The Science Behind Various Hindu Traditions: An Interesting Read

Tradition of applying tilak or kumkum in Hinduism
Hindu culture, like any other, has its own unique way of life. The traditions followed by Hindus since ages actually have scientific reasons, and are not mere religious rituals. Get to know the science behind some such Hindu traditions.
Traditional Medicine
Turmeric, besides being regularly used in South Asian cuisine, is one of the oldest known medicines in India.
Mahatma Gandhi, in one of his articles 'What is Hinduism?', has said "If I were asked to define the Hindu creed I should simply say: search after truth through non-violent means. A man may not believe even in God and still call himself a Hindu."

Hinduism is more about the culture and the way of life, primarily of the people living in India. Along with the religious facet, Hindu life is more of a pattern of living that the settlers here have acclimatized to. It is a system of knowledge given in the scriptures, which was compiled by the sages giving the gist of their studies transformed into simple actions that could be observed everyday, so as to lead a healthy and peaceful life.

Finding out and learning about the 'why' behind these routine or traditions lets us perceive them in a non-biased manner; as something any human being may practice for his/her well-being.
Scientific Reasons Behind Hindu Traditions
Looking at the vast expanse and immense cultural diversity that India is about, customs and traditions are found to be slightly different in different parts of the country. Also, the beliefs that encourage people to practice these acts are dissimilar. However, here is a brief description about the prominent scientific reasons behind a few common traditions.
Namaste, the Indian way of greeting
The word and gesture of joining both the hands together summarizes the essence of the Indian philosophy. The first and foremost emotion after you see a person is respect, which is expressed through this greeting. It is a great way of practicing equality amongst all. We say 'Namaste' when we welcome someone. It is believed of the gesture, that crucial acupuncture points at the fingertips are pressed and activated, which helps us remember the person.
'Kara' is hands, and 'darshan' is viewing, or the sight of. It is a tradition to first look at our palms (joining them together) when we wake up in the morning, and say the shloka 'Karagre vasate laxmi...'. After saying those few lines, we move both our hands by touching the forehead over the face and down until the navel point. Since we are heavy-eyed then, karadarshan helps us feel fresh and awake. Besides helping in motions, it also activates the acupuncture points on the face.
Ushapan - drinking water from a copper utensil
Drinking water from a copper utensil, is a traditional practice. It absorbs extra body heat, cooling naturally, and helps in maintaining body temperature. Water, kept overnight in the copper pot, is had in the morning. The ideal quantity of water for everyone is measured by the approximate area we see after joining both our palms together, forming a bowl-like shape. It comes to around one and a half liters. Water helps in bowel movement; also cleaning the stomach and creating digestive juices.
One may start by initially drinking quantity equaling two palms full of water, and increasing it gradually.
Indian Food - thali
Indian cuisine is famous for its spices and for being flavorful. Ayurveda (ancient Indian Vedic system of healing) describes the 'shadrasa', or the six different types of tastes necessary in our diet, which include sweet, sour, salty, bitter, pungent (hot), and astringent. These rasa or tastes need to be balanced through food intake, based on the type of nature (prakriti) or personality one has.
Here are some traditions followed before, during, and after having food.
Sitting down on the floor in a cross-legged manner is called 'sukhasan'. Having our food in this position makes us bend down and eat. We have to move little up and down while eating. The stomach gets pushed as we bend down, and we sit back straight after taking the next bite. This leads to muscular movement in our stomach, which helps in creating digestive juices and in taking the swallowed food ahead.
This is a quick afternoon nap after lunch. It literally means to sleep (by turning) on the left-hand-side. We do feel heavy after lunch, but sleeping for a long time makes us lazy instead. So, taking a nap in this manner allows us to be awake and fresh in around10 minutes. Going by the science of the human body, when we sleep on the left-hand-side, we begin to breathe from our right nostril. The right nostril is known as 'Suryanadi', which generates heat that helps in digesting the food.
Similar to the afternoon nap, a walk after dinner at night helps the process of digestion. Shatapawali means taking a walk of 100 (shata) steps (pawali). It helps the gas (created after having food) in our stomach move ahead, and also, thus, reduces the pressure felt in our chest.
The word 'upavasa' means to 'stay near' god. This is said to be achieved through fasting, which is a common tradition observed by Hindus, especially during the month of Śrāvaṇa in the Hindu calendar. This corresponds to the period of monsoon, when the digestion capacity slows down due to the frequent changes in weather.
Preparing and consuming food expends a lot of energy. Variety of food, or different kinds of food items are believed to generate different thoughts (good and bad). Some foods tend to make us feel heavy and dull, or even agitated. Therefore, once in a while, complete abstention from food, or having very light food like fruits is suggested. This gives some rest to the digestive system, and calms the mind too.
Tilak/Kumkum on the Forehead
The center between the eyebrows is considered a very important point, forming one of the plexuses in the body - the Ajna chakra. Men are seen with a 'tilak', and women put a round 'bindi', what is known as 'kumkum'. It is a red-colored powder made using dried turmeric and slaked lime. It has been an old tradition for women to mix this kumkum with a little water and apply it onto the forehead. The scientific reason being, this liquid kumkum, when applied daily, is absorbed into the skin. The position on the forehead is also an acupressure center of the pituitary gland. The medicinal properties of kumkum thus reach the pituitary gland, improving its functioning. Additionally, it helps in balanced hormonal secretions, which leads to regularizing menstrual cycles in women. Also, problems like menstrual pain are easily taken care of.

Married women in many regions of India apply 'sindoor' along the parting-line in their hair. It is different from the bindi, but women use kumkum as sindoor too. In some regions in north India, the color is a tint of orange. It is symbolic of a married woman. Considered significant as it helps keep blood pressure under control, the mercury content is known to reduce stress and strain on the mind. It provides the newly-wed bride some mental peace, especially when she has to adapt to a new environment after marriage. There are, however, concerns about the toxicity of what is sold as 'sindoor' in the market, as at times it is not made from natural ingredients.
Women in India wear a variety of ornaments, not usually seen in other cultures. Just like the traditional 'saree', there is beautiful jewelry to go along with it too.
Toe Ring
Toe ring - Hindu traditions
A silver ring worn on the second toe by married women connects to the uterus, and reaches the heart through a nerve. It maintains a healthy blood flow, strengthens the uterus, and also ensures regular periods. The ring, made of silver, also tones down body heat. A toe ring is very useful during pregnancy, when the mother has to carry more weight as the baby grows. The ring is believed to activate peculiar acupressure points, which act beneficial for the pregnant mother.
Bangles - Hindu traditions
Colorful, shiny, sparkling, and very well matching with the dress, bangles are very dear to every woman who loves to dress up. On the wrist and below our thumb lies the acupressure center for the uterus, and similarly, the point for the ovaries lies underneath the little finger. When a woman wears bangles, these points on both the hands are pressed. It acts as a cure for menstrual pain, and for pain in the heels that occurs after the age of forty.
Beautiful designs are drawn on the bride's hand with Henna in Indian weddings; also generally by women during some Hindu festivals. Mendhikā is the Sanskrit origin of the word Mehndi, which finds mention in olden Hindu Vedic texts. It is leaves of henna that are powdered and mixed with water to make a paste. It has medicinal properties, and help in taking away all excess body heat and stress. In rural areas, fresh leaves are ground, oil is added to this, and simple spheres are drawn, giving a darker color.
Ear Piercings
The modern world looks at them as a fashion ornament. However, Indian philosophy suggests this to assist in intellectual development, decision-making, and thinking abilities. The outer part of the ear is an important acupressure point too. It is a common ritual and tradition to have a new-born baby's ears pierced on the 12th day. As the spiritual thought signifies minimal speech, ear piercings are also known to help acquire this quality.
There are several famous Hindu temples in India, considered the most sacred places of worship for different deities. However, beyond pilgrimage, the temples and their spectacular construction have a purpose behind them. Although Hindu temple architecture is a topic of intense study due to its diversity, there are certain common core principles observed in their construction.
Temples - Science behind Hindu traditions
The built tries to establish a relation between the deities and humans, represent the five elements of earth, water, fire, wind, and ether, and largely replicate the theme of the cosmos. Mythological tales are magnificently carved out on stone. Ethos of the spiritual philosophy are depicted through a particular arrangement of carved figures that express different emotions.
The inner core, where the idol is placed in a temple, is the garbhagriha. Earlier, the idols were first established and then temples were built around them. This core sanctum is believed to be the source of abundant energy, achieved through strategic placing of the temples after considering the polar electric and magnetic wave distribution. Visiting a temple, therefore, lets us receive this energy.
The Turtle
At the entrance of temples, a turtle is seen on the floor. This turtle is worshiped too before we enter the temple, usually by touching it. We can see the turtle's head, its four limbs, and a tail as six different points. The structure of this turtle appears to be like two superimposed triangles, forming a hexagram (six pointed-star shape). The hexagram is believed to combine two triangles of energy: one of the 'Shiva' (potential form) and the other of the 'Shakti' (kinetic form). Touching this turtle implies offering of all our good and bad deeds to the supreme, to this energy structure. Therefore, it also stands for the act of surrendering of our ego.
Temple Bells
Temple Bells - Science behind Hindu traditions
The bells are made by mixing different metals, mainly including copper and zinc or brass. Ringing a bell produces an echo that lasts for several seconds. This enduring sound helps clean our minds of negative thoughts, and heals the seven chakras (healing centers in our body or plexus). The bells are so made that their sound and resonance are believed to unite our right and left brains.
Worshiping the Tulasī Plant
Worshiping the Tulasi Plant - Science behind Hindu traditions
Ocimum tenuiflorum or Ocimum sanctum, also known as holy basil, is an aromatic plant native to the Indian subcontinent, and is known for its medicinal properties. It is planted in front of the house, or at the center in the courtyard (tulsi vrindavan, as seen in the image), and is worshiped by women. This was considered a good source of oxygen for women who used to cook using firewood that created a lot of smoke.
Used in Ayurvedic preparations of herbal tea, it basically prevents various illnesses, helps relieve stress, and cures common cold, cough, and fever. As they strengthen the immune system, tulsi leaves are also added to some food preparations.
The Peepal Tree
Its scientific name is Ficus religiosa or sacred fig. The Peepal tree is utilized in traditional medicine to treat various diseases, like diabetes, asthma, gastric problems, diarrhea, epilepsy, inflammatory disorders, and infectious and sexual
disorders. It is a tree that generates oxygen 24 hours a day, and is thus revered and conserved.
Surya Namaskar
Surya Namaskar - Science behind Hindu traditions
This refers to a series of postures (asanas) in Yoga, also commonly known as 'Sun Salutation'. A best exercise for our human body, it combines various asanas (janu bhalasan, ashtangasan, bhujangasan, janu shirasan, tadasan, etc.) and paranayam (breathing techniques like bhasrika, swalpa kumbhak, poorna kumbhak, deergha shwasan, etc.) Surya Namaskar aids blood circulation, gives a good stretch and push to our organs, improves digestion and excretion, and strengthens the physique.
Besides, it is beneficial particularly for women, as it cures any lung ailments, and helps maintain a flat tummy.
Offering water to the early rising sun is another tradition of worshiping the sun, known as arghya. There is a peculiar way of doing it, when the gentle sun's rays are reflected through the water being poured. Looking at this coming together of sunlight and water is considered very beneficial for our overall health, particularly the eyes.
Yajna - Science behind Hindu traditions
Meaning 'sacrifice', yajna is an old Vedic ritual where sacrifices are made along with the chanting of certain mantras (sacred utterances or hymns). The material offered into the divine fire (Agni) include a variety of grains, plant stems, pure ghee (a form of clarified butter), etc., which changes with the kind of yajna being performed. These offerings are believed to reach the deities through the fire. Scientific researches studying impacts of yajna on the environment have concluded that, it helps in the purification of the surrounding environment. Apart from cleansing the environment, it also cleans the body of the person performing the yajna.
Touching the Feet
Respect for elders is expressed by touching the feet of parents and elders. They, in turn, bless us by placing their hands on our head. Bending down and touching the feet is a way to receive good wishes, blessings, and positive energy from the more experienced and mature elderly. The thumb of our foot is believed to be a significant point of energy flow. As per Indian spiritual thought, the 'shishya' (student) is known to place his/her forehead on the thumb of the 'Guru's (master) right foot.
Avoid Sleeping with the Head Pointing to the North
The South Pole denotes positive energy, whereas the North Pole denotes negative energy, according to the study of magnetism. If we sleep with our head pointing to the North, the magnetic field of the human body becomes asymmetrical with that of the Earth. Being already tired and drained out during the day, our brain getting more negative energy is not desirable. We might not get a good sleep. It is found to be easier to fall asleep and get good rest if we sleep with our head towards the south.
There are many more traditions, including those during festivals, and the food preparations associated with them. Though there is a list of dos and don'ts for different seasons of the year, during different times of the day, etc., following them all 'religiously' is certainly difficult in today's day and age, but still there are people who adhere to some of these, as they have simply made it into a habit.