Ninja Technology in Boruto part 2
Wall walking is a very common and rather easy skill for the ninjas in the world of Naruto to do compared to people in the real world.
Naruto is able to do this by using a mystical energy called chakra that circulates through the bodies of people in the world of Naruto. In the real world the term chakra is used by the religions of the Indian subcontinent to refer to energy they believe circulates through the body. Science has yet to prove the existence of chakra or other energies circulating through the human body, but that hasn’t stopped people from trying to climb buildings.
As I stated in the previous post on new ninja technology in Boruto, it seems that the manga is introducing more and more science based technologies as compared to the more mystical based skills found in Naruto. Another device that is introduced in the latest chapter of Boruto is a set of boots and gloves that allow anyone to walk on walls without using chakra as most ninja do.
Once again, an explanation is given, and this time it is Van Der Waals forces. The question this time is what are Van Der Waals forces, and what do they have to do with climbing walls?
Before I can fully explain Van Der Waals forces, I need to cover a little bit of basic chemistry, mainly the structure of the atom, and chemical bonding. There are three subatomic particles that make up atoms, which are the building blocks of all the observable matter in the universe.
Proton- A large positively charged particle
Neutron- A large neutral particle
Electron- A very small negatively charged particle
The proton and neutron are found in the center of the atom, while the electron orbits around the nucleus as shown below.
This basic structure does not change across all the elements. What does change is the number of protons, neutrons, and electrons.
Atoms combine with each other to form larger and larger compounds like water, or H2O. The number of atoms, variety of atoms, and how they are connected determine the final structure and properties of the compound. There are two main types of chemical bonds that hold different atoms together to make a compound: ionic and covalent bonds.
Ionic bonds are held together by electrical charges, with the positive charge being attracted to the negative charge.
“But Mr. Anime Science, I thought you said that all atoms were neutral in their natural state?”
Yes, all atoms are neutral in their natural state, but that doesn’t mean that the atoms are stable or like to be neutral. Fair warning, I am going to give a bit of an oversimplification for brevity and complexity’s sake as I am trying to keep this at a high school level. As previously stated, the electrons orbit around the nucleus, but they don’t just randomly fly around, they are arranged in energy levels 1-7; with the lower the number, the closer the electron is to the nucleus. Next, all of the electrons in a particular level are arranged into orbitals, or rooms. There are several different rooms, labeled S, P, D, and F. For brevity the only 2 we need to care about are S and P, which can hold a combined 8 electrons. This means that atoms like to have either 8 electrons or 0 electrons in the outermost level that they have, and will gain or lose electrons to reach that state.
So how do we know how many electrons an atom’s outermost level starts with? That’s easy- look at the numbers labeled with an A running from left to right across the top of the periodic table.
1A- 1 electron
2A- 2 electrons
3A- 3 electrons
4A- 4 electrons
5A- 5 electrons
6A- 6 electrons
7A- 7 electrons
8A- 8 electrons
The B numbers are beyond the scope of what I need to cover today, so I will save them for later.
Now let’s take a look at sodium, which is in column 1A, which means it has 1 electron in its outer row. Sodium with one electron in its outer row is neutral, but it doesn’t like having just 1 electron in its outermost level. To reach either 8 or 0 electrons in its outer level, this means sodium has to gain 7 electrons or lose 1, and it’s a lot easier to lose 1 electron than gain 7 electrons. When sodium loses 1 electron, its overall charge shifts from 0 or neutral to a positive +1. (That explosion you get when you drop sodium in water is all of the sodium atoms rapidly shifting from 0 to +1). Chlorine, on the other hand, is in column 7A and has 7 electrons in its outer level, and it’s easier to gain 1 electron than it is to lose 7 electrons, giving chlorine a charge of -1. The positive sodium is now attracted to the negative chlorine, creating table salt.
This means it’s rather easy to determine the charge the atom takes depending on which column it is in.
4A- +4 or -4 but this rarely ever happens
8A- Neutral all the time and does not form any bonds at all
In covalent bonds the atoms share electrons with each other instead of completely losing or gaining them. Since the atoms are sharing electrons, the goal is to reach a total of 8 for all of the atoms involved. For example, let’s take a closer look at H2O, or water.
Oxygen is in column 6A and has 6 electrons and Hydrogen is in column 1A and has 1 electron.
As you can see, the 2 hydrogen atoms share their electrons with the oxygen atom, giving the oxygen atom 8 electrons.
“But Mr. Anime Science, the hydrogens still only have 2 electrons each.”
Correct, but hydrogen is the one exception to the 0 or 8 rule and only needs 2 electrons instead of 8.
There are two types of covalent bonds. The first type is called non-polar covalent and is the same as what is described above. The second type is called polar covalent, and is slightly different.
When two atoms share electrons between them in a covalent bond, the sharing isn’t always equal. The easiest way to visualize this is to think of a tug of war contest. If both of the atoms are similar, then the electron will sit in the middle, spending an equal amount of time with either atom.
In a polar covalent bond if one of the atoms has a strong pull on the electrons (higher electronegativity), that atom wins the tug of war and the electrons spend more time near the stronger atom.
The electrons are still shared, it’s just that they are spending more time near the stronger atom and less near the weaker. What this means is that the stronger atom (the one with the higher electronegativity) ends up being just a tiny bit negative, while the weaker atom ends up being just a tiny bit positive.
Van Der Waals Force
Now that you have a basic understanding of atoms, and chemical bonds, I can begin to talk about Van Der Waals forces. First off on an individual basis Van Der Waals forces are very weak, but if you have enough weak bonds, you can create a strong bond. This is basically the chemistry version of the old adage, “It’s easy to break one arrow, but if you have a whole bunch of arrows, they are not so easy to break.”
As for why they occur, let’s remember that positive and negative charges are naturally drawn towards each other, as we see in ionic bonds. Now let’s add to that, polar covalent bonds, which share electrons, but as previously stated it’s not an equal sharing. This means that one side of the atom will be slightly positive, and one side will be slightly negative. These slightly positive and negative sides of the compound can be attracted to other charged particles.
This type of interaction is also called a hydrogen bond, as the hydrogen atoms of compounds are often involved in this type of bonding. While in the picture above we see the weak positive, and negative interactions between individual water molecules (H2O), hydrogen bonding (driven by Van Der Waals forces), these interactions can occur between different types of molecules. This is what makes it so difficult to pull apart those cups you stacked together before completely drying them off. The cups are virtually glued together by the water forming many hydrogen bonds to each of them.
So just how are geckos able to walk on walls? The answer is surprisingly simple and the answer is Van Der Waals forces. Van Der Waals interactions, or hydrogen bonds, can form between substances that have polar bonds, including the skin of living organisms. The reason why very few living organisms can actually climb on walls is that we are too heavy, and cannot make enough hydrogen bonds to overcome the force of gravity. The feet of geckos are not covered in a sticky substance as you might expect, but millions of tiny hairs. The actual surface area of a Gecko’s foot is much larger than you might expect.
All of the folds and hairs on the gecko’s foot give it a much larger surface area, which allows for more hydrogen bonding to occur. The sum total of all these small weak bonds add up to being more than the force of gravity, which is why the gecko does not fall down off the wall it climbs on.
Real World Application
The boots and gloves seen in chapter 18 of Boruto are not as far fetched as they might appear seeing that they are based on animals that can walk on walls in the real world. Scientists have even gone so far as to make adhesive tape based off the gecko’s feet.
Science has yet to completely replicate the feet of the gecko and other wall climbing lizards, not because we don’t full understand how they stick to the wall, but it is the regulation of the sticking and unsticking that allows it to more that is more difficult.
The Boruto manga is correct in stating that gloves and boots that could allow a person to walk on walls would be similar to the feet of a gecko, and would be powered by Van Der Waals forces. However, just like in the previous installment of new ninja technology in Boruto, this one is only plausible, because science has yet to actually create wall climbing gloves and boots.