Why Holi festival is celebrated in Hinduism and what is the scientific reason?

Holi is a big festival of India, and it is celebrated every year in month of Falgoon 
(February to March) of Hindu month. It is known to every one that Holi is celebrated after the death of Holikaa. Holikaa was the sister of Hiranakshya the evil king. Who was blessed from brahma that she can't be burn in fire. When she tried to kill Prahlaad the great devotee of Lord Vishnu and the son of her brother Hiranakshya. She was burnt herself because of evil thought about Devotee Prahlaad and to kill her. After the death of Holikaa, Holi is celebrated by merging colour to each other. All these are external meaning of Holi festivals. It can be said that behind the festival of Holi. There is various scientific and spiritual reasons. Very few peoples know that Holi is not just celebrated only with chemical colours. It is enjoyed by merging colour and mud to each other.
       Here is the scientific reason for celebrating Holi. As we know that Holi is celebrated in March, Which is the first month of summer season. In Hindi, Holi is also depicted as Fagu festival means the Festival of Hindu month Falgoon. In this month, lots of flower are observed on tree  and these flowers are collected to prepare natural colour. In these natural colours, lots of healing medicines are found which make skin to glow and prevent skin diseases. Before merging colour, peoples used to play with mud. These muds make skin smooth, which was dried up during winter season and open ups the pores of sweat gland and sebaceous gland. Then peoples use to play with fagoo (Colour prepared by natural flower). These medicinal colour penetrates internal part of skin and prevents harmful particals. This medicinal treatment also protect from Sunstroke during summer season and regulate the rate of perspiration etc.
       Youngness and beauty will not persist for long time in human life. And the peoples who have ego on their beauty and smartness, they must know that time and age cannot be stopped. The time will pass on day by day. Celebration of holi gives message to peoples to see there face in Holi. With coloured face, one can realizes that her beauty will not be forever and his human body will also not be forever, death of human body is true. Therefore  they experience divinity and achieves spiritual upliftment. They get to know the reality of life. Holi make every one Happy and says to laugh and enjoy the life of every moment and serve God under his feet. In reality, that almighty is only having beauty. Many time it is called in Sanskrit that Satyam Shivam sundaram means truth is God and God is beautiful (God is only truth and God is only beautiful) Nothing is beautiful than that almighty.
            There is a example found in Shrimad Bhagwat Puran, in which it is mentioned that Gopis (Ladies of Gopal community in Vrundavan) had ego for being beautiful and they were thinking that nothing is beautiful than them. Lord Krishna is incarnated and destroy the egoness of Gopis. All Gopis were strongly attracted toward Lord Krishna because of his beautiful and gorgeous incarnation. Lord Krishna played Holi with Gopis and destroy their ego and divert then to devotion.

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