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 their model. Except maybe if their bragging about that “model they dated back in college,” but we were all dating models then, weren’t we?

Image result for dating a model meme
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 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).

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 with results from physical experiments.

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 medicinealso 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 potentially 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 that 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 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 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!






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, that are a lot better than “not getting a jet lag”. However, I realize that it is hypocritical for me to comment on 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’t the point?

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

Sometime 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 play time 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 is crucial for pointing to work.

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.



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.

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.

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.

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.

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.

The circle of life

MufasaEverything you see exists together in a delicate balance. As king, you need to understand that balance and respect all the creatures, from the crawling ant to the leaping antelope.
SimbaBut, Dad, don’t we eat the antelope?
MufasaYes, Simba, but let me explain. When we die, our bodies become the grass, and the antelope eat the grass. And so we are all connected in the great Circle of Life.

(Hey, who else is nostalgically hyped for the Lion King?)

The circle of life. Simple really. (Arrows point from the one that does the eating.)

Obviously, actual ecosystems don’t work that way. In Mufasa’s circle, if one of the nodes disappears due to a mysterious antelope-plague, all of life would break down. But more likely, the lion would eat a zebra instead. And if there is no grass, the herbivore will eat some leaves of a tree. (Okay, I know that Scar then went ahead to mismanage everything and life did basically die, but there’s also the part where the little plant breaks through showing that life happens anyway.)

Ecosystems are intricate webs where everything is connected to everything. If one thing falls away, the balance probably shift, but it wouldn’t be a full blown mass extinction. Even if all bees disappear, we’d end up being okay.

We don’t fully understand the intricacies of the ecosystem. We’ve tried, for example through the Biosphere 2 project (planet Earth was considered number 1). This artificial earth was built in the late ’80s in the middle of the desert in Arizona. The “bubble in the desert” was intended as a testing facility, creating a “closed system” where nothing would come in or go out, recreating different natural biomes on a smaller scale to test if a small little earth with human interference would be sustainable.

One of the goals of this facility was to see how we would build human habitats in space, and whether such closed ecological could be maintained. Remember how in the Martian, Watney had to do crazy science to be able to grow potatoes (which is “kind of really possible”, apparently)?

Biosphere 2 looks really cool and futuristic but is essentially a failed experiment.

We wanted to recreate a complete ecosystem and failed. Biosphere 2 is on the list of the 100 worst ideas of the 20th century. We obviously do not understand complete ecosystems enough to create an artificial one. It should be noted, though, that the crew members, who spent the full 2 years in the the sphere, call the experiment a success.

I am currently watching The Expanse, and in one of the episodes they talk about the Cascade. This describes how one element in a closed system breaking down (in this case an agricultural biosphere on one of Jupiter’s moons) leads to the whole system will fail in a cascade of events we cannot predict. Cut out the lions at the top of the food chain, and the antelopes will overgraze the grass and everything will die.

We can try to recreate a tiny world, completely isolated from everything else, but do we really know enough to make it work? It’s not a circle of life, life’s an intricate mumble jumble of wiggly squiggly connections and wow I just sound like the doctor talking about time.

Writing this post just took me on a weird tip through time and space. This post is a mess… (Tardis Blue Space by Koko Priyanto)

Inspiration for this post was an article in ARCADE 37.1 by Nicole DeNamur: Recognizing our environmental arrogance: what an artificial earth taught me about failure

Note: apologies for the relative radio-silence. I am currently working on a few writing projects and job applications, leaving blog writing on the down-low. Apparently my brain and typing fingers can only handle so much?


The twin paradox states the following:

There are two identical twins. One of them travels through space in a high-speed rocket. When they return home, the Earth-bound twin has aged more. This is a result of special relativity. Very briefly, this is due to time slowing down as higher speeds are reached, and why Matthew McConaughey returned to Earth only to find his 90-something year old daughter on her dying bed.

This thought experiment has long been exactly that, a though experiment. But recently, we actually were able to learn what happens to twins when one is in space (granted, not in a high-speed rocket, but on the ISS) for almost a year, while the other twin stays on Earth.

Real Space Twinsies

On March 27 2015, astronaut Scott Kelly arrived at the International Space Station (ISS), while his brother, astronaut Mark Kelly, remained on Earth. (One can have a discussion on who was the luckier of the two.) They did the same activities, ate the same things, and followed the same schedule*, the only difference being that Scott was 400 km from the Earth’s surface, travelling at a speed of 7.66 km/s, while Mark was 0 km from the Earth surface, travelling at a speed of merely 460 m/second, as we all are.

340 days later, March 1 2016, Scott returned to Earth. For the full duration of his time on the ISS, as well as after his return, numerous samples were collected and tests were conducted to monitor his health and compare the physiological and biological changes that happened as a consequence of spacelife. Using his twin brother, a perfect genetic duplicate, as a control.

twins patch
The Twin Study, a massive undertaking involving lots of collaboration and fancy badge design.

The effects of space

There are many “unusual” aspects about living in space, compared to living on Earth, including the odd noises of the ISS, the isolation (Scott was in contact with a mere 12 people during those 340 days), the ultra-controlled environment, a disruption of the normal body clock (imagine perpetually being jet-lagged because of constant switching of time zones), living in micro gravity and the excess of radiation.

An ultra-combined effort, i.e. a major collaboration between a lot of different labs that looked at all possible aspects of physiological and biological function, the effects of 340 days in space (in this specific set of twins) was published last month. There are a lot of changes that occur to the human body in space, some more severe than others.

An immense effort and a lot of numbers went into creating, collecting and comparing samples from the twins. Credit: NASA

There are some changes that don’t really matter much, like changes in the gastrointestinal microbiome and changes in biomass, which were affected during Scott’s time in space, but rapidly returned to normal after he returned. Not much to worry about.

Mid-level risks included known effects of living in microgravity such changes in bone density (you don’t really need to use your skeletal muscles while floating around) and changes in how the heart pumps around blood (you don’t need to fight gravity to pump blood to the head). NASA already knows this and therefore has a rigorous rehabilitation program for returning astronauts to re-acclimatize to Earth’s gravity.

However, it’s the high-risk findings that we all have to worry about, which a mostly due to prolonged floating and prolonged radiation exposure. Due to changes in air pressure as well as that thing I mentioned about blood pumping, a lot of astronauts experience ocular issues after their return, a risk that only increases with increased dwell time off-Earth. This can severely compromise vision. There is also evidence of some cognitive decline. Both those aspects are worrying in the light of long term space travel, we would hope that space-explorers can see and think clearly while carrying out dangerous tasks in dangerous conditions. And that’s without considering a final severe risk…

Who’s the oldest twin?

In addition, the radiation that Scott experienced on ISS is pretty much equivalent to 50 years of normal exposure on Earth. This causes significant genomic instability and DNA damage, and consequentially an increased risk of developing cancer.

One example of this genomic instability has to do with telomeres**. Telomeres are bits of DNA that cap the end of chromosomes. Every time a cell divides, and in the process duplicates its whole DNA library, the telomeres get shorter. When they get too short, the cell can no longer divide. This is something that happens naturally during aging: shortening of telomeres phases out cells until they can no longer divide. Eventually, this leads to cell death.

1 year of space had an odd effect on Scott’s telomeres. Some of them grew longer, while others showed shortening. However, the lengthened telomere returned to normal after Scott’s landing on Earth, while the shortening persisted. So even though Scott was the space twin in our paradox, he seems to have ended up aging faster than Mark…

At a glance, the different effects of one year in space on a human body. Well, it probably takes more than a glance to read this.

A lot happens to a body in space

Overall, the results are pretty surprising, prolonged living in space had more of an effect on the human body than researchers expected. And there is probably a lot more to learn, even just with the data collected from Scott and Mark.

On one hand, the twin study showed how resilient and robust the human body is. 91.3% of Scott’s gene expression levels returned to his baseline level within six months of landing, and some of the changes that occurred to his DNA and microbiome were no different than what occurs in high-stress situations on Earth. That’s amazing, the human body has not evolved to survive in space, but it seems to do pretty well considering how outlandish the conditions are!

On the other hand, the prolonged exposure to microgravity and high radiation does have severe effects on the human health, leading to increased risk for compromised vision, cardiovascular disease, and cancer development. Even with the rigorous preparation and rehabilitation programs astronauts go through before and after spaceflight, some of these effects will be impossible to avoid.

The massive study, combining the effort of 84 researchers in 12 different universities is a feat of collaboration (though nothing compared to the black hole telescope, if I’m honest) and it’s definitely a first that the genomes of space vs. Earth could be compared with a true genetic control. This compiled study, and the many pieces of research that are expected to be published in the next year with the results from the individual studies, provide crucial insight on the effects of space in the long term. If we think that it takes approximately 1 year for a return journey to Mars, this research is valuable for the health of future astronauts and mankind’s ambition to explore further into space.

Want to know more? Watch NASA’s video on the three key findings, or read more in the Science paper or the NASA website (links below).


Markus Löbrich and Penny A. Jeggo. Hazards of human spaceflight. Science 364 (6436) p. 127-128. 2019. DOI: 10.1126/science.aaw7086

Francine E. Garrett-Bakelman, et al. The NASA Twins Study: A multidimensional analysis of a year-long human spaceflight.
Science 364 (6436) eaau8650. 2019. DOI: 10.1126/science.aau8650

Twin study on the NASA website: https://www.nasa.gov/twins-study

Cover image: The International Space Station crosses the terminator above the Gulf of Guinea, image credit NASA

*I remember reading this somewhere, but I cannot find the source anymore. It is thus possible that Mark just went about his normal life. Regardless, it is amazing that NASA had the opportunity to do this experiment with a perfect genetic control.

** Fun fact, my spelling check does not know the word “telomeres” and suggests that I mean “omelettes”. Well, I guess they both get super scrambled up in space? (Eeeeh for an inaccurate joke, sorry).

Earth Day Special

Happy Earth Day! To celebrate our amazing world, here are some amazing views of our blue planet from outer space:

The first photograph of our Earth from space was taken in 1946. Unfortunately, the beaut could not fit in the whole field of view!
(Image credit: White Sands Missile Range / Applied Physics Laboratory)
With some stitching magic, the first pictures of Earth from an altitude greater than 100 miles were published in 1947.
(Image credit: Johns Hopkins Applied Physics Laboratory)
The first full color view of our planet was taken by the ATS-3 satellite in 1967. This could have been prompted by Stewart Brand‘s campaign to have NASA release an image of the entire earth from space. He sold buttons (¢ 25) with the words: “Why haven’t we seen a photograph of the whole Earth yet?” and used the image above as a cover for his Whole Earth Catalog.
(Image credit: ATS-3 / NASA)
Earthrise, as seen from the moon.
I’m running out of words here, just enjoy the views!
(Image credit: Apollo 8 / NASA)
The Blue Marble, 1972. Taken from about 29,000 km (18,000 miles) from the surface by the Apollo 17 crew on its way to the moon.
(Image credit: Apollo 17 / NASA)
A final picture from 1990 to make you feel small. We are that Pale Blue Dot seen in the right band of sunlight reflected by the camera. The Voyager 1 space probe captured this image at a distance of about 6 billion km (3.7 billion miles) from earth.

Inspired by a talk by Dr. Oliver Fraser I attended at the Theodor Jacobsen Observatory (University of Washington)

Cover image: Apollo 10 / NASA

One printed heart, please

It goes without saying that 3D printing is cool*. The ability to think up any three dimensional structure, design it in a 3D design software and have it materialize blows my mind. Granted, I’m making it sound like it’s a very easy and fast process and I know that’s often not the case, but I also know that for a lot of engineering and physics laboratories, the ability to relatively quickly print a model or prototype for anything is extremely useful. In addition, it’s an amazing educational resource. You can print model organs, molecular structures, planets, … and have something physical to show or throw around during a science demo.

Just to name a few reasons why 3D printing is cool.

What is possible even cooler is the potential of printing tissues and organs. And now, for the first time according to a group of researchers in Tel Aviv, it has happened: a complete 3D heart was printed.

They started with some cells isolated from a sheet of fatty tissue from a human patient. These cells were reprogrammed to what’s called pluripotent stem cells. Pluripotent stem cells have the potential to give rise to many different cell types , depending on the biochemical cues they get – for example by changing the formulation of the culture media, which contains nutrients, hormones and other components to “feed” the cells.

In this case, the cells were driven towards being heart muscle cells and blood vessel cells. By mixing these cells with a personalized hydrogel, consisting of collagen (remember, from the reindeer eyes?) and glycoproteins (proteins have a sugar molecule connected to it), the researchers created a “bioink”, a material that could be used to print cardiac tissue in the same way a 3D printer prints 3D structures using a plastic “ink”.

3D printing a mini-heart (image credit AFP or licensors)

While the 3D printed heart – currently around the size of a rabbit’s heart – cannot beat yet, the possibility to be able to print custom organs, starting from a patient’s own cells and therefore eliminating an immune response, is of major importance for medical applications. To enable heart function, the heart cells would have to be taught how to contract in an organized manner, and create a beating heart.

Beating has already been achieved in heart organoids. Organoids are little mini-organs grown in a petri dish, that mimic the organization and function of an organ in a living organism. The difference between 3D printed organs and organoids, is that organoids are allowed to form their own structure and cell types, driven by the media cocktail they are given, while 3D printing positions already differentiated cells in a 3D scaffold. Heart organoids, starting from one or a few reprogrammed cells, grow into structured groups of cells that spontaneously start beating.

Beating heart organoids (gif from Popular Mechanics US)

These organoids, however, don’t really mimic the structure of the heart unless you “force” structure by growing these mini-hearts in a mold, basically geometrically confining the cells to form a predefined structure.

A model of a pumping heart was developed last year, creating an in vitro biomimetic system that could help with drug discovery and studying cardiac diseases. While it doesn’t look as much as a heart as the 3D printed one developed by the Israeli research group, it’s still pretty amazing to watch this little blob of tissue beating under electrical stimulation:

In any case, I hope to see a combined version of all of the above: a 3D printed, functional heart. Nevertheless, this first (though debatable if they actually were the first) 3D printed heart is pretty awesome and has a lot of potential applications in medicine and clinical research. Not to mention that it looks pretty cool:

3D confocal image of the printed heart (Advanced Science, scale bar = 1mm)

Sources used:

Noor N., Shapira A., Edri R., Gal I., Wertheim L., Dvir T. 3D Printing of Personalized Thick and Perfusable Cardiac Patches and HeartsAdv. Sci. (2019), 1900344. https://doi.org/10.1002/advs.201900344

Ma Z., Wang J., Loskill P., Heubsch N., Koo S., Svedlund F.L., Marks N.C., Hua E.W., Grigoropoulos C.P., Conklin B.R., Healy K.E. Self-organizing human cardiac microchambers mediated by geometric confinement. Nat. Comm. 6 (2015), 7413. https://doi.org/10.1038/ncomms8413

Li R.A., Keung A., Cashman T.J., Backeris P.C., Johnson B.V., Bardot E.S., Wong
A.O.T., Chan P.K.W., Chan C.W.Y, Costa K.D. Bioengineering an electro-mechanically functional miniature ventricular heart chamber from human pluripotent stem cells. Biomaterials 163 (2018), 116-127. https://doi.org/10.1016/j.biomaterials.2018.02.024

*Sudden realization that most (if not all) of this blog is me saying “Hey, did you hear about this science thing, it’s really cool!!”

Supermassive black hole

Step one – press play on this video:

Step two – stare into this picture for the full 3-and-a-half minutes (that’s the length of the song, you’re free to stare for longer):


Credit: Event Horizon Telescope Collaboration

Step three – find out more

Oh hey, scientists have taken the first ever picture of a black hole. This is amazing.

Note: I intend to write another blog post this week, I just wanted to share this black hole news!