Saw that WhatsApp forward on 'physics' behind IRCTC ticketing? It's rubbish

So, this fake message is going viral on Whatsapp. 

Do you know why IRCTC does not allow you to choose seats? Would you believe that the technical reason behind this is PHYSICS.

Booking a seat in a train is quite different from booking seats in a theatre.

A theatre is a hall, whereas a train is a moving object. So, safety is of primary importance in trains. 

Indian railways ticket booking software is designed in such a way that it will book tickets such that the load gets evenly distributed throughout the train. 

Let me take an example to make things clearer: Imagine there are sleeper class coaches in a train numbered S1, S2 S3... S10, and in every coach there are 72 seats. 

So when someone first books a ticket, the software will assign a seat in the middle coach like S5; middle seats are numbered between 30-40, and preferably in the lower berths (Railways first fills the lower berths than upper one so as to achieve low centre of gravity.

And the software books seats in such a way that all coaches have uniform passenger distribution and seats are filled starting from the middle ones (36) to seats near the gates i.e 1-2 or 71-72 in sequence from lower berth to upper. 

Railways just wants to ensure a proper balance that each coach should have for equal load distribution. 

That is why if you are one of the last persons to book a ticket, then you are always allotted an upper berth and a seat numbered around 2-3 or 70, except when you are not taking a seat of someone who has cancelled his/her seat. 

What if the railways book tickets randomly? A train is a moving object which moves at a speed of around 100km/hr on rails. So, there are a lot of forces and mechanics at play. 

Just imagine if S1, S2, S3 are completely full and S5, S6 are completely empty and others are partially full. When the train takes a turn, some coaches have to counter a higher centrifugal force as compared to others, and this creates a high chance of derailment. 

This is a very technical aspect, and when brakes are applied there will be different braking forces acting on each of the coaches because of the huge differences in weight of coach, so stability of the train also becomes an issue.  

When ABP news channel talked about this with railway board member Mohammad Jamshed, he said the booking of seat is not done according to physics but according to profile. Women above the age of 45 and senior citizens are given lower berth seats. Pregnant women also get lower berth seats.

Another QUORA question has an answer from a person who was involved in this. He also says that it depends on age and gender. 

“I was on the PRS project so I speak from knowledge. The Allocation logic was a 75 page document when it was implemented in 1987 in Mumbai - that's when I was part of the project.

‘Compact accommodation over choice’ is the overriding principle.

The answer about center of gravity and all that is pure nonsense - NOTHING like that happens.  Try and calculate what the typical weight of an empty coach is (built with steel) and how much additional weight the passengers and their luggage would add.”