technology – The Party Trick Physicist

How Pencil Lead and Sticky Tape Won a Nobel Prize

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By Bradley Stockwell

First off, I want to apologize to all of my six followers to this blog. I know I left you in anxious anticipation over my follow-up post to Climate Change Part I on future green technologies. However, after three months of procrastination, I confess I still haven’t written it. I’m sorry, but I’m easily distracted and while attempting to assemble it I came across a story too good not to tell about a fascinating material called graphene. Graphene is the thinnest, strongest and stiffest material on Earth; it conducts electricity and heat better than any other known material; it is transparent and two-dimensional and is the basis for all future technologies and A.I. At the moment, its potential of applications looks limitless. Oh did I mention it was discovered with nothing more than pencil lead and tape? They even gave the guys who discovered it the 2010 Nobel Prize in Physics. Shit, if I knew it was that easy I could’ve scratched Nobel prize in physics off the bucket list a long time ago.

So what is graphene exactly then? In short, it’s a sheet of pencil lead (graphite) an atom thick. But to understand how we arrived at the discovery of graphene, we need to tell another story, the story of carbon. Graphene is an allotrope of carbon which simply means it’s one possible way to structure carbon atoms. The carbon atom has six protons and typically six neutrons in its nucleus. Sometimes the nucleus has eight neutrons, in which case the carbon atom is known as carbon-14. Carbon-14 is unstable, meaning it radioactively decays, but the decay is consistent over long periods of time. Because this form of carbon is found in many materials, measuring its presence gives us a way to age materials—or what is known as carbon dating. Carbon-14 however is not an allotrope of carbon, it is what is known as an isotope, something covered in detail in a previous post, Flight of the Timeless Photon.

Allotrope formation is dependent on the electrons of a carbon atom and the way in which they bond to other carbon electrons. Carbon has six electrons, two of which are buried in its innermost shell near the nucleus, and four in its outermost shell which are called valence electrons. It is these four outermost electrons—and a ton of heat and pressure—that make the difference between a lump of coal and a diamond, another allotrope of carbon. In diamond, a carbon atom’s four valence electrons are bonded with four other carbon valence electrons. This produces an extremely stiff crystalline structure. In fact, a typical diamond is made up of about a million billion billion atoms (1 with 24 zeros after it) all perfectly arranged into a single pyramidal structure, which is key to its extraordinary strength. But diamond is not the strongest and most stable allotrope of carbon. Although DeBeers may want you to think otherwise, a diamond is not forever; every diamond in existence is actually slowly turning into graphite. The process however takes billions of years so no need to worry about your wedding ring just yet.

Graphite is not a crystalline structure like diamond, but planes of carbon atoms connected in a hexagonal pattern, with each plane having an extremely strong and stable structure—stronger and more stable than diamond. Some of you may be asking, is this not the same graphite we write with and grind up into fine powder lubricants? Yes indeed it is, and the conundrum of descriptives can be blamed on electrons. In diamond, a carbon atom shares its four valence electrons with four other carbon atoms, whereas in graphite it shares its electrons with only three (see graphic below). This results in graphite having no electrons left over to form strong bonds between layers, leaving it up to something called van der Waals forces, a weak set of forces generated by fluctuations in a molecular electric field. Basically it’s the universal glue of matter and is something all molecules naturally possess. Because these forces are so weak is why you’re able to write with graphite—a.k.a. pencil lead. As you press your pencil to paper, you’re breaking the van der Waals forces, allowing layers of graphite to slide across one another and deposit themselves on a page. If it weren’t for the weak van der Waals bonds, pencil lead would be stronger than diamond and this is behind the advent of carbon fiber. Carbon fiber is spun graphite, lathered in an epoxy glue to overcome the weak van der Waals forces. Restriction of van der Waals forces is also behind the phenomenality of graphene.

diamond-structure-graphite-structure

Since graphene is a single layer of graphite one atom thick, there is no need to worry about weak van der Waals forces. By default this makes graphene the strongest and thinnest material known to man. Also, because its carbon atoms are not structured in a crystalline lattice like diamond, which leaves no free electrons, it also conducts electricity and heat better than any known material. This means because of its transparency and thinness, we could literally add touch sensitivity to any inanimate object and possibly entire buildings. It also allows for something called Klein tunneling, which is an exotic quantum effect in which electrons can tunnel through something as if it’s not there. Basically it means it has the potential to be an electronic dynamo and may someday replace silicon chips and pave the way for quantum computing. Graphene was purely hypothetical until 2004 when Andre Geim and Konstantin Novoselov discovered it. As stated in the title of this post, they discovered it with nothing more than a lump of graphite and sticky tape. They placed the tape on the graphite and peeled off a layer. They then took another piece of tape and stuck it to the piece of tape with the graphite layer and halved the layer. They continued to do this until they were left with a layer of graphite one atom thick. I’m not exaggerating the simplicity of the procedure in any way. Watch the video below and you can replicate the experiment yourself, the only catch is you need an electron microscope to confirm you indeed created graphene. Until next time my friends, stay curious.

Climate Change Part I: Where It Went Wrong & Why It’s Stupid to Still Deny It

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By Bradley Stockwell

1878 World’s Fair: Augustin Mouchot’s solar-powered motor is a gold medal winner and initially receives generous government funding for development. However the funding is soon cut due to a dramatic decrease in the cost of coal production.

1900 World’s Fair: Commissioned by the French government, the Otto company displays the recently invented diesel engine running on peanut oil without any modification to the original design. The inventor of the engine, Rudolf Diesel, learns of this and becomes a leading proponent for the development of biodiesel fuels to spur agricultural development. However after his death in 1913 and with the emerging petroleum market on the rise, the motor is redesigned to run solely on petroleum diesel fuel.

The Egyptian desert 1913: Frank Shuman, the inventor of safety glass, presents a solar power plant which promises to make solar energy—a limitless, renewable energy source—more cost-efficient than coal. He too receives generous accolades and funding from the German and British governments, but ultimately with the outbreak of World War I shortly thereafter, funding is cut and put into the exploding petroleum market, leaving Shuman’s solar collectors to be recycled into weapons.

Detroit, Michigan 1908: Henry Ford’s first Model T rolls off the assembly line and it runs on gasoline and/or corn ethanol. Ford envisions one day however that all vehicles will run solely on agricultural fuel sources. One of particular interest to him is hemp. In 1941 he even constructs a lightweight car that runs on hemp biofuel and is constructed with plastic panels made partially of hemp. Nevertheless the Marijuana Tax Act of 1937—backed by the petrochemical company DuPont—would eventually kill the domestic hemp industry and with the onset of World War II, gasoline engine technology would only see further dominance.

Now that we’re facing down the barrel of a global climate crisis, it’s easy to look back and see where it might have been averted. It’s not like we weren’t warned; as far back as 1896 (read here) the scientific community has cautioned us about the consequences of a fossil-fueled civilization. But humanity’s myopic view of the future has not only undercut our ingenuity, but it now endangers the survival of our species—and many others I may add. However there’s hope and I’d like to pay tribute to this hope by highlighting today and tomorrow’s most innovative and coolest technologies on the frontline in the fight against climate change. But first…

THE PROOF:

Believe it or not, our planet breathes. In the spring, the forests of the Northern Hemisphere inhale carbon dioxide to grow and the amount of CO₂ in the air decreases while the amount of oxygen (O₂) increases. Then in the fall, when leaves fall and decay, that CO₂ is released back into the atmosphere. This same respiratory cycle happens in the Southern Hemisphere, but there is far more ocean than forest in the South. This has been happening for tens of millions of years, but wasn’t noticed until 1958 when the oceanographer Charles David Keeling devised a way to accurately measure the amount of CO₂ in the atmosphere. However this discovery also unearthed quite a big elephant in the room for humanity: climate change.

You see, CO₂in our atmosphere acts as an insulator for heat sent here from the sun. Without it, our planet would be a frozen wasteland and with too much of it, it’d be hell on earth and the difference between the two is not much—six molecules of CO₂per ten thousand to be exact. Since the formation of the earth, volcanoes have been spewing CO₂into the air. Then water and life came along and the CO₂was absorbed into the oceans and harvested into more organic matter. Over the course of millions of years, this bled our atmosphere of CO₂ (which is a good thing when you’re cultivating life) until CO₂comprised just three-hundredths of a percent of our atmosphere—three molecules per ten thousand. And for at least the last 800,000 years this percentage has stayed relatively the same until the rise of the Industrial Revolution. Hmm… anybody see a strange correlation? We know this because we’ve drilled into glaciers and extracted and measured trapped air from that long ago. Since about the turn of the century, CO₂levels have risen a staggering 40%. And as of January 2015, we’ve officially added another molecule of CO₂per ten thousand—four per ten thousand in total—in the span of about 100 years. Earth hasn’t seen CO₂levels this high in over three million years, when horses and camels roamed the high arctic and sea levels were at least 30 feet higher; a level that would drown many major cities today.

While one more molecule per ten thousand may not sound like much, remember the difference between frozen wasteland and hell on earth is only six molecules per ten thousand and life providing oasis sits delicately in the middle at three. And it’s not like the earth is just naturally dumping all this additional CO₂into the air. We know it’s man-made because CO₂created from the burning of fossil fuels is slightly lighter than that of say volcanic CO₂.

203_co2-graph-080315 — This graph, based on the comparison of atmospheric samples contained in ice cores and more recent direct measurements, provides evidence that atmospheric CO2 has increased since the Industrial Revolution. (Credit: Vostok ice core data/J.R. Petit et al.; NOAA Mauna Loa CO2 record.)

The strongest force driving climate change is us. It’s undeniable and those who deny it in my opinion are just too scared to admit it. And it is scary. It’s not like we can keep going along like this and still have another 200 years before we add two more CO₂molecules per ten thousand to the atmosphere. We’ve already set off a chain reaction of sorts. Because temperatures are rising, ground that’s been frozen for a millennia is now beginning to thaw. That ground is densely packed with organic matter and the thawing of that organic matter is releasing more CO₂ into the air, causing the temperature to rise even higher and thaw ground even quicker. This positive feedback loop is also happening with the melting of sea ice. As ocean temperatures rise, more sea ice melts and more heat is absorbed into the oceans instead of being reflected back into space, which causes ocean temperatures to rise faster which in turn melts the ice faster. Not only are we contributing heavily to climate change, but now we’ve triggered Mother Earth to follow suit.

But as I stated previously there is hope. We haven’t reached the “point of no return”—the point at which no amount of effort will save us from catastrophic global warming—yet. That point is at 4.5 molecules per ten thousand, so we are damn close. If we continue at our current rate, which is adding two more CO₂molecules per million per year, we’ll reach the “point of no return” somewhere around 2042. But I have faith in humans; faith that we’re too smart and too adaptive to let that happen. After all, we come from a long pedigree of very successful survivors, so let’s put it to use. If not for the sake of saving the world, at least for the sake of technological progression. We know fossil fuels won’t last forever so why not start solving that problem now? Also wouldn’t it be cool if we had concrete that healed itself and roads that talked to us while collecting solar energy? This is just a preview of some of the green technologies and innovations on the horizon that I’ll cover in part two of this series. Until then, stay curious my friends.