How Colours Change In The Sun

By Ryan | Published: April 4, 2012

Have you ever seen a t-shirt that changes colour when it is in direct sunlight? Or perhaps new colours become visible? Maybe you have some of those fancy prescription glasses that become tinted sunglasses as you step outside.

All that falls under the name Photochromism. Photo being light, and chromo being colour.

It’s a minutely complex chemical reaction that occurs in the presence of electromagnetic waves in the ultraviolet region of the spectrum. That is to say, UV light. When those UV waves hit the photochromatic substance, the chemical reaction occurs that causes a change in its ability to absorb visible light.

Now, here at LSNED I always try to take the hardcore science and boil it down to a casual explanation that makes sense. Just so you’re aware of my struggle, here’s the source material on this…

The conjugated system of the oxazine and another aromatic part of the molecule is separated by a sp³-hybridized “spiro” carbon. After irradiation with UV light, the bond between the spiro-carbon and the oxazine breaks, the ring opens, the spiro carbon achieves sp² hybridization and becomes planar, the aromatic group rotates, aligns its π-orbitals with the rest of the molecule, and a conjugated system forms with ability to absorb photons of visible light, and therefore appear colorful.

So, umm, to summarize, err… well… so every thing in the universe is made up of the same building blocks, as seen on the Periodic Table of the Elements. The difference between your eyeball and the computer screen you’re looking at is just a different arrangement of those basic parts. In the case of our colour-changing dye, the sunlight actually rearranges the physical bonds between the parts, and that teeny-tiny change makes for a dramatic and visible shift in the objects properties. Just like your eyeball, if the parts suddenly got scrambled, could end up being a potato dumpling.

When it comes to glasses that turn into sunglasses as you step outside, that chemical process is a little bit different. When they make the lenses, they add two special ingredients. Silver chloride and copper chloride. When that same UV light hits the silver chloride it oxidizes, or “rusts”. That throws the physical arrangement out of whack and leaves us with a pile of leftover electrons, which find new homes with silver ions to create new silver atoms that block some of the incoming light, making the glasses seem darker.

It might stay that way for a ling time, if not for the copper chloride that was also added into the lens. Like an atomic groundskeeper, the copper chloride not only keeps the stray chlorine from escaping the lens, but it reduces and re-sets the chemical change as soon as the UV light has faded away. The tinting process is reversed, and set to go again.

Personally, I find chemistry to be the most mysterious thing in the universe. I tend to have a logical grasp on the concepts of physics, but chemistry still seems like magic to me!

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The “Did You Just Eat My Goldfish?” Prank

By Ryan | Published: March 31, 2012

To make sure you’re ready to go for April Fools Day, I’m going to teach you how to eat a goldfish to shock and awe your friends. I’m not talking about Goldfish crackers. That’s less exciting. Rather, imagine you are at your friend’s house. You are admiring her fish-tank when you reach into the tank, pick up a fish by the tail, and drop it into your mouth. You chew, swallow, and stare straight at your friend’s face as the panic sets in.

Sounds like great fun to me!

Here’s how to pull of this prank. You need a large carrot. Using a peeler, slice of a wide but thin piece of carrot. It needs to be thin enough to be a bit floppy.

From the wide end of that slice, use a knife to carve it into the rough shape of a fish. Detail isn’t important, as your fiend only gets a fleeting glimpse as it passes your lips. Hide your carrot-fish in your pocket until you find yourself beside an unsuspecting aquarium.

As you make some breezy conversation about the fsh, your hand slips into your pocket and picks up the carrot-fish. Hide it in your loosely closed hand in a casual way. (Being casual is key. Don’t worry, nobody will ever suspect you’re secretly hiding a fish-shaped carrot. If they do, you have a complicated relationship with this person.)

When you’re sure that you’re being watched, dip your hand (still hiding the carrot) into the aquarium water and move your fake fish into view, pinching the tail. Pull it out, wiggling the fish a bit, and quickly drop it into your mouth. Do this fast, but not so fast that it is not clear what just happened. The impact of your prank relies on your calm execution of this moment.

Now you just need to try not to laugh as you chew and swallow your carrot fish. It’s up to you how much you want to torture your victim at this point. If you’ve pulled off the prank, they should be seriously shocked right now.

Now go have some fishy fun!

  • Source: Tricks With Your Head by Mac King, a fantastic book of tricks, gags, and stunts somehow involving your own head.
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Making The World Miniature with the Diorama Illusion

By Ryan | Published: March 30, 2012

Have you ever seen a photograph that makes the world look tiny? Even through you know it’s real, you can’t help but see it as a close-up of a miniature model train village in a retired-person’s basement. Have a look at this video of my city, Calgary, to see the illusion in action.


“Moving Calgary” video by Charlie Su. Watch on YouTube

Pretty neat, yeah? Charlie is not a retired man painting plastic people in his basement… not yet anyways… but a photographer who likes spending time on rooftops. All that footage is the real deal. So what makes it all look so cute and tiny?

That’s the diorama illusion, and it’s your brain playing tricks on you. Sometimes this illusion is mis-called the “tilt shift” effect, as a tilt-shift lens (a special moving lens for a camera) is one of the tools that can be used to create the illusion. However, most of the videos and photos you see with this illusion are created with digital effects. It’s surprisingly simple!

The key to the whole illusion is the blurry parts of the image. Watch the video closely. Notice how the edges of the screen are always blurry, and only a small area of the picture is in sharp focus. Photographers call this the depth of field. Whenever you look at something, any objects that are closer or farther from your eye will be slightly blurred. The further from your area of focus, the more blurred they are.

If you look out the window at things far away pretty much everything appears more or less in focus. You can see the whole landscape at once. Now, hold something up near your face and focus on that. Suddenly everything behind it becomes very blurry in your peripheral vision.

Your brain has a good understanding of the connection between blurriness of objects and their relative size and position to you. Far away, everything is in focus. Up close only small parts are in focus. It’s this understanding, or set of assumptions, that your brain has that is being forcefully manipulated to create the illusion.

When the edges of the photo or video are blurred just right, so that the area near the focus spot is blurred a little, and the outer edges are blurred a lot, it tricks your brain into thinking it’s looking at something very close-up.

Add that with the high angle of the photo, looking down from above, and it creates a very strong perception of being miniature. In the video the high-speed movement is just another layer of trickery, making the people look like scurrying ants.

Your brain means well, but it can always be manipulated.

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Answering Kids Questions About Space (Part 1)

By Ryan | Published: March 2, 2012

I have a friend who teaches a grade six class. Yesterday she began explaining how the moonlight is really just light reflected from the sun, when the whole class erupted into a volcano of curiosity. She couldn’t keep up with all the great questions they were asking, and had them write them all down. She shared some of them with me, and I thought I’d take a stab at answering them.

“What are planets for?”

Well… planets aren’t really for anything at all. They have no purpose. No particular reason for floating around space. When we look at the barren desert of Mars, or the thick clouds of Venus it’s easy to consider our lovely little earth to be a paradise. I think it’s important to realize that there is nothing special about earth. It formed out of chaos and clouds of dust just as randomly as any other planet in our system.

As for why earth has such a lush ecosystem compared to Mars’ red dust… I suppose it’s a bit like baking a cake. When the ingredients are mixed just right, the cake will rise up light and fluffy. If the recipe is too far off, you end up with a dried out lump of floury gunk. If you were mixing cake ingredients in the same crazy way that the planets were formed, throwing them all around and seeing which bowls they landed in, you’d end up with way more lumps of gunk than you would delicious cakes. It doesn’t make that one cake special… it just happened to work out alright.

“How big exactly was the big bang if it is not a theory and it is real?”

The first thing to talk about here is what scientists mean when they call something a “theory”. Sir Isaac Newton discovered his “Theory of Gravity”, but if you drop a rock on your toe it sure does feel real! A theory is another way of saying “I’m pretty sure I know how this works”. Scientists always like to say they are “pretty sure” instead of saying “I absolutely 100% know this is true”. The reason they do that is because other scientists will always be discovering new things that might change our understanding of something. There is always room for improvement and refinement in science.

When it comes to the Big Bang, it’s always been a challenge for astronomers to see what happened so long ago… 13.7 billion years back! It’s a bit like trying to do a jigsaw puzzle when all the pieces have been hidden all over your city. First you have to find the pieces, then you need to fit them together… and all the while you don’t know what the puzzle is supposed to look like!

Now back to the question… how big was the Big Bang? Well, I suppose you could say it was the biggest thing ever. Everything everywhere… planets, stars, galaxies… was all compressed into one little ball and then it exploded. It exploded so big it spread all the pieces (including you and me) all over the universe, which is almost too big to even imagine. It had more energy than our sun and all the stars in the sky. HUGE energy! ALL energy at once!

“Big” doesn’t even begin to explain it.

“How did people get on Earth?”

This is a bit like asking how you got to the town in which you were born. You never really moved there. You just started there from your beginning. Maybe your parents moved to that town from somewhere else. Or maybe it was your grandparents that first arrived. To find out how humans got here we need to go way back. Way way back. All the way back to that Big Bang thing.

You see, you and I are made up of tiny parts, atoms, just like everything else. At one point all these atoms were part of that Big Bang. Hydrogen and helium atoms were thrown across the universe, and they started combining and mixing into more complex things like carbon and oxygen. If we fast forward about 10 billion years, the cloud of dust, made up of those same original atoms, begins forming into the ball we lovingly call Earth. Fast forward another 2 billion years and some of those atoms just so happened to “bake a cake” and rise up as the first single-celled organisms. A living thing on an otherwise dead rocky planet.

Jump ahead 4 billion years and those single cells have fought and clawed their way (or, at least once they grew claws) to grow into animals and plants. It’s always just a new way of arranging those atoms. Some of those animals became dinosaurs about 300 million years ago. Other animals became mammals somewhat like a mole. Those mammals kept adapting and changing over the millions of years until about 25 thousand years ago our ancestors popped up in the mix. Those early humans kept on growing, becoming smarter and stronger, until… well… here we are.

So we never got here. The stuff that we’re made of has always been here.

 

Stay tuned for more great questions next time.

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Lodestones: The Original Magnet

By Ryan | Published: February 29, 2012

Back about 2000 years ago, the Greek scientists were becoming fascinated with magnetism when they stumbled upon lodestones, a naturally occurring magnet.

Lodestone is a piece of magnetite, an iron oxide, which produces a strong magnetic field. Now, to be clear, not all magnetite is magnetic (it won’t stick to your fridge by itself) but being a type of iron, all magnetite is attracted to a magnet (technical word: it’s ferrimagnetic).

The creation of a lodestone (magnetized magnetite) is still a bit of a mystery, but the leading hypothesis is that the magnetic properties were picked up after being struck by lightning. It’s sort of a geological superhero origin story. This theory is supported by the fact that a lodestone has never been found very far from earth’s surface.

The word magnet originates from Magnesia, which was a region of Greece where these original lodestones were popping up.

Magnetite lodestones are one of only two minerals that have been found to be naturally magnetized on earth. Which begs the question; how do the real estate agents and plumbers manage to get their hands on so many lodestones?

Most of the magnets we encounter on a daily basis have been artificially magnetized. You can start with any ferromagnetic material. (most commonly ferrite, a ceramic compound containing iron oxides) The simplest way to turn that into a magnet would be to rub it against something that is already magnetized in the same direction many times. (it’s sort of like you are “combing” the electrons)

To manufacture the strongest magnets, the material must be heated above the Curie temperature, which varies depending on the material, putting it into a receptive state. It’s then subjected to a strong electromagnetic field. As it cools, the magnetism remains in the material. If it’s ever re-heated past that Curie temperature again, it could lose it’s magnetic strength. I learned this the hard way when trying to use a hot glue gun on rare-earth magnets.

Now, this is just the tip of the iceberg for the fascinating science behind magnets. There is a lot to think about next time you go to clip up your grocery list.

  • Source: Magnet – Wikipedia
  • Good Book: Magnetic Magic – from Klutz Press, I had this book as a kid and loved it. Comes with magnets and a steel book cover to keep them on.
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Video: Simple Fun with Balloons & Science

By Ryan | Published: February 23, 2012

I’ve been wanting to work more video content into my LSNED blog, but I’ve been having enough trouble finding time to write and illustrate articles, let alone write, rehearse, record, edit, and post videos. Fortunately Steve from the Calgary International Children’s Festival offered to do all the hard work for me!

So, BEHOLD! The first, and hopefully not last, live video LSNED!

(Watch the video on YouTube)

In the video I cover a few experiments and “science tricks” using balloons that kids are encouraged to make themselves and try at home. Be sure to stick it out for the bonus experiment at the end, after the break, which may well be my favourite of the batch.

  • Good Book: Most of the experiments in the video came from my own memory, but I also had a flip through this “Balloon Science” book for additional ideas.
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How Airplanes Leave Trails of Cloud

By Ryan | Published: February 15, 2012

A plane zips across the sky, leaving in its wake a long line of white cloud. There is a conspiracy theory that swears this is the government spraying the world with “mind-control agents” for nefarious means. A little bit of science reveals the truth.

The white line, called a condensation trail, or contrail, is made of nothing but cloud. They are no different than any other cloud in the sky. Just tiny droplets of water that float through the air. These contrails are created behind a jet plane as it literally rips through the sky.

The exhaust from a jet engine spews out a lot of hot air, along with water vapour, soot, and a few other chemicals. As the body and wing of the plane move through the air it creates a lot of turbulence in its wake, like a speedboat moving across a calm lake. As a result the cold air in the upper sky is violently churned with the engine exhaust. It’s this mix that often provides the right environment for clouds to form.

The cold air in the sky causes the warm water vapour to condense into droplets around the tiny particles of soot. If the air around the contrail is dry, it can suck up the moisture like a sponge fairly quickly, and the trail fades away. However, if the air is humid the contrail can be seen as a sharp line across the sky for hours as it slowly spreads out.

It’s actually the exact same process, though on a larger scale, as when you exhale on a clod day and can see your breath. That’s the warm humid air from your lungs condensing as it meets with the chilled outside air.

So that trail is not brain-numbing chemicals. It’s not smoke, or even pollution of any sort really. (Any jet exhaust seems insignificant compared to the number of cars on the road) It’s nothing but a harmless fluffy cloud. Although, there have been some studies asking questions about whether the additional blanket of clouds may be warming up our world.

Questions are good. Questions can be dangerous! Questions can sometimes make governments wish they were spraying mind-altering cocktails in the air.

  • Source: Contrails – Cooperative Institute For Meteorological Satellite Studies, University of Wisconsin-Madison
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