Our hands are vital for performing tasks throughout our daily lives and must be taken care of and cleaned regularly. They can easily spread germs, bacteria, or viruses such as Covid-19 (Coronavirus). Coronavirus has spread rapidly throughout the entire world in the past few months and health officials are very adamant that hand hygiene can help prevent further escalation of the virus. The reason is simple; viruses can spread from our hands to other objects that we touch, to which other people can touch those same objects and possibly contract the virus by putting their hands on their face. According to the World Health Organization, proper hand sanitation that uses alcohol-based rub or hot water and soap can kill Coronavirus and other viruses [1].

For some people, such as healthcare professionals, there are actually major consequences for neglecting hand hygiene. For example, the dirty hands of these professionals have a negative impact of 40% in the transport and spread of resistant microorganisms among patients. Hospital infections are actually among one of the main catalysts for increased disability and death rates in hospitals, along with additional healthcare costs [2]. In the United States, 1.7 million patients develop health-related infections every year, and 100,000 of them die. This increases the length of hospital stay by 20 times and the cost of treatment by 5 times [3].

It was not until the 19^th century that we began to understand that infectious diseases can be prevented by washing our hands. In the middle of the same century, the pioneer of antiseptic processes, known as the “savior of mothers,” Hungarian physician Ignaz Semmelweis, showed that microorganisms could be transmitted to patients via the hands of medical staff. This discovery began a new era of hygiene and healthcare. It is now well known that microbes reproduce rapidly, and that it is possible to prevent the spread of disease by keeping the hands and body, which is possible by following personal hygiene rules.

Hand hygiene is maintained in different ways in modern medicine. In daily life, washing hands with soap and water to remove dirt is called “social hand washing.” Common examples include washing after a meal and when visiting the toilet. For this purpose, it is sufficient to rub the hands and fingers for 15 seconds with a non-antimicrobial feature soap, rinse, dry with a disposable towel, and turn off the tap with a towel. Cloth towels used by many people in public places are not considered suitable for hygiene.

The more serious and professional form of hand washing is “hygienic hand washing,” where antimicrobial soaps are used in the washing process before and after contact with patients and bodily fluids. Other hand hygiene methods during surgical operations cover applications where alcohol-based 3-5 ml hand-disinfectant is rubbed until dry along with hand disinfection and surgical hand antisepsis, which includes washing the hands, including the forearms, with chemical solutions such as soaps, isopropanol, chlorhexidine specifically produced for this purpose for 2-3 minutes, and later wearing sterile gloves until the end of any procedures.

The World Health Organization published a guide on proper hand hygienics and explained when, how often, and how healthcare providers should wash their hands [4]. Despite the development of various programs and policies, especially hand hygiene, and increasing material expenditures in the fight against infections observed in health services, the control of infections remains well below the desired level.

Today, research also looks at the effects of hand washing on individual psychology. An experiment carried out by two psychologists from the University of Michigan, Spike W.S. Lee and Norbert Schwarz, shows that hand-washing reduces this classic post-decisional dissonance effect:

In individual sessions, 40 undergraduates browsed 30 CD covers as part of an alleged consumer survey as if they were in a music store. They selected 10 CDs they would like to own and ranked them by preference. Later, the experimenter offered them a choice between their 5th and 6th ranked CDs as a token of appreciation from the sponsor. Following the choice, participants completed an ostensibly unrelated product survey that asked for evaluations of a liquid soap; half merely examined the bottle before answering, whereas others tested the soap by washing their hands. After a filler task, participants ranked the 10 CDs again, allegedly because the sponsor wanted to know what people think about the CDs after leaving the store.

For those who merely examined the soap, the preference for the chosen over the rejected alternative increased from before choice to after choice by an average of 1.9 ranks, replicating the standard dissonance effect. In contrast, for those who washed their hands, preferences were unaffected by their decision. Thus, handwashing significantly reduced the need to justify one’s choice by increasing the perceived difference between alternatives. “Washing one’s hands after making a choice eliminates post-decisional dissonance effects, suggesting that hand-washing psychologically removes traces of the past, including concerns about past decisions” [5].

In another study conducted in 2008, Schnall, et. Al. “hypothesized that physical cleanliness reduces the severity of moral judgments. In support of this idea, they found that individuals make less severe judgments when they are primed with the concept of cleanliness and when they wash their hands after experiencing disgust” [6]. This effect of hand washing, which relieves conscience, is called the “Macbeth Effect.”

Washing hands is one of those simple but compulsory practices we tend to take for granted and lose interest in as we progress in science and education. Simple practices like using each of our hands for different purposes and frequent hand-washing will surely contribute to the fight against healthcare infections and infectious diseases that threaten public health.

There are several traditions of Prophet Muhammad, peace be upon him, in which washing hands is strongly emphasized.

“The blessings of food lie in washing hands before and after eating.”

“Wash your hands after you wake up; you do not know where your hands have moved while you were sleeping.”

The Prophet advised using each hand for different tasks. It is narrated that his wife Aisha said: “The right hand of the Messenger of God (peace be upon him) was for his purification and food, and his left hand was for using the restroom and anything that was dirty.”

Notes

1. “Advice for Public.” World Health Organization, World Health Organization, www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public.
2. Pittet D, Allegranzi B, Storr J, Donaldson L. Clean care is safer care: the global patient safety challenge 2005-2006. Int J Infect Dis. 2006; 10(6): 419–24.
3. Allegranzi B, Storr J, Dziekan G, Leotsakos A, Donaldson L, Pittet D. The first global patient safety challenge “Clean care is safer care”: from launch to current progress and achievements. J Hosp Infect. 2007; 65(Suppl. 2): 115–23.
4. WHO Guidelines on Hand Hygiene in Health Care, www.who.int/gpsc/5may/tools/9789241597906/en/
5. Lee SW, Schwarz N. Washing away postdecisional dissonance. Science. 2010 May 7;328(5979):709. doi: 10.1126/science.1186799.
6. Schnall S, Benton J, Harvey S. With a clean conscience: cleanliness reduces the severity of moral judgments. Psychol Sci. 2008 Dec;19(12):1219-22. doi: 10.1111/j.1467-9280.2008.02227.x. Also see https://psycnet.apa.org/fulltext/2014-20922-011.html in which Johnson, D. J. et. al. suggest that “researchers investigating the connections between cleanliness and morality should therefore use large sample sizes to have the necessary power to detect subtle effects.”

The surfaces of soap bubbles have a very important feature. These surfaces which have minimum surface-tension potential energy also have minimum areas. That is, soap bubbles or clusters have a natural tendency to minimize area for the volumes they enclose. Two different frames and the areas formed are shown in Figure 1. For a given closed frame, at least one such minimal area can be formed; however, mathematicians have had to strive to prove it.

The famous mathematician Richard Courant (1888–1972), together with his students, did soap bubble experiments with various frames.

Minimal areas can also be formed by using more than one closed frames. Figure 2 shows the minimal surfaces obtained by holding two circular frames parallel. If the frames are kept too far from each other, no surface will form. If they are kept sufficiently near to each other, surfaces similar to those shown in Figures 2a and 2b will be obtained. If they are kept close enough to each other, then three minimal surfaces adjacent to each other as shown in Figure 2c can form.

The minimum energy principle is commonly observed not only in living organisms, but also in lifeless matter. A chain will take the shape which produces the least potential energy of attraction when it is fastened at two points onto a rod as shown in Figure 3. This form (function) is called “catenary” in mathematics.

The areas which are formed as a result of rotating the catenary curve around an axis A are called catenoids. Two different types of catenoids are shown in Figures 4a and 4b. As presumed, catenoids are minimal areas and can be obtained by the use of soap bubbles. If such formations were selected and used in everyday utensils, such as glasses, dishes and so forth, ideal shapes which cause the least loss of heat could be designed.

If the katenoid shown in Figure 5a is cut from its edge as shown in Figure 5b and turned by being slightly extended, a helical form or a helicoid will be obtained as shown in Figure 5f. This helicoid also is a minimal surface. Architects have widely used this form in spiral-shaped staircase structures. See Fig. 6.

Fig. 1-Closed frames and soap film surfaces formed1 Fig. 2a&b–Single foam film surfaces over two parallel circular frames1 Plus, the perpetual screw system which is widely in use in technology is also in a form similar to this geometry.

If a cylinder of the smallest volume that can house a helicoid is drawn (Fig.7a) and the lines on which the surface and the cylinder intersect are marked, then a double helix structure (Fig. 7b) is obtained; this is used in modeling DNA molecules which are the genetic codes of living species.

There are two elementary principles related to soap bubbles. The first principle says that if a bubble touches a surface that supports it, it unites with that surface in a way to make 90° angles. The soap bubble on that plain surface forms into a semi-spherical shape and the angle between the bubble surface and the supporting surface will be 90° at every point of contact. The second principle says that if three soap bubble surfaces come together, they form 120° angles along a line. If soap films come together within a tetrahedron frame as in figure 8, then the angles between the lines will be 109° 28′ 16″.

The Steiner problem which is an elementary problem in mathematics can be solved by the application of the 90° and 120° principles. The Steiner problem investigates how n points over a surface can be united in the shortest way by a web. Two transparent surfaces are connected with thin and parallel pins of equal lengths and then dipped into a soapy solution. When it is taken out, soap films will form. These films have a 90° angle with the supporting transparent surfaces and when three soap films come together, they connect at 120° angles with one another.

When observed from above, the intersecting lines between the soap film and one of the surfaces give the shortest web which unites the points in n numbers. How four points are united is shown in Figure 9a and how five points are united is shown in Figure 9b. Someone seems to have equipped lifeless objects such as soap bubbles with the ability to solve complex problems like a math genius.

Periodically repeated minimal areas have been observed on walls separating organic and inorganic substances in the skeletons of certain sea animals like the sea urchin and the starfish. Figure 10 shows the micro structure of a sea urchin’s skeleton. It has calculated that the geometry of its skeleton has perfectly been shaped in such a way as to prevent the extension of possible cracks.

Experiments with soap bubbles have been a source of inspiration also for architects. Such experiments have yielded inspiration for roof and tent designs. The German architect Frei Otto is one of the most eminent names in this regard. Figure 11 shows the minimal areas which Frei Otto managed to obtain by dipping hair-thin threads in soapy water.

In order for such a soap bubble model to be converted into an architectural structure, it is carefully photographed and precisely measured. Later, solid models are made and tested in wind tunnels. The tensile pressures likely to form under loads of wind and snow are measured by special precision instruments. In real structures, thin steel cables having high tensile strengths replace the hairy threads, and transparent plastic and synthetic materials replace the soap bubble film.

Figure 12 shows roof of the Munich Olympic Stadium, Figure13 shows the roof of the Munich Olympic Athletic Arena and Figure 14 shows the roof of the Olympic Swimming Arena in the same city. All these roofs have been designed and erected using the minimal surfaces obtained from soap bubble experiments.

Children love playing with soap bubbles very much; they usually blow a round circle after dipping a wand into soapy water and then watch the bubbles flying out of it. However, it is not only children who play with soap bubbles and soap films. Scientists have, for hundreds of years, been doing experiments with soap bubbles, developing mathematical theories, obtaining various surfaces and transferring the compiled data into technology.

Experiments with soap bubbles have been a source of inspiration also for architects. Such experiments have yielded inspiration for roof and tent designs.

2) These roofs can easily be erected, dismantled and transported to elsewhere, whereas traditional buildings cannot easily be re-located.

3) These structures which are designed according to tensile strengths are very sturdy all over, whereas the tensile pressures of classical buildings are so high that extremely heavy materials such as concrete and brick are used in order to balance the pressure.

The structures of light and strong materials granted to living things are splendid. The lightness and endurance of our skeleton system, the perfect endurance in the stems of slender plants such as wheat and barley, the extremely thin and elastic structure of a fly’s wing, and thousands of similar examples can be given.2 The word of German architect Frei Otto in this subject are expressive: “Biology has become indispensable for architecture.” Witnessing similar perfections also in inanimate structures such as soap bubbles proves that laws in nature originate from the same hand.

Obtaining minimal surfaces has become much easier as a result of immense increases in computer capabilities. Extremely complicated minimal surfaces which can be obtained through computer-aided-designs and calculations have become easily available as alternatives to soap bubble experimentations. If we, as human beings, are aiming to realize developments in science and technology, we should look,more carefully and meditatively, at events which are seemingly simple and unimportant around us and we should also discover the beauties and perfections that God has granted us and put them into service of humanity. The more our designs are compatible with the laws of nature, the higher our chances of success will be.

References

• S. Hilderbrandt, A. Tromba, The Parsimonious Universe, Springer-Verlag, New York, 1996.
• M. S. Polatöz, Tabiatta Mühendislik (Engineering In Nature), Kaynak Publications, Izmir, 2003.
• A. B. Smith, The stereom microstructure of the echinoid test. Special Papers in Palaeontology, 25, 1–85, 1981.