your day, and they only participate in science experiments when they feel like it.

Cats are strange and the scientific community at least agrees on this fact. A 2014 study wondered what the physical nature of cats was, asking the very important question: are cats solid or fluid?*

Fluid dynamics for some very fluid cats.

Marc-Antoine Fardin used a scientific approach to answer the question “Can a Cat Be Both a Solid and a Liquid?”

Here was his conundrum:
Cat’s are generally assumed to be solid. You know, you can touch them and they feel pretty solid. But on the other hand, cat’s fit into really small spaces and can seemingly adjust their form to the container they are in – a property usually attributed to fluids. This is commonly known in internet circles as I fits, I sits.”

A kitten fitting in a wine glass to illustrate that cats can fit into any small space.
Who needs a glass of whine when you can drink fur?
(Image credit: unknown)

The author takes a rheological approach (rheology = the study of the flow of matter) to try to differentiate between whether the deformation of a cat is solid deformation or fluid flow. Solids can be deformed, especially if they are soft. Think Play-Doh, which can take any shape while keeping the same volume as opposed to honey, which can also take any shape while keeping the same volume but can be poured.

To me, “Can a cat be poured?” is the question worth asking, and this might be difficult to test without ending up with a lot of scratches.

Reading the paper, I was starting to think the author didn’t take his research very seriously (among his acknowledgments he thanks two people – or cats, I don’t know – for “providing a reliable technique to load Felis catus in different geometries: 1.Bring an empty box; 2. Wait.”). That said, studying the physical nature of cats could bring us closer to understanding the nature of matter itself. More recent experiments are promising:

It seems that the duality of cats extends beyond dead or alive.


Source:
On the Rheology of Cats,” Marc-Antoine Fardin, Rheology Bulletin, vol. 83, 2, July 2014, pp. 16-17 and 30.

* The study won the 2017 Ig Nobel prize for Physics. The prize awarded to science that first makes you laugh and then makes you think. To be honest, it makes you think that the whole thing was a joke in the first place. It probably was.

Death Stare for Gullie

It’s happened to me. I’m sitting, calmly enjoying a sandwich outside on a bench, and then …

A seagull swoops in and tries to steal my food.

It’s terrifying. Seagulls are scary, especially up close and especially in Dundee, where I used to live and frequently sit outside eating something or the other. They have mean eyes.

I remember the seagulls in Dundee being quite peculiar. An anecdote: I was walking along the sidewalk, edging close to a corner where a seagull was digging through a ripped trash bag. When I was a few meters away, the seagull looked up and did this little walk away from the bag, pretending as if they weren’t just digging through trash. After I passed the corner, I glanced back and saw that they’d done a u-turn and went back to digging.

Okay, maybe I’m giving the bird too much of a personality. But it was weird.

Back to the food-stealing; a research conducted at the University of Exeter showed that if you stare at a gull, it is less likely to steal your chips (for US readers: french fries which are totally not from France but from Belgium and stop calling things the wrong name and, never mind, I’m okay).

Granted, the study had a limited scope. They tried to test 74 gulls, but more than half of them flew away. And it is likely that a lot of seagull related crime is due to a few bad seeds and most seagulls are perfectly happy leaving you and your food alone and digging through the trash for snacks.

Nevertheless, seagulls that were “looked at” while they were approaching food, were a lot less likely to touch that food. In fact, only a quarter of seagulls that were being watched while they tried to approach and eat food actually touched the food.

Maybe they were just scared of getting caught while committing food theft. Maybe they hate the color of our eyes. Maybe our stare is truly terrifying (I certainly know a few people with a scary stare). But next time you see a seagull approaching your food, give them the death stare. Perhaps your meal will be saved.

Grafitti of a seagull protecting a pile of fries
Come at me bro

Sources:

Wine tears

Perhaps drinking wine makes you all emotional. Perhaps drinking wine reminds you how you secretly enjoy beer better but then why do you have this weird stemmed glass in your hand? Perhaps you remember your early twenties when you lived in France and okay-to-good wine was very cheap and now you live in a country where okay-to-good wine is no longer cheap and cheap wine is sure to give you a headache the next day. Perhaps drinking whine makes tears run out of your eyes.

Gif of Will Ferrell crying and drinking a glass of wine

Did you ever stop to consider that crying over wine makes the wine cry as well?

Just kidding. I actually wanted to talk about wine tears. Which is the weird phenomenon where a ring of clear liquid forms in a wine of glass that has a bunch of droplets forming from it. Tears of wine. It’s a thing. A chemistry thing.

wine tears
No need to cry, it’ll be alright!

This type of “tears” appears because alcohol, you know that thing that is about 13% of that glass of wine your crying into, has a lower surface tension than water, which is that thing that most of the rest of that wine is made of. So like 85%, plus or minus a percent depending on how much crying you’ve done into the glass.

At the surface of the wine in your glass, where the liquid surface meets the side of the glass, capillary action causes the liquid to rise up the side of the glass. This thin film of liquid contains water and alcohol, both evaporate. Due to the higher vapor pressure of alcohol, it evaporates quicker than the water. This decreases the alcohol concentration in that liquid film, and consequentially also the surface tension, causing more liquid to rise up. Eventually, the liquid forms droplets that fall back into the wine. Gravity, it always gets ya!

A diagram explaining how tears of wine form.
Also called the Marangoni effect, γ is surface tension.

So there. When you drink wine, just remember, you’re not the only one crying.

Some tall stories

It is no secret that I’m a fan of giraffes. I have said this before, but I feel a certain sense of kinship with them. You know. Tall. Clumsy. Slightly derpy looking.

I was reminded of this when I found an old t-shirt on the bottom of my t-shirt shelf (yes, I have a t-shirt shelf. I’m incredibly organized. *ahem humblebrag ahem*). As you could have guessed, it has a giraffe on it. And that reminded me that I know a lot of random giraffe factoids.

So here are some tall stories, literally.

Giraffe Factoid Numero Uno:

Giraffes are about 2 meters (which is like 6ft6″ I think? Get with the metric, people!) tall at birth, making them world’s tallest baby and also the envy of all the guys on dating apps.

Baby giraffe in a pool - comic.
Which is still pretty deep actually.
(comic by Edward Steed for the NewYorker)

Giraffe Factoid II:

No two giraffes have exactly the same spot pattern. Basically, their spots are a bit like human fingerprints. This is very useful for giraffe-scientists – also known as girafologists (not really) – because it can help them recognize their study subjects easily without having to check for toe prints every time.

giraffe meme: I'm fabulous!
Fabulous, and unique!

Giraffe Factoid Number Three:

Giraffes’ tongues can be up to 50 cm (20 inches?) long. *insert another tinder joke here*

This long tongue helps them eat. Giraffes binge on acacia leaves, which unfortunately grow on thorny trees. Thanks to the long tongue, they can reach around the thorns and get to the tasty leaves without getting a scratched tongue!

Their tongue is also blue-black-purple in color because it has a lot of melanin. This is probably to protect giraffe tongues from sunburn.

photo of a giraffe sticking out it's tongue
Nahnahnahnah Nah Nah. The [sun and the thorns] can’t get me!

Giraffe Factoid Number 4:

Ironically, many giraffes have a fear of heights. I think this is why I identify so strongly with them… I too am tall and get dizzy even when just standing.

Spotted outside a bar in Brisbane. Hey, did I ever tell you I went to Australia?

Giraffe Factoid Number now-for-real-number-four

Male giraffes test a female’s fertility by tasting her urine.

On the subject of urine, did you know that early pregnancy tests relied on… frogs? In the late 20s, a South African researcher discovered that if you injected certain hormones in a certain frog (Xenopus laevis), they would start ovulating. These hormones are also present in the urine of a pregnant woman. With that, frogs became the first reliable pregnancy test!

Giraffe Factoid Number Fünf

If you have read Harry Potter, or any other British literature aimed at teens, you might think that necking means snogging. Which means kissing, the French way. But in the giraffe world, necking means smacking another giraffe with your neck. It looks scary.

Hey, did you know that giraffes have the exact same number of neck vertebrae as humans? They’re just a lot bigger. And presumably stronger, if they can do all that necking.

giraffe necking gif
And now… neck. No, that’s not what I meant!

Giraffe Factoid Number Final-One

Giraffes are awesome. And if you don’t agree, well, that’s just your opinion! (The giraffes being awesome thing is totally objective.)

Apollo 11

50 years ago, on this very day, the Apollo 11 was launched. 4 days later, it would be the first manned landing on the moon.

You can watch the whole launch here (with the actual take off around 3:27:10):

[CBS]

In the meantime, I spent (some of) the afternoon shooting water rockets with a group of campers. It was marvellous.

I’m a model and you know what I mean

Wait, what do I mean?

It’s perhaps a bit of a stereotype, but scientists don’t always know how to talk to non-scientists. To be completely honest, scientists don’t always know how to talk to other scientists! This can partially be attributed to the use of jargon – lingo that is used by a specific group of people that is difficult for people outside that group to understand.

Let me give an example.

If you look up the word “model”, Mirriam-Webster gives 14 different definitions; that’s already cause for misunderstandings without any science coming in!

Meaning number one: “I’m too sexy for my shirt!”

model noun [ mod·​el \ ˈmä-dᵊl ]
9 : one who is employed to display clothes or other merchandise //has appeared as a model in ads for swimsuits

In every-day, fashion lingo, a model is someone who shows off clothes or other merchandise on billboards, in magazines, on the catwalk, in tv ads, etc.

This version of the word model is probably not what any scientist means when they are talking about their model. Except maybe if they’re bragging about that “model they dated back in college,” but we were all dating models then, weren’t we?

dating a model meme: Leonardo DiCaprio saying: I'm dating a model now, she's a simplified representation of reality
I don’t believe you, Leo

Meaning number two: To see what cannot be seen

model noun [ mod·​el \ ˈmä-dᵊl ]
11: a description or analogy used to help visualize something (such as an atom) that cannot be directly observed

Some things we can’t really take a picture of. Or even if we can, it’s difficult to gather any meaningful information from the picture. A model of that thing can help; such as a model of an atom, or our solar system, or the universe. Such a model is usually simplified to allow a clearer understanding, and as a result, it is never 100% accurate.

For example, the model of the atom has gone through many iterations and has become more representative of the physical reality (in so far as we understand it). That doesn’t mean that older models are wrong, they’re often just insufficient. For many purposes, the Bohr model is enough to explain the formation of bonds and many aspects of physics and chemistry even though the quantum model is more details, and is needed to describe more advanced principles (like the types of bonds).

Models of the atom over time, a comic by xkcd
Hovertext: J.J. Thompson won a Nobel Prize for his work in electricity in gases, but was unfairly passed over for his “An atom is plum pudding, and plum pudding is MADE of atoms! Duuuuude.” theory.
From xkcd

Meaning number three: To the computer!

model noun [ mod·​el \ ˈmä-dᵊl ]
12: a system of postulates, data, and inferences presented as a mathematical description of an entity or state of affairs
alsoa computer simulation based on such a system (e.g. climate models
)

But not the type (i.e. model) of your computer. Wait. This is confusing.

The model of your computer might be 80NW. But a computer model – or a computer simulation – is a mathematical representation of a system and nowadays those mathematical representations are often running within a computer (because they can do math faster). Basically, a computer model/simulation is a program that is used to predict (hopefully) useful information based on a number of equations (or from learning data in the case of machine learning) that have been predefined.

In my PhD, I created a computer model for how ultrasound interacts with tissue. I told the program the properties of the ultrasound wave (its frequency, its shape, etc.); the properties of the tissue (size and shape, but also how stiff the tissue is); and the boundary conditions (how big the experiment was). After letting it run for some time, it would give me information back that I could use to understand this interaction better and compare it with results from physical experiments.

Graphical output of modelling ultrasound interacting with a penguin
Here is the incredibly useful test model I ran of an ultrasound wave (coming in from the left) interacting with a penguin. Image from PZFlex.

Computer models are very useful. Sometimes we would have to run experiments that are not possible to do physically, due to lack of resources or time or any other reason. Running a computer model is relatively cheap. In other cases, we are trying to make predictions on what will happen in the future, trying to do experiments on the unknown. An example of that is climate models.

Meaning number four:

model noun [ mod·​el \ ˈmä-dᵊl ]
14: ANIMAL MODEL an animal sufficiently like humans in its anatomy, physiology, or response to a pathogen to be used in medical research in order to obtain results that can be extrapolated to human medicine

also a pathological or physiological condition that occurs in such an animal and is similar to one occurring in humans

We are complex organisms, with a bunch of different types of organs and different types of cells that have a bunch of different processes going on at a bunch of different times. Sometimes, researchers can use cell lines – these are cells that have been isolated (often decades ago) and immortalized (they can be grown in petridishes and cultured for quite some time in said petridishes) to study biological processes and the effects of potential new drugs. But these isolated cells never give the whole picture (because they are so isolated), and sometimes animal models are needed for the next phase of genetic studies, cancer research, or drug development.

So unlike what I picture in my mind when I hear “animal model”, this does not mean mice in the bikini special. Rather, certain animals have traits that mimic a human condition or disease in such a way that research is meaningful. Whether it is ethical or not – that is a whole other discussing but just let me say that there are a lot of regulations and the principles of the 3Rs (Replacement, Reduction, and Refinement) are enforced in any proper lab conducting experiments using animal models.

The other note to make is that animal models don’t always give us the full information either. Again, it’s a model, An approximation. But since human experimentation is – well – inhumane, that’s often the only way to study genes and test drugs in a working-body-context.

A note on scientific theories

I don’t remember where I read this but: science theories are models for how the world works. In other words, like any model, they are not perfect! But they are a great way to try and understand the world better with our fairly limited brain capacity*. The fact that they are not perfect is actually really exciting: there is always more to discover, more to learn, more to understand!

In any case, if anyone tells you that they’re a model, if you know what they mean, you might want to ask them to specify… Just to avoid confusion.


*If you find this offensive, remember I’m mostly offending myself.

Definitions are taken directly from Mirriam-Webster dictionary.

Sinking ship

Ever feel like your on a sinking ship? Just one of those days where everything seems to be going wrong, the weather, work, writing…

Wait – I’m not here to write about exististential crises. I want to write about sinking ships. And bubbles.

An excited fish (from the movie Finding Nemo) seeing bubbles escaping for a treasure chest in an aquarium.
I have used this gif before. And I will use it again.

The Bermuda triangle seems to be one of those unresolved mysteries. In this triangle-shaped area near Florida, an unusual high number of ships have reportedly sunk to the bottom. Is it due to paranormal activity? Aliens? Magic?

It might just be due to methane bubbles – there are flatulent cows at the bottom of the North Atlantic Ocean.

Just kidding. There are no cows there.

There are large areas of methane hydrates. This natural gas cause periodic methane eruption, causing bubbly regions in the ocean. And it turns out that bubbles can cause ships to sink.

Bubbles cause the average density of the water to decrease, and when this is too low (lower than that of the floating object), an object that would normally float would sink. It sounds a bit like the opposite of a fluidized bed, where a solid is turned liquid, making things float on sand.

Methane bubbles are one of the possible reasons for the mysterious disappearance of boats in the Bermuda Triangle. Though violent weather and dramatic, exaggerated reporting are probably more to blame.

However, let’s not send any cows to the bottom of the ocean, just in case.

A comic of a cow snorkeling.
Stop it, Bella!

Sources:

https://www.newscientist.com/article/dn1350-bubbling-seas-can-sink-ships/

https://www.theage.com.au/national/bermuda-triangle-mystery-solved-its-a-load-of-gas-20031023-gdwlgx.html

https://aapt.scitation.org/doi/10.1119/1.1383600

https://en.wikipedia.org/wiki/Bermuda_Triangle#Methane_hydrates

When time is lagging

I’ve traveled quite a bit in my life. As a young girl, it wouldn’t bother me much. I would be able to sleep on the plane, or if I didn’t, I would bounce back from that sleep deprivation easily. But now, the combination of nearing my 30s (oh no!), being tall and therefore very uncomfortable in a plane, and general annoyance towards air travel, have made me start to feel the lags. Unfortunately.

Why do we get jet lagged?

Jet lag occurs due to disruption of the circadian rhythm of your body after you have traveled a long distance from east-to-west or west-to-east. The normal circadian rhythm – your built-in sleep-wake cycle – is a little over 24 hours long, pretty much tuned to the normal duration of the earth spinning around its axis. By traveling rapidly along the east-west line (or the other way around), you essentially cut a normal day short, or extend it, unnaturally. And that messes up your rhythm and consequentially some of your functioning. Often, this is also paired with fatigue, because sleeping on a plane is very uncomfortable (even if you’re not 1m84).

Common symptoms include trouble falling asleep or waking up, headaches, irritability, problems/disruption with your normal digestion and annoyance at air travel.

East by West

For me, flying west is always easier than flying east. Flying west feels like extending my day with a few hours, I just go to sleep really late. But flying east is like having two very short days with a bad night in between. [edited – see below]

However, last week was the exception. I flew west, a 6-hour flight with a three-hour time change. Unfortunately, there was also a 4-hour delay. As a result, I didn’t get home until 3 am. The next day, I felt miserable: sleep-deprived and annoyed, I had zero mental capacity to concentrate. Actually, I felt like I’d had a great night out partying – except that I hadn’t.

How to avoid a jet lag

It’s not really possible to avoid. The internet recommends only sleeping on the plane if it fits within the destination’s sleep-wake schedule. Doesn’t help me much; I find it very hard to sleep on planes [Side note: did you know that the background noise in a plane is on average 85 dB? That’s about the same noise as a food blender, and it’s recommended not to be exposed to this level of noise for more than 8 hours a day]. Professional athletes use light therapy, using special glasses that light up according to the new circadian schedule, to reduce their jet lag.

Definitely, it helps to stay hydrated and limit light exposure. Though that seems to be valid advice in general (you know, stay hydrated during the day and limit screen time to sleep better!).

You can also just fly north-south instead. No change in time zones; no jet lag! Unfortunately, all my family lives eastwards.

Hungover, without the fun*

So, if you ever want to feel hungover without actually having that one drink too many the day before, go travel by plane! *

Comparison between a hangover and jet lag. Both have random hours that seemingly go lost, result in a blasting headache and lack of productivity, but a hangover is the result of a fun night (maybe, I don't approve drinking too much).
Artistic rendition of how I felt. I don’t know why I gave myself a fringe, haven’t had one in decades. Also, drink responsibly, people!

*Just to make it clear: drink responsibly! You can have fun without having that one drink too many (and the headache the day after), I promise!

**There are a whole lot of reasons not to travel by plane, mostly the impact on the climate and the environment, which are a lot better than “not getting a jet lag”. However, I realize that it is hypocritical for me to comment on the environmental impact of plane travel when I resort to plane travel so often. I wrote this post because I felt hungover after a flight and had a badly-drawn doodle about it in mind. That’s all.

[Edit: initially said: For me, flying east is always easier than flying west. Flying east feels like extending my day with a few hours, I just go to sleep really late. But flying west is like having two very short days with a bad night in between. It seems that mixing up east and west is another symptom of jet lag!]

To the point

Quand le doigt montre le ciel, l’imbécile regarde le doigt.

(Jean-Pierre Jeunet)

For those who don’t speak French, or have never watched the fantastical modern fairy tale that is Amélie [in that case, stop reading and go watch it], this translates to: “When a finger is pointing up to the sky, only a fool looks at the finger.”

It’s not just fools; most animals would look at your finger and not the object that is being pointed at. Apparently, it is a rare trait to understand what pointing means.

Even though it is often considered rude to point – I surely remember being told that it was – it turns out that pointing is something very human.

What’s the point?

According to Michael Tomasello (Duke University), it all starts at the young age of 9 months.

Some time between being 9 and 12 months old, infants start pointing at things that they want or find interesting. While it is possible for some animals (we’ll get to that later) to look at the pointed-to object, infants understand that there is more to it.

There are different reasons to point. You can point to things that you want, like a cookie or a toy. You can point to things that you find interesting, like a dog or a toy. You can point to things that remind you of a shared experience, like a train or a toy. I guess I really like toys.

At a very young age, infants understand that pointing can be used to draw attention to something. The fact that pointing starts exhibiting itself at such a young age is an indication that it is – at least for some part – an evolved trait rather than learned. By creating a connection, and shared experiences, with another person, you start automatically pointing to things that refer to that shared experience – even before language is developed.

No matter where you travel, what language you speak, how old you are, pointing is universal. We understand that something pointed at is a request to share attention.

Get to the point

So toddlers know that when we point at something, we want them to look at it. While it is possible to teach chimpanzees – our closest cousins in the animal kingdom – to look at the object that is pointed at and to use pointing as a means to communicate, it takes a lot of conditioning. Most chimps fail the “pointing test”.

Dogs, however, pass easily. It seems that living with humans for centuries (millennia even), has led to dogs evolving to understand what pointing means.

Dogs have long been the prime example of understanding what pointing means. Our second-favorite-pet, however, was long considered to be untrainable and aloof. Until recently, when new studies have shown that cats can pass the pointing test – if they care to participate…

But cats that have a good connection with their owner, and spend a lot of playtime with them, often have the ability to not be the fool, and look at the object rather than the finger. It seems that again, shared experiences are crucial for pointing to work.

Someone with a cat pointing to one of two upside down bowls
Few species understand what human pointing means, but cats know. (Photo by Holly Andres)

In any case, next time someone tells you that it’s rude to point, tell them that it’s human to point.

Mostly.


Sources:

This blog post was partially inspired by my recent watching of Le Fabuleux Destin d’Amélie Poulin, my recent listening to Alan Alda’s podcast Clear and Vivid (Michael Tomasello On the Surprising Origins of Communication and Cooperation) and the feature in Science on behavioral research on cats: Ready to pounce by David Grimm.

Some kind of blue

Next week is time for the local Jazz Festival, and to prepare I switch my background music back to Miles’ iconic album. In addition, I have been made aware that I seem to be making blue my go-to color. On a slightly related note, it turns out that blue is a very hard color to make.

I spy, with my little eye, something blue…

It seems weird that blue would be hard to make. It’s so prominent in nature. The sky is blue. The ocean is blue. Blue jays are blue. Blue eyes are blue.

But as it turns out, blue pigment is very rare. Butterflies and birds with a blue color aren’t blue because their wings or feathers contain blue pigment, but because of nanostructures that reflect and diffract light in such a way that interference amplifies blue wavelengths, while cancelling out the others.

Macro photo of a butterfly wing
Butterfly wings aren’t actually blue, they’re just pretending to be. (Image Grover Schrayer/Flickr)

A blue pigment, however, absorbs all wavelengths except blue. Light absorption occurs when a photon supplies an electron with enough energy to jump to a higher energy band. As red light has the lowest energy, only electrons with a narrow energy gap can be excited. Only a few molecules have the right structure for this to happen. Absorption of red light is crucial for a blue pigment, and therefore it’s a rare thing.

Illustration of the bandgaps for blue and red absorption
Blue light has enough energy to allow an electron to jump a larger energy gap then red light. Last time someone explained light absorption to me, they did it in the form of interpretive dance. It made so much sense.

Out of the blue

Because of their natural rarity, the design of synthetic blue pigments is of high interest for science and industry. The bluest blue was created by accident, by Mas Subramanian, a solid state chemist who wanted to create a material with the combination of electronic and magnetic properties for microchips. One of his ideas didn’t lead to anything particularly useful for fast computers, but it was very blue.

Blue powder
The bluest blue: YInMn (Photo by Ian Allan)

The blue dream

Where did this quest for blue originate? Blue is most people’s favorite color; it symbolizes depth, stability, and serenity; and as it is the color of the sky and the sea, painters love it. True blue flowers are non-existent (violets are purple, people), even though horticulturists and scientists have tried endlessly. And even though blue food is unconsciously associated with toxins and spoilt food, some scientists’ life goal is to create true blue food coloring, rather than current food coloring that seems more green.

The blue man group: a blue man pouring yellow paint
And I’m sure that Blue Man Group would appreciate a bluer skin. (Photo: Blue Man Group)

While artists, foodies, and flower lovers dream of the truest blue, I’ll go back to some sweet tunes and feeling slightly melancholic. I mean… Blue.


Read more about blue in this Science feature.