iiinova — where your digital self keeps evolving

Dejan Vinković @dejanvinkovic.bsky.social · 17/06/2024

A new crystal in our collection: beautiful Calcium Copper Acetate CaCu(CH₃COO)₄·6H₂O It took some time for these crystals to appear because the solution had too much copper in the beginning and black Copper Acetate crystals formed first. 🧪🥽 #EduSky

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Dejan Vinković @dejanvinkovic.bsky.social · 20/05/2024

Matter is made up of atoms and molecules, and they are very picky about the colors they emit. Find out how to build your own gadget at home for observing the language of atoms and molecules. Ideal for kids! 🧪🍎🥽#EduSky 🔭

dejanvinkovic.substack.com

Hidden worlds in a speck of light

A simple home-made gadget can open a window into the language of atoms and molecules.

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Dejan Vinković @dejanvinkovic.bsky.social · 07/05/2024

Crystals of urea. When the crystal needles reached the jar wall, they bent but kept growing. 🧪🍎

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Dejan Vinković @dejanvinkovic.bsky.social · 27/04/2024

The Winder - a new super hero! He can wind a coil super quickly!!! (my kid's idea of fun with LEGOs).

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Dejan Vinković @dejanvinkovic.bsky.social · 25/04/2024

We don't have a macro lens to capture nice photos of beetles. So, we improvised and experimented with various manual parameters on the camera. The learning curve is now quite steep! Note: please, don't mind the needle position! We didn't know initially the rules of pinning. #entomology #EduSky

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Dejan Vinković @dejanvinkovic.bsky.social · 24/04/2024

What a nice day - beetle identification fever! Plenty of species recognized.

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Dejan Vinković @dejanvinkovic.bsky.social · 31/03/2024

Unexpected beauty: we are trying to grow copper-calcium-acetate crystal at home, but we put too much calcium acetate into the solution. This is why it crystalized first, but this is such a strange crystal formation! Tiny fragile needles forming a mass that feels like velvet on touch! 🧪🍎 ChemSky

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Dejan Vinković @dejanvinkovic.bsky.social · 30/03/2024

My kid and I managed to grow "snowflake" crystals again. This time we were a more analytic and prepared several solutions of different ratios between blue vitriol and monopotassium phosphate. Next challenge - how to make them bigger and more regular. 🧪 🍎 ChemSky

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Dejan Vinković @dejanvinkovic.bsky.social · 25/03/2024

Snowflake crystals are back! My kid and I managed to grow them again! We mixed 12g of blue vitriol and 22g of monopotassium phosphate, filtered the sludge, and then waited for 10 days. They first appear on the surface and then sink to the bottom where they keep growing. 🍎🧪#ChemSky

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Dejan Vinković @dejanvinkovic.bsky.social · 16/03/2024

Cosmic rays in DIY cloud chamber: straight track: fast muon or electron curved track: slow electron (produced probably by muon transformation) Work in progress...

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Dejan Vinković @dejanvinkovic.bsky.social · 10/03/2024

My kid and I trying to repeat the crystallization procedure where we got snowflake crystals from a mixture of monopotassium phosphate and copper sulfate. This time a partial success: blue crystals appeared at first, but then snowflakes crystalized. The recipe needs refinement. 🧪🍎 ChemSky

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Dejan Vinković @dejanvinkovic.bsky.social · 26/02/2024

Red printer ink mixed with potassium alum solution gets integrated into the growing crystals in this strange way. It deforms the crystal and creates a yellow cross. We are trying to grow bigger crystals, but it seems that the ink prevents growth of perfectly smooth surfaces. 🧪🍎#ChemSky

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Dejan Vinković @dejanvinkovic.bsky.social · 25/02/2024

Potassium alum crystal mixed with ink from yellow fluorescent marker and contaminated with something... My kid was preparing this for fun, but he didn't clean the container before pouring in this solution. The contaminant pushed the crystal into an almost perfect cube. 🧪🍎 #chemsky

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Dejan Vinković @dejanvinkovic.bsky.social · 22/02/2024

I first soaked beans in water full of carbon quantum dots (CQT) and then planted them and watered with more CQTs. Some other grains are sitting on a cotton soaked with CQTs. Now I hope plants will grow and glow under UV! 😀 🧪🍎🌾

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Dejan Vinković @dejanvinkovic.bsky.social · 20/02/2024

A fun part of simple homemade carbon quantum dots is the desire to experiment with various compounds because it is a simple procedure. Mix 0.1g of each material, three drops of water, and heat it in a microwave oven. Here are our three mixtures that produced bright luminescence. 🧪🍎🥽

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Dejan Vinković @dejanvinkovic.bsky.social · 19/02/2024

Alum crystal grown in a solution colored with yellow marker ink glows bright green under UV (black) light. We managed to grow a big crystal, which gives this impressive glow! This is a real crystal! Like a light bulb in your hand! If you are a STEM enthusiast, you should try it! 🧪🍎🥽

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Dejan Vinković @dejanvinkovic.bsky.social · 19/02/2024

Playing with drops of homemade concentrated carbon quantum dots under UV light. It is amazing that such tiny 3nm particles can be easily made in a kitchen microwave oven. 🧪🍎

Glowing blue droplets falling through water in a glass container.

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Dejan Vinković @dejanvinkovic.bsky.social · 18/02/2024

Carbon quantum dots (CQT), synthesized from urea and citric acid in my kitchen microwave oven, showing fluorescence in different colors when excited by UV light (365nm), blue laser (405nm), and green laser (532nm). The first photo is under normal lightning. 🧪🍎

4 test tubes: normal light, under UV, blue & green laser.

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Dejan Vinković @dejanvinkovic.bsky.social · 17/02/2024

Fluorescence of carbon quantum dots, synthesized from urea and citric acid, shows the optics of test tube. The UV light enters from below and the tube bottom behaves like a lens. 🍎🧪

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Dejan Vinković @dejanvinkovic.bsky.social · 16/02/2024

My first carbon quantum dots - tiny (2-3nm) carbon particles that fluoresce under UV light!! This will be now a playground for my kid and me for a while. Instruction on how to synthesize this at home are very simple: www.youtube.com/watch?v=Ipfb... 🧪🍎🥽

Light blue fluorescent liquid in a test tube, with UV light source in the background.

Yellow and light blue fluorescent liquids in test tubes, with UV light source in the background.

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Dejan Vinković @dejanvinkovic.bsky.social · 14/02/2024

Totally cool fractal shapes formed by electrolysis. Copper electrodes for a copper fractal in copper(II) sulfate solution (blue); iron electrodes for an iron fractal in iron(II) sulfate solution (yellow). Perfect for physics-chemistry-mathematics mix of education topics and easy to setup. 🧪🍎🥽

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Dejan Vinković @dejanvinkovic.bsky.social · 10/02/2024

Aargh! We're trying to repeat the crystallization procedure where we got snowflake crystals from a mixture of monopotassium phosphate and copper sulfate. But this time we got this pretty crystal, similar to copper sulfate crystals. I'm afraid that we're missing some important detail in our notes!🧪🍎🥽

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Dejan Vinković @dejanvinkovic.bsky.social · 10/02/2024

It took me some time to realize why the flame on my kitchen stove suddenly turned orange. It was not b/c of incomplete combustion. My kid was using a compressor nebulizer to treat his stuffy nose. This created a mist of saline solution, which contains sodium that emits orange light when excited. 🧪🍎

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Dejan Vinković @dejanvinkovic.bsky.social · 09/02/2024

Sometimes simple toys can be quite educational. I bought lots of magnetic blocks and then my kid and I looked at various ways how to build fullerenes and nanotubes. #EduSky #ChemSky 🧪 🥽

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Dejan Vinković @dejanvinkovic.bsky.social · 08/02/2024

I love this kid of research that reveals something new in mundane items! The blue color of blueberries, plums, or juniper cones is not due to a blue pigment! It comes from tiny randomly arranged wax crystals boosting UV and blue light by interference of scattered light waves. #EduSky #ChemSky 🧪

sci.news

Study: Tiny Structures in Wax Coating of Blue-Pigmented Fruits Give Them Their Blue Color | Sci.News

Scientists have investigated dark pigmented fruits with wax blooms, like blueberries, plums, and juniper cones, and found that a structural color mechanism is responsible for their appearance.

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Dejan Vinković @dejanvinkovic.bsky.social · 07/02/2024

Have you noticed that sometimes specks floating on water attract or repel one another? This is called the Cheerios effect and it is an fun example of surface tension force in action. en.wikipedia.org/wiki/Cheerio... #EduSky 🧪

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Dejan Vinković @dejanvinkovic.bsky.social · 03/02/2024

With crystals you have to be patient and they will return with beauty of colors and shapes. Our home made crystals are growing and some are ready to be stored in our collection. Most importantly, we got ideas for new mixtures of salts where we can expect new surprises! #EduSky #ChemSky 🧪

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Dejan Vinković @dejanvinkovic.bsky.social · 27/01/2024

We picked one of the weird "snowflake" crystals and let it grow. Now it is almost 2cm in size and similar smaller ones appeared in the solution of monopotassium phosphate and copper sulphate. The weirdest crystal so far in our home-made collection. #EduSky #ChemSky 🧪

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Dejan Vinković @dejanvinkovic.bsky.social · 24/01/2024

I'm lost. My kid, in his "crystallomania" fever, mixed monopotassium phosphate and copper sulphate, filtered it, and now this strange snowflake crystals are growing from this. I can't find explanation for this weird crystal behavior, which adds extra excitement to this experiment. #EduSky 🧪

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Dejan Vinković @dejanvinkovic.bsky.social · 17/01/2024

Ice mixed with cotton is much stronger than ordinary ice. The same method is used in the ground freezing construction technique and the frozen ice composite called pykrete: youtu.be/9hNXQ4aatX4 🧪 #EduSky

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Dejan Vinković @dejanvinkovic.bsky.social · 12/01/2024

My kid's "crystallomania" is producing the first beauties - crystals of various shapes and colors. Various double salts (of sulfates), alum+inks, potassium ferricyanide,... Crystals are still growing, now we filter solutions to keep monocrystals grow. #EduSky 🧪

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Dejan Vinković @dejanvinkovic.bsky.social · 11/01/2024

You might have noticed ice having a clear and a cloudy part. This is due to "directional freezing", where the freezing process pushes the impurities and air out of the way (notice the bubbles). If you love cocktails, then making clear ice is a thing for you: www.youtube.com/watch?v=bUHc... 🧪 #EduSky

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Dejan Vinković @dejanvinkovic.bsky.social · 07/01/2024

If you grow crystals in a shallow solution, the crystals will be forces to grow only horizontally. The results can be pretty and mathematically interesting. This is a crystal of chrome alum. 🧪 #EduSky

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Dejan Vinković @dejanvinkovic.bsky.social · 02/01/2024

I found a small styrofoam ball and noticed that it displays a strong Magnus effect - curved trajectory when spinning while moving through the air: en.wikipedia.org/wiki/Magnus_... Left: fall without spin; Right: fall with spin (rolling down an inclined surface). #EduSky

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Dejan Vinković @dejanvinkovic.bsky.social · 02/01/2024

Growing crystals by slow evaporation leads to a concentration gradient where the solution's surface gets more saturated than the deeper layers. This is why crystals might start appearing on the surface, like in this example of potassium ferricyanide solution prepared by my kid. 🧪 🍎

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Dejan Vinković @dejanvinkovic.bsky.social · 31/12/2023

My kid is out of control over his increasing obsession with crystal growing, but some crystals are really pretty. The quest is to get big monocrystals. We wait now for them to get much bigger. #EduSky

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Dejan Vinković @dejanvinkovic.bsky.social · 29/12/2023

Multiple reflections within prism - the same principle, just in a sphere, results with multiple rainbows: old.atoptics.co.uk/rainbows/ord... (the current record is a photo of the 5th order rainbow!) 🧪 #EduSky

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Dejan Vinković @dejanvinkovic.bsky.social · 28/12/2023

Today, my kid and I worked on taking spectra with our home-made spectrometer of luminol chemiluminescence (blue glow), uranine fluorescence (green), and a home-made big alum crystal mixed with fluorescent marker ink (green). The fluorescence is induced by UV or blue laser. It's magical!! 🧪 #EduSky

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Dejan Vinković @dejanvinkovic.bsky.social · 28/12/2023

Today my kid and I had a new wave of crystallomania - this time we pursue double salts! We've been mixing various sulfates, and copper and calcium acetates. Tiny crystals are already here, but we go slowly to make big monocrystals. I highly recommend crystal growing as a STEM activity! 🧪 #EduSky

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Dejan Vinković @dejanvinkovic.bsky.social · 27/12/2023

This is not a broken glass. This is calcium acetate crystals growing into very long needles. You can easily prepare calcium acetate by mixing real chalk (calcium carbonate) and vinegar or lime and vinegar. 🧪 #EduSky

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Dejan Vinković @dejanvinkovic.bsky.social · 26/12/2023

This year my kid picked a home project to make a wooden lamp for the Christmas present for his mum. We had access to a laser cutter, which enabled him to make a really nice lamp! Skills that kids learn through such handcraft projects will stay with them for their entire life! #EduSky

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Dejan Vinković @dejanvinkovic.bsky.social · 18/12/2023

How does a rock move once you let it free from rotational movement? A simple STEM@Home experiment, where I put together a sequence of frames from the video we recorded. #EduSky 🧪

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Dejan Vinković @dejanvinkovic.bsky.social · 16/12/2023

It is amazing that we live in times when you can simply buy a device that enables you to watch electric field waves sloshing back and forth through a wire with 60% of speed of light. Blue and yellow lines are signals from the opposite parts of an extension cord after touching a 9V battery. #EduSky 🧪

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Dejan Vinković @dejanvinkovic.bsky.social · 16/12/2023

If you ever wondered how diffraction through multiple gratings looks like - here are some examples. The pattern depends on how you orient individual gratings. #EduSky 🧪

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Dejan Vinković @dejanvinkovic.bsky.social · 15/12/2023

Some beetles reflect only left-circularly polarized light. Here are photos through circular filters of Green Rose Chafers and their evolutionary friends that my kid collected. #EduSky 🧪

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Dejan Vinković @dejanvinkovic.bsky.social · 15/12/2023

If you teach your kid programming, start with pretty stuff. Skip technical details that are not necessary. You can throw a truckload of details once they are addicted to programming. Mandelbrot set and Julia sets are examples of very simple mathematics and cosmic beauty. Start with that! #EduSky

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Dejan Vinković @dejanvinkovic.bsky.social · 09/12/2023

My kid witnessed his first Krampuslauf - a parade of Krampuses! My home county is in the most northern part of Croatia and we share this tradition with the Alpine region of Europe. Once, when I was a kid, Krampus came to our house and my father had to convince him not to take me!!!

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Dejan Vinković @dejanvinkovic.bsky.social · 04/12/2023

Spectrum of a green plasma and flame! NOTE: do this in a well-ventilated room! We still explore the world of spectra using our simple DIY spectrograph at home. This time using boric acid. First under the plasma from a Tesla coil... #EduSky 🧪

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Dejan Vinković @dejanvinkovic.bsky.social · 30/11/2023

If you are a scientist or an engineer, you hide yourself behind elegant math when handling wave phenomena. But if you are an educator, or have a kid who still kills you with the never-ending "why?" questions, then you are in a trouble. The true nature of wave phenomena is a HARD problem to grasp!🧪🍎

dejanvinkovic.substack.com

Waves may seem like a simple concept, but monsters are lurking beneath the surface

Show to kids how sounds can be transformed into water waves. It is a good start to a challenging, but very important topic.

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Dejan Vinković @dejanvinkovic.bsky.social · 30/11/2023

The latest digital elevation models based on the TanDEM-X radar satellite data have ~1m vertical resolution. I checked how my home in the north of Croatia looks like and noticed a long straight step. My house is exactly on this hill step, which is ~10m high (further in Slovenia it reaches 20-30m)...

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