
In 19th century people used to believe that, everything in nature could be precisely determined by classical physics. For eg. It says If we give initial condition like time, position, velocity etc., we can find all the information related to it after any time‘t’.
But at the beginning of 20th century the whole picture changed. With the discovery made by Rutherford, Bohr, Einstein and Planck and others there established a whole new branch of Physics called Quantum Mechanics. It deals with the world in quantum (microscopic) scale which describes event in probabilistic terms rather than deterministic. Then we come to know that our everyday world rules are governed with laws of probability and uncertainty.

We know that if we toss a coin, the probability is 1/2 for each event(for head and tail). But thats not exactly what we observe, we may toss a Coin for 10 times and each time we may get head. Then how did it made sense? well if we increased the number of trials ,the probability of each outcome tends to 1/2 and if we increase the number of trials to infinite then the probability of each outcome will exactly becomes 1/2.
Here comes the interesting part,

The probability of birth of a boy or girl(here we exclude case of twin, triplets & homosexuals being relatively low in quantity) by a pregnant woman is 1/2 as sperm carrying x or Y chromosome can fertilize the egg( assuming in millions of sperm distribution of X and Y chromosome are equal)(and if no pre ultrasound fetal sex determination and child abortion is not done).
i.e. there are nearly equally male and female.It then depicts that if a couple gives birth to 5 boys in one part of country ,it affects the outcome of birth of child in other part of country or in world.



Note: In countries like India and China,people prefer a boy child to a girl child and hence tend to practice sex-selective abortion. However, both the countries have taken important steps in curbing the illegal practice.Since India has legally banned sex determination before birth in 1994, but China eased-up on its one-child policy, which is the one main reasons for sex abortion.Similar cases happens in many countries that affects the outcome of birth.
Mission:No plagiarism!
Data Sources and Sites used:
- http://countrymeters.info/en/World#population_2017
- https://en.wikipedia.org/wiki/Human_sex_ratio
- https://en.wikipedia.org/wiki/Demographics_of_Nepal
- https://data.worldbank.org/

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