Radioactivity – Everybody cover your junk

I’ll bet you didn’t know that bananas are radioactive. It is one of those weird facts that science abounds with, but it is most certainly true. There is even a tongue-in-cheek unit of radiation exposure that some people (scientists seems too strong a word) refer to as the “Banana Equivalent Dose.”

It’s not anything worth worrying about (trust me, I’ve looked into it), but it’s interesting all the same. The best comparison that I came across while researching this article was made by Keith Yost, a columnist for MIT’s newspaper:

“The risk of death is on par with smoking 1/700th of a cigarette, or spending a third of a second in a canoe.”

But what is radioactivity, anyway? The short answer is that it is energy released by atoms as they turn from one substance into another. One of the cooler things about atoms is that some of them  come in different flavours… Unstable flavours. For example, about one in every 10,000 potassium atoms is an “unstable isotope.” What that means is that if a particularly feisty beta-particle comes shooting down from space and crashes into our unstable potassium atom, one of the protons in the nucleus can turn into a neutron.

                

When you change the number of protons in an atom, you change what that atom is. If you take an atom of mercury and subtract a proton, congratulations you just made some gold. Knock off another proton and it becomes platinum, even better. In our example with the potassium, when a proton turns into a neutron, the atom becomes argon; and when that happens, a little bit of radioactive energy is released.

                

The trouble with radioactive energy is that large doses of it don’t agree with DNA. When cells divide in the presence of radioactivity, they act like a 17 year old raiding his parents’ liquor cabinet... Things get messy. Mistakes happen when the DNA of cells tries to replicate and that can lead to out of control division down the road, AKA cancer. 

Radiation can also make you sick to your stomach, which is why, if you ever find yourself downwind of a nuclear blast, you don’t want to try catching anything on your tongue as is drifts down from the sky. Unfortunately, Native Pacific Islanders caught downwind from the experimental nuclear blasts on the Bikini Atoll in the 1940's and 50's got this advice a little too late.

               

Since humans discovered radioactivity in 1895, we haven’t been as careful with it as present common sense would suggest. Marie Curie, a Nobel laureate and co-discoverer of the element radium, died in 1934 from aplastic anemia; probably the result of radium mutating cells in her bone marrow. When the Enola Gay dropped the first atomic bomb on Hiroshima in 1945 it killed between 60,000 and 80,000 people instantly, but the total death toll from the bombing is estimated at around 135,000 when radiation related deaths are included.

And that brings us back to the banana. The reason that bananas are radioactive is because they are loaded with potassium. And, as we now know, 1 in every 10,000 potassium atoms is able to have an identity crisis. Bananas aren’t the only thing that might leave you glowing green if you spend too much time with them, though. Radioactivity is everywhere. Kitty litter, glossy magazine pages, granite counter tops, and even the city of Denver all increase your exposure to radiation. Again though, the doses are tiny, so don’t lose any sleep over it… 

But you might want to invest in some lead-lined underwear.

Ivan the Iceberg: An Exercise in Reckless Personification

Once upon a time over a mountain pass in Greenland a grayish-whiteish cloud chanced to drop a snowflake (we’ll call him Ivan) on the hillside below. Ivan wafted his way downward through the uneven breeze and settled into a drift at the top of a gully, overlooking the expansive landscape. He noted how lovely the view was in the brief moments that he was privy to it, but sadly –as is the case with most snowflakes– he was unable to enjoy it for long. Ivan was quickly buried beneath the accumulating mass of his brothers, sisters, and cousins.

The days turned into weeks and the weeks turned into months as more clouds blew over head, dropping their snowflakes into Ivan’s gully. Where he once had enough space to feel generally comfortable in his place, the growing weight bearing down on him from the amassing snow pressed him tighter and tighter into his neighbours. Eventually it was impossible to tell where Ivan ended and the next snowflake began.

As the years rolled on the pressure refused to let up; Ivan and his neighbours fused into crystals of glacial ice. Dreading an eternity with no room to stretch out, they hatched a plan to escape from the mountainside. It was brilliant in its simplicity: The former snowflakes would follow the pull of gravity and inch their way down the hill. 

Their growing weight made the going easy and sometimes they could cover as much as 30 meters per day, picking up boulders and eroding the landscape as they went. Eventually they hoped to find their way to the sea, and glorious, maritime freedom!

In the end, things took a bit longer than expected. Ivan, as part of the glacier, came to learn the meaning of patience. Every day was more or less the same. Wake up. Be squished. Move down the hill a bit. Sleep. Repeat. But one day, after some 4,000 years of flowing down mountains and valleys, something changed.

A thunderous crack tore through the ice, and the crystals on the downhill side of Ivan fell away! For the first time in what seemed like forever, he could see sunlight! He watched as the ice crystals he had come to call friends fell into the ocean and sent a gigantic rush of water in every direction. Far below he saw a crazed grad student with a wetsuit and surfboard catch the wave and ride it down the inlet.

Ivan could feel the instability all around him and was infinitely excited at the thought that he could soon be free of the crushing glacier. Over the years, as he had moved lower down the valley, Ivan had felt the temperature rising but he had no idea that the end was so close. Just as the tension became too much to bear, another crack tore through the ice. No longer a glacier, Ivan and his compatriots had graduated to iceberg status.

The life an iceberg was everything they dreamed it could be. Incredible coastal views, sunshine, constant travel, and even the occasional flipping over as crystals melted and shifted the balancing point of the ice.

Ivan was amazed at the things he saw both above and below the water, not least the intense blue colour that the iceberg had taken on as the compression of the glacier removed air bubbles and caused the ice to absorb all the shortest wavelengths of sunlight.

But as awe inspiring as his life had become, Ivan knew that it would soon end. While glaciers can last for thousands of years, icebergs are lucky to see their second birthday. The ice crystals around him were melting into the sea with increasing speed. On his last night, pondering his mortality and wishing he could have made a bigger impact on the world, Ivan saw his chance.

Out of the darkness a ship took form. As it neared the iceberg, Ivan organized his comrades. At the last possible moment, Ivan and his friends leapt from the night and tore into the ship’s hull. They cheered in triumph as they ripped through steel just below the waterline. Indeed, they had achieved what all ice crystals aspire to.

In conclusion, ice crystals are sociopaths.

Graphene Part II - The Thrilling Conclusion

If I wanted to write an exhaustive article about everything scientists have proposed using graphene for, I would be typing for a long time. There are encyclopedic websites that you can go to if you want to spend the next several weeks reading about graphene-based bomb detectors or how to give your car the greatest rust-proofing in the universe. Instead I’m going to spell out the 5 uses of graphene that I think are the most amazing and most likely to change the world:

1) Super-capacitors

A capacitor is a device that can take the place of a battery and power a piece of electronic equipment using energy stored in carbon. The problem with capacitors for a long time has been that they don’t hold much of a charge per unit of weight. The thing about graphene is that it is ridiculously light (0.77 grams per meter squared) and has a maximum surface area that anything can have.

Imagine electrons as tennis balls, and imagine the carbon inside of a capacitor as a cube that is coated in Velcro. You can stick a certain number of tennis balls onto your Velcro cube, but eventually you’re going to run out of space. If you cut the cube in half, you increase its surface area and you can attach a few more tennis balls. Now imagine that you were able to cut the cube into sheets that were one atom thick (minus the Velcro). If your original cube was 1mX1mX1m, you would need about 1.5 trillion tennis balls to cover all of your single-atom sheets. That’s a lot of tennis balls. That’s translates into a lot of electrons, and a lot of stored energy. A superconductor using graphene would be able to recharge in minutes or seconds and last for an impossibly long time. Imagine an electric car that you could recharge in 5 minutes and drive for a few weeks in between charges. That would change the world.

2) Fuel Cells

This one is pretty similar to supercapacitors, except replace electrons/tennis balls with hydrogen. Hydrogen can bind with the carbon in graphene and be used to fuel cars. Since graphene is lightweight and has incredible surface area, a fuel cell that incorporates graphene as a binding agent could make fuel celled cars a practical reality.

3) Lightning-Fast Circuits

Graphene is able to conduct electricity amazingly well. It’s super-fast and super-efficient. It has also been experimentally used to create circuit boards that could make a laptop 50 times faster and never need a cooling fan. The coolest part? Some people think that graphene circuit boards could be on the market in as little as 5 years.

4) Solar Cells

As we now know, graphene is the Rolls Royce of electrical conduction. That translates into awesome potential for things like solar panels. A panel that used graphene as its conductor and carbon nanotubes (CNT's) to absorb light and transfer electrons would be cheaper, lighter, and faster than anything we can conceive of today. Imagine driving your supercapacitor car with a graphene solar panel on the roof constantly recharging it. Road trip, anyone?

5) Disease Diagnostics

Last but not least, there is the potential to use graphene to diagnose diseases. This takes a bit of explaining, but if you’ve read this far it’s probably safe to say you’re at least vaguely interested. First off, graphene is able to bind with certain molecules that are sensitive to various diseases, call these “fluorescent molecules.” These molecules can also bind with DNA. If you want to make a graphene sensor for detecting disease, you take some DNA with markers for that disease and bind it with some fluorescent molecules. Then you bind your wacky DNA-fluorescent molecule to a piece of graphene. Next, take your sensor and put it in a science-type beaker with a DNA sample from a sick person. When a piece of DNA with the same markers as the DNA on the graphene floats by, it sticks to the sensor and creates a double-strand of DNA. The double strand breaks away and can be detected by looking for the fluorescent molecules. The awesome thing about graphene is that its incredible surface area allows you to test for an incredible amount of diseases at the same time. Imagine being able to test for every kind of cancer known to man simultaneously and to detect the disease at its earliest stages. Sign me up.

So there it is. Call me an optimist, but I can’t wait to fly by Geoff’s house in my supercapacitor powered car, blasting music from my iPod that never runs out of battery, on my way to the other side of the country, on my 150^th birthday, without stopping to recharge. I’ll toss him a shirt that says “I was totally wrong.”

Graphene: The Wonder Material to Save the World Part I

The decision to start this blog grew somewhat organically from many conversations my illustrator and I have had about various new discoveries across the realm of science. Our conversations usually build from a shared curiosity and one of us understanding something better than the other and being willing to explain it. There is one topic though, where we have continuously butt heads: graphene. I am always amazed and optimistic about the possibilities that might come from research into this so-called “wonder material,” while Geoff (who works in the field of nanotechnology) thinks graphene is the most over-hyped thing since those people who were in Twilight broke up. This week's discussion is an attempt to share our incessant bickering with you, avid reader. Now let’s get on with it!

Intro!

So first off, what is graphene anyway? The average person who doesn’t seek out science news on a regular basis could be forgiven for never having heard of it. Right now, it’s a bit of a niche material, but one day it will probably change your life.

When you get right down to it, graphene is the world’s first 2-dimensional anything. It is as thin as thin can be – a single atom thick. To put that in perspective, aluminum foil is about 193,000 atoms thick. A human hair is between 100,000 and 200,000 atoms in diameter. Graphene, in other words, is crazy thin. It is also made entirely of carbon, making it something like an infinitely squished diamond.

Graphene was discovered, as all great things in science are, by a couple guys screwing around with lab equipment. One day in 2004, Andrei Geim and Kostya Novoselov, a pair of Russian researchers working at the University of Manchester, decided to see what would happen if they took a piece of Scotch tape and used it to peel layers off of a piece of graphite. They weren’t the first people to do this (Scotch tape is commonly used by researchers to clean up a piece of graphite before putting it under a lens), but Geim and Novoselov where the first people to take it somewhat too far. They peeled and peeled flakes of graphite until they were left with a sheet only a couple atoms thick. From there, they used scientific ingenuity to transfer the bits they had left onto a silicon wafer and won themselves the Nobel Prize in Physics in 2010.

Now you might be wondering why they would get a Nobel prize for that. Sure making the thinnest thing physically possible is pretty cool. It might even be worthy of free pints for life at the university pub, but a Nobel Prize? The answer lies in the doors their research opened up for science and technology. They didn’t just make something one-atom thick, they made it out of pure carbon; and, as we will see in Part II of this post, carbon is pretty awesome stuff.

Come back tomorrow for the thrilling conclusion... (Geoff is drawing as we speak).

Lightning: The Sky! It's Exploding!

Written by Steve Kux, Illustrations by Geoffrey Lee

You’re out for a walk across a wide open mountain top when the sky rapidly begins to cloud over. Darkness overtakes you and rain begins to fall. Before long you are caught in a full-fledged thunderstorm. Suddenly you begin to feel an eerie tingling all over your body. A faint buzzing sound begins to grow around you. A sailor might call it Saint Elmo’s fire, but you’re no sailor. To you it’s just weird. A flash of light, and searing heat are your last sensations. You won’t be making it home for supper.

Lightning is one of nature’s most impressive displays, but the mechanics behind it aren’t much different from what happens when you shock yourself on a doorknob. Called electrostatic discharge, both the lightning and the shock are caused by electrons moving from one place to another. See, everything in the universe is made of atoms, and atoms are made of basically three things: protons, neutrons, and electrons. 

Protons and neutrons are the homebodies of the atomic world. They stay cooped up in an atom’s nucleus like an acne-ridden teenager on a Saturday night. Electrons are a little different. They like to party. 

Electrons move around, but when they do they create imbalances in the relative charges of atoms. Since electrons have a negative charge and protons have a positive charge, when electrons leave one atom and go to another, the original atom loses some of its negativity and takes on a positive charge. If you get enough charged particles in one place, you’ve got a recipe for electricity.

When you walk across a carpet wearing wool socks, the friction of your feet on the fibers in the carpet transfers electrons to your body, causing you to take on a negative charge. When you touch a metal doorknob, it acts as a conductor and ZAP! Mini fireworks show. 

The same thing happens in a thundercloud. Turbulent conditions cause the uneven buildup of charges across the cloud’s volume, once those charges reach a certain threshold it’s time to take cover.

Lightning comes in three main forms: Cloud-to-Cloud, Cloud-to-Ground, and Dark Lightning (band name anyone?).

Cloud-to-Cloud is the most common type of lightning, accounting for the majority of the 40-50 lightning strikes per second experienced around the world. Often called “heat lightning” because of its tendency to happen without the accompanying boom of thunder, Cloud-to-Cloud strikes usually occur when the positively charged “anvil” section of a thunderstorm exchanges energy with the negatively charged atoms closer to the ground.

Cloud-to-Ground lightning is basically the same thing, except instead of two sections of the cloud providing the opposite charges, the exchange happens with the earth. The tricky thing with this type of lightning is that it is unpredictable and ridiculously dangerous. Strikes that take place between the lower part of the cloud and the ground are relatively straightforward. They tend to follow a straight path and, for that reason, mostly happen directly beneath a foreboding sky.

Strikes that happen between the upper anvil portion of the cloud and the ground are where things get dicey. Since the lower portion of the cloud can act as a barrier to the transfer of electrons, bolts can travel in any crazy direction they want before finally veering towards the ground. Because of the zigging and zagging, and because storm clouds are generally pretty huge things, anvil-to-ground strikes can happen miles away from the cloud of origin. Some have even been called “bolts from the blue” since they can happen in places with little to no cloud cover, adjacent to a storm.

Last but not least, there is Dark Lightning. This is where things go from cool-but-familiar to just plain weird. Dark lightning happens roughly once for every thousand bolts of visible lightning and is thought to be the result of cosmic rays from space mixing themselves up with the already potent energy of a thunderstorm. When things reach critical mass the result is an invisible explosion of X-Rays and Gamma Rays that carries approximately one million times the energy of visible lightning. Just take a minute to let that sink it. One. Million. Times. Fortunately that energy is dissipated far and wide in every direction and not concentrated in a single bolt. Still, it is thought that dark lightning could harm anyone unlucky enough to get caught in it. Not the “burnt to a crisp” harm we typically associate with lightning, more like a “screwing up your DNA” kind of harm that is potentially way worse. Research into dark lightning is in its early stages, but it might be something to keep an eye on.

So there you have it. Lightning explained. It may be impressive enough to appreciate all on its own, but the science behind it is pretty awesome too… If only slightly less showy.