Graphene

I‘m sure that those who like to play with gadgets and toys will agree that there is a tremendous sense of satisfaction when what we’ve pulled apart is put back together again in working order. Ah, the simple joys of engineering and reverse-engineering things, be they mechanical or software or even organic in nature. Our innate sense of curiosity is what drives us to find out how things work and why things are the way they are.

There are no devices (yet) that I can think of that can dismantle the human body and put it back together again in working order. I do not mean simply carrying out a surgical operation or fixing a broken shin. I am talking about taking a live human being and pulling her/him apart like we would a mobile phone, say, by removing the limbs, the organs, the nervous system, the individual cells, etc., and, once every unit of this magnificent piece of engineering has been accounted for, put back together again to reconstitute the person in her/his original state. This is a gory example, I admit, but the principle behind it is intriguing, to say the least. We are machines, there are no doubts about this. I insist that by calling us machines I am not being disrespectful in any way. To say that we are mechanical in nature is not a diminutive qualifier. There is no denying that we are made up of parts fitted together to work as a machine, albeit a biological one. Like any other machines, we depend on an energy source, we use the energy to do work, we waste some along the way and we require regular servicing. And we all, inevitably, break down to the point where we can’t be fixed. But, with equal measure, I will also insist that the human body is a machine that does more than just exist for the purposes of accomplishing mechanical tasks. We are all endowed with a powerful computer, which we call a brain, that allows us to perform complex operations such as observing the world, processing the information we gather through our senses, regulating our bodily activities, controlling our speech, simulating scenarios before we execute the ones that are deemed most appropriate, allowing us to communicate our thoughts and storing our memories, etc. It is truly a wonderful piece of engineering.

Graphene

Graphene

But I want to look beyond that. We’ve already looked at the constituents of matter; we know that everything in the Universe is made up of fundamental particles called quarks and electrons. Taking this one level up, we can see how these particles fit together to form the chemical elements that constitute our body. The chemistry of life is a really fascinating area of study. And so, if we were to do an inventory of what chemical elements constitute the human body, then we’ll see that we are like other organic materials with oxygen, carbon and hydrogen as the main components.

Now there are two ways to go about this. When analysing our chemical composition, we can either do so by counting how many atoms of a particular element there are in our body or we can see how much of each element are needed to make up our mass. If we go by numbers alone, then we are mostly composed of hydrogen atoms. In fact, hydrogen is the most common element in the whole Universe, not just organic stuff. If we were to count all the atoms that make up the human body, nearly two-thirds of them will be hydrogen atoms. But, if we were to weigh the hydrogen atoms (which are the lightest of chemical elements, by the way) then they will amount to only a tenth of our total body mass. A person with a mass of 70 kg will have about 7 kg of hydrogen. The other vital component in our body is oxygen.

Counting the number of oxygen atoms in our body shows us that it makes up about a quarter of the total number of atoms. And there are billions upon billions upon billions of atoms in our body so where talking about a lot of oxygen atoms here. So much so that, if we were to measure the total mass of oxygen, it would amount to about 45 kg! Most of our body mass is actually due to oxygen. Isn’t that amazing!

The next most important component is undoubtedly carbon. It is the defining element for organic life as we know it. When we speak of life, in any form, on this planet, we inevitably hint to some carbon-based life-form, be it a virus or a vulture. Carbon makes up about 18 % of our body mass (roughly equivalent to 12.5 kg). Carbon is indeed an incredible element. It has some interesting chemical properties but here we’re more into its physical attributes. Hence why we’ll take a closer look at this element. It comes in many forms: coal, diamond and graphite, for example. But its most recent and, perhaps, most beguiling incarnation is graphene. So what is graphene?

(TO BE CONTINUED)

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